两个鲜食核桃品种冷藏期间生理特征变化研究

Study on Physiological Characteristics Changes of Two Fresh Walnut Varieties during Refrigeration Period

摘要:

为筛选耐储性好的鲜食核桃品种，以西岭、早硕核桃为试材，采用厚度0.33 mm聚乙烯袋包装，在(0±1)℃条件下，定期对两个核桃品种的褐变指数、腐烂指数、SOD活性、POD活性和MDA含量等指标进行分析。结果表明，早硕含水量、不饱和脂肪酸含量高于西岭。在贮藏期间，两个品种青皮率逐渐上升，出仁率和好果率逐渐下降；两个品种间脂肪、蛋白质含量差异极显著(P<0.01)，西岭脂肪含量逐渐升高，早硕脂肪含量变化并不明显；西岭蛋白质含量在60 d左右开始消耗，早硕在20 d开始消耗；POD、SOD活性先升高后降低；MDA含量先降低后升高。试验表明，在(0±1)℃条件下，西岭更耐贮藏，最佳贮藏期为40～60 d，早硕贮藏期在20～40 d。

Abstract:

To screen fresh walnut varieties with good storage tolerance, ‘Xiling’ and ‘Zaoshuo’ walnuts were used as test materials. The walnuts were packaged in 0.33 mm thick polyethylene bags and stored at（0±1） ℃, with regular determinations of browning index, rot index, superoxide dismutase（SOD） activity, peroxidase（POD） activity, and malondialdehyde（MDA） content. The results showed that the water content and unsaturated fatty acid content of ‘Zaoshuo’ were higher than those of ‘Xiling’. During storage, the rate of green skin retention of both varieties gradually increased, while the kernel yield and good fruit rate gradually decreased. The differences in fat and protein contents between the two varieties were extremely significant（P＜0.01）: the fat content of ‘Xiling’ gradually increased, while that of ‘Zaoshuo’ showed no significant change; the protein content of ‘Xiling’ began to be consumed after approximately 60 days of storage, whereas that of ‘Zaoshuo’ started to be consumed after 20 days of storage. The activities of POD and SOD first increased and then decreased, while the MDA content first decreased and then increased. The experiment indicated that under the condition of（0±1） ℃, ‘Xiling’ had better storage resistance, with an optimal storage period of 40-60 days, and the optimal storage period of ‘Zaoshuo’ was 20-40 days.