**6. Creating a New Paradigm of Indigenous Community Development**

Environmental scientists, policy makers, and community developers create and apply theories to the ever-evolving complex situations of a rapidly degrading global environment. Environmental educators create curricula to bring about both an awareness and deeper understanding of chronic ecological issues. New models are constantly being debated and alternatives applied to address specific environmental situations. Yet, most of this work continues to be done and viewed from the "old" paradigms of Western science and policy development. Success and impact of these models continue to be tied to traditional and mono-dimensional economic references such as numbers of people trained or graduated, goods and services delivered, loans or profits made, etc. While these are quantifiable indicators of impact or relative success, it must be remembered that they are but one kind of indicator. Deeper level indicators which reflect the broader dimensions of change or impact are rarely researched and when they are, they are rarely taken seriously. The so-called business "bottom line" psychology continues to predominate as what is most valued in measuring relative success of a development initiative, even as community and environmental issues continue and even worsen. This is the case in many Indigenous communities that attempt to apply Western concepts of development to their unique community development issues. In general, we know more about the issues than ever before yet continue with the old paradigm of thinking and actions, seemingly helpless as we continue to speed ahead to ecological disaster. A deeper and more conscious education about sustainability and the development of a new consciousness therein are key to making the necessary changes for our collective survival.

However, to measure long term "sustainability" of a model or initiative, the net must be cast much broader to be inclusive of the more holistic and less easily quantifiable context of a natural community inclusive of humans. Historically, the traditional Indigenous paradigm of "development" began with gauging the sustainability of an initiative or application of a body of knowledge in reference to how well it helped an Indigenous community "survive" through time and in a place. Indeed, Indigenous communities have the historical, philosophical, and even spiritual foundations from which they may build new and sustainable models for community renewal and revitalization. Many have the cultural and historical foundations to operationalize new sustainable paradigms if they build upon their own creative sense of what it takes to be sustainable and to survive [8].

The movement on the part of some Indigenous leaders and scholars to Indigenize foundational aspects of Indigenous development in ways that are more closely aligned with Indigenous world views is itself a very practical creative strategy to address very real issues of sustainability. In addition, this movement toward "indigenization" is tied to an evolving and increasingly holistic and comprehensive approach to building Indigenous nations. Recognizing the role of local Indigenous knowledge and creating infrastructures from the inside out based on inherent strengths with an eye toward "sustainability" are some of the key tenets of this movement toward indigenization. Indigenous people are learning, creating, and evolving in their development of models for sustainability. Much of these processes are occurring outside the confines of Western academe, institutions, government agencies, and NGOs. They are being engaged in by and through the communities themselves as emergent and organic creative actions directly addressed at the issues and needs of the communities in real time.

This community-based creative process might be summarized as follows: gaining firsthand knowledge of community needs through "problem-based action research", developing a comprehensive understanding of the history and "ecology" of a community economy, implementing strategies for regaining control of local economies, creating models based on lessons learned and the application of research of practices that work, and cultivating networks for mutual support and action. This reflects authentic empowerment of communities from grassroots activity within the communities themselves. This also implies the need for a community education process that is initiated by the community in partnership with external expertise to produce solutions.

This new movement and new thinking regarding Indigenous development is in direct contrast with the standard approaches of the past which mimic the Western mono-dimensional model of development. Indeed, the underlying assumptions, aims, and effect of the Western model must be questioned in terms of their ultimate sustainability. It is through the application of the lens of their own histories of sustainability that Indigenous people are coming to realize the wisdom and consequences of applying the Western model of development to their circumstances. It is also the application of the conceptual framework of sustainability that gives the greatest opportunity to the application and even evolution of Indigenous science as a living and evolving base of knowledge upon which Indigenous communities might rely.

In using "sustainability" from perspectives that originate from within Indigenous communities as a guiding paradigm for building Indigenous nations, the underlying assumptions and mono-dimensionality of the standard Western development model becomes apparent. Upon close examination, the limitations of the prevailing Western development paradigm in helping Indigenous communities realize their goals of empowerment, renewal, and revitalization are also apparent.


*5.3.2 Quantity of fruit harvest and marketable fruit quality*

The number of fruits harvested from the eight variants and the control was higher on average when the biostimulators were applied to the rhizosphere directly at the roots (**Figure 6**). The fresh weight of all cucumbers with market quality was about 500 g, therefore the number of fruits is representative for the cucumber yield. In particular, the treatment with biostimulators on the substrate that means to the root system, resulted in a higher yield at the first harvest. The number of fruits finally harvested was considerably higher after treatment of roots with Lactate and *B. subtilis* (FZB24®). The number of marketable fruits was higher than in the control in most variants treated with biostimulators.

