First, the chestnut storage technology Chestnut more than the actual breeding, many strains, different resistance to possession. Chestnuts are best preserved in late-maturing varieties, and northern varieties are more resistant to hiding than southern varieties. Chestnuts are susceptible to decay, germination, and weightlessness during storage. The technical measures that should be taken into account during storage are:
The harvesting period is determined: chestnuts harvested early are susceptible to rot during storage, so chestnuts that are stored for a long time should be harvested when they are fully matured, and the stored fruits are most resistant to storage. Harvested chestnuts are placed in a cool, ventilated place for perspiration, heat dissipation, and water loss. Chestnut cracking chestnuts out, dry 5 to 7 days into storage.
Chestnut storage of the appropriate conditions: the appropriate temperature is 0 °C 0.5 °C, relative humidity of 80% to 85%. Chestnut sprouts easily at high temperatures, and has high humidity and perishability.
The application of plastic film combined with anti-corrosion technology: chestnut water loss quality, high decay rate, so now widely used in the production of plastic film and preservatives combined with technical measures. The specific method is: the chestnut fruit is immersed in 50010↑(-6) 2,4-D and 200010↑(-6) thiophanate solution for 2 minutes, drain water, and put into a 0.06 mm thick polyethylene film bag. Stored at a constant temperature of around 0°C, it can be stored until the fifth year of June of the following year. The fruit is still full and fresh, and the good fruit rate is above 95%.
二ã€Processed products of chestnut 1 Canned water chestnut
a. Production process:
Raw material selection → raw material processing → color protection → trimming → precooking, rinsing → sorting → dispensing sugar liquid → canning → exhausting, sealing → sterilizing and cooling.
b. Process points:
Raw material selection: Choose fresh chestnut fruit without pests and mildew. The single fruit is more than 7 grams.
Raw material treatment: Put chestnut fruit in water of 95-100°C for 5-8 minutes, let cool, go to shell, then grind off lichen and yellow clothes.
Color protection: The chestnut fruit is easily discolored during processing, so the polished chestnut must be quickly put into a solution containing 0.2% salt or 0.3% citric acid. Use a small stone to remove the residue and trim the shape.
Pre-cooking and rinsing: Pre-cooking solution requires adding 0.2% potassium alum and 0.15% disodium ethylenediaminetetraacetate. The amount of pre-cooked liquid used is 2 times the weight of chestnuts. The fruit is placed in a precooking solution at 50-60°C for 10 minutes, then precooked at 75-85°C for 15 minutes, and precooked at 95-97°C for 25-30 minutes, until it is thoroughly cooked. When rinsing, first rinse in hot water at 60°C for 10 minutes, and then rinse in 40 to 50°C hot water for 10 minutes.
Sorting: Remove broken, discolored, spotted and other unqualified chestnut fruit. According to the fruit color, size classification.
With sugar solution: With 50% sugar content of sugar, while adding 0.02% sodium ethylenediaminetetraacetate to improve the chestnut color.
Canning: Glass jars need to be sterilized and then loaded with 205 grams of flesh. Add sugar.
Exhaust and sealing: Put the can into the exhaust box to heat the exhaust for 10 to 12 minutes so that the central temperature in the tank is not lower than 85°C, and then seal the can.
Sterilization, cooling: use the temperature inside the tank for sterilization. Cooling uses segment cooling.
c. Product Quality Requirements: Finished sugar canned chestnuts are light yellow or yellow, the same color in the same pot, allowing a slight browning at the seam. With the flavor of this product, moderate sweetness and no smell. The sugar water is transparent, allowing some debris that does not cause cloudy precipitation. The size of the fruit in the same jar should be uniform and the broken fruit must not exceed 10%. The weight of the chestnut fruit should not be less than 50% of the net weight, and the sugar concentration should not be less than 50%.
2 New Types of Sugar Chestnuts
a. Production process:
Raw material selection → shelling, color protection → precooking, rinsing → vacuum maceration → sugar coating, drying → coating → packaging
b. Process points:
Raw material selection: Select chestnuts that are full and fresh, each with a fruit weight of more than 6 grams, remove dry sticky and worm-eaten fruits, and divide them into two grades, big and small.
Hull protection: According to the common method of manual or mechanical shelling can be, and then use a small rub stone to greasy clothing, while grinding edge flushing. The grinded chestnut should be immediately put into a mixed aqueous solution containing 0.2% salt and 0.2% citric acid to soak and protect the color.
