Method for preparing preserved kiwi fruit by vacuum freeze drying

Abstract

A method for preparing preserved kiwi fruit by vacuum freeze drying. The method comprises steps of: peeling and slicing kiwi fruit, immersing the kiwi fruit in color protecting liquid, and then placing the kiwi fruit in a hardening liquid for hardening; after hardening, conducting an ultrasonic pretreatment in liquid glucose; and then successively carrying out vacuum sugar permeability, prefreezing, vacuum freeze drying, and packing to obtain the preserved kiwi fruit. According to the present invention, glucose lactone is added into a calcium chloride hardening liquid to coagulate protein in the fruit pieces and significantly improve hardening effect. The ultrasonic pretreatment and vacuum sugar permeability avoid a heat treatment process of rapid heating for a long time or short time, so that the kiwi fruit slices are still bright green (quite similar with an original fruit color). Vacuum freeze drying on the kiwi fruit realizes a high nutrient conservation rate.

Description

technical field [0001] The invention belongs to the field of agricultural product processing, and in particular relates to a method for preparing preserved kiwi fruit by vacuum freeze-drying. Background technique [0002] As we all know, the phylogenetic development of kiwi fruit is completed at a relatively high temperature, which is sensitive to ethylene, and it is difficult to store the fruit for a long time under natural conditions. Cause a lot of fresh fruit backlog and rot. If the fresh fruit can be processed into finished or semi-finished products in time, good storability can be obtained, the market can be enriched, the shelf life can be extended, and the added value of the industry can be increased. It also provides a feasible way for the transformation of kiwifruit resources. [0003] At present, the types of processed kiwifruit on the market include preserved fruit, fruit juice, fruit wine and so on. Among them, preserved kiwi fruit is favored by consumers becau...

AI Technical Summary

Problems solved by technology

Although the whole kiwi fruit has been punctured in the preparation process, it is still not conducive to the uniform sugar penetration, especially not conducive to the sugar penetration of the fruit core and the surrounding pulp tissue. Characters have a negative impact, and it is also unfavorable for large-scale production; and because the kiwi fruit is too large, the whole fruit preserved fruit made brings a lot of inconvenience to eating, and it is easy to cause waste

[0005] Published papers on low-sugar kiwi fruit preserves involve multiple long-term heat treatments in the production process, such as microwave sugar penetration, microwave drying, and hot air drying, which can easily cause browning of the finished fruit and loss of nutrients