摘要
为了使涂膜技术更有效地应用于果蔬采后保鲜,该文通过电喷雾技术将纳米SiO_2/马铃薯淀粉膜液喷涂在新鲜的双孢蘑菇上,研究了在(4±1)℃贮藏期间双孢蘑菇生理品质的变化,筛选出适于电喷雾涂膜的最佳膜液浓度,且对电喷雾形成涂层的性能(透水率、透O_2率、透CO_2率、水溶性、溶胀度、拉伸强度)和微观结构(scanning electron microscopy,SEM、X-ray diffraction,XRD、fourier transform infrared spectroscopy,FTIR)进行一定的研究。结果表明,适合双孢蘑菇电喷雾技术纳米涂膜保鲜的最佳膜液0配比为纳米SiO_2质量分数0.4%、马铃薯淀粉质量分数4%、甘油质量分数3%,其透水率、透O_2率、透CO_2率分别为514.35、126.84、778.06 g/(m2×d)、拉伸强度24.50 MPa、水溶性54.76%、溶胀度85.75%。电喷雾因液滴带同种电荷,形成的涂层比较均匀,纳米SiO_2分散性更好,分子间作用力较强,且涂层的性能更优。在贮藏保鲜期间电喷雾处理的双孢蘑菇相对普通喷雾处理组能保持较好(P<0.05)的感官品质及生理品质,研究结果为电喷雾技术在食用菌采后保鲜的应用上提供参考。
Among2000species 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 of improper 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-SiO2into 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 was0.4%nano-SiO2concentration,4%potato starch concentration,and3%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 bisporus during4?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 were514.35,126.84,and778.06g/(m2·d),respectively,which were decreased.Compared to potato starch films and nano-SiO2/potato starch films by ordinary spraying,the ensile strength of films by electrospraying was increased.The SEM of the films showed that nano-SiO2in 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-SiO2made the nano-SiO2molecules disperse into the potato starch matrix and destroyed the original crystalline domains of potato starch and nano-SiO2,which indicated this polymer and nano-SiO2had excellent miscibility of blend from XRD and FTIR.The thermogravimetric analysis(Tg)showed that blending with nano-SiO2could 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.
作者
张荣飞
王相友
Zhang Rongfei;Wang Xiangyou(School of Agricultural and Food Engineering, Shandong University of Technology, Zibo 255049, China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2017年第23期291-299,共9页
Transactions of the Chinese Society of Agricultural Engineering
基金
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)
关键词
喷雾
膜
优化
双孢蘑菇
纳米SIO2
马铃薯淀粉膜
保鲜
spraying
films
optimization
agaricus bisporus
nano- SiO2
potato starch coatings
keep-freshing
