**4. Conclusions**

Several technologies have been tested to reduce mycotoxin risk. Field management practices that increase yields may also prevent aflatoxin. They include use of resistant varieties, timely planting, fertilizer application, weed control, insect control and avoiding drought and nutritional stress. Other options to control the toxin causing fungi *Aspergillus flavus*  contamination in the field are use of non-toxigenic fungi to competitively displace toxigenic fungi, and timely harvest. Post-harvest interventions that reduce mycotoxins are rapid and proper drying, sorting, cleaning, drying, smoking, post harvest insect control, and the use of botanicals or synthetic pesticides as storage protectant. Another approach is to reduce the frequent consumption of 'high risk' foods (especially maize and groundnut) by consuming a more varied diet, and diversifying into less risky staples like sorghum and millet. Chemopreventive measures that can reduce mycotoxin effect include daily consumption of chlorophyllin or oltipraz and by incorporating hydrated sodium calcium alumino-silicates into the diet. Detoxification of aflatoxins is often achieved physically, chemically and microbiologically by incorporating pro-biotics or lactic acid bacteria into the diet. There is need for efficient monitoring and surveillance with cost-effective sampling and analytical methods. Sustaining public education and awareness can help to reduce aflatoxin contamination. Phytochemicals may successfully replace physical and chemical agents and provide an alternative method to protect agricultural commodities of nutritional significance from toxigenic fungi such as *Aspergillus flavus* and aflatoxin production.

### **5. References**

transgenic maize plants expressing the detoxification gene, zhd101 showed reduced contamination by the mycotoxin, zearalenone in maize kernels [Igawa et al., 2007]. Recently studies have been focused on identification of the aflatoxin detoxification genes from Trachyspermum ammi and to transfer them into crop plants in order to develop transgenic

Several technologies have been tested to reduce mycotoxin risk. Field management practices that increase yields may also prevent aflatoxin. They include use of resistant varieties, timely planting, fertilizer application, weed control, insect control and avoiding drought and nutritional stress. Other options to control the toxin causing fungi *Aspergillus flavus*  contamination in the field are use of non-toxigenic fungi to competitively displace toxigenic fungi, and timely harvest. Post-harvest interventions that reduce mycotoxins are rapid and proper drying, sorting, cleaning, drying, smoking, post harvest insect control, and the use of botanicals or synthetic pesticides as storage protectant. Another approach is to reduce the frequent consumption of 'high risk' foods (especially maize and groundnut) by consuming a more varied diet, and diversifying into less risky staples like sorghum and millet. Chemopreventive measures that can reduce mycotoxin effect include daily consumption of chlorophyllin or oltipraz and by incorporating hydrated sodium calcium alumino-silicates into the diet. Detoxification of aflatoxins is often achieved physically, chemically and microbiologically by incorporating pro-biotics or lactic acid bacteria into the diet. There is need for efficient monitoring and surveillance with cost-effective sampling and analytical methods. Sustaining public education and awareness can help to reduce aflatoxin contamination. Phytochemicals may successfully replace physical and chemical agents and provide an alternative method to protect agricultural commodities of nutritional

significance from toxigenic fungi such as *Aspergillus flavus* and aflatoxin production.

Adam, K.; Sivropoulou, A.; Kokkini, S.; Lanaras, T.; Arsenakis, M. (1998). Antifungal

Adams, S.; Kunz, B.; Weidenbörner, M. (1996). Mycelial deformations of *Cladosporium*

Alberts, J.F., Gelderblom, W.C.A., Botha, A., & Van Zyl, W.H. (2009). Degradation of

Allameh, A., Razzaghi-Abyaneh, M., Shams, M., Rezaei, M.B., & Jaimand, K., (2001). Effects

Allameh, A., Safamehr, A., Mirhadi, S.A., Shivazad, M., Razzaghi-Abyaneh, M., Afshar-

activities of *Origanum vulgare* subsp. *hirtum, Mentha spicata, Lavandula angustifolia*  and *Salvia fruticosa* essential oils against human pathogenic fungi*. J. Agric. Food*

*herbarum* due to the application of Eugenol and Carvacrol. *J. Essent. Oil Res., 8*, 535-

aflatoxin B1 by fungal laccase enzymes. *International Journal of Food Microbiology*

of neem leaf extract on production of aflatoxins and fatty acid synthetase, citrate dehydrogenase and glutathione S-transferase in *A. parasiticus*. *Mycopathologia*, 154,

Naderi, A., (2005). Evaluation of biochemical nd production parametersof broiler

resistance to aflatoxin contamination [Velazhahan et al., 2010].

**4. Conclusions**

**5. References**

540.

135, 47-52.

79–84.

*Chem., 46*, 1738-1745.

chicks fed ammonia treated aflatoxin contaminated maize grain. Animal Food Science and Technology. 122, 289-301.

Phytoinhibition of Growth and Aflatoxin Biosynthesis in Toxigenic Fungi 307

Dorman, H.J.D., Deans, S.G., (2000). Antimicrobial agents from plants: antibacterial activity

Dube, S., Upadhyay, P., Tripathi, S., (1989). Antifungal, physicochemical, and insect-

Dutton MF (1988). Enzymes and aflatoxin biosynthesis. Microbiological Reviews. 2: 274-295. Dwividi, S.A., Dubey, B.L., 1993. Potentionial use of essential oil of the trachyepermum

Ela, M.A.A., El Shaer, N.S., Ghanem, N.B., (1996). Antimicrobial evaluation and chromatographic analysis of some essential and fixed oils. Pharmazie 51, 993–994. El-Bazza, Z.E., Farrag, H.A., El-Fouly, M.Z., & El-Tablawy, S.Y. (2001). Inhibitory effect of

El-Maraghy, S.S.M., (1995). Effect of some spices as preservatives for storge of lentil (Lens

Fanelli, C., Fabbri, A.A., Finotti, E., Passi, S., (1983). Stimulation of aflatoxin biosynthesis by

Farag R.S., Daw Z.Y., & Abo-Raya S.H. (1989). Influence of some spice essential oils on

Farag, R.S., Rashed, M.M., Abo-Hgger, A.A.A., (1996). Aflatoxin destruction by microwave heating. International Journal of FoodSciences and Nutrition 47, 197–208. Frayssinet, C., LaFarge, C., (1970) Process for removing aflatoxins from peanut cake. French

Garcia, R.P., Garcia, M.L. (1988). Laboratory evaluation of plant extracts for the control of

Ghanem, I., Orfi, M., & Shamma, M. (2008). Effect of gamma radiation on the inactivation of aflatoxin B1 in food and feed crops. Brazilian Journal of Microbiology, 39, 787–791. Ghannadi, A. (2002). Composition of the essential oil of Satureja hortensis L. seeds from

Ghfir, B., Fonvieille, J.L., & Dargent, R. (1997). Effect of essential oil of Hyssopus officinalis

Gowda, N.K.S., Malathi, V., & Suganthi, R.U. (2004). Effect of some chemical and herbal

Gratz, S., Mykkanen, H., Ouwehand, A. C., Juvonen, R., Salminen, S., & El-Nezami, H.

vitro. Applied and Environmental Microbiology, 70, 6306–6308.

Patent 2.098,711, Recorded July 24, Accorded February 14, 1972.

esculenta L. seeds. Folia Microbiologica 40 (5), 490–492.

lipophilic epoxides. J. Gen. Microbiol. 129, 1721–1723.

Association of Mycotoxicology. 1, 190–193.

*Feed Science and Technology,* 116, 281-291.

Iran. Journal of Essential Oil Research, 14, 35–39.

toxin production of fungi. *Radiation Physics and Chemistry*, 60, 181-189. El-Bazza, Z.F., Mahmoud, M.T., Roushdy, H.M., Farrag, H.A. and El-Tablawy, S.Y. (1996).

repelling activity of the essential oil of Ocimum basilicum. Canadian Journal of

ammy against seed borne fungi of guar (Cyamopsis tetragonoloba L.).

gamma radiation and Nigella sativa seeds oil on growth spore germination and

Fungal growth and mycotoxigenic production in certain medicinal herbs subjected to prolonged cold storage and possible control by gamma irradiation. *Egypt. J.*

*Aspergillus parasiticus* growth and production of aflatoxins in a synthetic medium. *J.*

*Aspergillus* growth and aflatoxin production. In: Proceedings of the Japanese

on the chemical composition of the walls of *Aspergillus fumigatus*. *Mycopathologia*,

compounds on growth of *Aspergillus parasiticus* and aflatoxin production. *Animal*

(2004). Intestinal mucus alters the ability of probiotic bacteria to bind aflatoxin B1 in

of plant volatile oils. Journal of Applied Microbiology 88, 308–316.

