Plant based food/other physicochemical parameter testing

Since ancient times, Chinese people, except for some ethnic minorities, have mainly relied on plant-based foods. In addition to providing the three major nutrients needed by the human body, including protein, carbohydrates, and lipids, plant-based foods also provide most vitamins, minerals, and dietary fiber. Plant based food refers to food that uses plant seeds, fruits, or tissue parts as raw materials, directly or after processing, to provide energy or material sources for humans. Mainly including grains, potatoes, beans and their products, fruit and vegetable products, tea, etc. Compared to animal based foods, plant based foods have their own characteristics in terms of physiological functions. As they are still alive and undergo various physiological activities, they inevitably cause changes and losses in their quality, form, taste, and nutritional composition; At the same time, when physiological activities are affected by external factors and cannot proceed normally, it will also exacerbate changes in the quality of fruits and vegetables. 1. Respiratory function refers to the process in which fruits and vegetables obtain oxygen from the external environment and, with the participation of enzymes, oxidize and decompose their accumulated carbohydrates into substances and energy necessary for maintaining life. The energy generated by respiration is partly used for one's own metabolism, while the other is dissipated in the form of heat. 2. Evaporation refers to the natural outward evaporation of water contained in fruits, as well as the dissipation of heat through respiration and field heating (heat generated by the influence of light and temperature), which inevitably carries some water away. Evaporation can cause quality changes such as weight loss and freshness loss of fruits, as well as softening of the flesh. 3. Hormonal effects mainly refer to the adverse effects of endogenous ethylene produced in fruits and exogenous ethylene produced in the environment. Ethylene is a fruit ripening agent that promotes physiological metabolism and accelerates post ripening and aging. The principle of low-temperature preservation is that for plant-based foods, the cause of decay is respiration. When fruits and vegetables are stored after picking, although they no longer continue to grow, they are still an organism, that is, they still have life and respiration, which can resist bacterial invasion. The oxidation process during respiration can oxidize the hydrolytic enzymes secreted by microorganisms into harmless substances, protecting the cells of fruits and vegetables from toxicity, thereby preventing microbial invasion. Therefore, fruits and vegetables can control the function of enzymes in the body during storage and have a certain resistance to the invasion of external microorganisms that cause spoilage and fermentation. But on the other hand, as they are living organisms, they need to breathe, and unlike before picking, they can no longer obtain water and other nutrients from the mother plant, and can only consume substances in the body, gradually aging and becoming dead. Therefore, in order to store plant-based foods for a long time, it is necessary to maintain their living state while also weakening their respiratory function. Low temperature can weaken the respiratory function of fruits and vegetables and extend their storage life. But the temperature should not be too low, as too low a temperature can cause physiological diseases in plant-based foods, and even freeze them to death. Therefore, the storage temperature should be chosen at a temperature close to the freezing point without causing plants to freeze to death. If the components in the air (oxygen, carbon dioxide, moisture) can be adjusted simultaneously, better results can be achieved. Storage by adjusting temperature is called temperature controlled storage, storage by adjusting temperature drop is called low-temperature storage, and storage by changing air composition is called controlled atmosphere storage (CA storage). Controlled atmosphere storage has been widely used in the preservation of fruits and vegetables, and has achieved good results. In summary, to prevent the spoilage of plant-based foods, the main approach is to maintain an appropriate temperature (depending on the variety) and control the respiration of fruits and vegetables. This can achieve a good effect of maintaining the quality of plant-based food