Understanding Fermentation - Fermentation is a type of anaerobic respiration is the process of releasing energy that occurs in the absence of free oxygen. There are various types of fermented foods, but they all share some of the same characteristics.
Fermentation is a process that refers to the microorganisms to break down organic materials to get the energy it needs to stay alive and make organic compounds such as alcohols and organic acids, as well as inorganic compounds such as carbon dioxide and hydrogen. Depending on the substances that are formed, the process is called alcoholic fermentation, lactic acid fermentation, amino acid fermentation, etc.
Types of Fermentation:
Based on the resulting product, the fermentation is divided into two types, namely (Belitz, 2009):
Homofermentatif, namely fermentation end products only in the form of lactic acid. Homofermentatif example is the fermentation process that occurs in the blind of yoghurt.
Heterofermentatif, namely fermentation end products such as lactic acid and ethanol as much. Heterofermentatif example is the fermentation process that occurs in the manufacture of tape.
Factors Affecting Fermentation
The success of the fermentation is determined by several factors, namely:
a. Acidity (pH)
Acidic foods usually durable, but if the amount of oxygen enough and molds can grow and fermentation continues, then the lasting power of the acid will be lost. The level of acidity is very influential in the development of bacteria. Good acidity conditions for bacteria is 4.5-5.5.
Fermentation is usually done with a pure culture produced in the laboratory. This culture can be stored in a dry state or frozen.
Fermentation temperature will determine the kind of dominant microbes during fermentation. Each microorganisms have maximum growth temperatures, minimal growth temperature, and the optimal temperature is the temperature that gives the best and fastest self propagation.
Air or oxygen during fermentation must be regulated as possible to increase or inhibit the growth of certain microbes. Each different microbes require oxygen for growth in number or form new cells and for fermentation. Eg yeast bread (Saccharomycess cereviseae) will grow better in an aerobic, but both will ferment sugar much faster with anaerobic conditions.
The rate of multiplication of bacteria varies according to species and growing conditions. Under optimal conditions, bacteria will divide once every 20 minutes. For several generations which bacteria pick a time interval between the division, can be reached in 20 minutes. If the generation time of 20 minutes at suitable conditions a cell can produce several million cells for 7 hours.