Botany 67 (7), 2085–2087.

Mycopathologia 121 (2), 101–104.

*Pharmaceutical Sci*., 37: 85-95.

*Food Sci.*, 54, 74 -76.

138, 7–12.

Bluma, R.V., Amaide´n, M.R., Etcheverry, M.G., (2008). Screening of Argentine plant extracts

Bottone, E.J. and Peluso, R.W. (2003). Production by *Bacillus pumilus* (MSH) of an antifungal

Brophy, J.J., Thubthimthed, S., Kitirattrakarn, T. and Anantachoke, C. (2002). Volatile leaf oil of *Melaleuca cajuputi*. In *Proceedings of the Forestry Conference*, pp.304-313.

Bullerman, L.B., (1974). Inhibition of aflatoxin production by cinnamon. Journal of Food

Bullerman, L.B., Lieu, F.Y., Seier, S.A., (1977). Inhibition of growth and aflatoxin production

Burt, S. (2004). Essential oils: their antibacterial properties and potential applications in Foods- a review. International Journal of Food Microbiology, 94, 223−253. Buser, M. D., & Abbas, H. K. (2002). Effects of extrusion temperature and dwell time on

Cazzaniga, D., Basilico, J.C., Gonzalez, R.J., Torres, R.L., de Greef, D.M., (2001). Mycotoxins inactivation by extrusion cooking of corn flour. Lett. Appl. Microbiol. 33, 144–147. Chang, P.K., & Hua S-S.T. (2007). Nonaflatoxigenic Aspergillus flavus TX9-8 competitively

Codifer L.P. Jr, Mann G.E, Dollear F.G. (1976). Aflatoxin inactivation: treatment of peanut meal with formaldehyde and calcium hidroxide. J Am Oil Chem Soc., 53:204-6. Conner, D. E. (1993). Naturally occurring compounds, In *Antimicrobial in Foods*, pp.441- 468. Edited by Davidson, P. M. and Branen, A. L. Marcel Dekker Inc., New York

Daniels, J.M., Liu, L., Stewart, P.K., & Massey, T.E. (1990). Biotransformation of aflatoxin B1

Davidson, P.M., Naidu, A.S., (2000). Phyto-phenols. In: Naidu, A.S. (Ed.), Natural Food

Denissenko MF, Cahill J, Kondriakova TB, Gerber N, Pfeifer GP (1999). Quantitation and

Dollear, F.G., Mann, G.E., Codifer, L.P., Gardner, H.K., Koltun, S.P., Vix, H.L.E., (1968). Elimination of aflatoxins from peanut meal. J. Am. Oil Chem. Soc. 45, 862.

mapping of aflatoxin B1-induced DNA damage in genomic DNA using aflatoxin B1-8, 9-epoxide and microsomal activation systems. Mutat. Res. 425: 205-211. Devegowda, G., Arvind, B. I. R., & Morton, M. G. (1996). Saccharomyces cerevisiae and

mannanoligosaccharides to counteract aflatoxicosis in broilers. Proceedings of

morphotypes. *International Journal of Food Microbiology*. 114, 275-279. Chiruvella, R.V., Jaluria, Y., Karwe,M.V., (1996). Numerical simulation of the extrusion process for food materials in a single-screw extruder. J. Food Eng. 30, 449–467. Ciegler A. (1979). Control measures for aflatoxin contamination of agricultural commodities.

Coulombe Jr., R.A., (1993). Biological action of mycotoxins. J. Diary Sci.76, 880–891.

in rabbit lung and liver microsomes. Carcinogenesis. 11(5), 823-827.

Antimicrobial Systems. CRC Press, Boca Raton, FL, pp. 265–294.

Australian poultry science symposium Sydney. pp. 103–106.

Annals of the new York academy of Science. 329: 285-292.

by cinnamun and clove oils, cinnamic aldehyde and eugenol. J. Food Sci. 42, 637–

aflatoxin levels in cottonseed. Journal of Agricultural and Food Chemistry, 50,

prevents aflatoxin accumulation by A.flavus isolates of large and small sclerotial

Aspergillus section Flavi. Int. J. Food Microbiol.29;122(1-2):114-25.

report. *Journal of Medical Microbiology*. 52, 69-74.

Science 39, 1163–1165.

646.

2556–2559.

Bullerman LB (1986). Mycotoxins and food safety. Food Technol. 40:59-66.

to check their impact on growth parameters and aflatoxin B1 accumulation by

compound that is active against Mucoraceae and *Aspergillus* species: preliminary

Phytoinhibition of Growth and Aflatoxin Biosynthesis in Toxigenic Fungi 309

Inouye, S., Tsuruoka, T., Watanabe, M., Takeo, K., Akao, M., Nishiyama, Y., Yamaguchi, H.,

Inouye, S., Watanabe, M., Nishiyama, Y., Takeo, K., Akao, M., Yamaguchi, H., (1998).

Jalili, M., Jinap, S., & Noranizan, A. (2010). Effect of gamma radiation of mycotoxins in black

Jayashree, T., Subramanyam, C., (1999). Antiaflatoxigenic activity of eugenol is due to

Jiang Y., Wu N., Fu N.J., Wang W., Luo M., Zhao C.J., Zu Y.J., Liu XL. (2011). Chemical

Joseph, G.S., Jayaprakasha, G.K., Selvi, A.T., Jena, B.S., Sakariah, K.K., (2005).

Karolewiez, A., Geisen, R., (2005). Cloning a part of the ochratoxin A biosynthetic gene

Kimura, M., Tokai, T., O'Donnell, K., Ward, T.J., Fujimura, M., Hamamoto, H., Shibata,

Kshemkalyani, S.B., Ragini, Telore, Madhavi, B., Patel, G.S., Telore, R., (1990). The effect of

Kuliman-Wahls, M.E.M., Vilar, M.S., De Nijs-Tjon, L., Maas, R.F.M., & Fink-Gremmels, J.

Kurita, N., Miyaji, M., Kurane, R., & Takahara, Y. (1981). Antifungal activity of essential oil

Leonowicz, A., Matuszewska, A., Luterek, J., Ziegenhagen, D., Wojtas-Wasilewska, M., Cho,

Lillehoj, E. B., Zuber, M.S., (1974). Aflatoxin problem in corn and possible solutions. In: Proc.

Liu, D.L., Yao, D.S., Liang, R., Ma, L., Cheng, W.Q., & Gu, L.Q. (1998). Detoxification of

Maeba, H., Takamoto, Y., Kamimura, M., Miura, T., (1988). Destruction and detoxification of

Mahmoud AL., (1994) Antifungal action and antiaflatoxigenic properties of some essential

inhibition of lipid peroxidation. Lett. Appl. Microbiol. 28, 179–183.

synthase gene. Systematic and Applied Microbiology 28, 588–595.

expressed non-essential genes. *FEBS Letters* 539, 105–110.

components. *Agricultural Biology and Chemistry*, 45, 945–952.

aflatoxins with ozone. Journal of Food Science 53, 667–668.

by vapour contact. Mycoses 43, 1–2, 17–23.

fungi. Myoses 41(9–1 0), 403– 410.

pepper. *Food Control*, 21, 1388-1393.

Toxicol Pharmacol. 32(1):63-8.

J. Mycol. Plant Pathol. 20, 247–248.

*Toxicology and Pharmacology*, 11, 207-212.

fungi. Fungal Genet. Biol. 27, 175–185.

Association, Alexandra, VA. pp 230-250.

oil constituents. *Lett. Appl. Microbiol*. 2, 110 - 3.

*Toxicology*, 36, 563-574.