For future experiments should include more applications also during the fruit set because these additional applications could enhance the yield further, this could be especially important in long time cultivation.

The different application methods with Biostimulators on the leafs and to the roots have not only an influence on cucumber plant growth and yield, but also on the amount of marketable and non-marketable fruits (**Figure 7**). The percentage of non-marketable fruits (C class) was more than 25% in the control and could be reduced by leaf application of each Biostimulator investigated until 20% and even until 10% if substances were applied over the roots.

mechanisms including stimulation of plants'self-defense mechanisms, as it was demonstrated in chapter 5.2.1 and 5.2.2 in case of suboptimal pH, EC values. Furthermore, *Bacillus subtilis* can accelerate plant growth and stimulate the process of formation of plant organs. Furthermore, *B. subtilis* can increase the unspecific resistances of plants against stress conditions, such as extreme high temperatures,

*Effect of application biostimulators (lactate, K-Humate, FZB24®) on leaves and roots respectively on the percentage on non-marketable fruits. Different letters indicate significant differences (chi-square-test,*

*Growth Promoting and Stabilizing of Cucumber Plants Cultivated in Soilless Cultivation…*

*DOI: http://dx.doi.org/10.5772/intechopen.96536*

frost, drought, strong radiation, and deficiency of plant nutrients [18, 19].

lactates have been used as foliar fertilizers and as well as bioregulators.

on the growth of cucumber. The aim was to investigate the photosynthetic reactions to clarify first stress responses in the cucumber plants. Measuring of Chlorophyll Fluorescence is a very useful method for evaluation of plants' photosynthetic conditions and a tool in non-invasive stress detection and its

subsequent evaluation [12].

*5.4.1 Experimental design*

**81**

**Figure 7.**

*P = 0.05).*

Application of lactates in the form of LACTOFOL (**Table 2**) tends to reduce plant stress under suboptimal pH levels of nutrient solution (chapter 5.2.2) [6, 14, 16]. Introduction of Lactate as LACTOFOL into the growing system increases availability of micro- and macro-nutrients for plants. Investigations have shown that lactates have more stable bonds with several metal ions than other chelates do. Therefore,

In greenhouse cultivation of cucumbers in soilless culture systems, two stress situations are of importance, the pH and the temperature stress. In an experiment was the aim to investigate the physiological effect of a biostimulating complex consisting of *B. subtilis* (FZB24®), K-Humate and Lactate as LACTOFOL (**Table 2**)

(*Cucumis sativus* L.) cv. Jessica was cultivated in 'Mitscherlich' container volume

One half of the cucumber plants were not treated with the Biostimulator solution. The substrate of the other half of the plants was treated once a week with 300 ml of biostimulator solution (*B. subtilis* (0.2%) + K-humate (0.01%) + lactate (0.1%) per container. Treatments coincided with the following plant developmental

8 L filled with perlite with a physical and chemical properties as described in **Table 3**. The same nutrient solution was used as described in chapter 5.3. The cucumber plants were cultivated in a climatic chamber at 25°C and 80% RH.

## **5.4 Use of biostimulators to reduce abiotic stress in cucumber plants**

Different bacteria and in particular *Bacillus subtilis* are well known for their effects against soil-born fungal and bacterial diseases. There are selected strains in this regard with good effects in the field of plant protection. The strain *Bacillus subtilis* FZB24 is in addition capable of evolving different kinds of stress protective

#### **Figure 6.**

*Effect of application biostimulators (lactate, K-Humate, FZB24®) on leaves and roots respectively on number of marketable fruits in four harvesting periods of 9 days each. No significant differences.*

*Growth Promoting and Stabilizing of Cucumber Plants Cultivated in Soilless Cultivation… DOI: http://dx.doi.org/10.5772/intechopen.96536*

#### **Figure 7.**

However, the leaf treatment with the combination of all substances led to a reduction in leaf growth. After application of biostimulators via roots more or less the same ratio was found as in the control indicating the shoot and leaf growth was

