Fermentation
Fermentation is a process that involves the breakdown of carbohydrates or glucose to simpler forms namely: organic acids and alcohol through the utilization of micro-organisms. This method has been applied since ancient times by different communities for different kinds of foods.
The primary components necessary for food fermentation to occur are:
- Sugars/ glucose
- Bacterial culture
Fermentation can occur either naturally i.e. the fermentation of fruits , vegetables, legumes, etc or through the introduction of live cultures of either yeast or bacteria i.e. in yoghurt . When live cultures are utilized in fermentation they formulate products, that contain probiotics (beneficial bacteria that promote a healthy microbial balance in the gut).
However, note that probiotics are different from prebiotics wherein probiotics are bacteria themselves that provide certain health benefits such as proper immune function, reduced inflammation and a healthy GI tract, prebiotics are indigestible food materials that promote the development of these beneficial bacteria. Prebiotics are found naturally in foods such as leeks, asparagus, artichokes etc.
Aside from its importance to foods we consume, food waste is put into use through fermentation by being broken down and yielding by-products such as bio-fuels, pigments etc.
Foods Preserved By Fermentation
- Cereals
- Porridge
- Milk
- Meat
- Fish
- Cheese
- Alcoholic beverages such as wines and beers
- Fruits
- Vegetables
- Bread
Foods Produced By Fermentation
Among the food products produced by fermentation are:
- Kimchi-originally from Korea
- Sauerkraut-originally from Germany
- Chutney-originally from India
- Garii-originally from west Africa
Types Of Fermentation
- Lactic acid fermentation– This is the most extensively applied form of fermentation for most foods including vegetables, fruits, milk etc. Lactic acid is formed from pyruvate produced through glycolysis.
- Butyric acid fermentation– Sugar is first oxidized to pyruvate through glycolysis, then pyruvate is further oxidized to form acetyl-CoA, which undergoes reduction to release butyric acid. This fermentation process is mainly used in the production of rancid butter.
- Acetic acid fermentation –It involves the production of vinegar. Ethyl alcohol formed from the breakdown of sugar is further broken down to produce acetic acid.
- Alcoholic fermentation -It is involved in the production of alcoholic beverages such as beers, wines etc. The sugar is oxidized to pyruvate, which is broken down to acetaldehyde that forms alcohol.
The Importance Of Fermentation
- It enhances the palatability of foods -The foods that have undergone fermentation tend to have a distinct taste that can either be tangy, aromatic or pungent .
- Produces more nutritious foods -Fermentation contributes to the enhanced nutritive value of foods by making nutrients available.
- Enhances digestibility-Foods are broken down to simpler forms that are easily digested and absorbed.
- Safe– The fermentation process reduces your risk of food poisoning as it lowers the number of pathogens and toxins contained in a food.
Functions of fermentation process
- To impart aroma, good texture ad diverse flavours.
- Preserves foods
- Reduces cooking time
- Destroys anti-nutrients
Key Point
The essentiality of sterilization during the fermentation process cannot be understated as without it the replication of harmful bacteria may occur, rendering increased susceptibility to food borne illnesses. Usually, any form of discolouration or any off-flavours should be indicative of the invasion by harmful bacteria. Hence, proper care should be employed when fermenting foods at both the household and industrial levels.