An Overview of Cereal-Based Fermented Foods and Drinks (Part 1)

by Selina Fasuan

Introduction

Fermented cereal grains are considered to be one of the most important sources of dietary proteins, carbohydrates, vitamins, minerals and fibres for people all over the world. But before we go on, let’s briefly define what fermentation is.

Fermentation can be defined as a desirable process of biochemical modification of primary food matrix brought about by microorganisms and their enzymes.  And there are mainly two types, namely, Alcoholic Fermentation and Lactic Acid Fermentation. Recently added types are Acetic and Pure Culture Fermentation.

Lactic Acid Fermentation usually occurs in the human cells, for instance, the muscle cells, where glucose is converted to energy in the form of adenosine triphosphate (ATP) and lactic acid. Alcohol fermentation occurs in microorganisms, for intance, yeast cells, where glucose is converted to ATP, Carbon dioxide and alcohol.

Benefits of Fermentation

Fermentation is of immense benefits, and some of its benefits are:

1. reduction in the volume of materials to be transported
2. enhancement of the nutritive value of food through synthesis of certain amino acids, improvement of availability of B group vitamins and, minerals and protein digestibility
3. improvement in the appearance and tastes of some foods
4. salvage of the material otherwise not usable for human consumption
5. reduction in the energy required for cooking
6. removal of anti-nutritional compounds in food such as phytate, condensed tanis, trypsin and alpha-amylase inhibitors.

Cereals

Cereals are grains or edible fruits of the grass-monocot family that may be cultivated and used as foods. Examples are Rice, Wheat, Corn, Sorghum Maize, and Millet.

Fermentation of Cereals

The microorganisms mainly involved with cereal fermentation are Lactobacilli, Leuconostoc, Pediococci, Yeasts and Moulds. The end product fermentations depends on:

1. the chemical composition of the substrate like carbohydrate content, presence of electron acceptors, nitrogen availability e.t.c.
2. the environmental conditions like pH, temperature, presence of oxygen e.t.c.

Biochemical changes during fermentation

The nutritional quality of cereals and the sensorial properties of their products are sometimes inferior or poor in comparison with milk and milk products in the following ways:

1. lower protein content
2. deficiency of certain essential amino acids (lysine)
3. low starch availability
4. presence of determined anti nutrients (phytic acid, tannins and polyphenols)
5. coarse nature of the grains.

These are corrected with genetic improvement and amino acid supplementation with protein concentrates or other protein-rich sources.

Fermentation generally leads to improvement in the shelf life, texture, taste and aroma of the final product and lactic acid fermentation contributes towards the safety, nutritional value, shelf life and acceptability of a wide range of cereal based foods.