农业工程学报2016，Vol.32Issue(14)：284-292,9.DOI:10.11975/j.issn.1002-6819.2016.14.038
适宜微波处理保持山核桃贮藏品质
Suitable duration of microwave pre-treatment for maintaining postharvest qualities on pecan nuts during storage
摘要
Abstract
Pecan (Carya illinoensis Koch), a kind of famous nutritious nuts in the world, and it is important to explore novel storage technology in protecting qualities against sharp losses of nutritional value and the decreased of sensory qualities. The objective of this study was to investigate the effect of microwave heat treatment on nutritional ingredients, quality variation, and sensory indexes. Fresh pecan nuts (500 g) were exposed to microwave heating for 1, 2.5, 3, and 5 min at a frequency of 2 455 MHz, power of 650 W and then stored at (2±0.5)℃ for up to 120 days. Change of contents in moisture, fat, crude protein, total soluble sugar (TSS) and tocopherol, fatty acid composition, peroxide value (PV), and the sensory quality were determined at regular interval during storage. The results showed that some constituents changed progressively with storage time, featuring decreases in contents of moisture, lipid and tocopherols and increases in TSS and PV. Microwave treatments indeed affected storage-induced chemical changes. This effect largely depended on duration of microwaving. Compared with the control (0 min ), microwave pre-treatment for 2.5 min significantly (P<0.05) delayed the degradation of crude protein and decrease of lipids, and thus preserved total unsaturated fatty acids and tocopherol content at the end of storage in comparison with untreated control. In addition, the above treatment also significantly (P<0.05) inhibited moisture loss, and increased total soluble sugar content, therefore, remained sensory qualities of fresh pecan during storage in comparison with untreated control. On the contrary, a shorter duration (1 min) of microwaving had little (P>0.05) effect, while longer duration (3 or 5 min) of microwaving accelerated (P<0.01) the storage induced changes. Only a medium duration (2.5 min) of microwave suppressed the chemical change. It is concluded that fresh pecan nuts exposed to 2.5 min duration of microwave treatment can be stored at (2±0.5) ℃ for up to 120 d without any adverse effect on PV, fatty acid composition, or tocopherol content. This study provided theoretical foundation for application of microwave treatment on maintaining the quality against decrease of fresh pecan during postharvest storage.关键词
微波/贮藏/品质控制/营养品质/感官评价Key words
microwaves/storage/quality control/nutritional quality/sensory evaluation分类
轻工纺织引用本文复制引用
张继刚,丁之恩,梁进,程江华,杨松..适宜微波处理保持山核桃贮藏品质[J].农业工程学报,2016,32(14):284-292,9.基金项目
National Natural Science Youth Fund Project (31301448) （31301448）