Microbiol. 101, 153–160

(2000). Inhibitory effect of essential oils on spical growth of Aspergillus fumigatus

Antisporulating and respiration inhibitory effects of essential oils on filamentous

composition and antimicrobial activity of the essential oil of Rosemary. Environ

Antiaflatoxigenic and antioxidant activities of Garcinia extracts. Intl. J. Food

cluster of Penicillium nordicum and characterization of the ochratoxin polyketide

T.,Yamagushi, I., (2003). The trichothecene biosynthesis gene cluster of *Fusarium graminearum* F15 contains a limited number of essential pathways genes and

allicine and extracts of garlic on *Aspergillus flavus* and *Aspergillus parasiticus*. Indian

(2002). Cyclopiazonic acid inhibits mutagenic action of aflatoxin B1. Environmental

N.S., Hofrichter, M., Rogalski, J., (1999). Biodegradation of lignin by white rot

Annu. Corn & Sorghum Res. Conf. 1974. Chicago IL. American Seed Trade

aflatoxin B1 by enzymes isolated from *Armillariella tabescens*. *Food and Chemical*

Griffin, G.S.; Markham, L.J.; Leach, N.D. (2000) An agar dilution method for the

Haciseferogullary, H., Ozcan, M., Demir, F., & Caly´ sy´ r, S. (2005). Some nutritional and

Hagler WM, Hutchins JE, Hamilton P.B (1982). Destruction of aflatoxin in corn Bi with

Hagler WM, Hutchins JE, Hamilton P.B (1983). Destruction of aflatoxin in corn B, with

Halliwell B, Gutteridge JMC (1999). Oxidative stress: adaptation damage, repair and death,

Haskard C.A., EL-Nezami H.S., Kankaanpaa P.E., Salminen S.,Ahokas J.T. (2001): Surface

Heimbecher S.K., Jorgensen K.V, Price R.L., (1988) Interactive effects of duration of storage

Holmes RA, Boston RS, Payne GA (2008). Diverse inhibitors of aflatoxin biosynthesis. Appl.

Hope, R., Aldred, D., Magan, N., (2005). Comparison of environmental profiles for growth

Hsieh, D.P.H. (1973). Inhibition of aflatoxin biosynthesis of dichlorvos. J. Agric. Food. Chem.

Hua S.T. ( 2004). Reduction of aflatoxinin pistachio through biological control of aspergillus

Huang, J.Q., Jiang, H.F., Zhou, Y.Q., Lei, Y., Wang, S.Y., & Liao B.S. (2009). Ethylene

Hwang, J.H., & Lee, K.G. (2006). Reduction of aflatoxin B1 contamination in wheat by

IARC (1993). Some naturally occurring substances: Food items and constituents, heterocyclic

Igawa T., Takahashi-Ando N., Ochiai N., Ohsato S., Shimizu T., Kudo T., Yamaguchi I.,

*Oil Res., 12*, 149-255.

sodiumbisulfite. J Food Prot., 45, 1287-91.

Oxford University Press, New York, pp. 246-350.

wheat grain. *Letters in Applied Microbiology* 40, 295–300.

various cooking treatments. *Food Chemistry,* 98, 71-75.

68, 463–469.

67, 3086-3091.

Chem; 71:285-7.

21(3), 468-470.

489–521).

Reports. P 212- 220.

*Microbiology*, 130, 17-21.

Environ Microbiol. 73(5):1622-1629.

Microbiol. Biotechnol. 78: 559-572.

300.

determination of the minimum inhibitory concentration of essential oils. *J. Essent.*

technological properties of garlic (Allium sativum L.). Journal of Food Engineering,

sodiumbisulfite: isolation of the major product aflatoxin BS. J. Food Prot., 46,295-

in: Halliwell B, Gutteridge JMC (Eds.), Free Radicals in Biology and Medicine,

binding of aflatoxin B1 by lactic acid bacteria. Applied and Environmental Biology,

and addition of formaldheyde on levels of aflatoxin M, in milk. J Assoc Offic Anal

and deoxynivalenol production by *Fusarium culmorum* and *F. graminearum* on

flavus. Extension reports. California Pistachio Commision Production Research

inhibited aflatoxin biosynthesis is due to oxidative stress alleviation and related to glutathione redox state changes in *Aspergillus flavus*. *International Journal of Food*

aromatic amines and mycotoxins. IARC monographs on the evaluation of carcinogenic risks to humans. 56. International Agency for Research on Cancer (pp.

Kimura M. (2007). Reduced contamination by the Fusarium mycotoxin zearalenone in maize kernels through genetic modification with a detoxification gene. Appl

Phytoinhibition of Growth and Aflatoxin Biosynthesis in Toxigenic Fungi 311

Nychas G.J.E. (1995). Natural antimicrobial from plants. In New Methods of Food

O'Callaghan, J., Caddick, M.X., Dobson, A.D.W., 2003. A polyketide synthase gene required

Odamtten, G.T., Appiah, V., Langerak, D.I. (1986). Preliminary studies of the effects of heat

Ogiehor, I.S., & Ikenebomeh, M.J. (2004). Antimicrobial effects of sodium benzoate on the

Onyenekwe, P.C., Ogbadu, G.H., Hashimoto, S. (1997). The effect of gamma radiation on the

Ozcan, M. (1998). Inhibitory effects of spice extracts on the growth of *Aspergillus parasiticus*

Park, B.J., Takatori, K., Sugita-Konishi, Y., Kim, I.H., Lee, M.H., Han, D.W., Chung, K.H.,

Paster, N., Menasherov, M., Ravid, U., & Juven, B. (1995). Antifungal activity of oregano and

Pawar VC, Thaker VS (2007) In vitro efficacy of 75 essential oils against Aspergillus niger.

Payne G.A., & Brown M.P. (1998). Genetics and physiology of aflatoxin biosynthesis. Annu.

Penalva, M.A., Arst Jr., H.N., (2002). Regulation of gene expression by ambient pH in

Phillips TD, Kubena LF, Harvey RB, Taylor DR, Heidelbaugh ND. (1988). Hydrated sodium calcium aluminosilicate: a high affinity sorbent for aflatoxin. Poult Sci 67:243-7. Pier, A.C., (1992). Major biological consequence of aflatoxicosis in animal production. J.

Pietri A, Fusconi G, Blasi P, Moschini M. Azione sequestrante di una zeolite nei confronti di

Pinto E, Pina-Vaz C, Salgueiro L, Goncalves MJ, Costa-de-Oliverira S, Cavaleiro C, Palmeria

Piva, G., Galvano, F., Pietri, A., Piva, A. (1995). Detoxification methods of aflatoxins. A

ASPA, 141-6, Italy, Bologna, 31 maggio-6 giugno 1993

Park, D.L. (1993) `Controlling aflatoxin in food and feed. Food Technology, 47, 92-96.

in garri during storage. *Pakistan Journal of Nutrition,* 3(5), 300-303.

NRRL2999 strain. *Z Lebensm Unters Forsch A,* 207, 253–255.

*Biology and Technology*, 10, 161-167.

Journal of Food Protection, 58, 81–85.

Mycoses, 49: 316-323.

Rev. Phytopathol. 36, 329-362.

Anim. Sci. 70, (3964–3967).

*Microbiol.* 2006; 55 (10), 1367 – 73

review. *Nutrition Research,* 15(5), 767-776.

Professional.

3491.

348.

5737.

426–446.

Preservations ed. Gould GW. pp. 58-89. Glasgow, UK: Blackie Academic and

for ochratoxin A biosynthesis in Aspergillus ochraceus. *Microbiology* 149, 3485–

and gamma irradiation on the production of aflatoxin B1 in static liquid culture, by *Aspergillus flavus* link NRRL 5906. *International Journal of Food Microbiology,* 3, 339-

growth, survival and aflatoxin production potential of some species of Aspergillus

microflora and essential oil of Ashanti pepper (Piper guineense) berries. *Postharvest*

Hyun, S.O., Park, J.C. (2007). Degradation of mycotoxins using microwave-induced argon plasma at atmospheric pressure. *Surface and Coating Technology*, 201, 5733-

thyme essential oils applied as fumigants against fungi attacking stored grain.

filamentous fungi and yeasts. Microbiology and Molecular Biology Reviews. 66,

radionuclidi e aflatossina in diete per ruminanti e monogastrici. Proc X Congresso

A, Rodrigues A, & Martinez-de-Oliveria J. Antifungal activity of the essential oil of *Thymus pulegioides* on Candida, Aspergillus and dermatophyte species. *J. Med.*

Mahoney, N., Molyneux, R.J., (2004). Phytochemical inhibition of aflatoxigenicity in

Mann, G.E., Codifer, L.P., Garner, H.K., Koltun, S.P., Dollear, F.G., (1970). Chemical

Massum, M.M.I., Islam, S.M., and Fakir M.G.A. (2009). Effect of seed treatment practices in controlling of seed-born fungi in sorghum. Scient. Res. Essay. 4:22-27. McKenzie, K.S., Sarr, A.B., Mayura, K., Bailey, R.H., Miller, D.R., Rogers, T.D., Norred, W.P.,

Mendez-Albores, A., Arambula-Villa, G., Loarca-Pina, M.G.F., Castano-Tostado, E., Moreno-

Mendez-Albores, A., Del Rio-Garcia, J.C., & Moreno-Martinez, E. (2007). Decontamination of

Mendez-Albores, A., Veles-Medina, J., Urbina-Alvarez, E., Martinez-Bustos, F., Moreno-

Miller, R.C., 1990. Unit operations and equipment IV. Extrusion and extruders. In: Fast, R.B.,

Mishra, H.N., Das, C., 2003. A review on biological control and metabolism of aflatoxin. Crit.

