Food processing and product testing

The methods of food processing and product testing involve many aspects. The following is a detailed description of these two aspects:

1. Food processing methods
Food processing methods mainly include the following:

Cooking methods
Frying: Use hot oil in a pan to quickly stir-fry the ingredients so that the ingredients are evenly heated and have a fresh taste.
Boil: Put the ingredients in boiling water, use the pressure of the water to heat them, and take them out after they are cooked. Cooking methods also include steaming, stewing, and braising.
Frying: Put the ingredients in hot oil, slowly fry one side over low heat until golden, and then turn over and fry the other side. Frying can form a crispy layer on the surface of the ingredients and increase the taste.
Deep-frying: Put the ingredients in hot oil to make them expand rapidly and form a golden crust. Deep-frying is often used to make fried foods, such as French fries, chicken wings, etc.
Pickling methods
Salting: Put the ingredients in salt water to make them fully absorb salt to achieve the purpose of preservation, such as salted fish, bacon, etc.
Sugar pickling: Put the ingredients in sugar water to make them fully absorb sugar to achieve the purpose of preservation, such as candied fruit, preserved fruit, etc.
Soy sauce pickling: Put the ingredients in soy sauce to fully absorb the flavor of soy sauce to achieve the purpose of preservation, such as pickles, fermented bean curd, etc.
Fermentation method
Yogurt fermentation: After heating and sterilizing the milk, add yogurt bacteria and leave it for a period of time to ferment the milk into yogurt.
Fermentation of fermented rice: After steaming glutinous rice or rice, add wine yeast and leave it for a period of time to ferment it into fermented rice.
Tofu fermentation: Grind soybeans with water, add coagulant after boiling, leave it for a period of time, let the soy milk solidify into tofu, and then ferment it.
Other methods
Freeze drying method: Freeze the ingredients into ice crystals at low temperatures, then sublimate the ice crystals into water vapor under a vacuum environment, and finally collect water to make dry food. This method can effectively retain the nutritional content and taste of the ingredients.
Vacuum packaging method: Put the ingredients into a vacuum bag, extract the air in the bag, and isolate the ingredients from oxygen, so as to achieve the purpose of preservation and preservation. This method is suitable for all kinds of perishable foods.
2. Food testing methods
Food testing methods mainly include the following:

Sensory testing
Visual evaluation: By observing the appearance characteristics of food, such as color, shape, size, surface texture, etc., the freshness, maturity, and processing quality of food can be preliminarily judged.
Olfactory evaluation: By smelling the smell of food, judge whether it is spoiled or has a strange smell.
Taste evaluation: By tasting the taste of food, judge whether it is spoiled or has a strange smell. However, this method has certain risks and is not suitable for the detection of all foods.
Tactile evaluation: By touching the texture of food, judge its freshness and quality.
Chemical testing
Chromatography: Separate different components in food through chromatographic columns, and then detect their content through detectors. Chromatography can be used to detect pesticide residues, additives, heavy metals, etc. in food.
Spectroscopy: By analyzing the absorption or emission characteristics of food to light of a specific wavelength, the content of certain components in food can be judged.
Mass spectrometry: By analyzing the mass and structure of molecules in food, its composition and content are determined. Mass spectrometry has high sensitivity and high selectivity and can be used to detect trace components in food.
Microbiological testing
Total colony count test: By counting the total number of bacteria in food, the hygienic condition of food is judged.
Escherichia coli test: Escherichia coli is a common food contamination bacteria. The number of Escherichia coli can be tested to evaluate the hygienic condition of food.
Pathogenic bacteria test: By testing bacteria or viruses that may cause disease in food, such as Salmonella, Staphylococcus aureus, etc., the safety of food is judged.
Molecular biology test
PCR technology: It can be used to detect genetically modified foods.
DNA sequencing: By determining the DNA sequence of biological molecules in food, its type and source are determined. DNA sequencing can be used to identify the authenticity of food and trace the source of food.
Proteomics: By analyzing the type, quantity, and modification state of proteins in food, the quality and safety of food are evaluated. Proteomics can be used to detect allergens, toxins, etc. in food.
Physical testing
Mainly by measuring the physical parameters of food such as size, shape, specific gravity, hardness, etc., to judge the quality and safety of food.
Test strip test
A fast and simple on-site detection method for rapid screening of microorganisms, chemicals, nutrients, etc. in food. The test strip is coated with a specific reagent. When it comes into contact with the food sample, a chemical reaction will occur, resulting in a color change. The color change can quickly determine whether the food contains the target ingredient, or whether the content of the ingredient exceeds the standard.
In summary, there are many methods for food processing and product testing, each of which has its own characteristics and scope of application. In practical applications, appropriate processing and testing methods should be selected according to specific circumstances to ensure the safety and quality of food.