Study On Low Sugar Blueberry Preserved Processing Technology And Preservation

Blueberry (Semen Trigonellae) is blue fruit cranberry collectively, belongs to Ericaceae, Vaccinioideae, Vacciniodeae, deciduous thickets. Blueberries belongs to the berries, skin color is blue or violet, looks bright, peel surface bag is a layer of white fruit powder, round fruit shape(most of them are pentagon),each of the fresh blueberry weight is1.5-2.5g,seed is small and tastes soft. It not only has the proper flavor rate of sweet and sour, but also contains healthy material which is rich beneficial to human beings, and has the rich fiber, anthocyanins, tannic acid and folic acid, which can resist oxidation and antibacterial, that is the reason to be known as "the king of berries". Blueberry can be sold as fresh fruit, also can be processed into fruit juice, wine, jam and many other kinds of processing products.This experiment chose blueberry as raw material to develop low sugar blueberry preserved fruit, after the ex-processing of raw materials (heat treatments, protect color and sclerosis), filler selection and collotion, permeability of sugar, the way about drying process technology and blueberry fruit preservation research. This is the following results:1.Choose raw materials→lean→Heat treatment→Protect color and Hardening→Vacuum permeability sugar→Sugar-dipping→Low temperature leaching sugar→Drain in a colander→Dry→Reshaping→Packaging→Sterilize→Product2. Using steam iron float to make pretreatment, can greatly improve the preserved fruit permeability sugar rate, reduce the loss of VC. The test results show that the best heat drift process is:vapor,90s, directly boil after heat float, can make the maximum limit reduced VC the loss, storage rating can achieve to27.05%.3. Blueberry belongs to the berries, so after heat treatment and addition of suitable amount of stiffening agent and color fixative, it can not only prevent erosion, improve sensory quality, but also can prevent browning, and keep the blueberry bright color and luster. The test result shows that the best hardening process is:0.4%8-glucose acid ester,4h. The best protective coloration is:2.0%VC solution.4. During the process of vacuum permeability sugar, vacuum degree, pump down time, and temperature of permeability sugar can make the influence on permeability sugar speed, the result shows that the best vacuum permeability sugar conditions is:vacuum0.085MPa, pump down time is40min,60℃temperature, then permeability can achieve to16.9%.5. Add filler can make preserved fruit appears full, improve the quality of the preserved fruit senses, the result shows that the best filler is:0.5%gelatin+0.5%CMC-Na (proportion:1/1).6. After comparing3methods of wind drying, vacuum drying, and microwave drying,it is found that after vacuum drying,fruit sensual evaluation is the highest, the test shows that the best dry conditions is:in the vacuum0.085MPa, the temperature of60℃dry for4h. 7. Addition of appropriate amount of appropriate hydrophilic materials can reduce Aw values; the study shows that when Aw<0.65, microorganism growth and breed will be inhibition. Through the comparison of the hydrophilic matter concentration and Aw values, the experimental result shows that the best hydrophilic substance is:0.25%lactic acid sodium solution.8. Microwave sterilization can prolong the preservation period of preserved fruit, so as to improve the quality of the fruit, through the different microwave irradiation sterilization time comparison, the result shows that:the microwave20s, the aerobic bacterial count can achieve National Health Standards.