Study On The Preparation And Fresh Function Of Nano-TiO₂/SPI Complex

There are many reports about the film properties and applications of food preservation of SPI.The single SPI film always has deficiency in mechanical properties and storage effects. So adding nano-materials to strengthen the effects of SPI on preservation has become a research hotspot. In this study, we added the nano-TiO2 into the SPI solution to make the nano-TiO2/SPI complex film, and then studied its membrane performance and application in food preservation.First, we studied the ratio of different ingredients and preparation conditions on the mechanical properties of nano-TiO2/SPI complex film, and the addition of nano-TiO2 on a variety of other properties of the complex fim. The results showed that:the best ratio of ingredients was 5% SPI,0.05g nano-TiO2,3% glycerol, and the best preparation condition was pH 9,80℃water bath for 30min,40℃dry. Also, the addition of nano-TiO2 can effectively reduced water vapor transmission and water-soluble; reduced membrane permeability of oil, and improve the membrane permeability. When we added 0.05g nano-TiO2, the composite film had the best performance.In order to study the effects of nano-TiO2/SPI compound on the quality changes of grass carp during storage, grass carp samples, after being washed and sliced up, were given a dip treatment in nano-TiO2/SPI compound solution for 5min. And then, they were stored at 4℃.The sensory scores, hardness, L values, weight loss, pH values, TVB-N values, total acidity, hydrogen sulfide levels, and bacterial count were used to evaluated the fish quality. Results indicated that the total bacterial count, hardness, weight loss, pH values, TVB-N values, total acidity, and hydrogen sulfide levels, which was processed with nano-TiO2/SPI compound, could be significantly restrained, and sensory scores decreased slowly as well. So it can be concluded that nano-TiO2/SPI compound have great effects on the inhibition of bacteria growth and preservation, and thus significantly delay the spoilage of grass carp.In order to study the effects of nano-TiO2/SPI compound on the quality changes of fresh-cut carrot during storage, carrot samples, after being cut into pieces, were given a dip treatment in nano-TiO2/SPI compound solution for 5min. And then, they were stored at 10℃. The weight loss, WI, hardness, ethylene production, total phenolic content, activities of PPO and POD, and bacterial count were used to evaluated the carrot quality. Results indicated that the total bacterial count, WI, ethylene production, total phenolic content, hardness, weight loss, and activities of PPO and POD, which was processed with nano-TiO2/SPI compound, could be significantly restrained. So it can be concluded that nano-TiO2/SPI compound have great effects on the inhibition of bacteria growth and preservation, and thus significantly extend shelf life of carrot.