Frozen-dried, preserving and sterilizing method for with combined nanometer silver film and microwave drying method

Abstract

The present invention relates to a quality-assuring sterilization method of freeze-dried food by adopting combination of nano silver film-coating technique and microwave drying technique, belonging to the field of food safety control technology. Said method includes the following steps: selecting freeze-dried food raw material, defrosting, cleaning, coating film with nano silver, freezing, freeze-drying, microwave treatment and packaging.

Description

Technical field

[0001] A method for pretreatment of a safe dose of nano silver coating film in combination with microwaves to uniformly sterilize freeze-dried foods while maintaining quality. The invention belongs to the technical field of food safety control. Background technique

[0002] Frozen food is more and more popular because the vacuum freeze-drying technology overcomes the lack of quality of the food processed by traditional processing methods, so that the product quality can maximize the color, flavor and nutrition of the food, and the rehydration is good. However, freeze-dried food also has some disadvantages, such as high operating cost, long production cycle, and difficult to control microorganisms. In terms of microbial control, the latest pasteurization with continuous electric heating is adopted. However, due to expensive equipment or processing fees charged for processing, the cost of the product has been virtually increased. General freeze-dried food productio...

Examples

Embodiment 1

[0023] Example 1: Production and application of nano-silver coating pretreatment and microwave combination to uniformly sterilize freeze-dried sea cucumbers

[0024] Frozen sea cucumbers are first subjected to warm thawing, selection, intestinal removal, and cleaning, then nano-silver soaking (10s, concentration 0.045ppm), draining free water, freezing (material center temperature -25℃), freeze drying (drying chamber pressure 100Pa, material Sublimation section temperature -18℃, cold trap temperature -50℃), microwave treatment (2.6W / g, 3~5min). The freeze-dried product obtained by this method is cultured and the total number of colonies is within 1000 / g; after the fermentation tube is cultured, there is no discoloration and no bubbles are observed, that is, the coliform (or E. coli) meets the standard (negative).

Embodiment 2

[0025] Example 2: Production and application of uniformly sterilizing freeze-dried abalone with nano-silver coating film and microwave

[0026] Frozen abalones are first subjected to warm thawing, selection, intestine removal, and cleaning, then nano-silver soaking (15s, concentration 0.045ppm), draining free water, freezing (material center temperature -25℃), freeze drying (drying chamber pressure 100Pa, material Sublimation section temperature -18℃, cold trap temperature -50℃), microwave treatment (2.6W / g, 3~5min). The total number of colonies of the FD product obtained by this method after culture is less than 1000 / g; after fermentation tube culture, there is no discoloration and no bubbles are observed, that is, the coliform (or E. coli) reaches the standard (negative).

Embodiment 3

[0027] Example 3: Production and application of nano-silver coating and microwave to uniformly sterilize freeze-dried strawberries

[0028] Fresh strawberries are first selected, cleaned, and removed, then nano-silver soaked (10s, concentration 0.045ppm), drained free water, frozen (material center temperature -25), freeze-dried (drying chamber pressure 100Pa, material sublimation section temperature- 18°C, cold trap temperature -50°C), and finally microwave treatment (2.6W / g, 3~5min). The total number of colonies of the FD product obtained by this method after culture is less than 1000 / g; after the fermentation tube is cultured, there is no discoloration and no bubbles are observed, that is, the coliform (or E. coli) reaches the standard (negative).

Technical field

[0001] A method for pretreatment of a safe dose of nano silver coating film in combination with microwaves to uniformly sterilize freeze-dried foods while maintaining quality. The invention belongs to the technical field of food safety control. Background technique

[0002] Frozen food is more and more popular because the vacuum freeze-drying technology overcomes the lack of quality of the food processed by traditional processing methods, so that the product quality can maximize the color, flavor and nutrition of the food, and the rehydration is good. However, freeze-dried food also has some disadvantages, such as high operating cost, long production cycle, and difficult to control microorganisms. In terms of microbial control, the latest pasteurization with continuous electric heating is adopted. However, due to expensive equipment or processing fees charged for processing, the cost of the product has been virtually increased. General freeze-dried food productio...

Examples

Embodiment 1

[0023] Example 1: Production and application of nano-silver coating pretreatment and microwave combination to uniformly sterilize freeze-dried sea cucumbers

[0024] Frozen sea cucumbers are first subjected to warm thawing, selection, intestinal removal, and cleaning, then nano-silver soaking (10s, concentration 0.045ppm), draining free water, freezing (material center temperature -25℃), freeze drying (drying chamber pressure 100Pa, material Sublimation section temperature -18℃, cold trap temperature -50℃), microwave treatment (2.6W / g, 3~5min). The freeze-dried product obtained by this method is cultured and the total number of colonies is within 1000 / g; after the fermentation tube is cultured, there is no discoloration and no bubbles are observed, that is, the coliform (or E. coli) meets the standard (negative).

Embodiment 2

[0025] Example 2: Production and application of uniformly sterilizing freeze-dried abalone with nano-silver coating film and microwave

[0026] Frozen abalones are first subjected to warm thawing, selection, intestine removal, and cleaning, then nano-silver soaking (15s, concentration 0.045ppm), draining free water, freezing (material center temperature -25℃), freeze drying (drying chamber pressure 100Pa, material Sublimation section temperature -18℃, cold trap temperature -50℃), microwave treatment (2.6W / g, 3~5min). The total number of colonies of the FD product obtained by this method after culture is less than 1000 / g; after fermentation tube culture, there is no discoloration and no bubbles are observed, that is, the coliform (or E. coli) reaches the standard (negative).

Embodiment 3

[0027] Example 3: Production and application of nano-silver coating and microwave to uniformly sterilize freeze-dried strawberries

[0028] Fresh strawberries are first selected, cleaned, and removed, then nano-silver soaked (10s, concentration 0.045ppm), drained free water, frozen (material center temperature -25), freeze-dried (drying chamber pressure 100Pa, material sublimation section temperature- 18°C, cold trap temperature -50°C), and finally microwave treatment (2.6W / g, 3~5min). The total number of colonies of the FD product obtained by this method after culture is less than 1000 / g; after the fermentation tube is cultured, there is no discoloration and no bubbles are observed, that is, the coliform (or E. coli) reaches the standard (negative).