Specific operation steps of processing technology of small package chestnut

Chestnut belongs to Fagaceae and has been cultivated in China for more than 3000 years. At present, there are 26 provinces in China, with an annual output of 600000 tons, accounting for about 1/3 of the world's total output. Chestnuts are one of the "Woody grains" with high nutritional value. Every 100 grams contains 60-70 grams of sugar and starch, 5-10 grams of protein and 3-7 grams of fat.

After harvest, chestnut is easy to mold, lose water, breed insects, and then sprout. The loss rate usually exceeds 30%. The processing of Canned Chestnuts in bags is an effective way to solve this problem.

1. Processing technology of small package chestnut

Raw material selection → shelling and peeling → color protection → hardening → water drainage → packaging → drying → canned sugar water → vacuum packaging → sterilization → finished products.

2. Key points of operation

(1) The selection of raw materials requires the use of fresh and full chestnuts with normal flavor, no moth, no mildew and no germination as raw materials. (2) Shelling and peeling can be carried out mechanically in the process of industrial production, and manual peeling can be used for a small amount of processing. After peeling, immediately soak the chestnuts in the color protection solution to prevent the oxidation and discoloration of the chestnuts.

(3) Browning of color preserving chestnut kernel is mainly divided into enzymatic browning and non enzymatic browning. In order to prevent chestnut kernel browning, chestnut kernel was first treated with inactivating enzyme, and then treated with color protecting solution. ① Inactivate enzyme treatment. Put the peeled chestnut kernel into hot water at 95 ℃ -98 ℃ for 3 minutes to kill the surface microorganisms and enzyme activity. It needs to be cooled immediately after scalding. Add 0.3% phytic acid, 0.3% ascorbic acid, 0.7% citric acid and 1% sodium chloride to the inactivated enzyme hot water, and adjust the pH to 3 with phosphoric acid. Adopt the step cooling method. First, cool it with 50 ℃ -60 ℃ water for 1min, then cool it with room temperature water for 1min, and then fully cool it with 0 ℃ cold water. ② Color protection liquid color protection. Soak the cooled chestnut kernel in the color protection solution (the formula of the color protection solution is: 0.3% ascorbic acid, 0.7% citric acid, 0.3% phytic acid, 1% sodium chloride) for 30 minutes, and take it out.

(4) Hardening: using 0.15% calcium chloride solution to harden chestnut fruits for 5 minutes can reduce fruit cracking and soup mixing during sterilization.

(5) Dry the precooked chestnuts, rinse them quickly with water, remove the sugar liquid on the surface, and dry the surface moisture of chestnuts under 65 ℃ and sandblasting conditions.

(6) Soak the processed chestnut in 1% chitosan glacial acetic acid solution for 1min-2min, take it out, put it into a tray, bake it at 68 ℃ -70 ℃ for 8min-10min, and dry the surface.

(7) Filling with sugar solution ① preparation of sugar solution. Generally, the sugar is heated and dissolved in a small amount of water in the jacketed pot to form a clear and viscous syrup, remove and filter the floating impurities on the syrup, and then add a certain amount of water. Edta-2na with a mass fraction of 0.02% was added to the sugar solution as a color retention agent, and the sugar solution was boiled for later use. ② Fill with high temperature resistant cooking bags and add sugar.

(8) Vacuum packaging is packaged and sealed under the pressure of 0.09mpa to ensure product quality. Packaging materials should choose packaging bags with good barrier property, high mechanical strength and good heat resistance.

(9) Disinfect vacuum packaging immediately after disinfection. The sterilization method is to sterilize at a high temperature of 121 ° C for 25 minutes.

(10) The finished products can be stored indoors at a temperature above 25 ° C for 7 days, and the quality inspection is qualified. They can be transported as finished products without expansion bags or deterioration.

3. Product quality standards

(1) Sensory indicators ① chestnuts are orange yellow, without discoloration, turbidity, and syrup is transparent; ② The original flavor of chestnuts can be well maintained, with moderate sweetness and no peculiar smell; ③ The chestnuts in the can are basically the same size, and the fruit is soft and hard. Moderate, the cleanliness of chestnut is not less than 70%; According to the refractive index, the concentration of sugar water is 50%.

(2) Physical and chemical microbial indicators ① the total number of miscellaneous bacteria is not greater than 150/g, and the coliform group is not greater than 30/100g, so pathogenic bacteria cannot be detected. ② The content of tin in the product shall not exceed 200mg/kg, the content of copper shall not exceed 10mg/kg, and the content of Lead shall not exceed 2mg / K.

The above is the specific operation steps of the processing technology of small packaged chestnut. Hebei Yanshanhong Food Co., Ltd., founded in September 2000, is a comprehensive production enterprise specializing in the R & D, processing, production and sales of chestnut, peanut and other agricultural and sideline products. The company covers an area of 20000 square meters and a construction area of 6000 square meters, including food processing workshops, low-temperature warehouses, quick-frozen warehouses and high-temperature warehouses. If you have any need, please contact us!