Moerck KE, McElfresh P, Wohlman A, Hilton BW. Aflatoxin destruction in corn using

Monroe D.H. & Eaton D.L. (1987) Comparative effects of butylated hyroxyanisole on hepatic

Montes-Belmont, R., Carvajall, M., 1998. Control of Aspergillus flavus in maize with plant essential oils and their components. Journal of Food Protection 61 (5), 616–619. Moore, G., 1994. Snack food extrusion. In: Frame, N.D. (Ed.), The Technology of Extrusion Cooking. American Association of Cereal Chemists, St Paul, MN, pp. 111–143. Morozumi, S., 1978. Isolation, purficiation and antibiotic activity of o-

Moslem, M.A., & El-Kholie, E.M. (2009). Effect of neem (Azadirachta indica A.Juss) seeds

Namazi, M., Allameh, A.A., Aminshahidi, M., Nohee, A., and Malekzadeh, F. (2002).

Aspergillus parasiticus NRRL. Acta Pol Toxicol. 10, 65-72.

B-aflatoxins in maize. Food Chem. Toxicol.43 (2), 233–238.

Association of Cereal Chemists, St Paul, MN, pp. 135–193.

52, 1882–1889.

*and Chemical Toxicology*, 35, 807-820.

*Technology,* 135, 249-262.

Rev. Food Sci. 43, 245–264.

*Sciences,* 12(14), 1045-1048.

mouse. *Toxicol Appl Pharmacol* 90: 401-409.

150, 316-329.

43:571-4.

577–583.

173.

Aspergillus flavus by constituents of walnut (Juglans regia). J. Agric. Food Chem.

inactivation of aflatoxins in peanut and cottonseed meals. J. Am. Oil Chem. Soc. 47,

Voss, K.A., Plattner, R.D., Kubena, L.F., & Phillips, T.D. (1997). Oxidative degradation and detoxification of mycotoxins using a novel source of ozone. *Food*

Martnez, E., (2005). Safety and efficacy evaluation of aqueous citric acid to degrade

aflatoxin duckling feed with aqueous citric acid treatment. *Animal Feed science and*

Martinez, E. (2009). Effect of citric acid on aflatoxin degradation and on functional and textural properties of extruded sorghum. *Animal Feed Science and Technology*,

Galdwell, E.F. (Eds.), Breakfast Cereals and How They Are Made. American

sodium bisulfite, sodium hydroxide and aqueous ammonia. J Food Prot 1980;

in vivo DNA binding and in vitro biotransformation of aflatoxin B1 in the rat and

methoxycinnamaaldyde from cinnamon. Applied Environmental Microbiology 36,

and leaves extract on some plant pathogenic fungi. *Pakistan Journal of Biological*

Inhibitory effects of ammonia solution on growth and aflatoxin production by

Phytoinhibition of Growth and Aflatoxin Biosynthesis in Toxigenic Fungi 313

Rasooli, I., Rezaei, MB., & Allameh, A. (2006a). Growth inhibition and morphological

Razzaghi-Abyaneh M., Allameh A., Al-Tiraihi T., and Shams M. (2005a). Studies on the

Razzaghi-Abyaneh, M., Allameh, A., & Shams, M. (2000). Screening of aflatoxin producing

Razzaghi-Abyaneh, M., Allameh, A., Tiraihi, T., Shams-Ghahfarokhi, M., and Ghorbanian,

Razzaghi-Abyaneh, M., Shams-Ghahfarokhi, M., Yoshinari, T., Rezaee, M B., Jaimand, K.,

Reddy, C. S., Reddy, K. R. N., Prameela, M., Mangala, U. N., & Muralidharan, K. (2007).

Reichling, J., Schnitzler, P., Suschke, U., Saller, R. (2009). Essential oils of aromatic plants

Rokey, G.J., 1994. Petfood and fishfood extrusion. In: Frame, N.D. (Ed.), The Technology of

Rustom, I. Y. S. (1997). Aflatoxin in food and feed: occurrence legislation and inactivation by

Samarajeewa, U., Sen, A.C., Cohen, M.D., Wei, C.I., 1990. Detoxification of aflatoxins in

Santin, E., Paulilo, A. C., Maiorka, A., Nakaghi, L. S. O., Macan, M., de Silva, A. V. F., et al.

Santos, C. C. M., Lopes, M. R. V., & Kosseki, S. Y. (2001). Ocorreˆncia de aflatoxinas em

Saxena, M., allameh A.A., mukerji, K.G., & Raj H.G. (1989). Studies on glutathione –

Rio Preto/SP. Revista do Instituto Adolfo Lutz, 60(2), 153–157.

*porlock. Food Control,* 17, 359 –3 64.

grains. *Food Control*, 20, 173-178.

*Forsch Komplementmed*, 16, 79-90.

physical methods. Food Chemistry, 59, 57–67.

ultraviolet light. *Acta Med. Iranica,* 38, 67-73.

*International Journal of Food Microbiology*, 12, 228-233.

127).

570.

144–189.

489–501.

Science, 2, 241–344.

Toxicology-Toxin Rev., 8; 319-328.

alterations of *Aspergillus niger* by essential oils from *Thymus eriocalyx* and *Thymus x-*

mode of action of neem (Azadirachta indica) leaf and seed extracts on morphology and aflatoxin production ability of Aspergillus paraiticus. Acta Hort., 675, (123-

mould isolates based on fluorescence production on a specific medium under

M, (2005b). Morphological alterations in toxigenic *Aspergillus parasiticus* exposed to neem (Azadirachta indica) leaf and seed aqueous extracts. *Mycopathologia*, 159, 565–

Nagasawa, H., & Sakuda, S. (2008). Inhibitory effects of Satureja hortensis L. essential oil on growth and aflatoxin productionby *Aspergillus parasiticus*.

Identification of antifungal component in clove that inhibits Aspergillus spp. colonizing rice grains. Journal of Mycology and Plant Pathology, 37(1), 87–94. Reddy, K.R.N., Reddy, C.S. & Muralidharan, K. (2009). Potential of botanicals and biocontrol

agents on growth and aflatoxin production by *Aspergillus flavus* infecting rice

with antibacterial, antifungal, antiviral, and cytotoxic properties. an overview.

Extrusion Cooking. American Association of Cereal Chemists, St Paul, MN, pp.

foods and feeds by physical and chemical methods. Journal of Food Protection 53,

(2003). Evaluation of the efficiency of Saccharomyces cerevisiae cell wall to ameliorate the toxic effects of aflatoxin in broilers. International Journal of Poultry

amendoim e produtos de amendoim comercializados na regia~o de Sa~o Jose´ de

transferase of Aspergillus flavus group in relation to aflatoxin production. J.

Pomeranz, Y.I., Bechtel, D.B., Sauer, D.R. and Seitz, L.M. (1990) `Fusarium Headblight (scab)

Poppenberger, B., Berthiller, F., Lucyshyn, D., Sieberer, T., Schuhmacher, R., Krska, R., et al.

Prado, G., Carvalho, E.P.D., Oliveira, M.S., Madeira, J.G.C., Morais, V.D., Correa, R.F., et al.

flora in peanut. Brazilian Journal of Microbiology, 34(Suppl. 1) (Sao Paulo). Prakash, B., Shukla, R., Singh, P., Mishra, P.K., Dubey, N.K., Kharwar, R.N. (2011). Efficacy

Proctor, A.D., Ahmedna, M., Kumar, J.V., Goktepe, I., (2004). Degradation of aflatoxins in

Proctor, R.H., Brown, D.W., Plattner, R.D., Desjardins, A.E., (2003). Co-expression of 15

Prudente Jr., A.D., King, J.M., (2002). Efficacy and safety evaluation of ozonation to degrade

Ramos, A.R., Falco L.L, Barbosa G.S., Marcellino L.S., and Gander E.S. (2007). Neem

Rasooli, I., Allameh, A.A., Rezaee, M.B. (2005). Antimicrobial efficacy of thyme essential oils

Rasooli, I., Fakoor, M.H., Allameh, A., Rezaee, M.B., & Owlia, P. (2009). Phytoprevention of

Rasooli, I., Fakoor, M.H., Yadegarinia, D., Gachkar, L., Allameh, A.A., & Rezaei, M.B.