The number of fruits harvested from the eight variants and the control was higher on average when the biostimulators were applied to the rhizosphere directly at the roots (**Figure 6**). The fresh weight of all cucumbers with market quality was about 500 g, therefore the number of fruits is representative for the cucumber yield. In particular, the treatment with biostimulators on the substrate that means to the root system, resulted in a higher yield at the first harvest. The number of fruits finally harvested was considerably higher after treatment of roots with Lactate and *B. subtilis* (FZB24®). The number of marketable fruits was higher than in the

For future experiments should include more applications also during the fruit set because these additional applications could enhance the yield further, this could be

The different application methods with Biostimulators on the leafs and to the roots have not only an influence on cucumber plant growth and yield, but also on the amount of marketable and non-marketable fruits (**Figure 7**). The percentage of non-marketable fruits (C class) was more than 25% in the control and could be reduced by leaf application of each Biostimulator investigated until 20% and even

**5.4 Use of biostimulators to reduce abiotic stress in cucumber plants**

Different bacteria and in particular *Bacillus subtilis* are well known for their effects against soil-born fungal and bacterial diseases. There are selected strains in this regard with good effects in the field of plant protection. The strain *Bacillus subtilis* FZB24 is in addition capable of evolving different kinds of stress protective

*Effect of application biostimulators (lactate, K-Humate, FZB24®) on leaves and roots respectively on number*

*of marketable fruits in four harvesting periods of 9 days each. No significant differences.*

stimulated in the same manner.

*5.3.2 Quantity of fruit harvest and marketable fruit quality*

*Cucumber Economic Values and Its Cultivation and Breeding*

control in most variants treated with biostimulators.

until 10% if substances were applied over the roots.

**Figure 6.**

**80**

especially important in long time cultivation.

*Effect of application biostimulators (lactate, K-Humate, FZB24®) on leaves and roots respectively on the percentage on non-marketable fruits. Different letters indicate significant differences (chi-square-test, P = 0.05).*

mechanisms including stimulation of plants'self-defense mechanisms, as it was demonstrated in chapter 5.2.1 and 5.2.2 in case of suboptimal pH, EC values. Furthermore, *Bacillus subtilis* can accelerate plant growth and stimulate the process of formation of plant organs. Furthermore, *B. subtilis* can increase the unspecific resistances of plants against stress conditions, such as extreme high temperatures, frost, drought, strong radiation, and deficiency of plant nutrients [18, 19].

Application of lactates in the form of LACTOFOL (**Table 2**) tends to reduce plant stress under suboptimal pH levels of nutrient solution (chapter 5.2.2) [6, 14, 16]. Introduction of Lactate as LACTOFOL into the growing system increases availability of micro- and macro-nutrients for plants. Investigations have shown that lactates have more stable bonds with several metal ions than other chelates do. Therefore, lactates have been used as foliar fertilizers and as well as bioregulators.

In greenhouse cultivation of cucumbers in soilless culture systems, two stress situations are of importance, the pH and the temperature stress. In an experiment was the aim to investigate the physiological effect of a biostimulating complex consisting of *B. subtilis* (FZB24®), K-Humate and Lactate as LACTOFOL (**Table 2**) on the growth of cucumber. The aim was to investigate the photosynthetic reactions to clarify first stress responses in the cucumber plants. Measuring of Chlorophyll Fluorescence is a very useful method for evaluation of plants' photosynthetic conditions and a tool in non-invasive stress detection and its subsequent evaluation [12].

#### *5.4.1 Experimental design*

(*Cucumis sativus* L.) cv. Jessica was cultivated in 'Mitscherlich' container volume 8 L filled with perlite with a physical and chemical properties as described in **Table 3**. The same nutrient solution was used as described in chapter 5.3. The cucumber plants were cultivated in a climatic chamber at 25°C and 80% RH.

One half of the cucumber plants were not treated with the Biostimulator solution. The substrate of the other half of the plants was treated once a week with 300 ml of biostimulator solution (*B. subtilis* (0.2%) + K-humate (0.01%) + lactate (0.1%) per container. Treatments coincided with the following plant developmental stages, first treatment at 5–6 leaf stage (week 1); second at 7–8 leaf stage (2 weeks) and the third at 9–10 leaf stage (3 weeks).

After the last treatment with the biostimulator solution (4 weeks), the stress factor was applied. For the pH stress experiment, pH values were adjusted to a suboptimal level (pH 3.2) by adding H3PO4 to the nutrient solution. This pH stress was maintained for 1 week. For temperature stress, temperature in the growth chamber was lowered from 25 to 6°C for 3 h.

