Effects of Simulated Transportation Vibration on Quality and Softening Metabolism of Winter Jujube

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.