【作者】 赵艺泽；

【导师】 屠康；

【作者基本信息】 南京农业大学 ， 食品科学， 2005， 硕士

【摘要】 以两种中晚期成熟的苹果品种,金冠(Malus domestica Borkh.,cv.Golden Delicious)和红富士苹果(Malus domestica Borkh.,cv.Fuji)为材料,探讨38℃,72h或96h热空气处理对不同品种苹果贮藏品质的影响,以及采后热处理对苹果贮期主要病害——青霉病和灰霉病的控制。 1.实验一主要研究热水和热空气处理两种方法对红富士苹果苹果贮藏品质的影响。结果表明,45℃或50℃热水短时处理对苹果采后品质影响不明显。而高于42℃热空气处理24h以上容易造成果实热伤害。38℃热空气处理72h或96h的处理条件对于苹果果实是适宜的。 2.采用38℃,72h或96h热空气处理能有效保持金冠和红富士苹果的贮藏品质。经过16周0℃的冷藏期后,与对照组相比,热处理组的苹果果皮褪绿较快,颜色较黄,失重率较高,叶绿素浓度较低,果实糖酸比上升,果汁pH值较高,呼吸强度和乙烯释放量保持较低水平。冷藏期间,热处理苹果的硬度较高,其可溶性果胶低于对照组,而不溶性果胶含量高于对照。可溶性蛋白和热稳定蛋白含量下降缓慢,热稳定蛋白含量在可溶性蛋白中所占比例较高。热处理可以较好地保持果肉细胞膜稳定性,MDA积累较少。货架期后热处理组苹果具有较好的外观品质和内在品质。 3.采用38℃热空气处理能有效抑制扩展青霉(Penicillium expansum)和灰葡萄孢(Botrytis cinerea)的孢子活性和菌丝生长。灰葡萄孢热敏感度较高,B.cinerea孢子38℃热处理48h即能完全抑制孢子萌发,热处理72h的B.cinerea平板均无菌丝生长。P.expansum的孢子活性和菌丝生长随热处理时间的延长而明显减缓。热处理后的霉菌孢子在苹果果实内生长缓慢,热处理72h的B.cinerea孢子在苹果中的生长完全受抑制,腐烂发生率为零。P.expansum热处理72h后才能显著抑制苹果的腐烂发生。苹果接种霉菌后再进行热处理(38℃,96h),无论是0℃还是20℃下放置,均未发现腐烂,显著减少贮期灰霉病和青霉病的发生。更多还原

【Abstract】 Apple fruits (Malus domestica Borkh., cv. Golden Delicious and Fuji) were treated by postharvest heat treatment, the effects of postharvest heat treatment on quality and controlling main diseases of apple fruits during cold storage were focused on.1. The effect of hot water treatment and hot air treatment on the quality of apple fruit was discussed firstly. Fuji apples were immerged in hot water at 45 ℃ or 50℃ for short time. There had no obvious effect of hot water treatment on the quality of fruits during cold storage. Apples were easily suffered heat damage when air temperature were higher than 42 ℃. Hot air treatment could maintain postharvest quality of apple fruit treated at 38℃ for 72h or 96h.. After shelf life, heated fruits were firmer and had a better apparent quality, compared with unheated fruits.2. Hot air treatment could maintain postharvest quality of Golden Delicious and Fuji apple fruit treated 72h or 96h at 38℃. After 16 weeks of cold storage at 0℃, heated fruits had a yellower pericarp at the end of the 16 weeks storage and a higher solids/acid ratio and juice pH, a lower respiration rate and ethylene production as well, compared with unheated fruits. Firmness of heated fruits were much higher,; soluble pectin content were lower and insoluble pectin content were higher than control. Soluble protein and heat-stable protein descended slowly, and the proportion of heat-stable protein/soluble protein were much higher. Heat treatment could maintain cell membrane stability preferably, and malonaldehyde accumulated less. After shelf life, heated fruits were firmer and had a better apparent quality.3. Mycelial growth and spore germination of Botrytis cinerea and Penicillium expansum were efficiently controlled by hot air treatment. B. cinerea is much sensitive than P. expansum under heat stress. Spore germination of B. cinerea suspension was completely inhibited for 48h at 38℃, and no mycelium grown in PDA plates for 72h at 38℃. Spore germination and mycelial growth of P. expansum were distinctly slowed to length ofexposure time. Heated spores germinated slowly when inoculated into Fuji apple fruit. Fruits inoculated with B. cinerea spores heated for 72h were found no decay, inoculated with P. expansum spores were found controlled decay distinctly, though the decay incidence was high. Heating apple fruit inoculated with fungi for 96h at 38℃ completely inhibited decay development, whether incubated at 0℃ or 20 ℃, compared with unheated inoculated control fruit.更多还原