Technological Innovation and Optimization of Sugar - Curing Process in Preserved Fruits

The sugar - curing process of preserved fruits is a key link in endowing preserved fruits with their unique flavor and texture. The innovation and optimization of this technology are of great significance for improving the quality of preserved fruits and meeting the increasingly diverse needs of consumers. The traditional sugar - curing process of preserved fruits mainly adopts the hot sugar - curing method, in which fruits are soaked in a high - concentration sugar solution and heated to promote the penetration of sugar into the fruit tissue. However, this method has some drawbacks, such as the potential loss of nutrients in fruits during the heating process, changes in color, and deterioration of flavor.

To overcome the shortcomings of the traditional hot sugar - curing method, the cold sugar - curing technology has emerged. Cold sugar - curing involves soaking fruits in a sugar solution at room temperature and using the principle of osmotic pressure to slowly allow sugar to penetrate into the fruit cells. This method avoids the adverse effects of heating on fruits and can better preserve the natural color, flavor, and nutrients of fruits. For example, when making cherry preserves, fresh cherries are washed, pitted, and then placed in a sugar solution containing an appropriate amount of citric acid and pectinase and soaked at room temperature for several hours. Since the cold sugar - curing process is relatively slow, to improve efficiency, a decompression treatment can be adopted, that is, sugar - curing is carried out in a vacuum environment. This can accelerate the penetration of sugar and reduce the risk of microbial contamination. The cherry preserves made by cold sugar - curing have a bright color, a sweet - and - sour taste, and retain the original flavor of cherries to the greatest extent.

In the sugar - curing process, the formulation of the sugar solution is also an important factor affecting the quality of preserved fruits. The traditional sugar - curing process usually uses a single sucrose as a sweetener. However, with the increasing attention of consumers to healthy diets, the development of low - sugar and multi - sugar formulations has become a trend. Some producers have begun to try adding some functional sugars to the sugar solution, such as fructooligosaccharides and xylitol. Fructooligosaccharides have health - care functions such as regulating the intestinal flora and promoting mineral absorption, while xylitol has characteristics such as anti - caries and low calorie. The rational combination of these functional sugars with sucrose can not only reduce the sugar content of preserved fruits but also endow preserved fruits with certain health - care effects. For example, when making pear preserves, mixing sucrose and fructooligosaccharides in a certain proportion to make a sugar solution can not only reduce the sweetness of the preserved fruits but also give the preserved fruits a unique refreshing taste, and at the same time increase the added value of the product.

In addition to the optimization of the sugar - solution formula, the improvement of sugar - curing equipment also provides strong support for the innovation of the sugar - curing process of preserved fruits. New - type continuous sugar - curing equipment can achieve continuous feeding and discharging of fruits, greatly improving production efficiency. This kind of equipment usually adopts a multi - stage sugar - curing design, and fruits pass through sugar solutions of different concentrations in turn, allowing sugar to gradually penetrate into the fruit interior, thus ensuring the uniformity of the sugar - curing effect. At the same time, the equipment is also equipped with an automated control system, which can accurately control parameters such as the temperature, concentration, and soaking time of the sugar solution, reducing the impact of human factors on product quality. For example, some large - scale preserved fruit production enterprises use continuous vacuum sugar - curing equipment, which can quickly complete the sugar - curing process in a vacuum environment, and the produced preserved fruits have stable quality and consistent taste.

In addition, the application of ultrasonic technology in the sugar - curing process of preserved fruits has also achieved remarkable results. Ultrasonic waves can generate high - frequency vibrations, causing slight ruptures in the fruit tissue cells, thereby increasing the permeability of the cells and accelerating the penetration of sugar. During the sugar - curing process, an ultrasonic generator is installed in the sugar - curing container. By adjusting the frequency and power of the ultrasonic waves, the sugar - curing time can be significantly shortened without affecting the quality of the fruits. Studies have shown that when using ultrasonic - assisted sugar - curing technology to make grape preserves, the sugar - curing time can be shortened by about one - third, and at the same time, the color, taste, and nutrient retention of the preserved fruits have been significantly improved.

The technological innovation and optimization of the sugar - curing process of preserved fruits is a continuous development process. By adopting cold sugar - curing technology, optimizing the sugar - solution formula, improving sugar - curing equipment, and introducing new technologies such as ultrasonic waves, the quality of preserved fruits can be effectively improved to meet consumers' demands for healthy and delicious preserved fruits. In the future production of preserved fruits, with the application and innovation of more advanced technologies, the sugar - curing process of preserved fruits will be continuously improved, injecting new vitality into the development of the preserved - fruit industry.