1-甲基环丙烯和不同贮藏温度对油桃果实硬度与细胞壁果胶的影响

Effects of 1-Methylcyclopropene and Different Ambient Temperature on Firmness and Cell Wall Pectin in Postharvest Nectarine

以"中油13号"为试材,研究1-甲基环丙烯(1-Methylcyclopropene,1-MCP)和不同贮藏温度对油桃果实硬度与细胞壁果胶的影响。结果表明:1-MCP处理能有效地抑制常温下油桃果实硬度下降,贮藏第2 d,1-MCP处理组与未经1-MCP处理组油桃硬度分别下降12.31%和54.53%,差异极显著(P<0.01),但贮藏后期抑制效果减弱,差异不显著(P>0.05);而结合低温贮藏效果更好,贮藏至结束,1-MCP处理组与未经1-MCP处理组油桃硬度分别下降54.38%和62.96%,差异显著(P<0.05)。1-MCP主要通过影响油桃WSP半乳糖醛酸主链和阿拉伯糖支链的积累、CSP与SSP阿拉伯糖支链与半乳糖支链的分解,抑制油桃水溶性果胶(Water-soluble pectin,WSP)含量的升高与螯合性果胶(Chelate-soluble pectin,CSP)和碱溶性果胶(Sodium carbonate-soluble pectin,SSP)含量的降低,延缓油桃软化;低温主要通过抑制SSP阿拉伯糖支链与半乳糖支链的分解,减缓SSP含量降低,延缓油桃软化。油桃质地软化与果胶多糖的含量及主侧链变化密切相关,1-MCP处理和低温能有效地抑制贮藏期油桃硬度下降。

‘Zhongyou 13’was selected as the experimental material,the effects of 1-MCP and storage temperature on firmness and pectin of postharvest nectarine was researched.The results showed that,1-MCP treatment could inhibit the decline of peach fruit firmness at room temperature.At the second day of storage,the difference of nectarine hardness between the group with 1-MCP treatment and the group without 1-MCP treatment were significant(P<0.01),which were decreased by 12.31%and 54.53%,respectively.But the inhibition was declined at later storage,the difference were not significant(P>0.05).While at low temperature,the effect was better.At the end of storage,the difference of nectarine hardness between the group with 1-MCP treatment and the group without 1-MCP treatment were significant(P<0.05),which were decreased by 54.38%and 62.96%,respectively.1-MCP could delay nectarine softening by affecting the accumulation of the main chain of galacturonic and the branched chain of arabinose in WSP,the decomposition of branched chain of arabinose and galactose in CSP and SSP,thus inhibiting the decomposition of the content of CSP and SSP and the increase of the content of WSP in nectarine.While,nectarine softening could be delayed at low temperature,because the decomposition of arabinose and galactose branched chain of SSP was inhibited,thus slowing down the decrease of SSP at that temperature.Nectarine texture was significantly correlated with the content and the main side chain changes of pectin polysaccharides,1-MCP treatment and low temperature could effectively inhibit the decline of firmness at nectarine storage.