Digestion size of the meal, and the process of digestion normally takes between 24 and 72 hours. Digestion begins in the mouth with the secretion of saliva and its digestive enzymes. Food is formed into a bolus by the mechanical mastication and swallowed into the esophagus from where it enters the stomach through the action of peristalsis. Gastric juice contains hydrochloric acid and pepsin which would damage the walls of the stomach and mucus is secreted for protection. In the stomach further release of enzymes break down the food further and this is combined with the churning action of the stomach.
Microbial food cultures from 1970s—production of first industrial concentrated cultures, frozen or freeze-dried cultures, for the direct inoculation of processed milk, improving the regularity of production processes. Microbial food cultures preserve food through formation of inhibitory metabolites such as organic acid (lactic acid, acetic acid, formic acid, propionic acid), ethanol, bacteriocins, etc., often in combination with decrease of water activity (by drying or use of salt). Further, microbial food cultures help to improve food safety through inhibition of pathogens or removing of toxic compounds. Microbial food cultures also improve the nutritional value and organoleptic quality of the food. The microbial food cultures used