Study Of Preservative And Fresh-keeping Effect Of Ginger Extract On Fresh-cut Apple

In this paper, to find a safe and edible fresh-keep and preservative to fresh-cut apples, thered Fuji apple （Malus domestica Borkh. cv.‘Red Fuji’） as test materials, the preservative andfresh-keeping effect of ginger extract and its adible composite films on fresh-cut ‘Red Fuji’apple were studied. Firstly, the ultrasonic extraction technology and best conditions of gingerflavonoids was optimized with the RSM （Response Surface Method） under this experimentenvironment. Then the effect of different concentration of ginger extract on fresh-cut ‘RedFuji’ apple was researched and the best concentration of ginger extract was be screened.Finally, the effect of presrevative of edible composite films on fresh-cut apple was beenstudied and the optimal combination was been determined.The primary conclusions were as follows:1、 On the basis of single factor experiment, the five factors and three levelsBox-Behnken central composite was been designed to explore the optimal extractionconditions of ginger total flavonoids. The regression equation between response value andfactors as follows:Y＝7.38860－1.95000X1－0.00337500X2－0.067152X3－0.007875X4－0.079662X5＋0.0475X₁X₄＋0.000492157X₃²＋0.000508824X₅²Through the significant inspection, the variance of the model p=0.0002<0.01, thecorrection coefficient R2=0.9998, the quadratic polynomial model was showed had a highdegree of feasibility and a good of test fitting degree. The optimum extraction parametersunder the experimental conditions were: material ratio1:30（mL:g）, the ethanol concentration70%, temperature80℃, frequency90Hz, extraction time60min.2、The effect of ginger extract on preservation of fresh-cut ‘Red Fuji’ apple wasresearched under immersing process with different concentrations, and physiological-qualityindexes and microbial dynamic change were determined during the storage period. The resultsshowed that: the respiratory rate and ethylene release quantity were significantly delayed. Theweightlessness rate and the loss of acid titration were significantly reduced. The PPO activityand the accumulation of MDA were effectively inhibited. Combined with sensory quality thatfuzzy evaluation, the best preservation effect was the0.1g·ml^-1(the effective content of flavonoids was19.947mg.g^-1) ginger extract.3、Four treatments of sterile distilled water （CK₁）,1%sodium alginate （CK₂）,0.5%sodium alginate+0.1%ginger extract （A）,1%alginate sodium+0.1%ginger extract （B） wereset to study the effect of edible composite film on the fresh-cut apple. The results showed that,compared with CK₁, the quality of fresh-cut apple was been improved significantly and theshelf-life was extended effectively by the coating.Specifically, the A and B processing better than only the handling of sodium alginatecoating on prevent transpiration, maintain hardness, lower browning degree, reduce the lossof nutrients, inhibition PPO activity and the accumulation of harmful derivatives MDA,reduce microbial infection. The worst effect of the fresh-cut apples was sterile distilled waterprocessing. In the late of the storage, judged by fuzzy mathematics sensory evaluationmethods to different processing fresh-cut apple, optimum edible coating combination was1%sodium alginate+0.1%ginger extract.