农业工程学报2017，Vol.33Issue(23)：291-299,9.DOI:10.11975/j.issn.1002-6819.2017.23.038
电喷雾纳米涂膜工艺优化及其对双孢蘑菇保鲜效果
Process optimization of Nano-SiO2/potato starch coatings and its improving effect for storage of agaricus bisporus by electrospraying
摘要
Abstract
Among 2000 species of edible mushrooms, only a handful are worldwide cultivated and processed at industrial level, in which Agaricus bisporus is included. Apart from its nutrition, this mushroom has been valued by human as a kind of medical resource, containing a number of bioactive molecules, with therapeutic properties that confer a powerful source of new pharmaceutical products, such as its anticancer property. However, the quality of mushrooms deteriorated, evidenced by cap-opening, browning, shrinkage, and decomposition because ofimproper postharvest storage and preservation. This deterioration in quality seriously affects the commercial value of the mushrooms. Electrospraying is a novel technique for the application of coatings to foods. It is an effective technique to atomize liquids, in which an electric potential difference is applied across a droplet emerging from a capillary. The electrical field induces accumulation of charge near the surface of the nascent droplet, and destabilizes the surface of droplet which is disrupted into multiple diminutive charged droplets. Potato starch, being polysaccharides, as amylose and amylopectin, exhibits good film-forming properties and chemical stability and may also be edible.Despite this, the use of potato starch in the field of packaging materials has some limitations, and the main one is the poor properties of coatings. Incorporation of essential nano-SiO2 into potato starch coatings may greatly enhance the coatings' antimicrobial properties, restrict enzyme immobilization and inhibit fruits and vegetables decay. In this study, nano-SiO2/potato starch coatings were prepared by electrospraying for the preservation of Agaricus bisporus. The optimal concentration of coatings for electrospraying was obtained, and their structural characteristics were evaluated with scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), as well as the properties including water vapor permeability (WVP), oxygen permeability (OP), carbon dioxide permeability (COP), water solubility, swelling and tensile strength. The results showed that the optimum treatment of coatings by electrospraying for fresh keeping of Agaricus bisporus was 0.4％ nano-SiO2 concentration, 4％ potato starch concentration, and 3％ glycerol concentration. Nano-SiO2/potato starch films by electrospraying markedly reduced browning index, retarded weight loss and hardness decrease, and extended shelf life of Agaricus bisporusduring 4?C storage. Furthermore, electrospraying made droplets with the same electric charge form the coatings more evenly. WVP, OP, and COP of nano- SiO2/potato starch films by electrospraying were 514.35, 126.84, and 778.06 g/(m2·d), respectively, which were decreased. Compared to potato starch films and nano-SiO2/potato starch films byordinary spraying, the ensile strength of films by electrospraying was increased. The SEM of the films showed that nano-SiO2 in the films by electrospraying was more uniform than that by ordinary spraying. Also, it could be expected that the intermolecular interactions between potato starch and nano-SiO2 made the nano-SiO2 molecules disperse into the potato starch matrix and destroyed the original crystalline domains of potato starch and nano-SiO2, which indicated this polymer and nano-SiO2 had excellent miscibility of blend from XRD and FTIR. The thermogravimetric analysis (Tg) showed that blending with nano-SiO2 could improve the thermo-stability of potato starch films. In short, coatings prepared by electrospraying have stronger intermolecular force and better properties. During storage, electrospraying can obtain the desired sensory attributes for Agaricus bisporus along with prolonged shelf life. These data indicate that nano-SiO2/potato starch coatings by electrospraying might provide an attractive alternative in improving preservation quality of fresh Agaricus bisporus after harvest.关键词
喷雾/膜/优化/双孢蘑菇/纳米SiO2/马铃薯淀粉膜/保鲜Key words
spraying/films/optimization/agaricus bisporus/nano- SiO2/potato starch coatings/keep-freshing分类
农业科技引用本文复制引用
张荣飞,王相友..电喷雾纳米涂膜工艺优化及其对双孢蘑菇保鲜效果[J].农业工程学报,2017,33(23):291-299,9.基金项目
国家自然基金(31301570 （）
30871757) （）
山东省农业重大应用技术创新课题-食用菌物流保鲜与质量安全控制关键技术研究及产业化示范(鲁财农字[2014]38号) （鲁财农字[2014]38号）
