Key Technical Points of Quality Control in Preserved Fruit Production

Preserved fruits, as a popular snack food, their quality is directly related to consumers' health and satisfaction. In the production process of preserved fruits, there are multiple links, and each link has an important impact on the quality of preserved fruits. Therefore, mastering and strictly controlling the key technical points in preserved fruit production is crucial for ensuring the stability and reliability of the quality of preserved fruits.

Raw material selection is the first and foremost link in the quality control of preserved fruits. High - quality fruit raw materials are the basis for producing high - quality preserved fruits. When selecting fruits, fresh fruits with appropriate maturity, no pests, diseases, and mechanical damage should be preferentially selected. Different types of fruits have different requirements for maturity. For example, when making apple preserves, apples at about 80% maturity should be selected. At this time, the apples have a moderate sweet - and - sour taste and a relatively firm texture, which is conducive to subsequent processing. When making peach preserves, the maturity is preferably 70% - 80% ripe. Such peaches have a moderate soft - hard texture of the pulp and a bright color, and the made peach preserves have a better taste. In addition, the variety of fruits also affects the quality of preserved fruits. Some varieties of fruits have unique flavors and textures and are more suitable for making preserved fruits. For example, Hami melons from Xinjiang, due to their high sugar content and rich aroma, are high - quality raw materials for making Hami melon preserves.

The cleaning and pretreatment steps are of great significance for removing impurities, microorganisms, and residual pesticides on the surface of fruits. When cleaning fruits, running water should be used, and an appropriate amount of detergent should be added to ensure that the dirt on the surface of fruits is thoroughly removed. For some fruits with villi on the surface, such as peaches and kiwis, special cleaning methods are also required, such as gently brushing with a soft - bristle brush to ensure the cleaning effect. After cleaning, the fruits need to be pretreated, such as peeling, pitting, and cutting. During the peeling process, attention should be paid to controlling the thickness of the peel. Peeling too thick will lead to waste of pulp, and peeling too thin will leave the peel residue, affecting the taste. When pitting, it is necessary to ensure that the fruit core is completely removed to avoid affecting the eating experience of the preserved fruits. When cutting fruits, according to the variety and specification requirements of the preserved fruits, the fruits should be cut into uniformly sized pieces or slices. This can ensure uniform heating and sugar - curing in the subsequent processing, thereby improving the consistency of the quality of preserved fruits.

Sugar - curing and drying are the core links in the production of preserved fruits and also the key steps affecting the quality of preserved fruits. During the sugar - curing process, the concentration, temperature, and soaking time of the sugar solution all need to be strictly controlled. If the concentration of the sugar solution is too high, the preserved fruits will be too sweet and prone to frosting during the drying process; if the concentration of the sugar solution is too low, it will not be able to effectively penetrate into the fruit interior, affecting the taste and shelf - life of the preserved fruits. Generally, the concentration of the sugar solution for making preserved fruits is more appropriate between 40% - 60%. The sugar - curing temperature should not be too high either. Excessive temperature will cause the loss of nutrients in fruits and may also lead to a darker color and worse taste of fruits. Usually, the sugar - curing temperature is controlled between 40°C - 60°C. The soaking time depends on the type and size of the fruits, generally ranging from several hours to more than ten hours. In the drying process,