LOLULU
3.
Which of the following components of a food item does yeast act upon duri
fermentation?
a. Fats
b. Proteins
c. Sugar
d. Vitamins
Answers
Answer:
Abstract
Fermented foods have long been produced according to knowledge passed down from generation to generation and with no understanding of the potential role of the microorganism(s) involved in the process. However, the scientific and technological revolution in Western countries made fermentation turn from a household to a controlled process suitable for industrial scale production systems intended for the mass marketplace. The aim of this paper is to provide an up-to-date review of the latest studies which investigated the health-promoting components forming upon fermentation of the main food matrices, in order to contribute to understanding their important role in healthy diets and relevance in national dietary recommendations worldwide. Formation of antioxidant, bioactive, anti-hypertensive, anti-diabetic, and FODMAP-reducing components in fermented foods are mainly presented and discussed. Fermentation was found to increase antioxidant activity of milks, cereals, fruit and vegetables, meat and fish. Anti-hypertensive peptides are detected in fermented milk and cereals. Changes in vitamin content are mainly observed in fermented milk and fruits. Fermented milk and fruit juice were found to have probiotic activity. Other effects such as anti-diabetic properties, FODMAP reduction, and changes in fatty acid profile are peculiar of specific food categories.
Keywords: fermented foods, health benefits, antioxidants, anti-hypertensives, anti-diabetics, bioactive peptides, lactose-intolerance, FODMAP, healthy diet, dietary guidelines
1. Introduction
Fermented foods are obtained through the action of microorganisms, namely bacteria, yeasts, and mycelial fungi, and their enzymes, in a process referred to as fermentation [1]. Microorganisms may be indigenously present on the substrate, or added as a starter culture, or they may be present in or on the ingredients and utensils, or in the environment. Basically, a suitable substrate, appropriate microorganism(s) and proper environmental conditions, such as temperature, pH, and moisture content must coexist in order to enable food fermentation.
During fermentation, carbohydrates and related compounds are partially oxidized and energy is released in the absence of any external electron acceptor [2]. Factors like type of sugar, limited or unlimited nutrient and oxygen availability, presence of competitive microorganisms, and time influence the process.