贮运过程中振动损伤对蓝莓品质的影响

Effect of Vibration Damage on Blueberry Quality during Storage and Transportation

【目的】研究模拟蓝莓鲜果在物流运输车辆中的机械振动情况,分析其在不同机械振动频率及不同贮运温度条件交互作用下的品质变化规律,为蓝莓鲜果采后冷链运输流通提供参考。【方法】选取新鲜“蓝丰”蓝莓装于透明塑料小包装件中,置于4、10和25℃下分别贮存备用,选择模拟公路运输方式,将蓝莓包装件置于振动试验台上,通过扫频振动测试得其固有频率值为85 Hz,选择3个振动幅值有显著差异的频率值分别进行蓝莓包装件定频振动试验。模拟运输振动试验后,将蓝莓包装件立即分别置于4、10和25℃贮藏,将未经历振动的蓝莓鲜果分别作为3种贮藏温度条件下的对照组。对蓝莓丙二醛(MDA)含量、可溶性固形物(SSC)含量、抗坏血酸(Vc)含量和硬度等共7个指标进行评价,研究机械振动后的蓝莓在4、10和25℃下贮藏品质的变化情况。【结果】在贮藏过程中,振动因素对蓝莓MDA和花青素含量的影响相对显著(P<0.05),温度因素对蓝莓Vc、SSC含量和硬度的影响相对显著(P<0.05)。双重因素的交互作用对蓝莓SSC、Vc、可滴定酸(TA)含量产生更为显著的影响。通过回归分析可得蓝莓MDA、SSC与Vc含量关于贮运温度(X 1)和振动频率(X 2)的回归方程,为预测蓝莓的成熟甚至衰败程度提供理论依据。【结论】蓝莓贮运品质受到振动频率和贮藏温度的共同影响,振动及高温加速了蓝莓腐败的速度。因此,在蓝莓贮运过程中,应减少包装件受到固有频率85 Hz的共振影响,振动后贮存于4℃条件下更利于蓝莓果实各项指标的稳定,延缓果实衰老。

【Objective】In this paper,the mechanical vibration of blueberry fresh fruits in logistics and transportation vehicles was simulated,and the quality change law under the interaction of different mechanical vibration frequency and different storage and transportation temperature conditions was analyzed,so as to provide a reference for the cold chain transportation and circulation of blueberry fresh fruit after harvest.【Method】Fresh“Lanfeng”blueberries were selected and stored in transparent plastic small package at 4,10 and 25℃.The blueberry package was placed on the vibration test bench that was subjected to the simulated road transportation.Through the frequency sweep vibration experiment,the measured natural frequency of the blueberry package was 85 Hz.The three vibration amplitudes were selected to carry out the blueberry constant frequency vibration experiment.After the simulated transport vibration test,the blueberry packages were immediately placed at 4,10 and 25℃for storage test,and the fresh blueberries that did not undergo vibration were used as the control group under the three storage temperature conditions.A total of 7 indicators including malondialdehyde(MDA)content,soluble solids(SSC)content,ascorbic acid(Vc)content and hardness were evaluated.Changes of storage quality of mechanical vibrating blueberries at 4,10 and 25℃were studied.【Result】During storage,the vibration significantly(P<0.05)affected MDA and anthocyanin content of blueberries,whereas the storage temperature factors significantly(P<0.05)affected Vc,SSC content and hardness of blueberries.The interaction of two factors had a more significant effect on the content of SSC,Vc and titratable acid(TA)of blueberries.The equation between MDA,SSC and Vc content on storage and transportation temperature(X 1)and vibration frequency(X 2)was obtained by regression analysis,that could provide a theoretical basis for predicting the maturity and even decline of blueberries.【Conclusion】Both vibration frequency and storage temperature affect storage quality of blueberry.Vibration and high temperature accelerate the rate of blueberry corruption.Therefore,in the process of storage and transportation of blueberries,the resonance effect of the package at the natural frequency of 85 Hz should be reduced.Storage at 4℃is more conducive to the stability of various indicators of blueberry fruit and delaying fruit senescence.