Study On Nutritional Quality And Safety Of Chinese Onion Leaf Sauce By Ultra-high Pressure Treatment

ZhangQiu’s chinese onions have many protein,amino acids,vitamins andminerals.In addition also contain "Selenium",they are also known as "se onion"at thelocal.Green onions contain such a high nutritional content, but people generally onlyeat light blue with some chinese onions, and chinese onion leaves often discarded.Butin fact they have same nutrients,and chinese onion leaves even have more nutrientsthan the part of light blue.In this paper, been discarded onion leaves as raw material, the main content andresults of the study are as follows:1.Effect of HPP on chinese onion leaf sauce’s physical and chemical propertiesWith the increasing high pressure and the increasing dwell time,the chineseonion leaf sauce’s pH declined, but the decline is not obvious.This phenomenonindicates that sample’s H+are increased after treatment.The sample’s total sugarcontent and total acid are decreased slightly with increasing pressure.But the changeis not obvious.Sauce of chinese onion leaves’s soluble solids in contrast to the originalblank sample was increased.When the pressure rises to400Mpa,the chinese onion leafsauce’s soluble solids increased slowly.Compared to heat treatment,HPP can betterprotect the color of the sample than the heat treatment,sample’s browning reduced.2.Effect of HPP on onion leaf sauce’s nutritional qualityChinese onion leaf sauce’s protein reduced with the pressure’s enhanced andtime extended.But the rate of decrease is not large.Chinese onion leaf sauce’s solubleprotein decreased with increasing temperature.As the temperatureincrease,protein’decrease apparently.Chinese onion leaf sauce’s Vc preservation rate is decreased with the increasinghigh pressure and the increasing dwell time.When the pressure is400Mpa,time are5min and10min,the Vc preservation rate appeared a small peak.When the timeare15min and20min,the pressure is400Mpa,the Vc preservation rate decreased.Thesample’s Vc preservation rate lost severely in the heat treatment.When the pressure less than200Mpa,the chinese onion leaf sauce’s POD andOPP’s ac tivities are increased with the pressure’s increased.But when the pressureabove200Mpa,the activity of both enzymes showed a significant decreased with the pressure increased.When the pressure is400Mpa,the activity of both enzymes reducedsignificant.3. Effect of HPP on onion leaf sauce’s chlorophyllAccording to the orthogonal analysis,the most significant factor in the extractionof chlorophyll is the extraction time,the best combination of extraction is A2B3C1.Thesolid-liquid ratio is1:30,the temperature is50℃,extraction time is5min.According to the orthogonal analysis,the order of significant factor is A>B>C,Ais the pressure,B is the time,C is the temperature,the best treatment combination isA2B1C2.4.Effect of HPP on chinese onion leaf sauce’s sterilizationAccording to the orthogonal analysis,the pressure(A) is the best significantfactor,When the pressure is higher than400Mpa,the HPP treatment can make thesample’s total number of colonies less than100cfu/g.In line with national commercialsterility requirements.When the pressure above300Mpa，we can not check the E.coliin the sample.The best of sterilization program is A3B1C3.When the pressure is300Mpa or400Mpa,the high pressure can kill the most of the sample’smicroorganisms.The sample’s microbial growth will be very slow during storage.As aresult,HPP can effectively extend the preservation of the sample.