Characterization of starch from different non-traditional sources and its application as coating in ‘Palmer’ mango fruit

ABSTRACT Yam, cassava, jackfruit seed and mango seed kernel have potential for the extraction and use as starch in the food industry of starch or for the formulation of biodegradable coatings. As a biodegradable coating, starch can be applied in fruits characterized by a fast maturation, such as mango, which requires technologies to increase its shelf life. The aim of this study was to characterize starch from four non-traditional sources and to evaluate their potential as coating for ‘Palmer’ mango fruit. Starches used were extracted from cassava, mango seed kernel, jackfruit seed, and yam, and had their physical, optical, and chemical properties characterized for later use as coatings of ‘Palmer’ mango fruit. Fruits were coated with 3% cassava starch, 3.5% jackfruit seed starch, 3.5% mango seed kernel starch and 3.5% yam starch, and were compared to the control (uncoated). They were then stored at 24.4 ± 0.3 °C and 87 ± 2% RH and evaluated for 12 days. A 5x7 factorial arrangement in a completely randomized experimental design was adopted. Total starch content was higher than 70% in the four sources of starch. Starches from jackfruit and yam had higher amylose content. The four sources of starch had low water solubility and swelling power, with jackfruit seed starch having the highest values. The coating sources were effective in maintaining quality, particularly mango seed kernel starch because it reduced respiratory rate and weight loss in 27.7% and 33.8%, respectively, as well as jackfruit seed starch as it delayed fruit skin yellowing.

摘要 山药、木薯、菠萝蜜籽与芒果籽仁具备提取淀粉的潜力，可应用于食品工业作为淀粉原料，或用于制备可生物降解涂层。作为可生物降解涂层材料，淀粉可用于芒果这类成熟速度较快的水果——这类水果亟需可延长货架期的相关技术。本研究旨在表征四种非传统来源的淀粉，并评估其作为帕尔默（Palmer）芒果果实涂层的应用潜力。本研究提取的淀粉分别来自木薯、芒果籽仁、菠萝蜜籽与山药，先对其物理、光学及化学性质进行表征，后续将这些淀粉用于帕尔默芒果的涂层处理。实验设置的涂层组分别为3%木薯淀粉、3.5%菠萝蜜籽淀粉、3.5%芒果籽仁淀粉及3.5%山药淀粉，并以未涂层组作为对照。所有样品均在温度24.4±0.3℃、相对湿度（Relative Humidity，RH）87±2%的条件下贮藏12天。本研究采用完全随机试验设计下的5×7因子排列方案。四种淀粉的总淀粉含量均高于70%，其中菠萝蜜籽淀粉与山药淀粉的直链淀粉（amylose）含量更高。四种淀粉均表现出较低的水溶性与溶胀力，其中菠萝蜜籽淀粉的相关数值最高。各类涂层材料均可有效维持芒果果实品质，其中芒果籽仁淀粉的效果尤为突出，可分别将果实呼吸速率与重量损失降低27.7%与33.8%；而菠萝蜜籽淀粉则可延缓果皮黄化进程。