Rasooli, I., Owlia, P. (2005). Chemoprevention by thyme oils of *Aspergillus parasiticus* growth

Rasooli, I., Razzaghi-Abyaneh, M. (2004). Inhibitory effect of thyme oils on growth and aflatoxin production by *Aspergillus parasiticus. Food Control*, 15, 479-483. Rasooli, I., Rezaei B., Allameh, A.A. (2006b). Ultrastructure studies on antimicrobial efficacy

Y., ed), pp. 373±473, AACC, St. Paul

of spices. Food Research International, 44, 385-390.

*moniliformis*. *Fungal Genetics and Biology* 38, 237–249.

aflatoxin in corn. Journal of Food Science 67, 2866–2872. Rahman, S., 1995. Food Properties Handbook. CRC Press, New York.

Riley. Chapter one, pp. 1-33 Nova Science Publishers. Inc.

aflatoxin production. *Journal of Medicinal Plants*, 8(5), 97-104.

and aflatoxin production. *Phytochemistry,* 66, 2852-2856.

Infectious disease. 10, 236-241.

Additives and Contaminants 21, 786–793.

278, 47905–47914.

162: 238-243.

in Cereal Grain' in Advances in Cereal Science and Technology Vol.10., (Pomeranz,

(2003). Detoxification of the Fusarium mycotoxin deoxynivalenol by a UDPglucosyltransferase from Arabidopsis thaliana. Journal of Biological Chemistry,

(2003). Effect of gamma irradiation on the inactivation of aflatoxin B1 and fungal

of chemically characterized Ocimum gratissmum L. essential oil as an antioxidant and a safe plant based antimicrobial against fungal and aflatoxin B1 contamination

peanut kernels/flour by gaseous ozonation and mild heat treatment. Food

contiguous genes delineates a fumonisin biosynthetic gene cluster in *Gibberella*

(Azadirachta indica A. Crinipellis perniciosa and Phytophtora spp. Microbiol. Ress.

as food preservatives. In: Food Policy, Control and Research. Editor: Arthur P.

(2007). Antimycotoxigenic characteristics of Rosmarinus officinalis and Trachyspermum copticum L. essential oils*. Int. J. Food Microbiol*., 29, 135-139. Rasooli, I., Fakoor, M.H., Yadegarinia, D., Gachkar, L., Allameh, A., Rezaee, M.B. (2008).

Antimycotoxigenic characteristics of Rosmarinus officinalis and Trachyspermum copticum L. essential oils. International Journal of Food microbiology. 122, 135-139.

of thyme essential oils on Listeria monocytogenesis. International Journal of

Phytoinhibition of Growth and Aflatoxin Biosynthesis in Toxigenic Fungi 315

Teniola, O.D., Addo, P.A., Brost, I.M., Farber, P., Jany, K.D., Alberts, J.F., Zyl, W.H.V., Steyn,

Thanaboripat, D., Suvathi, Y., Srilohasin, P., Sripakdee, S., Patthanawanitchai, O.,

Thiesen, J., 1977. Detoxification of aflatoxins in groundnut meal. Anim. Feed Sci. Technol. 2,

Trail F, Mahanti N, Linz J (1995). Molecular biology of aflatoxin biosynthesis. Microbiology,

Valko M, Rhodes CJ, Moncola J, Izakovic M, Mazura M (2006). Free radicals, metals and antioxidants in oxidative stress-induced cancer Chemico Biol. Interact. 160: 1-40. Van Egmond, H. P. (1989). Current situation on the regulations for mycotoxins. Overview of

Velazhahan, R., Vijayanandraj, S., Vijayasamundeeswari, A., Paranidharan, V., Samiyappan,

Veldman A. Effect of sorbentia on carry-over of aflatoxin from cow feed to milk (1992).

Velluti, A., Sanchis, V., Ramos, A.J., Ergido, J.,Marin, S., 2003. Inhibitory effect of cinnamon,

Velluti, A., Sanchis, V., Ramos, A.J., Marin, S., 2004. Effect of essential oil of cinnamon, clove,

Wu F., Khlangwiset (2010). Health economic impacts and cost-effectiveness of aflatoxin

Wu Q., Jezkova A., Yuan Z., Pavlikova L., Dohnal V., & Kamil Kuca K. (2009). Biological

Xu, A., 1999. Use of ozone to improve the safety of fresh fruits andvegetables. Food

Yabe K, Nakajima H (2004). Enzyme reactions and genes in aflatoxin biosynthesis. Appl.

Yagen B, Hutchins JE, Hagler WM, Hamilton PB. Aflatoxin B,S: revised structure for the

sodium sulfonate formed by destruction of aflatoxin B, with sodiumbisulfite. J Food

Fusarium verticilloides in maize grain. J. Sci. Food Agric. 89, 145–154. Wang JS, Groopman JD (1999). DNA damage by mycotoxins. Mutat.Res. 424: 167-181. Winfree RA, Allred A. (1992). Bentonite reduces measurable aflatoxin B in fish feed.

interventions. Food Additives and Contamination, 27 (4): 496-509.

degradation of aflatoxins. *Drug Metabolism Reviews*, 41(1): 1–7

*International Journal of Food Microbiology*, 105, 111-117.

*Aspergillus flavus. KMITL Sci. Tech* J, 7:1, 1-7.

*Additives and Contaminants*, 6, 139–188.

aflatoxin G1. *Food Control*, 21, 719-725.

Progressive Fish-Culturist, 54: 157-62.

Microbiol. Biotechnol. 64: 745-755.

Technology 53, 58–62.

Prot 1989; 52574-7.

Milchwissenschaft, 47:777-80.

67–75.

141: 755-765.

145–154.

P.S., & Holzapfel, W.H. (2005). Degradation of aflatoxin B1 by cell-free extracts of *Rhodococcus erythropolis* and *Mycobacterium fluoranthenivorans* sp. Nov. DSM44556.

Charoensettasilp, S. (2007). Inhibitory effect of essential oils on the growth of

tolerances and status of the standard methods of sampling and analysis. *Food*

R., Iwamoto T., Friebe B., & Muthukrishnan S. (2010). Detoxification of aflatoxins by seed extracts of the medicinal plant, Trachyspermum ammi (L.) Sprague ex Turrill- Structural analysis and biological toxicity of degradation product of

clove, lemongrass, oregano and palmarosa essential oils on growth and fumonisin B1 production by Fusarium proliferatum in maize grain. Int. J. Food Microbiol. 89,

lemongrass, oregano and palmarosa on growth and fumonisin B1 production by

reduction strategies in Africa: case studies in biocontrol and postharvest

Schmidt-Heydt, M., & Geisen, R. (2007). A microarray for monitoring the production of mycotoxins in food. *International Journal of Food Microbiology,* 117, 131-140. Šegvić Klarić, M., Kosalec, I., Mastelić, J., Piecková, E., Pepeljnack, S., 2006. Antifungal

Sharma, A., Padwal Desai, S.R., Tewari, G.M., Bandyopadhyay, C., (1981). Factors affecting

Shetty, P.H., & Jespersen, L. (2006). *Saccharomyces cerevisiae* and lactic acid bacteria as

Singh, P., Srivastava, B., Kumar, A., & Dubey, N. K. (2008). Fungal contamination of raw

Sinha, K.K., Sinha, A.K., Prasad, G., (1993). The effect of clove and cinnamon oils on growth

Smiley, R.D., Draughon, F.A., 2000. Preliminary evidence that degradation of aflatoxin B1 by

Snyder, O.P. 1997 *Antimicrobial Effects of Spices and Herbs*. Hospitality Institute of Technology

Sokovic M.D., Vukojevic J., Marin P.D., Brkic D.D., Vajs V., Van Griesnsven L.J.L.D (2009).

Soliman, K.M., Badeaa, R.I. (2002). Effect of oil extracted from some medicinal plants on different mycotoxigenic fungi. *Food and Chemical Toxicology* , 40, 1669–1675. Sommartya T, Jatumanusiri T, Konjing C, Maccormac C. Aspergillus flavus in peanut in

Soni, K.B., Rajan, A., Kuttan, R., 1992. Reversal of aflatoxin induced liver damage by

Sova Z, Pohunkova H, Reisnerova H, Slamova A, Haisl K. Haematological and histological

Stankov M, Obradovic V, Obradovic J, Vukicevic 0. Effect of a micronized zeolite

Strosnider H., Azziz-Baumgartner E., Banziger M., Bhat R.V., Breiman R., Brune M., et al.

Takahashi-Ando, N., Ohsato, S., Shibata, T., Hamamoto, H., Yamaguchi, I., & Kimura, M.

in developing countries. Environ. Health Perspect, 114: 1989-1903.

from damp dwellings. Letters in Applied Microbiology 44, 36–42.

oil as herbal fungitoxicant. Microbial Ecology, 56, 555−560.

