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Rearch On Comprehensive Fresh Packing Of Typical Fruits And Vegetables

Posted on:2009-05-07Degree:MasterType:Thesis
Country:ChinaCandidate:Y LiuFull Text:PDF
GTID:2121360272956567Subject:Industrial Engineering
Abstract/Summary:PDF Full Text Request
Fruits and vegetables are indispensable foods to human life. But they have a high rotness due to their seasonal and regional and less developed packaging technology . Now the single packing technology likes atmosphere modified packing still has some problems and could not satisfied customers well. In this case, the integrational packing technology combined several single packing technologys. In this paper, the effects of integrationa packing technology on qualitys of products were discussed.The research work mainly included as follow:(1) The respiration rate of Lentinus edoes and Lily were measured by the close system method.The parameters of the respiration model were determined by applying the Michanelis-Menten equation. The results showed that the pretreatment and low temperature can reduce the respiration rate. The models are suitable for charactering the respiration rate of fresh-cut apples and lotus roots.(2) The Lentinus edoes was coated with 1% chitosan solution prior to different MAP type, and then was stored at a low tempreture.The effects of different packaging technologies on organoleptic test,loss of weight,content of VC and permeability of Lentinus edoes were disscused. The results showed that preservation effect could be achieved when Lentinus edoes was coated by 1% chitosan solution along with 314μm2 OPP/PE microporous membranes MAP .The treatment could extent the shelf life of Lentinus edoes to 19 days and the nutrition ,the desirable quality could be well kept.(3) Lentinus edoes was treated with different concentration ozone (3.1 ug/L 4.4ug/L) ,placed into PP hard trays and then sealed with BOPP/PE films. And the Lentinus edoes were packaged with PP hard trays with a 314μm2 microperforated in coverd films after pretreated with different concentration ozone and 1% chitosan were also investigated. Results demonstrated that MAP could extent the shelf life of Lentinus edoes to 19 days with a loss of weight below 10% and low Vc lose. But the anaerobic respiration was detected in common packaging groups , and that could be solved by using microporous MAP method .(4) The lily was packaged in different packaging film bags and then stored at different temperture .The changes of Vc, total sugar , color, loss of weight and quality of lily were studied during storage time. The results showed, low temperature storage reduced the loss of weight significantly and kept relative stability of color and total sugar, prolonged the shelf life of lily. Among different packaging materials, the PE,OPP films with high permeability had most positive preservation effect followed by OPP/PE film. Low temperature interacts well with the package.(5) The lily was treated with different concentration ozone,MAP with different original atomoshpere and packed in PE film bags. The results showed that the lily treated with ozone or MAP was better than untreated one,and the MAP groups had a shelf-life of 35d, treatment of 4.4μg/l ozone is the best one among the ozone treatment groups. Little differences were found during various concentrations of ozone treatment; all treatment effectively reduced the loss of weight and kept the nutrition of lily, prolonged the shelf life of lily. (6) The lily was treated with ozone pretreatment , coating pretreatment combine with MAP technology. The result showed this method could keep the color and the quality of the product well compared to single packing method.
Keywords/Search Tags:Comprehensive fresh packing, MAP, Ozone, Coating, Lentinus edoes, Lily
PDF Full Text Request
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