#### *5.4.2 pH stress for cucumber plants*

One week after transplanting the cucumber plants the chlorophyll fluorescence Fv/Fm-value increased from 0.760 (**Figure 8**) to 0.790 in plants treated with biostimulating complex and 0.770 in plants without treatment. A drastic decrease in electron efficiency was observed after imposition of a strong lowering the pH value. Between the 4th and 5th measurements, Fv/Fm of treated plants decreased to 0.747 and that of the non-treated ones even to 0.654.

given for a short time from three hours and the lowest temperature was 6°C. This stress was applied by lowering the air temperature in the climate chamber right

*Growth parameters of cucumber plants treated with biostimulators mixture prior to pH- stress (pH 3.2) for*

**Leaf weight (g/plant)**

*Growth Promoting and Stabilizing of Cucumber Plants Cultivated in Soilless Cultivation…*

Not-treated 325.75 b 230,25 b 460 ns 7002.3 ns 275.75 ns 45.08 ns

315.25 a 350 a 477.75 ns 7105.2 ns 265.5 ns 52.93 ns

**Leaf area (cm2**

**/plant)**

**Root weight (g/plant)**

**Root length (m/plant)**

Fm development showed its peculiarities (**Figure 9**). Measurement 1 to 4 gave equal electron efficiency levels. After temperature stress, Fv/Fm values decreased considerably indicating a reduction in photosystem II efficiency. Only the treated plants were able to reach higher levels of Fv/Fm after stress and could recover much

The Fv/Fm parameter had the same pattern as in case of pH stress. However, Fv/

At the end of this temperature stress experiment, the plant growth parameters were also determined (**Table 11**). The effect of the biostimulator mixture led to a

*Electron efficiency in photosystem II of cucumber plants treated with biostimulators mixture before and after*

**Leaf weight (g/plant)**

Not-treated 341,75 b 244,5 b 477,75 ns 7333,7 b 206 b 4,86 b

*Growth parameters of cucumber plants treated with biostimulator mix prior to temperature - stress at 6°C for*

**Leaf area (cm2**

390 a 358,5 a 548,25 ns 9637,4 a 321,25 a 6,98 a

**/plant)**

**Root weight (g/plant)**

**Root length (m/plant)**

after the third treatment with the biostimulating mixture.

**Shoot weight (g/ plant)**

*Different letters indicate significant differences (LSD, p = 0.05); and ns = non-significant).*

better than non-treated plants.

*low temperature treatment with 6°C for 3 h. [12].*

**length (cm)**

**Shoot weight (g/plant)**

*Different letters indicate significant differences (LSD, p = 0.05); and ns = non-significant.*

**Variants Shoot**

Treated with biostimulator

**Table 11.**

*3 h [12].*

**83**

**Variants Shoot**

Treated with biostimulator

**Table 10.**

**Figure 9.**

*one week [12].*

**length (cm)**

*DOI: http://dx.doi.org/10.5772/intechopen.96536*

Whereas without biostimulator treatment, the fluorescence Fv/Fm-value was slightly decreasing after second and third week. In the time of the pH stress influence in the fifths week, it is visible, the stress effect was much stronger (**Figure 8**), where the lowest Fv/Fm value was 0.620. Four weeks later the plants treated with the biostimulator treatment recovered completely from the stress, but the plants without Biostimulator were still in weak condition. The plants treated with biostimulator mixture showed a higher electron efficiency of photosystem II (0.765 Fv/Fm-value) at the end of the experiment as compared to the plants without treatment (0.670 Fv/Fm-value).

The final evaluation of cucumber plants showed that this plants treated with biostimulators had significant shorter shoot length and but heavier weight than non-treated plants (**Table 10**). The roots were longer than non-treated plants and treated plants also yielded some marketable fruits (data not shown). Obviously, the biostimulators mixture was effective for reduction of the pH-stress.

