BY- Ria Fazulbhoy (MSIWM031)
Fermentation is a process of metabolism that produces chemical changes within organic substrates with the assistance of enzyme action. Microorganisms like lactic acid bacteria or yeasts are important for many kinds of fermentation as they produce the necessary enzymes required for the process. (These enzymes include proteinase, amylase, cellulase, etc.)
In the fermentation process, these microorganisms convert carbohydrates in the food like sugars and starches to acids and alcohols, which enhance the flavour and texture of foods, and also acts as natural preservatives. Many different day to day foods and drinks that we consume are fermented products. This includes beer, wine, cheese, amongst others. Fermentation can also be done at home for various foods like kimchi, curd, yogurt, kombucha, etc.
Benefits of Fermentation
Fermentation is and was one of the best ways to preserve fermentable foods, before pasteurization and refrigeration was discovered. It is a simple, easy, convenient method which extends the life of produce and dairy products, without needing added stabilizers and preservatives.
A range of complex flavours can be unlocked by fermenting foods. Bland and undesirable food can transform into salty, sour, tangy or sweet. Many of the largest contributors to the flavour of the food industry are fermented products including vinegar, cheese and wine.
We have a natural flora of microorganisms in our gut which consists of “good bacteria” which contributes to maintaining a good balance in our digestive and immune systems. It also protects us from preventing growth of other harmful microorganisms. This may deteriorate by excess use of antibiotics or consumption of processed foods. Fermented foods are rich in good bacteria and help maintain healthy, balanced gut flora, thus strengthening the immune system.
TYPES OF FERMENTS
Different types of ferments are categorized on the basis of types of starter culture and microorganisms used.
Generally, bacterial strains are of beneficial bacteria and they are also present in the desired food to be fermented.
- Yogurt: Lactobacillus bulgaria and Streptococcus thermophilus are used in the fermentation of yogurt. It consumes lactose, milk sugar, in milk to form lactic acid.
- Sauerkraut: This fermented cabbage uses Lactobacillus strain of bacteria.
Yeast ferments are very common and are used for various foods. Yeasts ferment on the naturally occurring sugars in the food to form alcohols.
- Wine: This alcoholic drink is formed by using sweet sugary fruits. The most common is grapes. Yeasts digest the sugars and form alcohol. When air is allowed, wine can be converted to vinegar by the formation of acetic acid.
- Beer: When malted grains like barley and wheat are fermented by yeasts, which consume the sugars present, to form alcohol, beer is formed. Ginger beer is made when a fermented starter is made from fresh ginger and wild yeast, which are naturally present in the ginger, in the presence of air.
Sometimes, bacterial strains and yeast strains are used together in symbiosis for the fermentation of particular foods. Most starters need to be maintained and shared. Examples include kefir, kombucha, sourdough bread, Tha bai, etc.