模拟运输振动对冬枣品质及软化相关代谢的影响

Effects of Simulated Transportation Vibration on Quality andSoftening Metabolism of Winter Jujube

为探究运输路面等级对冬枣品质及软化相关代谢的影响,本实验通过模拟高级路面、中级路面和低级路面的实际运输振动情况,利用振动试验台设定4、10和20 Hz的振动频率,分别对冬枣进行模拟运输处理,分析运输振动对冬枣营养成分、软化代谢及细胞壁多糖含量的影响,并对冬枣在常温下(25.0±1.0℃)货架品质进行研究。结果表明,随着振动频率的增加,冬枣出现腐烂果的时间提前,硬度随之下降,果皮转红指数上升;振动处理组冬枣果实呼吸强度较高,货架期间20 Hz处理组其呼吸强度始终处于较高水平,果实生理活动进程加快,可溶性固形物(total soluble solids,TSS)及抗坏血酸(ascorbic acid,AsA)含量被大量消耗。在振动处理下,多聚半乳糖醛酸酶(polygalacturonase,PG)、果胶甲酯酶(pectin methylesterase,PME)和纤维素酶(cellulase,Cx)活性增强;原果胶、纤维素、半纤维素等细胞壁多糖组分降解加快,水溶性果胶含量上升,造成冬枣软化。低频率振动(4 Hz)对冬枣货架期品质的影响最小,适合于冬枣的长途运输,而高频率振动(10、20 Hz)会加速冬枣的品质劣变,缩短货架期时间。

In order to investigate the effects of transportation pavement grade on the quality and softening metabolism of winter jujube,this study simulated the actual transportation conditions of winter jujube on high,medium,and low road surfaces through setting vibration frequencies of 4,10 and 20 Hz on a vibration test bench.The effects of transport vibrations on nutrient composition,softening metabolism,and polysaccharide content in winter jujube were evaluated.Additionally,the shelf life quality of winter jujube was evaluated at room temperature(25.0±1.0℃).Results showed that winter jujube appeared earlier decay,hardness decline was accelerated and red index increased with the increase of vibration frequency.The respiration intensity of winter jujube fruit in the vibration treatment groups increased.Throughout the shelf life,the respiratory intensity of the 20 Hz treatment consistently showed a higher level,thereby accelerating the physiological activity of the fruit and leading to substantial consumption of total soluble solids(TSS)and ascorbic acid(AsA).The activities of polygalacturonase(PG),pectin methylesterase(PME),and cellulase(Cx)were enhanced under vibration treatment.The degradation of cell wall polysaccharide components such as protopectin,cellulose and hemicellulose was accelerated,and the content of water-soluble pectin was increased,resulting in softening of winter jujube.Additionally,the content of water-soluble pectin increased,leading to the softening of winter jujube.Low frequency vibration(4 Hz)has minimal impact on the shelf life quality of winter jujube,making it suitable for long-distance transportation.Conversely,high frequency vibration(10,20 Hz)could expedite quality deterioration and reduce the shelf life of winter jujube.