#### *5.4.3 Temperature stress for cucumber plants*

Temperature stress can be happens in greenhouses if the heating system is not working or the ventilation is not proper functioning. Therefore, this stress was

#### **Figure 8.**

*Electron efficiency in photosystem II of cucumber plants treated with biostimulators mixture before and after pH-stress (pH 3.2) for one week. [12].*

*Growth Promoting and Stabilizing of Cucumber Plants Cultivated in Soilless Cultivation… DOI: http://dx.doi.org/10.5772/intechopen.96536*

#### **Table 10.**

stages, first treatment at 5–6 leaf stage (week 1); second at 7–8 leaf stage (2 weeks)

After the last treatment with the biostimulator solution (4 weeks), the stress factor was applied. For the pH stress experiment, pH values were adjusted to a suboptimal level (pH 3.2) by adding H3PO4 to the nutrient solution. This pH stress was maintained for 1 week. For temperature stress, temperature in the growth

One week after transplanting the cucumber plants the chlorophyll fluorescence

Whereas without biostimulator treatment, the fluorescence Fv/Fm-value was slightly decreasing after second and third week. In the time of the pH stress influence in the fifths week, it is visible, the stress effect was much stronger (**Figure 8**), where the lowest Fv/Fm value was 0.620. Four weeks later the plants treated with the biostimulator treatment recovered completely from the stress, but the plants without Biostimulator were still in weak condition. The plants treated with

biostimulator mixture showed a higher electron efficiency of photosystem II (0.765 Fv/Fm-value) at the end of the experiment as compared to the plants without

The final evaluation of cucumber plants showed that this plants treated with biostimulators had significant shorter shoot length and but heavier weight than non-treated plants (**Table 10**). The roots were longer than non-treated plants and treated plants also yielded some marketable fruits (data not shown). Obviously, the

Temperature stress can be happens in greenhouses if the heating system is not working or the ventilation is not proper functioning. Therefore, this stress was

*Electron efficiency in photosystem II of cucumber plants treated with biostimulators mixture before and after*

biostimulators mixture was effective for reduction of the pH-stress.

Fv/Fm-value increased from 0.760 (**Figure 8**) to 0.790 in plants treated with biostimulating complex and 0.770 in plants without treatment. A drastic decrease in electron efficiency was observed after imposition of a strong lowering the pH value. Between the 4th and 5th measurements, Fv/Fm of treated plants decreased to 0.747

and the third at 9–10 leaf stage (3 weeks).

*Cucumber Economic Values and Its Cultivation and Breeding*

chamber was lowered from 25 to 6°C for 3 h.

and that of the non-treated ones even to 0.654.

*5.4.2 pH stress for cucumber plants*

treatment (0.670 Fv/Fm-value).

**Figure 8.**

**82**

*pH-stress (pH 3.2) for one week. [12].*

*5.4.3 Temperature stress for cucumber plants*

*Growth parameters of cucumber plants treated with biostimulators mixture prior to pH- stress (pH 3.2) for one week [12].*

given for a short time from three hours and the lowest temperature was 6°C. This stress was applied by lowering the air temperature in the climate chamber right after the third treatment with the biostimulating mixture.

The Fv/Fm parameter had the same pattern as in case of pH stress. However, Fv/ Fm development showed its peculiarities (**Figure 9**). Measurement 1 to 4 gave equal electron efficiency levels. After temperature stress, Fv/Fm values decreased considerably indicating a reduction in photosystem II efficiency. Only the treated plants were able to reach higher levels of Fv/Fm after stress and could recover much better than non-treated plants.

At the end of this temperature stress experiment, the plant growth parameters were also determined (**Table 11**). The effect of the biostimulator mixture led to a

**Figure 9.**

*Electron efficiency in photosystem II of cucumber plants treated with biostimulators mixture before and after low temperature treatment with 6°C for 3 h. [12].*

#### **Table 11.**

*Growth parameters of cucumber plants treated with biostimulator mix prior to temperature - stress at 6°C for 3 h [12].*

#### *Cucumber Economic Values and Its Cultivation and Breeding*

significant difference in all parameters as compared to the non-treated plants, except for the leaf area.

The question is what could be the reason, that the temperature stress was less disturbing the cucumber plant if the plants were several time treated with Biostimulator. The biostimulators used in this experiment had shown also in previous experiments a positive reaction on the root growth [14]. It can be assumed plants with well-developed root systems have higher resistance against different stress situations. Therefore, a correlation between the green biomass of the cucumber plants and the root mass were calculated. In the experiments without treatments with biostimulators, no correlation could be found (**Figure 10**).

**6. Conclusions**

*DOI: http://dx.doi.org/10.5772/intechopen.96536*

(EC) at about a value of 2 EC.

root growth.

