Processing Technology of Sulfur-free and Low-sugar Preserved Apricot

Yanggao Jingxing apricot, one of the four famous apricots in Shanxi province, has a single fruit mass of 34.8 g, contains vitamin C 10.4 mg/100g, refractive sugar 13.1%, reducing sugar 4.7%, and acid 2.4%. This variety is the best variety of processed preserved apricot, which has the advantages of strong aroma, low nucleation rate and high acid content. Yanggao preserved apricot is golden and transparent in color, soft in meat, sweet and sour and delicious. It is the best preserved fruit. The products have been exported to Southeast Asia and Japan, and are known as "Chinese precious snacks" and "small golden persimmons" in Japanese supermarkets. Yanggao preserved apricot is a new local product that local people like to talk about. it has won gold medals in Hangzhou, Beidaihe and Taiyuan.

In recent years, with the development of society and the improvement of living standards, people pay more and more attention to the nutrition and health function of food, and pay more and more attention to the safety and hygiene of food. As the sugar content of traditional preserved fruit is high, which can be as high as 70%, it is very disadvantageous to people who are not suitable for sugar intake, such as diabetes. In addition, the product quality of preserved fruit processing enterprises is mixed, resulting in sulfur dioxide in many preserved fruit on the market seriously exceeding the standard, causing damage to the human body. After a large number of experiments and using more advanced equipment and technology, we have developed sulfur-free and low-sugar preserved apricot. In production, sodium chloride is used instead of sulfur dioxide solution as color protection agent, which greatly reduces the residual sulfur dioxide in the product, and the advanced vacuum sugar infiltration technology not only improves the sensory quality of the product, but also reduces the sugar content. In view of the problems existing in the storage of low-sulfur and non-candy preserved apricot, vacuum nitrogen-filled packaging was adopted, which greatly increased the shelf life of low-sulfur and low-sugar preserved apricot and raised the outer packaging of the product to a higher level. In the whole production process of preserved apricot, the introduction of HACCP system control and the establishment of the corresponding HACCP management system can effectively improve the food quality and safety of preserved apricot products. The preserved apricot processed by this process fully meets the requirements of national food hygiene standards and is a kind of snack food in line with modern consumer fashion.

1. Raw materials and equipment

(1) raw material Yanggao false Beijing apricot, cotton white sugar and refined salt, etc.

(2) equipment sandwich pot, vacuum sugar permeation tank, hot and cold cylinder, drying room, steam boiler, hand-held sugar meter, vacuum nitrogen packing machine, baking pan and Baume sugar meter, etc.

two。 technological process

Apricot → sorting →, impurity removal, → weighed → cut flap →, core digging, → color protection, → draining, → blanching, → vacuum sugar infiltration, → drawer, controlled dry → plate, → baking, → out of the room, → reshaping, →, secondary baking, →, →, reshaping, → pruning, ultraviolet irradiation, sterilization, en20# vacuum nitrogen filling packaging finished product inspection storage.

3. Key points of operation

(1) preserved apricots must be taken from good raw materials, and special attention should be paid to the selection of raw materials. Apricot fruit is required to be fresh and full, moderate maturity, no moth, no hard injury, no spots, no hail. The most suitable apricot fruit for processing Yanggao preserved apricot is pseudo-Beijing apricot with a diameter of more than 3cm, a single fruit mass of 35g, containing vitamin C 10.37 mg/100g, total acid 2.41%, dry matter 14.26%, and the best maturity of 90%.

(2) the raw materials purchased by sorting are sorted first, the green and overripe ones are singled out, the hard green apricot is made into sugar apricot, the soft ripe apricot is roasted as dried apricot, and other mixed varieties of apricot are treated separately. After weighing, use a cutter to dig the core, and all apricot fruits harvested on the same day should be disposed of on the same day.

(3) the apricot bowl was soaked in 1% sodium chloride solution to prevent enzymatic browning, protect the color of apricot bowl, and inhibit the activity of microorganisms, and the soaking time was about 15min.

