Influences Of Different Drying And Storage Methods On The Quality Of Chinese Jujube Fruit

Chinese jujube (Ziziphus jujuba Mill.) belongs to the genus Ziziphus Mill.(Rhamnaceae), and is one of the most traditional fruit trees in our coutry. Jujube has planty of nutrition, and has functions of sedation, nourishing blood, antitumor effect, immune-modulability, and etc. Recent research mostly study the nutrition component of fresh jujube of different kind and different growth stage, however, jujube with appropriate water content as well as the impace of different drying, conserving method on nutrition preservation has not been sufficiently studied. Using two main variety of‘Zanhuangdazao’and‘Jinsixiaozao’jujube fruits as material, the impact of different drying method on the maing nutrition component has been studied; using ’Jinsixiaozao’ jujube with different water content, the impact of different conserving method and conservation time on the nutrition quality has been analysed. Aims to find a new dried jujube product and provide theoretical basis for science storage. The main research results are as follows:1. The sense quality, main nutrition content, and cAMP content of ’Zanhuangdazao’ and ’Jinsixiaozao’ jujube, after being dried through 4 different method, has been analysed. The result indicates that, when drying ’Zanhuangdazao’, microwave-assisted method takes the least time, 78h, followed by oven method, 113h; as to ’Jinsixiaozao’ jujube, vacuum drying takes the least time, 54h, followed by oven drying drying method, 76h; the sense quality is well kept through oven drying and vacuum drying, and the vacuum dried jujube is suitable to eat directly with soft pulp and larger air vent; the impact of different drying method on the soluble sugar content is not remarkable; the impact of natural drying, oven drying, and low temperature oven drying on the titratable acid content is not remarkable, and the titratable acid content is increased after vacuum drying and microwave-assisted drying; once dried, the Vitamin C content is dramatically reduced; drying will cause reduction in cAMP content, but not remarkable. Oven drying and vacuum drying are the best drying methods. 2. The nutrition quality and sense quality of dried jujube with different water content are analysed. The result indicates that, jujube with 45% water content, whose soluble sugar, titratable acid and cAMP content are not remarkably varied, is suitable to directly eat, and thus expected to be developed as a new product. Jujube with 25% water content is suitable to eat as dry fruit.3. ’Jinsixiaozao’ jujube with appropriate water content is conserved using natural storage and cold storage. Determination sence quality and nutrients of jujube when storage time reach 90d and 180d. Jujube with 45% water content is divided into spraying natamycin and non- spraying anticorrosive under natural storage. The result indicates that, jujube with 45% water content are found fermented and rotten, and found hyphae when 180d storage time. After spraying anticorrosive, jujube with 45% water content are conserved with good sense quality. Jujube’s sence quality and nutrients with 45% water content and 25% water content are at good save when 90d storage time under cold storage. Compared with jujube before storage, sence quality of cold storage jujube is not varied remarkably, while titratable acid content has raised and the Vitamin C and cAMP content has decreased remarkably. Therefor, jujube with 45% water content can be conserved 90d by natural storage after spraying anticorrosive, or directly by cold storage; as to jujube with 25% water content, it can be conserved 90d by natural storage, or 180d by cold storage, both without anticorrosive.