鲜切苹果生理与品质保持技术

Study on physiology and quality of fresh-cut apples

为提高鲜切苹果品质、延长货架期,研究乙醇熏蒸和高氧预处理对其生理与品质的影响。乙醇体积分数分别为200、400和600μL/L,熏蒸时间2、4 h。高氧预处理O2体积分数为95%~100%,处理时间分别为12、24和36 h。分别测定鲜切苹果在0~1℃、相对湿度90%~95%下贮藏期间呼吸速率、菌落总数、褐变度、多酚氧化酶(polyphenol oxidase,PPO)酶活力、过氧化物酶(peroxidase,POD)酶活力和丙二醛(malondialdehyde,MDA)含量,并进行感官评价。结果表明,乙醇熏蒸与高氧预处理均能够推迟鲜切苹果呼吸高峰,降低呼吸峰值。贮藏第6天后乙醇熏蒸组菌落总数显著低于对照组(P <0.05),高氧预处理在贮藏前期抑菌效果明显。在贮藏后期,乙醇熏蒸与高氧预处理组褐变度、PPO和POD酶活力均低于对照组(P <0.05)。乙醇熏蒸组MDA含量低于对照组(P <0.05),第9天后高氧预处理组MDA含量明显低于对照组(P <0.05)。乙醇熏蒸与高氧预处理组感官评分均高于对照组(P <0.05)。其中乙醇熏蒸最佳条件为400μL/L乙醇熏蒸2 h,高氧预处理最佳条件为O2体积分数为95%~100%处理24 h。结果表明,采用乙醇熏蒸与高氧预处理对保持鲜切苹果较高的生理与品质是可行的。

In order to improve the quality and prolong shelf life of fresh-cut apples,the effects of ethanol fumigation and high-oxygen pretreatment on the physiology and quality of fresh-cut apples were studied.The fumigation concentration of ethanol was 200,400 and 600μL/L respectively,with the fumigation for 2 and 4 h.The oxygen volume content in high-oxygen pretreatment was 95%-100%with the treatment for 12 h,24 h and 36 h.The respiration rate,total number of colonies,browning degree,polyphenol oxidase(PPO)activity,peroxidase(POD)activity and malondialdehyde(MDA)content of fresh-cut apples were measured,and sensory evaluation was performed during storage at 0-1℃with relative humidity of 90%-95%.The results showed that both ethanol fumigation and high-oxygen pretreatment could delay the respiration peak and reduce the peak value.And the total number of colonies in ethanol fumigation group was significantly lower than that in the control group after stored for six days(P<0.05).Moreover,the antibacterial effect of high-oxygen pretreatment was obvious in the early stage of storage. The browning degree, PPO activity and POD activity of ethanol fumigation and high-oxygen pretreatment group were all lower than the control group ( P <0.05) at the later stage of storage. MDA content in the ethanol fumigation group was lower than that in the control group ( P <0.05 ), and MDA content in the high-oxygen pretreatment group was significantly lower than that control group after the ninth day ( P <0.05). The sensory evaluation scores of ethanol fumigation and high-oxygen pretreatment were higher than those of the control group( P <0.05 ). Among which, the best condition for ethanol fumigation was 400 μL/L ethanol fumigation for 2 h, and the best condition for high-oxygen pretreatment was 95%-100% pretreatment for 24 h . So ethanol fumigation and high-oxygen pretreatment are feasible to maintain the high physiology and quality of fresh-cut apples.