Module 3: Fermentation Flashcards
What is fermentation?
Fermentation is the anaerobic decomposition of organic compounds to organic products, which could not be further metabolized by the enzyme systems of the cells without the intervention of oxygen.
What are fermented foods?
Fermented foods are those foods or beverages made through controlled microbial growth and enzymatic conversions of major and minor food components.
What are the roles of fermentation in food processing?
Fermentation plays several roles in food processing, including food preservation through the formation of inhibitory metabolites, food safety through pathogen inhibition and toxic compound removal, and food quality through the enhancement of nutritional value and organoleptic quality.
What are the types of fermentation?
he types of fermentation include lactic acid fermentation, alcoholic fermentation, mixed acid fermentation, and acetic acid fermentation.
What is lactic acid fermentation?
Lactic acid fermentation is an anaerobic fermentation that occurs when Lactic Acid Bacteria (LAB) convert sugars to cellular energy and lactate.
What is alcoholic fermentation?
Alcoholic fermentation is a fermentation process carried out by yeasts and some other fungi and bacteria. It is involved in several important transformation, stabilization, and conservation processes for sugar-rich substrates.
What is mixed acid fermentation?
Mixed acid fermentation occurs when bacteria utilize two or more different pathways in the terminal steps of fermentation.
What is acetic acid fermentation?
Acetic acid fermentation is an oxidative fermentation performed by Acetic Acid Bacteria (AAB) growing on carbon substrates under aerobic conditions.
What are some examples of fermented products?
Examples of fermented products include sauerkraut, kimchi, yogurt, wine, beer, and vinegar.
What is Yogurt?
Yogurt is a fermented dairy product made from the lactic acid fermentation of milk by Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus. During fermentation, microorganisms convert lactose (found in milk) to lactic acid, resulting in a decrease in pH and changes in physicochemical and sensory properties.
How is Yogurt prepared?
he preparation of yogurt involves adjusting the milk composition by adding cream, nonfat dry milk, or stabilizers. The milk is then pasteurized, homogenized, and cooled to the ideal incubation temperature of 42-45°C. Starter cultures are inoculated to ferment lactose into lactic acid, and the milk is held at the same temperature until the pH reaches 4.4. The yogurt is then cooled, flavored, and packaged.
What are the effects of fermentation on physicochemical properties?
Fermentation of milk into yogurt leads to a decrease in pH due to the conversion of lactose into lactic acid by LAB strains. This increases the acidity and alters the physicochemical properties of the milk.
What are the effects of fermentation on sensory properties?
Fermentation of milk into yogurt results in the formation of volatile compounds that give rise to an intense, refreshing, and acid taste with a fresh smell. Conversion of lactose into lactic acid changes the taste of the fermented milk, and the presence of S. thermophilus results in the production of texturizing agents that increase the viscosity and rheological quality of the product.
What are the health benefits of consuming Yogurt?
Consuming yogurt provides health benefits such as alleviating lactose intolerance, improving digestion, and increasing the bioavailability of nutrients. LAB produce lactase, enzymes, and vitamins B and C during fermentation, which make fermented food richer in nutrients.