Sison JA. Sequestering mycotoxins in animal feeds. Feeds Cotnp 1992; 12:34-35.

and Management, St Paul, Minnisota.

antifungal activities. Molecules 14:238-249.

Jap. Assoc. Mycotox., 1988; Suppl. N" 1, 71-2.

Acta Vet Brno 1991; 60:31-40.

Microbiology, 70, 3239–3245.

1992; 46:91-6.

turmeric and curcumin. Cancer Lett. 66, 115–121.

Flavobacteria aurantiacum is enzymatic. J. Food Prot. 63, 415–418.

Sci. 46, 741–744.

17, 48-55.

117.

activity of thyme (Thymus vulgaris L.) essential oil and thymol against moulds

antifungal activity of onion extractives against aflatoxin producing fungi. J. Food

potential mycotoxin decontaminating agents. *Trends in Food science and Ttechnology*,

materials of some herbal drugs and recommendation of Cinnamomum camphora

of and aflatoxin production by Aspergillus flavus. Lett. Appl. Microbiol. 16, 114–

Chemical composition of essential oils of Thymus and menthe species and their

Thailand with special reference to aflatoxin contamination, and detoxification. Proc.

response to the diet containing aflatoxin B, and zeolite in broilers of domestic fowl.

preparation on the health and production of weaned piglets. Veterinarsky Glasnik

(2006). Workgroup report: public health strategies for reducing aflatoxin exposure

(2004). Metabolism of zearalenone by genetically modified organisms expressing the detoxification gene from Clonostachys rosea. Applied and Environmental

**16**

 *México*

**Aflatoxins Biochemistry and**

*Facultad de Ingeniería, CA Ingeniería de Biosistemas,*

Laura Mejía-Teniente,

*Universidad Autónoma de Querétaro,*

**Molecular Biology - Biotechnological**

Angel María Chapa-Oliver, Moises Alejandro Vazquez-Cruz, Irineo Torres-Pacheco and Ramón Gerardo Guevara-González

Fungi play a very important, but yet mostly unexplored role. Their widespread occurrence on land and in marine life makes them a challenge and a risk for humans (Bräse *et al.,* 2009). Fungi are ingenious producers of complex natural products which show a broad range of biological activities (Bohnert *et al.,* 2010). However, a specific characteristic is the production of toxins. Mycotoxins (from "*myco*" fungus and toxin), are nonvolatile, relatively low-molecular weight, fungal secondary metabolic products (Bräse *et al.,* 2009). The most agriculturally important micotoxins are aflatoxins (AF) which are a group of highly toxic metabolites, studied primarly because of their negative effects on human health. Aflatoxins belong to a group of difuranocumarinic derivatives structurally related, and are produced meanly by fungi of genus *Aspergillus* spp. Its production depends on many factors such as substrate, temperature, pH, relative humidity and the presence of other fungi. It has been identified 18 types of aflatoxins; the most frequent in foods are B1, B2, G1, G2, M1, and M2 (Bhatnagar *et al.,* 2002). These secondary metabolites contaminate a number of oilseed crops during growth of the fungus and this can result in severe negative economic and health impacts (Cary *et al.,* 2009). The higher levels of aflatoxins have been found in cotton and maize seeds, peanuts, and nuts. In grains like wheat, rice, rye or barley the presence of aflatoxins is less frequent. Mycotoxins may also occur in conjugated form, either soluble (masked mycotoxins) or incorporated into/ associated with/attached to macromolecules (bound mycotoxins). These conjugated mycotoxins can emerge after metabolization by living plants, fungi and mammals or after food processing. Awareness of such altered forms of mycotoxins is increasing, but reliable analytical methods, measurement standards, occurrence, and toxicity data are still lacking (Berthiller *et al.,* 2009). A variety of studies has been conducted in order to understand the process of crop contamination by aflatoxins. Mycotoxins are dangerous metabolites that are often carcinogenic, and they represent a serious threat to both animal and human health (Reverberi *et al.,* 2010). Mycotoxins are considered secondary metabolites because

**1. Introduction**

*Centro Universitario Cerro de las Campanas s/n, Querétaro, Qro,*

**Approaches for Control in Crops**


**5. Machine learning approach**

This preliminary model aims at predicting COF based on topographical characteristics of interfaces (surface pores and texture) rather than investigating the physical mechanisms associated to the tribological behavior.

The average coefficient of friction from 6228 experiments was organized in a training dataset of 1704 different combinations of geometric and operational parameters and, subsequently, used as inputs to a Hardy Multiquadric Radial Basis Function (RBF), as illustrated schematically in **Figure 6**. The mathematical development and detailed results are reported in [33]. Similar to several Artificial Neural Networks (ANN) methods, the RBF approach can produce a correct input–output mapping even for noisy and dispersed data. The RBF and experimental COF output were compared using the coefficient of determination (*R*2 ) evaluation to avoid that the variation among the tribological experiments could be wrongly assessed as a surface feature or test parameter (*i.e.* overfitting). The results were considered satisfactory under this perspective because the error percentage was not significantly different from the maximum relative standard deviation of the dataset.

A summary of the model fitting capacity is shown in **Figure 7**, where the RBF and experimental COF results were plotted together. Overall, results from all the

#### **Figure 6.**

*Schematic of the machine learning model proposed to predict the frictional behavior of porous and textured interfaces from the experimental dataset.*

**Figure 7.**

*Comparative plots for some surface features. Each number in the horizontal axis represents a single experimental test (single combination of surface and test parameters) sorted in ascending order according to friction results rather than in chronological order for improving readability.*

different samples presented a high fitting capacity (*R*2 ≈ 0.94), being the worst Ball-Sint (≈0.64) and the best fitting Disc-Si4 (≈0.97). The *R*2 values from the other surface configurations are distributed between these two extremity values.

The proposed model is more sensitive to high values of *W*, *D* and *Ca*. Low values of *W* and *D* for shallow configurations could be difficult to be interpreted by the model since the overall topography is not mathematically significantly different from the smooth samples NP. Furthermore, shallow features in Ball-Sint and Disc-Di also occupied a very small area (low *Ca* values), making it even more challenging to discern between NP and shallow features.

Together with the continuous improvement of the mathematical model and expansion of the dataset to shallow and less dense surfaces, these results indicate that the RBF methodology can be an effective tool for designing novel surface features for tribological applications.

#### **6. Conclusions**

The frictional performance of textured discs and balls containing surface pores or laser textures was assessed carrying out a wide range of experiments under lubricated non-conformal contact and varying kinematic conditions (speed and slide-to-roll-ratio).

Between the different texture geometries studied, dimples generally performed best, demonstrating the lowest COFs and lowest lift-off speed, which can be traced

#### *Tribological Performance of Random Sinter Pores vs. Deterministic Laser Surface Textures… DOI: http://dx.doi.org/10.5772/intechopen.100245*

back to the increment of the hydrodynamic load-carrying capacity at lower speeds, further separating the rubbing surfaces and consequently reducing asperity contact. This was proven by film thickness and electric contact resistance measurements. Perpendicular grooves demonstrated beneficial performance compared with polished reference samples, depending on depth and transversal dimension. Potential beneficial effects of perpendicular grooves were partially mitigated by textures' excessive transversal dimension or depth. Longitudinal grooves led to unbeneficial tribological behavior, as equal entrainment and groove direction probably promoted lubricant migration out of the contact.

Sintering parameter tuning permitted to obtain different porosities and pore characteristics. The pore configuration achieved by machining the sintered ball samples reduced friction compared to the unstructured reference at the same specific film thickness.

Deterministic laser textures seem to outperform surface pores with random distribution and size despite the difficulties of comparing sintered with laser textured samples. This is particularly evident when considering the entrainment speed, showing that laser textures can significantly decrease the lift-off speed, after which full-film lubrication prevails by generating additional hydrodynamic pressure. Both textures have in common that textures of small dimensions being smaller than the contact area yielded the best results. However, it should be noted that laser texturing requires an additional manufacturing step, thus making the production process more complex.

Finally, considering that using advanced machine learning methods to describe tribological problems is still in its infancy, the proposed radial bias function approach showcased promising results that open new perspectives for its extension to support the optimum design of surface texturing for tribological applications in the future.

