预处理对增加红富士苹果细胞壁物质降解和出汁率的影响

为了通过简便易行的预处理增强果实细胞壁物质降解,提高苹果果实出汁率。文中测定了500mg/L乙烯利(E_1)和100mg/L乙烯利配合60℃热水(E_2)处理,对红富士果实堆放期细胞壁酶活性、细胞壁物质含量和出汁率的影响。结果表明:E_1使其果胶甲酯酶(PME)、纤维素酶(CS)活性高峰分别比对照提前6、3d,多聚半乳糖醛酸酶(PG)活性在前15d持续高于对照,木聚糖酶(Xyl)活性基本不变;处理12d后,果实细胞壁多糖中果胶类多糖、半纤维素类多糖和细胞壁残渣多糖含量分别下降到对照的80.1%、70.4%和75.7%;处理后9～18d,红富士苹果的出汁率较对照提高2.3%～4.0%;E_2抑制了果实PME活性,却普遍增强了0～6d内PG、Xyl、CS活性,亦促进了各类细胞壁物质的降解,0～9d内果实出汁率较对照高3.2%～7.1%。

Effect of Pretreatment on the Degradation of Cell Wall and Juice Yield of Red Fuji ＇Apple

In order to enhance the degradation of cell wall and increase the juice yield through easy-operated pretreatment, 'Red Fuji' apple were treated with two sets of selected conditions;500 mg/L Ethylene(E1 ) and 100 mg/L Ethylene plus 60℃hot water(E2).Cell wall metabolism related enzymes,cell wall compositions and juice yield were measured.The results showed that E1 had stronger effect on ' Red Fuji' apple.The activ peak of pectin methylesterase(PME) and cellulase(CS) of ' Red Fuji' apple appeared 6d and 3d earlier than the control,respectively. The activity of polygalacturonase(PG) increased obviously than control till the 15th day.The activity of xylanase (Xyl) was essentially the same.After 12d later,the contents of pectin polysaccharides,hemicelluloses polysaccharides and cell wall material residue polysaccharides decreased to 80.1%,70.4%and 75.7%of the control and juice yield from ' Red Fuji' apple was 2.3～4.0 percentage higher than the control after 9～18 days.E2 inhibited PME activity,enhanced PG,Xyl,CS activity and increased degradation in most cell walls than the control.E2 gained 3.2%～7.1%higher of juice yield than the control during 0～9 days.