The preservation and storage of food

Everyone cares about the food health and safe problems and prefers to read the labels of foods. When faced with a longer shelf life foods, customers’' first reaction is there must be a lot of preservatives in the food. But, there are many food does not contain preservatives, such as sugar, honey, canned foods and frozen foods.

Experts explain food preservatives are added to avoid microbial (bacterial or fungal) growth to lead to food spoilage. Microbial growth requires nutrients, water, proper temperature and acidity. If any of them does not meet the requirements for microbial growth, microbial will not be able to reproduce. so some people may use drying, salting, sugaring, low temperature, filling method to deal with microbial. As I have said before, my grandma likes to preserve food by using salt. Then, we can enjoy the food for a whole winter without fridge. Of course, microbes which can cause food spoilage can't grow below below-18 Celsius. Therefore, most of the frozen food at low temperatures storage can solve the food spoilage problems, but long-term low temperatures preserves cannot change the results of food spoilage. During the low temperature storage, fats or protein is oxidized, the food flavor will gradually deteriorate. As a result, the frozen food need to be consumed as soon as possible within the warranty period.

By the way, the freezing process of household refrigerator is different from factory "frozen", it was unable to bring the temperature down to-18 c, especially too many things in the fridge will further reduce frozen rate. At this time, bacterial breed can damage the food flavor. So, compared to industrial production food, homemade food should eat as quickly as possible and not be kept in refrigerator for a long time. According to this qualified products are safer than the homemade foods.

When it refers to ice creams, some people may say there are thousands of food additives in the ice creams. Sweeteners, sour agents and flavors are responsible for seasoning; emulsifiers and thickening agents are responsible for "shaping"; pigment is responsible for coloring. In fact, adding a number of food additives is a normal phenomenon, they also guarantee the ice cream taste and shape. If the food additives meet the standard, there's no need to worry about them. Sugar and milk in ice cream, freezing temperature and the required storage environment is lower than -18 ℃, but household refrigerators can not reach the needed temperature. The ice creams bought from the supermarket may occur the high temperature softening and the freezing process, the flavor may change and even pathogen will bury a safety hazard. So customers should not purchase too much ice creams for storage, and they'd better eat up the ice creams in the refrigerators as soon as possible.