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The influence of microbial fermentation on the safety of traditional brewing food

Abstract: The process characteristics and biotransformation mechanism of China's brewing food were elaborated, and the influence of microbial fermentation on food safety factors such as biological

physical contamination, chemical contamination, and physical contamination in the process of fermentation on the process of food brewing were analyzed, and it was concluded that the traditional brewing in China has more safety characteristics due to the decomposition, elimination, and filtration processes. It was concluded that the traditional brewing in China has more safety characteristics due to the microbial fermentation through the process of decomposition, elimination and filtration

over.

Keywords: traditional brewed food; fermentation; food safety

Food provides nutritional elements for human beings and is also a natural medium for microbial growth. China's traditional brewing foods (soy sauce, sauces, vinegar, fermented bean curd, white

wine, sauerkraut, kimchi, etc.) are mostly made from cereals, beans, vegetables, etc., and the natural

community of microorganisms is introduced into the fermentation process*** with the same action to form the unique flavor of

food. Through the microbial fermentation caused by the bioconversion of food with good

good quality, sensory characteristics, digestibility and nutritional value.

With the development of modern industry, industrial "three wastes" in the toxic and harmful substances

(such as heavy metal poisons, N-nitroso compounds, polycyclic aromatic hydrocarbons compounds, etc.) in the

environmental pollution is gradually increasing, these toxic and harmful substances through the soil, water,

air These toxic and hazardous substances are contaminated through soil, water,

air and other environmental pollution brewing food ingredients, food containers and packaging materials.

Chemical pesticides, fertilizers and storage agents (such as insecticides, fungicides, herbicides, plant

growth regulators, grain fumigants, protective agents, etc.) contaminate

food brewing raw materials through a variety of channels, and food as fermented raw materials in the production, processing, storage and other

links are subjected to biological contamination by molds, bacteria, parasites and so on. This paper analyzes the process characteristics of traditional

food brewing in China, the role of microbial biotransformation mechanisms on food contamination

, and explores the safety

problems of traditional brewed foods in the fermentation process.

1 Process Characteristics of Traditional Brewed Foods

China's traditional brewed foods have a long history, and after thousands of years of practice to form

unique brewing process characteristics.

1.1 Open-mouth solid-state fermentation

Traditional brewing generally uses solid-state fermentation technology, after adding grain bran or rice

shells and other auxiliary materials for the side of the saccharification side of the fermentation of the "bilateral fermentation" process, with a long time of

fermentation time, the product has a strong flavor, the management of the characteristics of the rough and so on. The whole process

adopts the open process, makes full use of the material resources and natural resources, enriches various functional microorganisms during the process, domesticates and cultivates a specific microbial group

structure system, and integrates the main microorganisms with the environmental microorganisms. At the same time

figured out a complete set of temperature, humidity, pH, aeration, fermentation time

and other brewing process conditions, the creation of the product aroma and a variety of processing technologies, to create

Creating China's unique brewing food flavor and ensure product quality has a very important

role.

1.2 A variety of microorganisms **** the same role

The brewing process is a complex biochemical reaction process, product quality

mainly depends on a variety of microorganisms synergistic effect. Microorganisms mainly from the

quasses and the environment, including molds, yeasts, bacteria, etc., a variety of microorganisms *** habitat

growth, giving grains of complex and complete enzyme system, with strong saccharification, liquefaction

and proteolytic capacity. A variety of microorganisms in the fermentation process, alternating, this

disappearance, synergistic effect, produce a single species of bacteria can not be compared to the role. In the

fermentation process, hydrolysis and fermentation are carried out alternately, avoiding the negative impact of too high a concentration of substrate on beneficial microorganisms and biochemical reactions. The fermentation time is long, the enzymatic reaction

is deep and perfect, the metabolites are rich and colorful, and the product flavor is mellow and rich[1-2].

1.3 Diversified product preservation measures

Traditional brewing food to take a flexible and diversified product safety measures, one is to rely

on the metabolite itself preservative effect (such as white wine is relying on the bactericidal effect of alcohol

, vinegar is relying on the bacteriostatic effect of acetic acid); the second is the use of high concentrations of salt to inhibit the growth and reproduction of microorganisms

inhibit microorganisms (such as soy sauce, soy sauce, rotted bean curd, soybean curd, soybean paste, soy sauce, soybean curd). (e.g. soy sauce, paste, curd, etc.).

2 Bioconversion Mechanism of Traditional Brewing Foods

The traditional brewing process involves a variety of microorganisms converting macromolecules such as starch, proteins

and lipids in raw materials into a variety of small-molecule flavor substances

that make up the main components of the product. The flavor substances of soy sauce can be divided into alcohols, esters, acids, aldehydes and acetals, phenols, furans and ketones

and sulfur-containing compounds according to their compound nature

[3-4]; in addition to acetic acid, the main ingredient of vinegar, vinegar also contains

sugar, amino acids, esters, aldehydes, alcohols, phenols, ketones, and other chemical constituents [5-6]. The flavor substances of brewed foods such as soy sauce and

vinegar constitute the product's characteristic color, aroma, and taste, and their

sources are mainly from 2 aspects, one is the "primary biomass" of plant raw materials (such as protein

quality, starch, etc.", and the secondary substances " such as tannins, aromatic compounds, isoflavones);

The second is the metabolites of microorganisms and their enzymes after they act on the plant material. In addition,

White wine, soy sauce, vinegar, etc. in the storage process of various metabolites interact with each other

The formation of a variety of flavor substances, according to the analysis of soy sauce contains more than 300 kinds of flavor substances [4].

2.1 Polysaccharide conversion

The main component of traditional brewing food raw materials is starch, which is decomposed into glucose under the action of Aspergillus differentiation

secretion amylase. These monosaccharides are used partly as a carbon source and energy source for the growth and reproduction of

molds, yeasts and bacteria, and partly to form various metabolites of fermentation products under the action of micro

organisms. The metabolites from starch conversion

include various acids, alcohols, phenols, and oligosaccharides [7].

The sugars in soy sauce include oligosaccharides (such as fructose, raffinose

, etc.) converted from soybeans, and sucrose, oligofructose, oligogalactose, oligoisomaltose, and oligosaccharides converted from wheat starch, etc., whereas small molecule products such as acids, alcohols, and phenolics in brewed foods are the material basis of the flavor of the product.

2.2 Protein conversion