## **Acknowledgements**

The State of São Paulo Research Foundation, Brazil (FAPESP grant N. 2016/25067-9), the Brazilian National Council for Scientific and Technological Development (CNPq) and the"Austrian COMET Program" (project InTribology, no. 872176) via the Austrian Research Promotion Agency (FFG) and the federal states of Niederösterreich and Vorarlberg are acknowledged for funding this work. Part of this work was carried out within the "Excellence Centre of Tribology" (AC2T research GmbH). C. Gachot acknowledges the government of Lower Austria for financially supporting the endowed professorship tribology at the TU Wien (Grant No. WST3-F-5031370/001–2017) in collaboration with AC2T research GmbH. D. Dini also acknowledges the support received from the Engineering and Physical Sciences Research Council (EPSRC) via his Established Career Fellowship EP/N025954/1. M. Roudrigues da Silva thanks the Centro Educacional da Fundação Salvador Arena and Termomecanica São Paulo S.A. for the financial support.


**2. Material and method**

#### **2.1 Plant material**

The plant material consisted of 42 sorghum genotypes including 22 sweet grain sorghum, 10 sweet sorghum, and 10-grain sorghum (common sorghum). The seeds of sweet grain sorghum and sweet sorghum came from the germplasm of the Laboratoire Biosciences of Université Joseph KI-ZERBO. The seeds of grain sorghum were obtained from the "Institut de L'Environment et de Recherche Agricole (INERA)," "Kamboinsé," Burkina Faso.

#### **2.2 Experimental site**

The agro-morphological evaluation took place under rainfed conditions in 2020 at the experimental station of the "Institut du Développement Rural (IDR)" in "Gampéla." The locality is located in the northern Sudanese climatic zone with geographical coordinates of 12°25' North latitude and 1°21' West longitude. The soil is very heterogeneous, deep, of low chemical fertility, and predominantly sandy loam texture [19]. During the trial from July to October, the average monthly temperature ranged between 26 and 28°C for a cumulative rainfall of 769 mm.

#### **2.3 Experimental design**

The experimental setup was an incomplete Fisher block with three replications, each subdivided into three sub-blocks. Each sub-block consisted of 14 lines and 11 patches per line with 0.8 m row spacing and 0.4 m inter-patches. Each replication had 42 lines with one line per genotype and two borderlines. The distances between replications and sub-blocks were respectively 2 and 1 m for a total area of 504 m2 .

#### **2.4 Cultivation techniques**

The field was plowed with a tractor and leveled before sowing on July 18, 2020. In the course of the trial, a wedding with one plant per stake was carried out 15 days after sowing, followed by two weedings on the 18th and 35th day after sowing respectively. Ridging was then carried out toward the end of the vegetative development of the plants in order to counteract the lodging caused by the high winds. NPK fertilizer (14–23-14) was applied at each weeding at a rate of 50 kg/ha, and urea was applied at the time of weeding at a rate of 50 kg/ha.

#### **2.5 Data collection**

A total of 20 quantitative traits, of which 19 were agro-morphological and one (01) biochemical, were determined by measurement or counting. These traits are related to phenology, vegetative organ characteristics, yield parameters, and soluble sugar content (Brix).

#### *2.5.1 Phenology-related traits*

Four variables have been determined. These are the sowing-emergence cycle, the sowing-heading cycle, the sowing-flowering cycle, and the heading-flowering difference.

#### *2.5.2 Vegetative-organs-related traits and the soluble sugar content of the stem (Brix)*

The leaf characteristics were the number of leaves per plant, the length of the third leaf under the panicle, the width of the third leaf under the panicle, the length of the leaf sheath, and the separation, which corresponds to the half-distance between the base of the blade of the third leaf and the fifth leaf under the panicle. On the stem, the length of the internode, the number of internodes, the diameter of the main stem, and the number of vegetative tillers were determined. The height of the plant at maturity (HPL) was also measured. The soluble sugar content of the stem (Brix) was determined at the hard grain stage using a portable digital refractometer (ATAGO PAL-α) with an accuracy of ±0.2% on the two central internodes located in the middle of the stem.

#### *2.5.3 Yield-related traits*

Five traits were measured. These are the number of productive tillers per plant, the length of the peduncle, the weight of 100 grains, and the length and width of the panicle.

#### **2.6 Data analysis**

Data processing and analysis were carried out with the Excel 2016 spreadsheet and Xlstat 2016 software. An analysis of variance coupled with a Newman–Keuls test of the separation of means at the 5% threshold was carried out in order to evaluate the variability of the material studied and to determine on the one hand the variables that discriminate the types of sorghum and on the other hand the effects of the factors "genotype" and "type of sorghum" on the expression of the characters through the coefficient of determination (R2 ). A principal component analysis (PCA) was also carried out to highlight the variables that characterize each type of sorghum. A hierarchical ascending classification (HAC) was finally carried out according to the genotypes, using the majority of the quantitative characters in order to observe the grouping of the genotypes. The groups obtained were finally characterized by discriminant factor analysis (DFA).

#### **3. Results**

### **3.1 Comparison of sweet grain sorghum with other cultivated sorghums based on phenology-related traits**

The results recorded in **Table 1** showed an absence of significant differences between sweet grain sorghum and the two other types of sorghum grown in Burkina for the number of days to emergence and the sowing-flowering cycle. On the other hand, the two other characteristics significantly discriminated grain sorghum from

*Assessment of Genetic Variability of Three Types of Sorghum Cultivated in Burkina Faso... DOI: http://dx.doi.org/10.5772/intechopen.105984*

#### **Table 1.**

*Results of the Newman–Keuls mean separation test of phenological traits according to sorghum type.*

the two other sorghum types. Indeed, it has a longer sowing-flowering cycle and a shorter mean time to flowering (1 day) than sweet sorghum (3 days) and grain sorghum (4 days).

### **3.2 Comparison of sweet grain sorghum with other cultivated sorghums based on vegetative traits and soluble sugar content of the stem**

The analysis of the results in **Table 2** reveals that of the 10 agro-morphological traits, only the number of leaves and the number of internodes did not significantly discriminate the three types of sorghum studied. A significant difference was observed between sweet grain sorghum and the other two sorghums in terms of leaf sheath length and stem diameter. Indeed, sweet grain sorghum was clearly distinguished from the other two types of sorghum by longer leaf sheaths and larger stem diameter. However, it has similar characteristics to grain sorghum in terms of leaf size and sweet sorghum in terms of vegetative shoot production, separation, internode length, and plant height.

As for the soluble sugar content (Brix), a significant variation according to the type of sorghum was observed. Sweet grain sorghum expressed a Brix value (12.32%) significantly lower than grain sorghum (13.98%) and sweet sorghum (18.89%).

#### **Table 2.**

*Results of the Newman–Keuls mean separation test of vegetative traits and Brix according to sorghum type.*

#### **Table 3.**

*Results of the Newman–Keuls mean separation test of yield and Brix parameters according to sorghum type.*

### **3.3 Comparison of sweet grain sorghum with other cultivated sorghums based on yield-related traits**

All yield-related traits significantly discriminated all cultivated sorghum types (**Table 3**) but panicle length showed no significant difference between sweet grain and sweet sorghum. Sweet grain sorghum is clearly distinguished from the other two types of sorghum by an intermediate peduncle length, wider panicles, lighter grains, and a higher number of productive tillers.

#### **3.4 Effect of "genotype" factor and "sorghum type" factor on trait expression**

The results recorded in **Table 4** showed variability of the material at the level of most of the characters except for the number of productive tillers. The comparative analysis of the coefficients of determination (R2 ) revealed a preponderance of the genotype factor in the expression of all the characteristics, explained by higher values (>50%) except for the production of productive tillers (36%). However, the influence of the "sorghum type" factor was quite important in the expression of heading-flowering difference (54%), Brix (44%), panicle width (37%), and plant height (31%).

#### **3.5 Description of sorghum types grown**

The results of the principal component analysis (PCA) indicate that the first two axes contribute 100% of the total variance (**Figure 1**). Thus, the projection in the ½ plane in the biplot of the variables and the sorghum type factor shows that axis 1 with an inertia rate of 55.06% negatively associated with the variables' sowing-flowering cycle, the number of internodes, leaf width, stem diameter, and panicle width and positively the variables leaf length and Brix. Axis 2, which explains 44.94% of the total variability, is positively associated with the variables panicle length, mean heading-flowering distance, and 100-grain weight. They are opposite to the variables plant height, vegetative tillering, and productive tillering. The biplot shows that sweet sorghum positively related to axis 1 is characterized by long leaves and a high Brix value. Grain sorghum positively associated with axis 2 is opposite to sweet grain sorghum. Sweet grain sorghum is characterized by a short panicle, a short difference between flowering and heading, taller plants, and a large number of vegetative and productive tillers. Grain sorghum is characterized by a long panicle, a long average time between flowering and heading, shorter plants, and a smaller number of vegetative

*Assessment of Genetic Variability of Three Types of Sorghum Cultivated in Burkina Faso... DOI: http://dx.doi.org/10.5772/intechopen.105984*

#### **Table 4.**

*Effects of genotype and sorghum type factors on the expression of the studied traits.*

and productive tillers. Moreover, the analysis of Euclidean distances (**Table 5**) revealed greater proximity between sweet grain sorghum and sweet sorghum (11.025). The greatest distance was recorded between sweet grain sorghum and grain sorghum (65.771).