**85**

In general can be stated, intensively in greenhouses cultivated crops such as cucumbers, suffer often from inadequate abiotic or biotic growth conditions in particular in the rhizosphere. Many studies were done to find growth promoters or biostimulators to stabilize the production process or to enhance plant growth of cucumbers under these conditions. One task was to find substrates with appropriate physical and chemical properties for root growth of cucumbers desirable from organic materials. Sheep wool slabs, peat slabs and coconut fiber slabs were therefore successful tested with and without Biostimulator treatments and compared with perlite and rockwool slabs. It was to decide which of the biostimulators and their modifications should be tested and could be recommended. Based on the research with different Humates the K-Humate was selected. From the different lactates the LACTOFOL"O" (CO. ECOFOL) a foliar fertilizer was chosen after many previous experiments. From the different strains of Bacillus subtilis the strain FZB24® was successful tested and can be recommended. Under the growing conditions in soilless culture, using different substrates a buffer is missing completely or partly for regulation of the nutrient availability and regulation of the sorption capacity as in the natural soil. Therefore, different stress situations can occur, the Biostimulators used in all investigations as single component or in treatments combined in order to reduce such stress situation. Very successful was used for cucumber plants growing in substrate with a high EC value the application of K-Humate and *B. subtilis* (FZB24®) as single component and combined the salt concentration could be stabilized convenient for cucumbers. The mixture of all three components, however, was as effective as Humate alone and stabilized the salt concentration

*Growth Promoting and Stabilizing of Cucumber Plants Cultivated in Soilless Cultivation…*

In general, pH values affect the nutrient availability and uptake, in particular of micronutrients. The pH of substrates in soilless culture systems, changed with the duration of cultivation. Application of Lactate (LACTOFOL) and *B. subtilis* (FZB24®) stimulated root growth and shoot development even at pH 7.5 and the

Application of the biostimulators solution with all three components BS-FZB24® (0.2%), K-Humate (0.01%), and LACTOFOL "O" (0.1%) were tested regarding their effects in case of strong but short time pH and temperature stress the growth of cucumber plants. The chlorophyll fluorescence Fv/Fm value showed a positive effect of the curative biostimulator treatments under the stress counteraction in plants. Results showed that there was strong correlation between green biomass of treated cucumber plants and their root mass. It can be assumed that the effect of stress prevention by the biostimulator was based mainly on enhancing the

In the experiments using the biostimulator for stabilization of cucumber plant growth, the biostimulators were applicate only in the rhizosphere that means direct to the roots. Lactate was originally developed and used as foliar-fertilizer. Therefore, it came to the thought to use the biostimulators to the root zone and on the leaves. Following the experimental results, it can be assumed, the application of the combined biostimulators with all substances if applied over the roots was a stimulating effect visible, whereas if applied over the leaves an inhibiting effect for cucumber plant growth. The number of fruits harvested from all variants and the control was higher on average when the biostimulators were applied to the

rhizosphere directly at the roots in comparison to the leaf application.

pH of the substrates treated with biostimulators was more stable.

On the other hand, those cucumber plants treated with biostimulators showed a very close correlation (R2 linear =0.949) between green biomass and mass of roots (**Figure 11**). This close relationship confirms the hypothesis that increases in root mass lead to formation of larger shoots and leaf mass even under stress conditions if treated with some biostimulators.

**Figure 10.**

*Correlation between green biomass and root mass of cucumbers in plants exposed to pH and temperature stress condition, without biostimulators treatment [12].*

#### **Figure 11.**

*Correlation between green biomass and root mass of cucumbers in the experiment with pH and temperature stress condition, with biostimulators treatments [12].*

*Growth Promoting and Stabilizing of Cucumber Plants Cultivated in Soilless Cultivation… DOI: http://dx.doi.org/10.5772/intechopen.96536*


*Editorial* **Preparation of Novel Nanomaterial and Its Application in Food Industry**

**Hong Wu 1,\* and Hui Zhang 2,\***

	- **\*** Correspondence<EMAIL_ADDRESS>(H.W<EMAIL_ADDRESS>(H.Z.)

Nanotechnology has offered a wide range of opportunities for the development and application of structures, materials, or systems with new properties in the food industry in recent years. The developed nanomaterials could greatly improve not only food quality and safety but also the foods' health benefits. In this special issue, different nano-sized vehicles (e.g., nanoparticle, nanoliposome, nanofiber, nanobody) are reported as efficient bioactives delivery systems and sensitive detection materials.

