Study On Microwave-Pretreated Processing Technology Of Onion Wine And Onion Vinegar

Onion (Allium cepa L.) belong to Allium herbs plant, rich in nutrients, have flavonoids, phenylpropanoids, sulfur compounds, prostaglandins and other physiological active substances. Onion are capable of reduction of blood clots, lowering blood pressure, lower blood pressure, reduce atherosclerosis, sterilization treatment of dysentery, healing, skin ulcers and inhibit tumor formation and proliferation of other physiological functions, and was called the "queen of vegetables." At present, onion cultivation throughout the world, but little onion were deep-processed, the mainly reason is onion smell limited it development. In this paper, the quality of microwave treatment on onion were researched ,and microwave pre-treatment processing of onion wine and onion vinegar were studied, onion wine and vinegar antioxidant active were also studied , onion wine and vinegar aroma components were analyzed .Main results are as follows:1.Onion microwave drying curve is the typical exponential curve. The drying mathematical model accords with Page formula. With the microwave power increases, the color and organization of onion were deterioration. The onion quality were better at low microwave power, the color and organizational status of onion under a good state in 119W and 231W power, and the rehydration ratio were 4.87 and 4.67. Microwave treatment can limit onion malodorous odor significantly.2. The onion wine was palatable when onion was treated 20minute under microwave with 539w. The optimal fermentation parameters are as follows: fermentation temperature 25℃,yeast bacillus inoculation quantity 0.84% and fermentation time 48h. Under these optimized conditions, the alcoholic content of onion wine is 9.7% and the flavone extraction rate of onion wine is 65.12%. Onion vinegar quality was better by submerged fermentation, and acid transfer rate is 69.6%, the flavonoids extraction rata is 51.58%.3. The antioxidant test showed that onion wine and onion vinegar has strong antioxidant capacity, and related with the content of flavonoids. 1ml of onion wine and onion vinegar have similar DPPH scavenging rate, clearance rates were 95.9% and 95.81%; 2ml of onion wine on hydroxyl radical scavenging rate of 92.68%, onion vinegar was 72.13%;, onion wine reduction capacity was better than onion vinegar in reducing capacity. 4. The substances of onion wine in types and content have great change under aging before and after. It mainly compounds as the content and kind of esters increasing , the kind of sulfur compounds reduced, the content of alcohols and acids decreases and it type increase. onion wine after aging flavor content of esters 48.3%, alcohols 28.01%, carboxylic acids 10.11%, the characteristics types of sulphide of onion wine was reduced from 14 to 8 . After aging, the onion wine were palatable.5. Onion vinegar aroma is mainly ester 28.61%, sulfur compounds 1.21%, alcohol 12.8%, carboxylic acid 49.71%. The sulfur compounds are substantially lower after acetic acid fermentation, and can improve the acceptability of onion vinegar.