#### **3.6 Organization of the diversity of sorghum grown in Burkina Faso**

The dendrogram (**Figure 2**) derived from the hierarchical ascending classification (HAC), based on the Euclidean distances between individuals, divides the sorghum genotypes into three groups with one truncation at inertia level 100 (truncation 1) independently of the sorghum types. Thus, group I consists of all sweet grain sorghum genotypes and three sweet sorghum genotypes. Group II is composed of five sweet sorghum genotypes and two-grain sorghum genotypes. Group III consists of seven-grain sorghum genotypes and two sweet sorghum genotypes. In addition, a subdivision of group I genotypes into sweet grain sorghum and sweet sorghum is observed at truncation level 50 (truncation 2) conforming sweet grain sorghum is

#### **Figure 1.**

*Projection of variables and sorghum types in the ½ plane of the principal component analysis. Legend: STS: sweet sorghum, SGO: Grain sorghum, SGS: Sweet grain sorghum, NJF: Sowing – flowering cycle, EE-F: Difference flowering - earing, TAV: Vegetative tillers, LAF: Leaf width, LOF: Leaf length, NEN: Internodes number, DTI: Stem diameter, HPL: Plant height, TAU: Productive tillers, LAP: Panicle width, LOP: Peduncle length, PCG: 100-grain weight.*

#### **Table 5.**

*Matrix of Euclidean distance between sorghum types.*

more homogeneous. Sweet sorghum is the most heterogeneous as its genotypes are distributed in all three groups.

#### **3.7 Characterization of the sorghum groups obtained**

The characterization of the groups obtained from AHC by discriminant factor analysis (DFA) is shown in **Figure 3**. Group I, which includes all sweet grain sorghum genotypes and three sweet sorghum genotypes, is characterized by wider stalks and panicles and a greater number of productive tillers. Group II, which is mainly made up of sweet sorghum genotypes, is characterized by taller plants, longer internodes and

*Assessment of Genetic Variability of Three Types of Sorghum Cultivated in Burkina Faso... DOI: http://dx.doi.org/10.5772/intechopen.105984*

#### **Figure 2.**

*Dendrogram of the hierarchical ascending classification of the genotypes of the three types of sorghum grown in Burkina Faso. Legend: STS: sweet sorghum.*

panicles, and a higher Brix value. Group III, which is predominantly grain sorghum, contains genotypes with a longer sowing-flowering cycle, a longer mean time between flowering and heading, a higher number of internodes, and wider leaves.

#### **4. Discussion**

The absence of significant differences between the three types of sorghum grown in Burkina Faso in terms of the characters, sowing-emergence cycle, sowing-flowering cycle, number of internodes, and number of leaves, coupled with the low influence of the "sorghum type" factor in the expression of the characters, could testify to the genetic proximity between the three types of sorghum grown. This is confirmed by the organization of genotypes into agro-morphological groups independently of the "sorghum type" factor in the hierarchical ascending classification. Similar results are reported by [18] and [17] on these sorghum types using molecular markers. Indeed, the three sorghum types generally coexist in combination in traditional production systems. A gene flow could exist between them insofar as sorghum, although it is preferentially self-pollinated, has an outcrossing rate that can vary from 7–40% [20, 21]. The genetic proximity between these sorghums could confirm that they belong to the same species [17]. Therefore, the only determining factor in their differentiation would be the genotype, hence the high values of coefficients of determination recorded in the study with this factor. However, the smaller gap between heading and flowering observed in sweet grain sorghum and its preferential harvesting at the doughy grain stage could explain its earliness compared with the two types of sorghum grown. In addition, the duration of the sowing-flowering cycle of all three types of sorghum studied is lower than the results reported by [22] on sweet sorghum (76 days), by [23] on sweet grain sorghum (91 days), and by [24] on grain sorghum (79 days). This difference could be explained by the late establishment of the trial. Flowering was early and clustered for the genotypes of the three sorghum types studied. These results could be explained by the sensitivity of these sorghums to photoperiod variation as reported by several previous studies [24–26].

Seven of the 15 characteristics related to vegetative organs and yield, as well as the Brix, made it possible to clearly discriminate sweet grain sorghum from grain sorghum and sweet sorghum. Indeed, sweet grain sorghum is characterized by a more robust and less sweet stem emitting more productive tillers, longer leaf sheaths, a wider panicle supported by an intermediate-sized peduncle, and carrying lighter grains. This is confirmed by principal component analysis, which revealed an association between this sorghum and these variables. Similar results on panicle width and grain weight of sweet grain sorghum and Brix are reported in previous studies [10, 17]. The weak grain weight of sweet grain sorghum could be explained by its asymmetric shape and mealy consistency in contrast to the other two types, which have elliptical and glassier grains. In addition, the weakly stem Brix value of sweet grain sorghum compared with sweet sorghum and grain sorghum could be related to a difference in the accumulation organs. Sweet grain sorghum would accumulate its sugars a lot in the grains as the stem.  This suggests that Brix is a trait more influenced by genotype than sorghum type, which is a simple classification criterion. Similar results were reported by [27] on grain sorghum under mineral fertilization conditions and [22] on sweet sorghum (8.88–21.83%). The Brix would be a polygenic trait with epistatic interactions and additive effects [28–30] unlike the sweet taste of the grain, which is controlled by a single biallelic gene [31, 32].

#### *Assessment of Genetic Variability of Three Types of Sorghum Cultivated in Burkina Faso... DOI: http://dx.doi.org/10.5772/intechopen.105984*

Finally, several results obtained revealed greater genetic proximity between grain sorghum and sweet stem sorghum. Indeed, among the variables discriminating the types of sorghum, similar characteristics were recorded between sweet grain sorghum and sweet sorghum in five variables (number of vegetative tillers, separation, internode length, plant height, panicle length). However, only two of these variables, i.e., leaf length and width, bring sweet grain sorghum closer to grain sorghum. This is confirmed on the one hand by the Euclidean distances, which showed a smaller distance between sweet sorghums and on the other hand by the results of the hierarchical classification where a composite group consisting of all sweet grain sorghum genotypes and three sweet sorghum genotypes was obtained. [18] also showed that sweet sorghums (sweet sorghum, sweet grain sorghum) are genetically more closely related (Fst = −0.0558) to grain sorghum [17], however, showed greater proximity between sweet grain sorghum and grain sorghum using molecular markers. This difference in molecular and phenotypic proximity could be explained by the generally polygenic determinism of the traits taken into account in the estimation of phenotypic distance, which can lead to convergence phenomena [33]. According to [34], lines with the same value for a quantitative trait may have different alleles for each of the loci involved. The effect of environmental factors on phenotype expression could also explain this difference in molecular and phenotypic distances.

Finally, the fact that all sweet grain sorghum genotypes belong to the same agromorphological group could indicate a greater homogeneity of this type of sorghum compared with the other two types [17] also reported low diversity within this sorghum type compared with the other two sorghum types.

#### **5. Conclusion**

The study revealed a weak influence of the factor "type of sorghum" in the expression of all the characters. Nine characters, including two related to phenology, six to vegetative organs and yield, and Brix, allowed us to distinguish sweet grain sorghum from sweet sorghum and grain sorghum. Sweet grain sorghum is characterized by a robust, low-sugar stem, longer leaf sheaths, a broad panicle, and lighter grains. The study shows also that sweet sorghums are genetically similar to grain sorghum. These results could contribute to better management of sorghum genetic resources in Burkina Faso through their use in the national sorghum breeding program. Indeed, crosses could be made between these different types of cultivated sorghum to create single, three-way or double hybrids containing sweet grains and sweet stems. These hybrids could then be evaluated in multi-location trials in contrasting environments to select genotypes by environment. Marker-assisted selection could also be used to identify drought-tolerant genotypes of interest. Furthermore, the analysis of the nutritional composition of the grains of these genotypes of interest, in particular their profile in essential amino acids (lysine), vitamins, and sugars, could be the basis for their exploitation in the food industry for the manufacture of infant porridges and biscuits.

#### **Acknowledgements**

This paper is dedicated by the coauthors to Boureima sawadogo, who passed away in November 2021. The coauthors would like to acknowledge Members of

"Laboratoire Biosciences" for their assistance. They would also like to thank sincerely Dr. Mariam Kiébré for the corrections and suggestions.