What are the main physicochemical factors to be considered in the production process of traditional fermented foods

The main physicochemical factors that need to be considered in the production process of traditional fermented foods are:

1. List of ingredients: Different ingredients have different nutritional and chemical compositions, which have an impact on the fermentation process and the quality of the final product. For example, ingredients with high protein content are good for hydrolyzing proteins into amino acids during the fermentation process, thus improving the nutritional value of the product; while ingredients with high carbohydrate content are good for producing more alcohol and carbon dioxide during the fermentation process, thus improving the taste and stability of the product.

2. Production steps: During the production process, parameters such as temperature, humidity, oxygen content, and pH need to be controlled to ensure that microbial growth and metabolic activities are in an optimal state. For example, too high or too low temperature will affect the growth and metabolism of microorganisms, resulting in prolonged or shortened fermentation time; too high or too low oxygen content will affect the growth and metabolism of microorganisms, resulting in the production of excessive acids or alcohols and other substances during the fermentation process; and too high or too low pH will also affect the growth and metabolism of microorganisms, resulting in the production of excessive hazardous substances or inhibiting microbial growth during the fermentation process.

The following is a list of ingredients and preparation steps for some common traditional fermented foods:

1. Sauerkraut:

- List of ingredients: Chinese cabbage, salt, water.

- Preparation steps: Cut the cabbage into cubes, add the right amount of salt and water and mix well, put it into a clean and oil-free container and seal it for fermentation. Keep the temperature between 20-30 degrees Celsius during fermentation, the time varies according to the season and temperature, usually takes 3-7 days.

2. Yogurt:

- Ingredients list: Milk, Lactobacillus species, sugar.

- Preparation steps: Heat the milk to about 40 degrees Celsius, add the right amount of sugar and mix well, cool to room temperature. Add the lactic acid bacteria species into the milk, stir well, and then put it into the yogurt machine to ferment. Keep the temperature between 40-50 degrees Celsius during fermentation, the time varies according to the lactobacillus species and the type of milk, and usually takes 2-6 hours.

3. Kimchi:

- List of ingredients: cabbage, salt, water, chili, garlic, ginger and other seasonings.

- Preparation steps: cut the cabbage into cubes, add the right amount of salt and water and mix well, put into a clean and oil-free container, sealed fermentation. Keep the temperature between 20-30 degrees Celsius during fermentation, the time varies according to the season and temperature, usually takes 3-7 days. Remove the fermented kimchi