Authors

Abstract

The texture of apple peel, as an important quality attribute of the fruit, is directly relevant to a fruit’s ability to resist mechanical injury. In order to explore the variations in texture of two apple peels under different puncture test conditions and evaluate the relation of apple peel puncture force to whole fruit firmness percentage, at 0.1, 1, 5, 11, and 17 mm/s loading speeds, puncture mechanical measurements were performed using an electronic testing machine mounted with 2, 3.5, 7.9 or 11 mm-diameter probes. For the same probe, the mean values of peel puncture force and stiffness, as well as the fruit puncture force, for Danxia and Fuji cultivars increased firstly and then changed a little with the increase of loading speed. Moreover, at the same loading speed, the puncture measurements of each cultivar increased significantly (P≤0.05 ) with increasing probe diameter and the peel puncture force has a significant linear correlation with probe diameter. Among the different cultivars, under the same loading speed, the Fuji peel and fruit samples had the greater puncture force; the Fuji peel contribution change was relatively big with the increasing of loading speed, and Fuji cultivar was more likely to be injured than the other cultivar. The results were expected to serve as a reference for investigating the puncture injury sensitivity of different apple varieties during transportation and storage and to enrich the texture evaluation index of apple peel.

Abstract in Chinese

苹果果皮作为果实的最外层组成部分，其质地特征是评价果实抵抗机械损伤能力的重要指标。为探索不同品种苹果果皮穿刺质地的差异及研究果皮穿刺质地对果实硬度的贡献率，采用直径为2, 3.5, 7.9, 11 mm的圆柱体压头，在0.1, 1, 5, 11, 17 mm/s的加载速度下对红富士和丹霞苹果果皮及整果果实进行了穿刺力学特性试验，获得果皮及果实的穿刺载荷—位移曲线、破裂抗力与果皮的刚度。试验结果表明：同一品种苹果，在相同压头下随着加载速度的增加，果皮破裂抗力及刚度、果实破裂抗力均呈现先增大后变化幅度不大的趋势；在相同加载速度下随着压头尺寸的增大，果皮及果实的穿刺力学特性参数间存在显著性的差异（P≤0.05），果皮破裂抗力与压头直径之间呈显著正线性相关。不同品种苹果，在相同的加载速度下果皮及果实的破裂抗力均以红富士的为最大；随着加载速度的增加，红富士果皮穿刺质地对果实硬度贡献率的变化相对较大；红富士苹果比丹霞更容损伤。研究结果为不同品种苹果果皮贮运损伤敏感性的评价提供参考依据，丰富苹果果皮质地的评价指标。