Precooking and rinsing: There are two methods for precooking, one is constant temperature precooking, that is, boiling in hot water at 80-90°C for 40-55 minutes; the second is preheating in stepwise heating, and firstly putting chestnut at 55°C. Cook in hot water for 10-15 minutes, cook in hot water at 75-85°C for 10-15 minutes, and finally cook in hot water at 95°C for 15-20 minutes. Both methods are available. In actual production, the first method is preferable, but the middle one is best to change the water once. When precooking, the ratio of liquid to liquid is 1:3 until it is cooked.
In order to prevent browning of the chestnut during the precooking process, the precooked chestnut must be cooked in a pre-cooked solution. Pre-cooked liquid formula: 0.25% disodium ethylenediaminetetraacetate (EDTA-2Na), 0.2% potassium alum and 0.15% citric acid. After precooking, the chestnuts are first rinsed in hot water at 50-60°C for 10 minutes and then rinsed in hot water at 40-50°C for 10 minutes.
Vacuum impregnated sugar: After the chestnut fruit is cooked, it is immersed in the sugar solution so that the sugar content gradually infiltrates. In order to reduce the time of dipping sugar and improve product taste, vacuum segmented dipping process can be used. The concentration of sugar liquid is 30% to 50% to 70%, which is incremented in turn. After vacuum-exhaust-re-evacuation-exhaust air is circulated, the sugar liquid penetrates rapidly into the fruit. The temperature was room temperature, the ratio of solid to liquid was 1:2, the vacuum degree was 53328.96 Pa, and the time was maintained at about 2 to 3 hours.
Sugar-coated and coated: After soaking the sugar, the chestnuts are placed in a concentrated sugar boiled liquid and the pan is immersed for a layer of icing on the surface. According to different needs can add a little flavor in the sugar solution, such as osmanthus soaking liquid. It is then dried in two stages. The temperature in the first stage is controlled at 40-45°C and the humidity is about 60% so that the moisture in the fruit slowly evaporates. In the second stage, the temperature rises to about 60°C. Bake to the final water content of chestnut fruit 22% to 25%. The dried sugar-coated chestnuts were added with a 1:10 peach alcohol solution in a rotary pan, and the mixture was immediately blow dried to dry.
The sugar-coated chestnuts are packed in a soft-packed composite film bag. The vacuum packaging machine is used for air-tight sealing and packaging.
The harvesting period is determined: chestnuts harvested early are susceptible to rot during storage, so chestnuts that are stored for a long time should be harvested when they are fully matured, and the stored fruits are most resistant to storage. Harvested chestnuts are placed in a cool, ventilated place for perspiration, heat dissipation, and water loss. Chestnut cracking chestnuts out, dry 5 to 7 days into storage.
Chestnut storage of the appropriate conditions: the appropriate temperature is 0 °C 0.5 °C, relative humidity of 80% to 85%. Chestnut sprouts easily at high temperatures, and has high humidity and perishability.
The application of plastic film combined with anti-corrosion technology: chestnut water loss quality, high decay rate, so now widely used in the production of plastic film and preservatives combined with technical measures. The specific method is: the chestnut fruit is immersed in 50010↑(-6) 2,4-D and 200010↑(-6) thiophanate solution for 2 minutes, drain water, and put into a 0.06 mm thick polyethylene film bag. Stored at a constant temperature of around 0°C, it can be stored until the fifth year of June of the following year. The fruit is still full and fresh, and the good fruit rate is above 95%.
二ã€Processed products of chestnut 1 Canned water chestnut
a. Production process:
Raw material selection → raw material processing → color protection → trimming → precooking, rinsing → sorting → dispensing sugar liquid → canning → exhausting, sealing → sterilizing and cooling.
b. Process points:
Raw material selection: Choose fresh chestnut fruit without pests and mildew. The single fruit is more than 7 grams.
Raw material treatment: Put chestnut fruit in water of 95-100°C for 5-8 minutes, let cool, go to shell, then grind off lichen and yellow clothes.
Color protection: The chestnut fruit is easily discolored during processing, so the polished chestnut must be quickly put into a solution containing 0.2% salt or 0.3% citric acid. Use a small stone to remove the residue and trim the shape.
