采收成熟度对刺梨果实贮藏品质的影响

为了延长刺梨鲜果的贮藏期，分别以盛花后85（七成熟）、95 d（八成熟）及105 d（九成熟）的‘贵农五号’刺梨鲜果为试材，经保鲜膜包装，于（1±0.5）℃、相对湿度80%～85%条件下贮藏105 d，定期观察刺梨鲜果品质变化。结果表明：七成熟果实贮藏过程中硬度保持在较高水平，还原糖和VC含量在贮藏后期下降最快，感官品质较差；八成熟果实硬度下降缓慢，质量损失率和腐烂率较低，VC、总糖和还原糖含量损失较少，呼吸速率受到抑制，未出现早衰现象，保持了果实的正常品质和风味；九成熟刺梨果实贮藏期间成熟衰老过程较快，硬度下降、膜透性上升、质量损失和腐烂率较高。不同处理间过氧化物酶除第15及45天外，活性变化无显著差异（P＞0.05）；多酚氧化酶除第45天外差异显著（P＜0.05）。除贮藏15 d和90 d外，不同处理间MDA含量变化无显著差异（P＞0.05）。八成熟的刺梨鲜果耐藏性优于七成熟、九成熟，能保持较好的品质。

Effect of Harvest Maturity on Quality of Rosa roxburghii Tratt during Storage

To prolong the shelf life of Rosa roxburghii Tratt, the fruits with different degrees of maturity, 70%, 80% and
90%, harvested at 85, 95 and 105 days after anthesis, respectively, were wrapped with a cling film and stored at (1 ± 0.5) ℃
with a relative humidity of 80% - 85% for 105 days. During the storage, fruit quality and physicochemical indexes were
determined periodically. Results showed that the flesh firmness of the fruits with 70% maturity was maintained at a
relatively high level, and the contents of reducing sugar and vitamin C (VC) declined fastest at the late stage of storage
while poor sensory quality was observed. The fruits with 80% maturity showed a slow decline in flesh firmness, weight loss
rate and decay incidence, maintained higher contents of VC, total sugar and reducing sugar, revealed inhibited respiration
rate without premature senescence, and had better sensory quality. The fruits with 90% maturity exhibited accelerated
senescence, a decline in harness, an increase in cell membrane permeability, and higher levels of weight loss and decay
incidence. Except on the 15th and 45th days of storage, no significant difference in peroxidase (POD) activity was observed
among three degrees of maturity (P > 0.05), while polyphenol oxidase (PPO) activity showed a significant difference except
on the 45th day of storage (P < 0.05). As for MDA content, no significant difference was noted among three degrees of
maturity (P > 0.05) except on the 15th and 90th days. Therefore, 80% maturity is suggested as the best harvest maturity for
Rosa roxburghii Tratt.