To resolve the low chemical instability, poor water solubility, and intestinal efflux limitations and challenges of bioactive ingredients, constructing an effective delivery vehicle using food-grade polymers is supposed to be a novel and feasible strategy. For example, Chen et al. [1] encapsulated hydrophobic naringenin and naringin in nanoliposomes based on the gradual reduction in their water solubility after the pH changed to acidity. The naringenin-loaded nanoliposomes were predominantly nanometric (44.95–104.4 nm), negatively charged ( −14.1 to −19.3 mV) and exhibited relatively high encapsulation efficiency (EE = 95.34% for 0.75 mg/mL naringenin within 1% *w*/*v* lecithin). Additionally, the naringenin-loaded nanoliposomes still maintained good stability during 31 days of storage at 4 ◦C. Zhou et al. [2] fabricated a caseinate-stabilized thymol nanosuspension by pH-driven methods. Thymol was extremely stable at pH 7.0–12.0 even after incubation for 24 h, which means the loss of thymol during the pH-driven process is negligible. The physicochemical properties of thymol nanosuspensions are highly dependent on the caseinate concentration. Caseinate could stabilize thymol nanosuspensions even at a relatively low caseinate concentration, and the loading capacity can be as high as 45.9%. Chen et al. [3] compared two polysaccharides [sodium alginate (ALG) and sodium carboxymethyl cellulose (CMC)] to establish zein/sophorolipid/ALG (ALG/S/Z) and zein/sophorolipid/ALG (CMC/S/Z) nanoparticles to encapsulate 7,8-dihydroxyflavone (7,8-DHF), respectively. They found that CMC/S/Z possessed lower polydispersity index, particle size and turbidity, but higher zeta potential, encapsulation efficiency and loading capacity compared to ALG/S/Z. Compared to zein/sophorolipid nanoparticles (S/Z), both ALG/S/Z and CMC/S/Z had better stability against low pH (pH 3~4) and high ionic strengths (150~200 mM NaCl). Apart from the above particle forms, nanofibers have emerged as a novel delivery system due to its simplicity and effectiveness. Electrospinning, solution blow spinning, and eletro-blow spinning are the most common techniques for continuously producing nanofibers with a fiber diameter range from sub-nanometers to micrometers. The electrospun films were also adopted to stabilize the sensitive bioactives. Cui et al. [4] fabricated an antimicrobial food packaging film with controlled release by loading cinnamaldehyde (CIN) on etched halloysite nanotubes (T-HNTs) and adding it to sodium alginate (SA) matrix. It was found that CIN could be successfully loaded into the T-HNTs and the addition of T-HNTs-CIN significantly improved the water vapor barrier properties and tensile strength of the film. Additionally, the SA/T-HNTs-CIN film could delay the release of CIN into fatty food simulation solution compared with that of SA/CIN film. Wen et al. [5] reported that the incorporation of a Nervilia fordii extract (NFE) in the

**Citation:** Wu, H.; Zhang, H. Preparation of Novel Nanomaterial and Its Application in Food Industry. *Foods* **2022**, *11*, 1382. https:// doi.org/10.3390/foods11101382

Received: 29 April 2022 Accepted: 9 May 2022 Published: 11 May 2022

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**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

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electrospun poly(vinyl alcohol) (PVA) and polyvinyl(pyrrolidone) (PVP) bio-composite film could retain its antioxidant capacity, avoiding the fish oil's oxidation (and thus extending its shelf life). Yang et al. [6] fabricated gelatin/nylon 66 (PA66) composite nanofibers by solution blow spinning (SBS). Morphology observations show that GA/PA66 composite films had a nano-diameter from 172.3 to 322.1 nm. Nylon 66 (PA66) was proved to improve the mechanical properties and the ability to resist dissolution of gelatin nanofibrous films. Another study was performed by microfluidics to encapsulate lutein to improve its bioaccessibility in the gastrointestinal tract [7]. Two types of oils (safflower oil (SO) and olive oil (OL)) were selected as a delivery vehicle for lutein, and two customized microfluidic devices (co-flow and combination-flow) were used. The results demonstrated that the types of oil and device do not affect the lutein bioaccessibility. Findings from this study may provide scientific insights into emulsion-based delivery systems that employ microfluidics for the encapsulation of bioactive compounds into foods. Finally, Deng [8] systematically summarized that soy-based emulsifiers are currently extensively studied and applied in the food industry for its applications in bioactive and nutrient delivery.