(4) the sugar solution of 17 °be'~ 19 °be 'was prepared by vacuum impregnation and placed in a stainless steel sandwich pot with a capacity of 400L. The volume of sugar solution should not be too full, and it is appropriate to account for 2 to 3 of the volume of the sandwich pot. Put into the high-pressure steam of 0.15MPa~0.20MPa and heat the sugar liquid. After the sugar solution boils, pour into the apricot bowl that protects the color and drains. The amount of apricot bowl treated each time is 20kg~30kg. Continue to heat and cook until the tissue of the apricot bowl softens (squeeze softly by hand). When the apricot bowl floats on the surface of the water, it can be removed and sent into a vacuum sugar infiltration jar. In a 500L vacuum sugar permeation tank, the apricot bowl can be treated with about 200kg each time. Vacuum to 0.06MPa~0.08MPa and keep 20min~30min. Then pressurize it to 0.15MPa~0.20MPa. After restoring the normal pressure, out of the jar into the tank, and then soak the 24h~72h with sugar solution, remove it and bake it in a drawer.

(5) remove the apricot bowl soaked in sugar for the second time from the jar and put it on the dry drawer to control the moisture. After the apricot bowl is dried, the apricot bowl is placed downwards to remove the boiled and broken apricot bowl, and the apricot bowl must not be damaged.

(6) Baking put the baking pan with the apricot bowl on the grill and send it into the baking room for baking. The baking temperature entering the roasting room must be above 50 ℃ to avoid apricot bowl softening and browning. During the baking process, the temperature of the baking room should be kept at 60 ℃ ~ 70 ℃. The baking time lasts 24 hours. Pay attention to dehumidification at any time when baking. Normally, it takes 4 times per hour and 5 times per hour. Baked preserved apricot generally does not need to turn the plate, baking until the moisture content of preserved apricot is reduced to less than 20%, in order to non-stick hands. After getting out of the room, the apricot bowl was resurrected for 2 ~ 3 days, and the impurities attached to the preserved apricot were removed. The apricot bowl was squeezed into a piece by hand and sent to the baking room for the second baking. The temperature of the baking room is kept at 55 ℃ ~ 60 ℃, and the baking time is about 18 hours, until the apricot slices feel elastic when they are pinched by hand, and you can leave the room when the moisture is reduced to 17% to 19%. After 1-3 days, the finished product will be reshaped. The temperature of the roasting room is high, the fire is urgent or the baking time is too long, which will make the color of preserved apricot darken, darken and lower the grade.

(7) before inspection and packaging, the preserved apricot after pruning and shaping and the packaging materials such as moisture-proof paper and cartons used for packing shall be irradiated and sterilized with ultraviolet lamp, and then can be packed separately. In order to ensure the storage quality of sulfur-free and low-sugar preserved apricot, the product had better be packed with vacuum nitrogen. Before packing, preserved apricots should be inspected in strict accordance with quality standards, cut off spots, hard scars and lace, remove miscellaneous colors or flakes and other unqualified products, put them in polyethylene environment-friendly plastic boxes, 150g in each box, add fruit forks and label them, and pack them after the factory date.

4. Quality requirement

(1) sensory index ① color standard. The first grade is orange, the maximum diameter of each tablet is not less than 2.5cm; the second grade is dark tangerine, with a small amount of pan-green tablets, and the maximum diameter of each tablet is not less than 2.3cm. ② taste and taste. Apricot fragrant, sweet and sour palatable, no peculiar smell, good taste. ③ histological morphology. Rich meat, no crude fiber, soft appearance, enucleated with skin, flaky, natural and clean epidermis, no wound, no scar, no wrinkle, translucent, no soup, no sand, no broken, no cracked skin, uniform and neat pieces, no moth.

(2) the total sugar content of the physical and chemical index is not less than 50%, the maximum residual amount of sulfur dioxide is not greater than 50mg/kg, moisture is 17%-19%, contains acid 2.78%, vitamin C3.6 mg/100g, copper is not more than 5mg / kg, arsenic is not greater than 0.1mg/kg, lead is not greater than 1mg/kg, benzoic acid and saccharin sodium can not be detected.

(3) the total number of microbiological index colonies is not more than 400 / g, the number of molds is not more than 25 / g, and the number of coliform bacteria is not more than 15 / 100g. Streptococcus aureus, Shigella and salmonella can not be detected.

(4) the pesticide residue is not more than 0.05mg/kg and DDT is not more than 0.05mg/kg.