CHAPTER ONE

• Introduction

Fermentation is the chemical transformation o organic substances into simpler compounds by the action of enzymes, complex organic catalysts which are produced by microorganisms such as molds yeasts or bacterial. Enzymes act by hydrolysis a process of breaking down or predigesting complex organic molecules for form smaller (and in the case foods, more easily digestible) compounds and nutrients for example, the enzyme protease breaks down huge protein molecule first into polypeptides and peptides, then into numerious amono acids, whih are readily assimilated by the body DUTCH MERCHANT 1975).

In some fermentation important by-products such as alcohol or various gases are also produced the word “fermentation” is derived from the latin meaning “to boil” fermented foods often have numerous advantages over the raw materials from which they are made. As applied to soy foods, fermentation not only makes the end product more ditestible, it can also create improved flavor and texture, appearance and aroma, synthesize vitamins. WANG and HESSELTING 1979. Fermentations is a metabolic process that converts sugar to acids, gases or alcohol it occurs in yeast and bacterial, but also in oxygen – starved muscle cells, as in the case of lactic fermentation. It is also used more broadly to refer to the bulk growth of microorganisms on a growth medium, often with a good of producing a specific chemical product.

Fermentation takes place in the lack of oxygen (when the electron transport chain is unusable) and becomes the cell’s primary means of ATP (energy) production (DICKSON J. R. (1999).

• Background of  the Study

Since fruit ferments naturally, fermentation precedes human history. However, human began to take control of fermentation process art some points in time. There is strongest evidence that people were fermenting beverage.

In Babylon about 5000 BC, ancient Egypt about 3000BC, pre – Hispanic Mexico about 2000 BC, and Sudan about 1500 BC. There is also evidence of leavened bread in ancient Egypt about the year. 1500BC. The Chinese were probably the first to develop vegetable fermentation (Wikipedia, 2006). Fermentation has been used to make alcoholic beverage, since ancient times, people who lived along the Nile River in North east Africa brewed beer around 3000 BC. It was not until the 1800’s that  scientists particularly the French scientist Louis Pasteur discover how microbes cause fermentation in beer, milk and wine (world book Encyclopedia, 1992). In the 1900’s other types of fermentation were developed, fermentation of bacterium produced ingredients for explosive during chmist Josep Louis Gay – Lussac, demonstrated that alcoholic fermentation could be expressed by the following reaction: C6HO12O6  – 2CO2 +2C2H5OH, in which one molecule of the sugar glucose is decomposed to yield two molecule of carbon dioxide, and two molecules of ethyl alcohol. In 1837, it was independently proposed by German physiologist Theodor Schwann, the Germen botanist Friedrich Kutzing, and a French physicist Charles cagniard dela tour that alcohol fermentation  on require yeast cells and is a physiological function of this organism (yeast is the common name for certain types of fungus). Beginning in 1985, the French Chemist Louis Pasteur further elucidated the fermentation process, through a series of experiments which showed that all fermentation is the result of microbial activity.

Additionally, he recognized by different micro organism, and that both fermentation and microbial growth proceeds in the absence of air. This led to his definition of fermentation as “life without air” Pasteur was also able to demonstrate that the decomposition of a given amount of sugar in the absence of air leads to much less microbial growth than the decomposition of the same amount of sugar in the presence of air (Encyclopedia America,1998).

A more sophisticated attempt to interpret fermentation in chemical term made by the German scientist Moritz Traube, who  in 1856 suggested that all fermentation was caused by “ferments” in the organism and that the ferments are related to proteins. This account prediction was supported by German chemist Richard Willstatter who isolated the enzymes invertase  from yeast in the 1920s.