Research Of Fresh-keeping Effect Of Ginger Extract Coating Compounds On’Red Fuji’Apple

The fresh-keeping effect of ‘Red Fuji’ apple was studied by coating with gingerextract-sodium alginate, and the gingerol in ginger extract was the target product for activeingredient. Ginger extract prepared by ultrasonic assisted method, and its active ingredient-gingerol were determined. The preservation effect of ginger extract was studied through thebacteriostatic effect and the antioxidant activity of DPPH radical scavenging. In order toobtain optimum coating composition, the ‘Red Fuji’ apples were soaked in differentconcentrations of compound coating agent, and physiological indexes were measured duringthe storage period at0±1℃,The result showed:1. Ginger extract prepared by ultrasonic assisted method, and the vanillin was selected asstandard sample to determine the extraction rate and content of gingerol. Fitting byleast-square method, the linear regression equation between absorbance and vanillin contentas follows: A=0.0639C+0.0698，R2=0.9991.The yield of gingerol was7.223mg/g byultrasonic assisted method, and gingerol content was1.445mg/mL in the dope of0.2g/mLginger extract.2.The effect of DPPH radical scavenging were measured of0.02,0.05,0.1,0.2,0.4g/mLof ginger extract and20μg/mL Vc.The ability of DPPH free radical scavenging of gingerextract was increased along with the increase of concentration, and the antioxidant activity ofginger extract was proved by comparing with the Vc of20μg/mL. In order to investigate theinhibitory effect and antioxidant activity,0.05,0.1,0.2,0.4g/mL of ginger extract was used to‘Red Fuji’ apples. The results showed that the infection of pathogenic microorganisms of ‘RedFuji’ apple could be reduced by ginger extract, and the ability of DPPH radical scavengingalso could be enhanced. The inhibitory effect and the antioxidant activity of DPPH radicalscavenging was increased along with the increase of concentration. However, the inhibitoryeffect and antioxidant capacity decreased rapidly in late storage when the ginger extractconcentration was0.4g/mL, which had an unfavorable influence on the preservation of fruits.3.In order to investigate the fresh-keeping effect of ginger extract combined with sodiumalginate coating compounds on ‘Red Fuji’ apples,0.1g/ml ginger extract combined with0.5%,1.0%,1.5%concentration of sodium alginate respectively was used to be coated on ‘RedFuji’ apples, which was compared with untreated control and the sample was coated with1.0%sodium alginate, The results showed that the rate of weight loss and hardness werereduced in the treatment groups; the content of SSC、TA and Vc were better maintained. Theproduction of ethylene was inhibited and the occurrence of the respiratory peak was delayed.Also, the antioxidant activity of radical scavenging of cellular defense system of ‘Red Fuji’apple was increased by ginger extract, the MDA contents of were restrained, the activities ofPOD、CAT and SOD were increased to maintain better integrity and stability of cellmembrane. Therefore, the senescence of apples were deleted.4. Ginger extract combined with sodium alginate coating compounds treatment werebetter than the use of the sodium alginate treatment method and coating fusion liquid with0.1g/mL ginger extract and1%sodium alginate had better effect on the storage of the ‘RedFuji’ apple. Under this condition, the ‘Red Fuji’ apple also maintained a good quality whenstored105d.