Process Optimization And Quality Evaluation Of Complex Rice Flour-Konjac Sheet Jelly

Taking konjac powder as raw material to innovate konjac foods is the trend of development for konjac foods.The sheet jelly made from konjac powder is hard to accept by customer because of bad taste and cooking quality,as a result,it has bad influence on large scale production,which can trigger lower economic benefit.Rice noodle made from rice flour has better taste and cooking quality.Therefore this study is focusing on creating new sheet jelly that is a mixture of konjac powder and rice flour,based on a certain ratio.The soaking effect of konjac powder has great effect on the quality of konjac gel.This paper studied the influence of the processing technology of mixed konjac powder and rice flour on the sheet jelly's quality after researching of konjac powder soaking technology,and the best cooking property of sheet jelly was studied so that scientific evidence on theory and practice for commercial process of sheet jelly can be provided.The main results are as follows:(1)In order to optimize the konjac powder soaking process and obtain the best soaking process conditions,the single factor test was carried out on based of swelling rate as the index.Single factors include of konjac powder partical size,ratio of water and powder,soaking temperature and soaking time.In addition,three-factor and three-level orthogonal test are carried out.The results show that the best condition for soaking process is 40 mesh konjac powder,and the ratio of water and powder is 1:40,and the soaking temperature is50??70 ?,and the soaking time is 20 min?40 min.This condition is conducive to control production and processing.(2)To study the best processing method of sheet jelly made from konjac powder and rice flour,Firstly,the effects of three processing methods(the homogeneous without standing method,the homogeneous with standing method,the standing without homogeneous method)on the texture and quality of sheet jelly were investigated.Then the effects of single factors,such as alkali dosage,rice flour dosage,standing time and thickness,on the sensory quality and texture characteristics of compound sheet jelly were studied.The results show that the method of the standing without homogeneous method is adopted,and the ratio of konjac powder and rice flour is 1:2,and amount of alkaline is 5%,and the thickness of the sheet jelly is about 2 mm,and the cooking temperature is 100 ?,and cooking time is 30 min,and standing time is 150 min at room temperature.On this condition,the texture and sensory quality of compound sheet jelly was the best.(3)The cooking loss rate,gel strength,sensory evaluation,water retention and rehydration of the sheet jelly were used as the indexes.The quality of compound konjac sheet jelly,pure konjac sheet jelly and rice noodle were compared.The results show that:(1)Compound konjac sheet jelly is better than pure konjac sheet jelly in respect of water retention.The water loss rate of compound konjac sheet jelly was 13.5%,and pure konjac sheet jelly was 31.1%.The water loss rate of rice noodle was the lowest,only 7.2%.(2)The cooking loss rate of compound konjac sheet jelly was the lowest,10.5%,followed by rice noodle,12.2%.The percentage of pure konjac powder was 19%.(3)In terms of gel strength,the gel strength of rich noodle was the best,accouting 30.5%,followed by compound konjac sheet jelly(2.76%)and pure konjac sheet jelly(1.1%).(4)In respect of rehydration,the rehydration rate of compound konjac sheet jelly was 27.5%,and pure konjac sheet jelly was15.4%,and rice noodle was 98.5%.(5)Sensory evaluation was conducted in terms of appearance,taste,smell,and touch.Rice noodle and compound konjac sheet jelly had better sensory acceptance than pure konjac sheet jelly.Adding rice flour can improve the quality of pure konjac sheet jelly,which can let finished product be pure,less fishy smell,uniform texture,smooth surface,light color.