Research On Production Process And Quality Improvement Of Tiger Nut Noodles

Tiger nut is rich in nutrition and is a high-quality,high-yielding,multi-purpose cash crop with high comprehensive utilization value of grain,oil,feed and fertilizer,but its high oil content and lack of gluten protein make it difficult to be formed,which limits the application of tiger nut in food processing.In this thesis,we systematically studied the effects of the physicochemical properties,extrusion process parameters and quality improvers on the quality of tiger nut noodles with different oil content,and analyzed the edible quality of tiger nut noodles,compared the antioxidant activity and in vitro digestibility of starch of tiger nut before and after extrusion,in order to obtain a kind of tiger nut noodles with good edible quality and strong antioxidant property,and provide a theoretical basis for the development of tiger nut food.The main studies were as follows:(1)Effect of oil content on the physicochemical properties of tiger nut flour and its noodle quality.The physicochemical properties including basic physicochemical indexes,solubility,gel characteristics and pasting characteristics of the five types of tiger nut flour with different oil content,as well as the texture and cooking quality of the noodles,were compared and analyzed.The results showed that the highest amylose content of 42.63g/100 g was obtained for defatted tiger nut flour,and the raw material with higher amylose content could support a stronger starch gel skeleton.The solubility of tiger nut flour decreased with the decrease of oil content,from 36.00% to 33.00%;the quality of defatted tiger nut noodles improved significantly,the cooking loss decreased from 19.46% to14.35%,the breakage rate decreased from 73.33% to 26.65%,and the hardness increased from 271.91 g to 2457.21 g.The defatted tiger nut flour was identified as the most suitable raw material for processing.The test raw material was determined to be the most suitable for processing.(2)Effect of extrusion process parameters on the quality of tiger nut noodles.The effects of extrusion temperature,material moisture content and screw speed on the texture,cooking quality and microstructure of the noodles were investigated.The optimum process parameters were determined by response surface optimization test,and the optimum process parameters were: extrusion temperature of 104°C,material moisture content of24 %,and screw speed of 76 r/min.The results showed that the noodles prepared under the optimum process parameters had the best quality and the cooking loss rate of 10.67%.(3)Quality improvement study of tiger nut noodles.In the study on the quality improvement of tiger nut noodles,rice flour,sucrose ester,xanthan gum and corn starch were selected as improvers to study the effects of the addition of improvers on the raw material properties of tiger nut flour and the texture and cooking quality of tiger nut noodles.The results showed that when rice flour,xanthan gum,sucrose ester and corn starch were added at 40 g/100 g,0.4 g/100 g,0.4 g/100 g and 6 g/100 g,respectively,the texture and cooking quality of tiger nut noodles were significantly improved.(4)Study of nutritional value and functionality of tiger nut noodles.The functionality of the extruded tiger nut noodles prepared under optimal conditions was evaluated.The total amount of hydrolyzed amino acids in the extruded noodles increased from 5.47 mg/100 g to 6.43 mg/100 g.The noodles had strong antioxidant activity.The starch hydrolysis rate of tiger nut before and after extrusion was 52.26% and 73.96%,respectively.The starch hydrolysis rate of tiger nut noodles was increased after extrusion compared to that of tiger nut flour.