Pre-cooking and rinsing: Pre-cooking solution requires adding 0.2% potassium alum and 0.15% disodium ethylenediaminetetraacetate. The amount of pre-cooked liquid used is 2 times the weight of chestnuts. The fruit is placed in a precooking solution at 50-60°C for 10 minutes, then precooked at 75-85°C for 15 minutes, and precooked at 95-97°C for 25-30 minutes, until it is thoroughly cooked. When rinsing, first rinse in hot water at 60°C for 10 minutes, and then rinse in 40 to 50°C hot water for 10 minutes.
Sorting: Remove broken, discolored, spotted and other unqualified chestnut fruit. According to the fruit color, size classification.
With sugar solution: With 50% sugar content of sugar, while adding 0.02% sodium ethylenediaminetetraacetate to improve the chestnut color.
Canning: Glass jars need to be sterilized and then loaded with 205 grams of flesh. Add sugar.
Exhaust and sealing: Put the can into the exhaust box to heat the exhaust for 10 to 12 minutes so that the central temperature in the tank is not lower than 85°C, and then seal the can.
Sterilization, cooling: use the temperature inside the tank for sterilization. Cooling uses segment cooling.
c. Product Quality Requirements: Finished sugar canned chestnuts are light yellow or yellow, the same color in the same pot, allowing a slight browning at the seam. With the flavor of this product, moderate sweetness and no smell. The sugar water is transparent, allowing some debris that does not cause cloudy precipitation. The size of the fruit in the same jar should be uniform and the broken fruit must not exceed 10%. The weight of the chestnut fruit should not be less than 50% of the net weight, and the sugar concentration should not be less than 50%.
2 New Types of Sugar Chestnuts
a. Production process:
Raw material selection → shelling, color protection → precooking, rinsing → vacuum maceration → sugar coating, drying → coating → packaging
b. Process points:
Raw material selection: Select chestnuts that are full and fresh, each with a fruit weight of more than 6 grams, remove dry sticky and worm-eaten fruits, and divide them into two grades, big and small.
Hull protection: According to the common method of manual or mechanical shelling can be, and then use a small rub stone to greasy clothing, while grinding edge flushing. The grinded chestnut should be immediately put into a mixed aqueous solution containing 0.2% salt and 0.2% citric acid to soak and protect the color.
Precooking and rinsing: There are two methods for precooking, one is constant temperature precooking, that is, boiling in hot water at 80-90°C for 40-55 minutes; the second is preheating in stepwise heating, and firstly putting chestnut at 55°C. Cook in hot water for 10-15 minutes, cook in hot water at 75-85°C for 10-15 minutes, and finally cook in hot water at 95°C for 15-20 minutes. Both methods are available. In actual production, the first method is preferable, but the middle one is best to change the water once. When precooking, the ratio of liquid to liquid is 1:3 until it is cooked.
In order to prevent browning of the chestnut during the precooking process, the precooked chestnut must be cooked in a pre-cooked solution. Pre-cooked liquid formula: 0.25% disodium ethylenediaminetetraacetate (EDTA-2Na), 0.2% potassium alum and 0.15% citric acid. After precooking, the chestnuts are first rinsed in hot water at 50-60°C for 10 minutes and then rinsed in hot water at 40-50°C for 10 minutes.
Vacuum impregnated sugar: After the chestnut fruit is cooked, it is immersed in the sugar solution so that the sugar content gradually infiltrates. In order to reduce the time of dipping sugar and improve product taste, vacuum segmented dipping process can be used. The concentration of sugar liquid is 30% to 50% to 70%, which is incremented in turn. After vacuum-exhaust-re-evacuation-exhaust air is circulated, the sugar liquid penetrates rapidly into the fruit. The temperature was room temperature, the ratio of solid to liquid was 1:2, the vacuum degree was 53328.96 Pa, and the time was maintained at about 2 to 3 hours.
Sugar-coated and coated: After soaking the sugar, the chestnuts are placed in a concentrated sugar boiled liquid and the pan is immersed for a layer of icing on the surface. According to different needs can add a little flavor in the sugar solution, such as osmanthus soaking liquid. It is then dried in two stages. The temperature in the first stage is controlled at 40-45°C and the humidity is about 60% so that the moisture in the fruit slowly evaporates. In the second stage, the temperature rises to about 60°C. Bake to the final water content of chestnut fruit 22% to 25%. The dried sugar-coated chestnuts were added with a 1:10 peach alcohol solution in a rotary pan, and the mixture was immediately blow dried to dry.
The sugar-coated chestnuts are packed in a soft-packed composite film bag. The vacuum packaging machine is used for air-tight sealing and packaging.