Method for fresh keeping of fresh walnuts by slow-freezing and slow-unfreezing freshelizing technology

A fresh walnut, slow technology, applied in the field of fresh walnuts by slow freezing-slow thawing and refreshment process, can solve the problems of unbreakable walnut freshness period, affecting the flavor of walnut kernels, and difficult production operations, so as to achieve product supply control Strong, increase storage capacity utilization efficiency, and facilitate the effect of centralized processing and utilization

Pending Publication Date: 2018-01-09
甘肃省农业科学院农产品贮藏加工研究所
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] However, due to the high water content of fresh walnuts, they are prone to germination, dehydration, mildew and quality deterioration during storage, and the preservation period is short. The problem of freshness has become a bottleneck restricting the development of fresh walnut industry; the freshness of fresh walnuts has caused almost all freshness Researchers are concerned, but at present, at the laboratory level, the walnut preservation period has not exceeded 4 months; it is reported that the refrigerated preservation period of walnuts without green skin does not exceed 2 months, and if more than 2 months, the walnut shell will be sticky and moldy, which will further affect walnut flavor
The fresh-keeping period of walnuts with green skins does not exceed 4 months, and the green skins brown and rot, and the rot rate exceeds 50%, which further affects the flavor of walnut kernels and has no production operability
It has been proposed to keep the green peel for about 80 days, and then remove the green peel for about 40 days, so that the freshness period of walnuts can reach 4 months, but the production and operation of this technology are difficult; some scholars have also proposed the method of storing walnuts at a freezing temperature of -10~-20°C , the proposed supporting freezing and thawing method is: "Put the walnuts that have been frozen with ice coats after leaving the warehouse to thaw naturally at room temperature, or wash them with tap water to melt them, or put them in warm water at 30-60°C to thaw them, or take other heating methods. However, a large number of studies have found that the color of frozen-thawed walnut kernels using this method is yellowish, the kernels become softer, the taste becomes sweeter, the hardness, crispness and chewiness are reduced, and the fresh flavor and taste are lost. range, unacceptable in the market

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] (1) Timely harvesting: Stop irrigation and spraying 2 weeks before walnuts are harvested; choose sunny days for harvesting, and avoid high-temperature periods on sunny days when harvesting to reduce field heat carried by walnuts. Avoid rainy days, after rains and when there is dew Harvesting; the walnuts are fully matured and harvested with green skins. If the walnuts are harvested too early, the flavor is not fully formed, and after slow freezing, they are water-soaked and cannot be thawed and freshened; if they are harvested too late, the skins are dark brown and the moisture content is low. Decrease, affect the sensory commodity and taste flavor.

[0019] (2) Peel off, grading: Spray 0.5% ethephon after the walnuts with green peel are harvested, stratify and accelerate the ripening for 5 days, remove the green peel and carry out size classification;

[0020] (3) Slow freezing: put the walnuts in a fresh-keeping bag within 12 hours and place them at -2°C for slow free...

Embodiment 2

[0025] (1) Timely harvesting: Stop irrigation and spraying 2 weeks before walnuts are harvested; choose sunny days for harvesting, and avoid high-temperature periods on sunny days when harvesting to reduce field heat carried by walnuts. Avoid rainy days, after rains and when there is dew Harvesting; the walnuts are fully matured and harvested with green skins. If the walnuts are harvested too early, the flavor is not fully formed, and after slow freezing, they are water-soaked and cannot be thawed and freshened; if they are harvested too late, the skins are dark brown and the moisture content is low. Decrease, affect the sensory commodity and taste flavor.

[0026] (2) Peel off, grading: Spray 0.5% ethephon after harvesting the walnuts with green skin, stratify and accelerate ripening for 4 days, remove the green skin and carry out size classification;

[0027] (3) Slow freezing: put the walnuts in a fresh-keeping bag within 12 hours and place them at a temperature of -10°C fo...

Embodiment 3

[0033] (1) Timely harvesting: Stop irrigation and spraying 2 weeks before walnuts are harvested; choose sunny days for harvesting, and avoid high-temperature periods on sunny days when harvesting to reduce field heat carried by walnuts. Avoid rainy days, after rains and when there is dew Harvesting; the walnuts are fully matured and harvested with green skins. If the walnuts are harvested too early, the flavor is not fully formed, and after slow freezing, they are water-soaked and cannot be thawed and freshened; if they are harvested too late, the skins are dark brown and the moisture content is low. Decrease, affect the sensory commodity and taste flavor.

[0034] (2) Peel off, grading: Spray 0.4% ethephon after the walnuts with green peel are harvested, stratify and accelerate the ripening for 4 days, remove the green peel and carry out size classification;

[0035] (3) Slow freezing: put the walnuts in a fresh-keeping bag within 12 hours and place them at a temperature of -...

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PUM

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Abstract

The invention relates to a fresh-keeping method for fresh walnuts, in particular to a method for fresh-keeping walnuts by slow freezing-slow thawing and refreshment process. The technical scheme of the invention includes peeling, grading, slow freezing, frozen storage, slow thawing and freshening. The technology of the invention extends the preservation period of fresh walnuts from 2 to 4 months to more than 10 to 12 months, and realizes the annual supply of fresh walnuts.

Description

technical field [0001] The invention relates to a fresh-keeping method for fresh walnuts, in particular to a fresh-keeping method for fresh walnuts by slow freezing-slow thawing refreshment process. Background technique [0002] Walnuts are favored by consumers due to their rich nutritional value and health care value. In addition, they are characterized by strong adaptability, wide cultivation, and remarkable ecological benefits. In recent years, the walnut industry has developed rapidly across the country. In 2002, the national walnut production was only 343,000 tons. By the end of 2014, the national walnut planting area reached more than 7,228,500 ha 2 , resulting in an area of ​​more than 2.856 million hm 2 , the output has reached 2.713 million tons, and the average annual growth rate of output has reached 18.81%. Both the area and output rank first in the world. However, with the decline of the overall economic development, the efficiency of the walnut industry has d...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): A23B9/10A23B9/12
Inventor 颉敏华陈柏吴小华王学喜张永茂
Owner 甘肃省农业科学院农产品贮藏加工研究所
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