Another focus of the published articles in this special issue is the sensitive detection of various contaminants (pesticides, drug, copper (II) ions, pathogenic bacterium) associated with food safety through different nano-techniques. In the study by Feng et al. [9], a novel nano/micro-structured pesticide detection card was developed by combining electrospinning and hydrophilic modification, and its feasibility for detecting different pesticides was investigated [9]. This self-made detection card showed a 5-fold, 2-fold, and 1.5-fold reduction of the minimum detectable concentration for carbofuran, malathion, and trichlorfon, respectively, compared to the national standard values. In another study, Li et al. [10] created a portable, rapid, and sensitive time-resolved fluorescence immunochromatography for on-site detection of dexamethasone in milk and pork. A parallel experiment for 20 milk and 10 pork samples with LC-MS/MS was carried out to confirm the performance of the developed TRFM-ICA. The results of the two methods are basically the same. In addition, the nanobody, as an important tool in immunoassay for chemical contaminants, was developed and its efficiency was examined by detecting a secondary metabolite of cyanobacteria, namely nodularin (NOD-R) [11]. The ic-ELISA method based on the nanobody N56 was validated with spiked water sample and confirmed by UPLC–MS/MS, which indicated that the ic-ELISA established in this work is a reproducible detection assay for nodularin residues in water samples. Xu et al. [12] prepared a highly sensitive and selective fluorescence probe that used mercaptopropionic acid (MPA)-capped InP/ZnS quantum dots (MPA-InP/ZnS QDs) for the detection of trace amounts of Cu2+ in water. This probe exhibited an extremely low limit of detection of 0.22 nM. Meanwhile, a possible fluorescence-quenching mechanism was proposed in this study. In another study, to achieve the rapid detection of *Listeria monocytogenes*, Zhu et al. [13] used aptamers for the original identification and built a photoelectrochemical aptamer sensor using exonuclease-assisted amplification. In brief, tungsten trioxide (WO3) was used as a photosensitive material, which was modified with gold nanoparticles to immobilize complementary DNA, and amplified the signal by means of the sensitization effect of CdTe quantum dots and the shearing effect of exonuclease I (Exo I) to achieve high-sensitivity detection. This strategy had a detection limit of 45 CFU/mL in the concentration range of 1.3 × 101–1.3 × 107 CFU/mL, providing a new way to detect *Listeria monocytogenes*.

Overall, these articles extend the knowledge on the application of nanomaterials in food nutrition and safety, promoting the development of nanotechnologies in food industry.

Finally, we would like to thank all of the authors for their submissions, and all of the referees for their valuable suggestions for improving the manuscripts.

**Author Contributions:** H.W. and H.Z. conceived and wrote this editorial. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Conflicts of Interest:** The authors declare no conflict of interest.


*2.1. Topology Optimization Method*

The variable density topology optimization problem [32] can be expressed as follows:

$$\begin{aligned} \min\_{\rho\_{\varepsilon}} & \phi(\rho) = \mathcal{U}^{T} K \mathcal{U} = \sum\_{\varepsilon=1}^{N} \left(\rho\_{\varepsilon}\right)^{P} u\_{\varepsilon}^{T} k\_{0} u\_{\varepsilon} \\ \text{s.t.} & \begin{cases} K \mathcal{U} = F \\ \sum\limits\_{\varepsilon=1}^{N} \rho\_{\varepsilon} V\_{\varepsilon} \le V^{\*}, 0 \le \rho\_{\min} \le \rho\_{\varepsilon} \le 1 \end{cases} \end{aligned} \tag{1}$$

where *φ* means a sum of each element's compliance. *U*, *K* and *F* mean the global displacement, stiffness matrix and force vectors, respectively. *k*0 and *ue* mean the element stiffness matrix and displacement vector. *ρ* means the design variable vector, viz element density vector. *N* means the element amount of design domain. *Ve* and *V*∗ mean the unit element volume and total volume for the design domain. To make sure of the numerically stable iteration, *ρ*min = 0.001 is chosen as the lower limitation of design variable. Additionally, a convolution-type filtering operation is used to filter the holes, viz.

$$\rho\_{\varepsilon} = \frac{\sum\_{i \in N\_{\varepsilon}} w(r\_i, r\_{\varepsilon}) v\_i x\_i}{\sum\_{i \in N\_{\varepsilon}} w(r\_i, r\_{\varepsilon}) v\_i} \tag{2}$$

where *Ne* = { *i*| *ri* − *re* ≤ *R*} means a neighborhood set within the radius, *R*. *ri* and *re* mean the spatial central coordinate of elements *i* and *e*, respectively. *w*(*ri*,*re*) = *R* − *ri* − *re* means the weighting function. *vi* is the volume of element *i*.