【作者】 曲凤静；

【导师】 李丽萍； 韩涛；

【作者基本信息】 北京农学院 ， 果树学， 2008， 硕士

【摘要】 本文“大盖”柿(Diospyros kaki L..)和“大久保”桃(Prunus persica L.)果实为试验材料,分别研究了不同浓度乙醛熏蒸处理对果实软化及相关生理生化指标的影响,通过果实品质指标的分析,确定适宜的乙醛处理浓度。同时,以柿果实为试验材料,以不同浓度乙醛复配10 ml/kg乙醇,观察其对果实软化及相关生理生化指标、品质的影响。结果表明:(1)乙醛处理能够在一定程度上延缓柿果实软化,其中以10 ml/kg处理的果实硬度最好,对果胶及多聚半乳醛酸酶及β-半乳糖苷酶活性的影响不明显;5、10 ml/kg处理果实的果胶甲酯酶活性高于其他处理。乙醛处理能够延缓柿果实不溶性单宁转化为可溶性单宁,但对可溶性固形物和原花青素没有影响。(2)在2个贮藏温度下,适当浓度的乙醛处理能使桃果实保持较高硬度、较低呼吸强度,并降低果实可溶性果胶含量。室温条件下,经0.5 ml/kg和2 ml/kg处理的果实多聚半乳醛酸酶活性(PG)低于对照及1 ml/kg处理;各浓度处理有提高果实果胶甲酯酶活性(PE)、降低β-半乳糖苷酶活性(β-GAL)的趋势;乙醛处理对桃中的糖和酸的影响不大,在0.5 ml/kg和1 ml/kg处理浓度下加快了果实的失重。0℃下,乙醛处理后果实多聚半乳醛酸酶活性(PG)及果胶甲酯酶活性(PE)与对照无明显差异,经1 ml/kg和2 ml/kg处理果实β-半乳糖苷酶活性(β-GAL)高于对照及0.5 ml/kg处理,但差异不显著;经乙醛处理的果实可溶性固形物高于对照,总酸低于对照,1、2 ml/kg浓度处理使果实失重增加。(3)乙醇:乙醛= 1:2混合处理对柿果实的硬度保持有明显的效果,其他处理间差异不显著,乙醇及混合处理对柿果实的可溶性固形物、原花青素及原果胶的含量影响不明显,可溶性果胶含量在乙醇:乙醛= 2:1处理和乙醇:乙醛= 1:1处理中高于其他处理,β-GAL酶活性在乙醇:乙醛= 1:2处理高于其他处理,但差异不显著;不溶性单宁含量在混合处理中乙醇:乙醛= 1:2处理要高于乙醇:乙醛= 2:1处理。更多还原

【Abstract】 In this paper, the effects of acetaldehyde on fruit softening and its related physiological changes in“Dagai”persimmon (Diospyros kaki L..) and“Okubao”peach (Prunus persica L. Batsch. cv. Okubao) were investigated. The combinations of ethanol (10 ml/kg) in various ratios to acetaldehyde in persimmon were also observed. The results were as follows:1. The acetaldehyde treatments, to some extent, delayed fruit softening in persimmon, the concentration in 10 ml/kg showed the best. The acetaldehyde treatments had no obvious effects on pection contents, activities of polygalacturonase andβ-galactosidase, the PE activities in 5,10 ml/kg fruits were higher than in 0 and 2 ml/kg. The changes of insoluble tannin to soluble tannin were delayed, but the contents of soluble solids and proanthocyanidins were not influenced by the acetaldehyde treatments.2. The appropriate concentrations of acetaldehyde treatments kept higher firmness or lower respiration rates of peach fruits than control, and decreased the soluble pectin contents of fruits both at room temperature (20℃) and 0℃. At 20℃,the activities of PG in fruits with 0.5 ml/kg and 2 ml/kg acetaldehyde were lower than those in control and 1 ml/kg fruits. The acetaldehyde treatments tended to increase PE and decreaseβ-galactosidase activities, and had little effect on contents of soluble solids and titratable acid. At 0℃, there were no obvious differences on activities of PG, PE, orβ-galactosidase among acetaldehyde fruits and control, the soluble solids contents were higher, or the titratable acid contents were lower in treated fruits.3. The combined treatment in ethanol: acetaldehyde = 1:2 had significant effect on the maintaining flesh firmness in persimmon, and the other ratio combinations showed no obvious diffenences. The treatments of ethanol and its combinations with acetaldehyde had little effect on the contents of soluble solids, proanthocyanidins and insoluble pectin, soluble pectin, theβ-galactosidase activities in fruits.更多还原