The Development Of Sweet Potato Rice Cake And The Study On Its Storage Quality

The rice cake in South China is very famous folk traditional specialty made by high-quality rice,do not add any preservatives and pigments.They are famous for thire white jade appearance,soft waxy taste smooth and long soak cooking fried paste,but their products are single and short shelf life problems greatly restrict the market development space.The sweet potato granules are sweet potatoes with low water content and easy storage and transportation,which greatly improved the storage period and utilization of sweet potato.The sweet potato granules have the flavor and nutrition of fresh sweet potato,so it can be used as a good raw material.The main purpose of this paper is to develop a new rice cake which use sweet potato granules as raw materials,and to study its quality characteristics,sterilization methods and storage quality.The main conclusions are as follow:(1)The effect of three kinds of different quality of raw materials on the quality of the new kind of rice cake were compared.The results showed that the sensory evaluation quality of rice cake made by quality rice in Northeast is best,followed by the ecological rice in Northeast,rice in Northern Jiangsu Province is the worst relatively.There is no significance between two kinds of rice in Northeast on cooking quality and hardness while rice in Northern Jiangsu Province is the highest.The basic material composition is related to the quality of rice cake.The amylose starch,starch and protein content of raw material directly affect the hardness,cooking quality and sensory evaluation of rice cake.Through a comprehensive comparison,the final determination of the best quality called quality rice in Northeast and the worst called rice in Northern Jiangsu Province of the two kinds of rice under the study.(2)Through the single factor experiment,the different ratio of sweet potato granules were added to the rice cake and compared the effect of different additives of sweet potato granules on quality of rice cake with different indexes including sensory evaluation score,texture characteristics(hardness,adhesiveness,chewiness)and cooking lose.The results show that when adding 10% sweet potato granules,the sensory evaluation score was the highest,hardness and chewiness is moderate.(3)Volatile compounds were determined by headspace solid-phase micro-extraction(HS-SPME)and gas chromatography-mass spectrometry(GC-MS)between blank rice cakes and the new kind of rice cakes which were added 10% sweet potato granules.The results show that compared with not adding sweet potato granules in rice cake,the new kind of rice cakes made by quality rice in Northeast and rice in Northern Jiangsu Province were detected a total of 39 and 51 volatile flavor substancesunique respectively.Hydrocarbon content is the highest in two kinds of blank rice cakes,while the content of aldehydes in two kinds of raw materials for the production of rice cake is the highest.There are lots of same volatile components between sweet potato granules and the new kind of rice cake,such as hexanal,nonanal and decanal etc.(4)Different ways of sterilization and temperature were taken to deal with the new kind of rice cakes.The results showed that with the increasing temperature of sterilization,sensory quality,cooking lose,amylase starch and starch digestibility were decreased.Effect of sterilization,the best sterilization effect was 121?,and 60?was the worst.However,the sensory of the rice which were sterilized by60? were the best.The effect of sterilization between 80? and 105? was similar,but the texture of80? is better than 105?.In terms of physical and chemical indicators,105? is better than 80?.The texture of rice cake made by quality rice in Northeast is better than rice in Northern Jiangsu Province after sterilization.In general,the way of water sterilization is milder than high-pressure steam sterilization.(5)Study on the storage characteristics of the new kind of rice cake in different storage temperature.The results show that amylase starch and resistant starch content of the new kind of rice cake were increased slowly,with the increasing of storage time,while moisture,cooking loss,starch digestibility were declining.Storage at room temperature,the change tend of hardness and starch digestibility of rice cake less than storage at 4?.The growth of microbial were inhibited when storage at 4?.In the 60 d,the sterilized effect of 80? is not as good as 105?,but the texture is better.