Effects Of Different Packing Materials And Methods On Storage And Preservation Quality Of Rice

Rice is one of the primary food of our country. Problems of aging, mildew and pests lead to the poor quality of rice or even loss of edible value during storage. As a result, it brings a large amount of waste. Therefore, the food researchers in China and abroad give more attention on the preservation and storage of rice. Currently, there have been a number of studies on the fresh-keeping packaging. With the enhanced awareness of healthy, traditional packaging in the form of sacks or plastic bags have already not met the demands, more efficient, practical, low-cost packaging and packaging technology are more and more popular among consumers.To measure the changes of rice quality in the processing of storage, this study choose fresh Wuyujing3#as material, selecting the typical physicochemical index such as moisture, fatty acid, reducing sugar, combining with the evaluation of the texture properties and cooking properties to research the effect of different packaging materials and packaging methods. Put forward a kind of combination packaging, that is Ag/PE nano-packaging as an inner lining layer coupled with PE as an outer lining layer, researched the preserving effects of the new combination, and also provide a theory basis and technique for the innovative applications of packaging technology. The contents and results are as follows:Firstly, the effects of four different barrier packaging materials on the quality of rice during storage were determined and analysised. Due to the excellent barrier, the two nano-packaging could effectively decreased the loss of water and the rate of fatty acid changing. In particular, the rice packed with Ag/PE nano-packaging showed a relatively modest change on the quality index such as water absorbing, adhesiveness, the pH and iodine blue value of rice water. According to the comprehensive evaluation, the order of the preservation effect is Ag/PE nano-packaging> TiO2/PE nano-packaging≈BOPP/PE>PE.Secondly, the effects of two different packaging methods on the quality of rice during storage were investigated, taking the ordinary polyethylene packaging as control sample. In comparison, the rice stored in the modified atmosphere packaging (100%CO2) and vacuum packing (-0.07MPa) exhibited less loss of water, the increasing rate of water absorbing and the descending rate of adhesiveness, the pH and iodine blue value of rice water had been restrained effectively in the absence of oxygen. Apart from these beneficial effects, modified atmosphere packaging (100%CO2) is able to delay the fatty acid peak, vacuum packing (-0.07MPa) is able to delay the hardness peak and the quality of rice packed with vacuum packing have better eating quality. As a result, the order of the preservation effect is vacuum packing (-0.07MPa)> modified atmosphere packaging (100%CO2)> PE.Finally, considering the inferior mechanical properties of Ag/PE nano-packaging, a novel combination packaging of different packaging materials based on the preserving of rice is proposed, that is Ag/PE nano-packaging as an inner lining layer coupled with PE as an outer lining layer. Compared with vacuum packing, the fresh-keeping effect was performed and with the result that the rice packed with the combination packaging showed a similar effect to slow the increasing rates of hardness and water absorbing. It was especially noted that combination packaging achieves better inhibitory effects on the increase of fatty acids and reducing sugars, and the decrease of springiness and adhesiveness. Hence, combination packaging is an efficient, practical, low-cost and excellent quality method for the preservation of rice.