Dried pears processing technology points and process flow?

(1)Technological process

From raw material selection→cleaning→peeling→color protection→half-cutting→heart removal→sulfur dipping→vacuuming→sugar making→shabu-shabu→baking→finishing→finished product packaging.

(2) Technical points

①Raw material selection and cleaning. Because the fruit characteristics of the oriental pear and the western pear are different, therefore, when used for pear preserves processing, the maturity of the two are required to be different. Oriental pear flesh flavor is light, low maturity is more, and the hardness of the flesh with the increase in maturity is not much change, so it is appropriate to use the fully mature fruit. And the western pear fruit slightly ripe, its fruit flavor that is rich and pleasant, and fully ripe when the flesh is easy to become soft. Therefore, the harvest is not easy to fully mature. After the fruit harvest, the fruit can be divided into two or three according to the size, remove disease, insect, injury fruit.

②Peeling, color protection, cutting and heart removal is the same as canned duck pear with sugar water.

3 dip sulfur. The purpose of dipping sulfur is to protect the color. Producing raw materials in the process of not only more contact with the air is prone to enzymatic oxidative browning, and the sugar solution in the high content of reducing sugar, high temperature processing time is long, so it is also easy to carbonyl ammonia reaction caused by non-enzymatic browning. The color protection treatment in the previous section can only control enzymatic oxidative browning, but not non-enzymatic browning. Sulfur dioxide on the two types of browning are very good control, and sterilization effect is better, the production of dried process is generally used to prevent browning of raw materials for high concentration of sulfur treatment. Pear blocks can be soaked in 1% to 2% sodium bisulfite solution for 15 to 20 minutes, fished out and drained; also available sulfur fumigation method, 0.3% of the fruit weight of sulfur fumigation for 2 hours.

④Pumping. Pear block cell gap contains more air, accounting for about 15% to 20% of the volume of the fruit block, the process is not only easy to cause oxidative browning, but also affects the speed of sugar seepage.

Therefore, it is best to evacuate before the sugar system. Pumping treatment also helps to improve the fullness of the product. Flesh tissue softened by heat after the air escapes, the volume of fruit is bound to shrink accordingly, and thus is not conducive to maintaining the fullness of the product; and evacuation of the fruit, in the case of fruit tissue has not been softened out of the air, instead of sugar can maintain the original volume, so help to improve the fullness of the product. When evacuating, submerge the pear pieces in 30% sugar solution (add 0.1% citric acid), and keep 7997 Pa vacuum for 2 to 3 minutes. Soak for 1 to 2 hours after breaking the vacuum.

5 Sugar preparation. The purpose of sugaring is to penetrate the sugar into the interior of the fruit pieces, and the method of multiple cooking is often used.

First cooking: put the evacuated pear pieces into 40% sugar solution (add 0.15% ~ 0.25% citric acid), boil for 10 minutes, together with the sugar solution poured into the tank, soaked for 12 hours.

The second cooking: the concentration of sugar solution to 60%, together with the pear pieces boiled for 10 minutes, also poured into the tank, soaked for 24 hours.

The third cooking: the concentration of the sugar solution to 70%, together with the pears boiled for 10 minutes, poured into the tank to wait for the temperature to drop a little for the next process.

Currently the production of dried fruit has begun to apply the vacuum cooking method. This method is the use of low pressure under the boiling point of sugar to reduce the principle of low-temperature cooking, can reduce the destruction of nutrients due to high temperature; cooking process repeatedly change the vacuum or pressurization, in order to promote the penetration of sugar to the fruit block; with the evaporation of water in the process of cooking, the concentration of sugar solution gradually increased. The whole cooking process can be shortened to about 1 hour. This method of cooking, not only product quality, and because of the short process time, easy to realize continuous, mechanized production.

Regardless of the cooking method, the process should pay attention to the following two issues: First, add an appropriate amount of citric acid in the sugar solution to ensure that the sucrose conversion rate of about 40%, thus preventing the finished product "back to the sand", while the flavor is also better; Second, the concentration of sugar solution in the cooking process should be gradually increased, or else it is easy to cause the block of fruit Water seepage, affecting the fullness of the product.

6 Shabu-shabu. In the traditional process, the fruit pieces made with sugar are slowly drained of the sugar solution and then directly baked. Due to the surface of the fruit pieces are stained with thick syrup, not only leaching sugar liquid slow, and drying speed full. For this reason, you can add a "shabu-shabu" process, that is, the fruit pieces after fishing in 20% to 30% of the sugar solution gently shaken, wash away the surface of the thick syrup.

7 baking, finishing, packaging. Pear blocks in the drying room or tunnel drying equipment, control temperature at 50 ~ 60 ℃, about 20 hours, baked to the surface is not sticky until. At this time the sugar content of about 70%, water content of about 20%. After drying, after flattening and shaping, it can be bagged and packed.

The above production of dried pears is the traditional high sugar dried fruit, due to the high sugar content so that the original fruit flavor is not very prominent, health care function is also low. With the improvement of the consumption level and people's health consciousness, the call for low sugar dried fruit is getting higher and higher. Low-sugar dried fruit due to the reduction of sugar content, but also bring the product sweetness is not enough, poor fullness, poor storage and other issues. These problems can be solved in the following ways: insufficient sweetness, can add an appropriate amount of low-calorie sweetener; poor fullness, can be added to the pumping liquid or cooking sugar solution in an appropriate amount of pectin and other polymer colloidal substances; poor storage, can be vacuum-sealed packages or filled with inert gas, microwave or radiation sterilization treatment after packaging.