Preparation method of freeze-dried apple slices

Abstract

The invention discloses a preparation method of freeze-dried apple slices, and relates to the technical field of food processing. Based on an original traditional process including refrigeration, sublimation and drying, the method omits the quick-freezing procedure. The method provided by the invention is as below: 1 hour before sending the materials into a freeze-drying warehouse, starting a refrigerating system; after sending the materials into the warehouse, realizing a vacuum degree of less than 133.3 Pa in 30 min, in order to froze the materials; starting a heating system to control the temperature of the apple slices at 10 DEG C-40 DEG C during a dehydration process; and dehydrating for a cycle of about 14 hours to obtain apple slices with moisture content below 5%. The preparation method of apple slices not only overcomes the shortcomings of the process including refrigeration, sublimation and drying, such as high energy consumption and non-crisp taste, but also has advantages of little loss of nutrients, light yellow color and crisp taste.

Description

Technical field: [0001] The invention relates to the technical field of food processing, in particular to a method for preparing apple slices using freeze-sublimation drying equipment. Background technique: [0002] There are three existing techniques for making dried apple products, namely AD (hot air drying), VMD (microwave vacuum drying) and FD (vacuum freeze-sublimation drying). Dried apple products made by drying process, commonly known as AD method, its technological process is: apple peeling, core removal, slicing, hot air drying. The advantage is that the energy consumption is the lowest, but the disadvantage is that the nutritional components of apples are seriously lost, the surface of the apple slices shrinks, the shape is poor, and the color turns yellow; VMD (microwave vacuum drying) is used to remove moisture from apples, and the disadvantage is that the nutritional components of apples are seriously lost. The color of the apple slices made by the AD method is...

AI Technical Summary

Problems solved by technology

The advantage is that the energy consumption is the lowest, but the disadvantage is that the nutritional components of apples are seriously lost, the surface of the apple slices shrinks, the shape is poor, and the color turns yellow; VMD (microwave vacuum drying) is used to remove moisture from apples, and the disadvantage is that the nutritional components of apples are seriously lost. The color of the apple slices made by the AD method is better than that of the apple slices, but the shape of the product shrinks and the shape of the slices is not good; the vacuum freeze-sublimation drying method (FD) to make apple slices usually uses the following processes, raw material selection, fruit washing and sterilization, and dehydration. Core, cut, pasteurize, plate, freeze, sublimation dry and pack

Its disadvantages are high energy consumption, soft but not crisp taste, pale and distorted apple product after freeze-drying

[0003] The current quality problem of dried apple products: Apple crisps made by AD, VMD, and existing FD technologies all have obvious disadvantages: Apple crisps produced by AD and VMD technologies lose serious apple nutrients, and the surface of the apple slices shrinks and loses its shape. and color distortion; the quick-freezing process in FD technology is also a necessary process for FD production in the general sense, but only for apple slices, the apple slices produced by existing FD technology are completely due to the quick-freezing process. The internal structure of apple slices is honeycomb-shaped, which makes the apple slices soft but not crisp, without the feeling of crispness, which makes the taste bad

At the same time, in terms of energy consumption: all apple slices produced by the existing FD technology have a quick-freezing process. The quick-freezing of apple slices is also the main reason for the high energy consumption of apple slices produced by FD technology. Generally, the storage temperature is required to be -30°C Below, quick freezing for 4-6 hours, resulting in high energy consumption in the production process and high production cost of FD apple slices

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