The Study On Production, Quality And Application Of Water Chestnut Flour

The water chestnut, also known as horseshoe, is a kind of fruits and vegetables foodwith the excellent function of medicine and consumption effects. It has wide planting areain China, high yield, and higher nutritional value. Water chestnuts is strong seasonal,perishable, therefore water chestnuts main direct consumption of fresh fruit, and the deepprocessing products is little. The research of water chestnuts powder production providesan important intermediate raw material for the food processing industry in the future,which has a positive and practical significance.This thesis mainly discusses production, quality and application of water chestnutspowder, including study of the water chestnuts on color protection; study of characteristicsand process conditions of water chestnuts in the drying process; the quality of the waterchestnuts; analysis and determination of four flavonoids in water chestnut by highperformance capillary electrophoresis; the production of the water chestnuts biscuit.The test finds out a conclusion shown as follows:1. Determine the optimum soaking time and3level of color protection by singlefactor test, then the conditions are obtained by L9(33)test: the soak time is10min, theconcentration of Vc is0.4%, the concentration of citric acid is0.9%, the concentration ofNaCl is0.4%.2. The following conclusions are obtained by heated hot air drying test: taking500gwater chestnuts as experimental materials, constant temperature hot air drying on80℃needs300min, and the discoloration critical time of the water chestnuts is120min; constanttemperature hot air drying on90℃needs270min, and the discoloration critical time of thewater chestnuts is90min; constant temperature hot air drying on100℃needs240min, andthe discoloration critical time of the water chestnuts is60min; constant temperature hot airdrying on70℃and60℃need s360min and420min, the water chestnuts’color keepsteady in the whole drying process.3. Through the segmentation dry experiment, the best dry conditions of the waterchestnuts are obtained: first dry120min in temperature of80℃, then dry150min intemperature of70℃. The rate of rehydration is90.3%, yield is12.9%and color is white.4. Detecting the component percentage of various nutritional elements in the waterchestnuts powder: the moisture is7.5%, and the starch is74.1%, protein is8.9%, fat is0.7%, crude fiber is3.4%. 5. Capillary electrophoresis (CE) method has been used in the determination offlavonoids and the content of rutin, quercetin, kaempferol, Chlorogenic acid in waterchestnut. Based on researching the effects of several parameters such as composition andconcentration of running buffer, pH, separation temperature and separation voltage, theoptimal conditions has been found: the running buffer consist of20mmol/LKH2PO4—20mmol/L borax, the UV detection wavelength is202nm, separation voltage is24kv,separation temperature is30℃. Under the optimal chromatographic conditions, the fourflavonoids can be separated within7minute. Moreover, the calibration curves about theconcentrations of four flavonoids and their corresponding peak areas showed goodlinearity in the range3.125from100mg/L, The correlation coefficient is above0.999. TheRSD of migration times is between0.78%and0.98%, and the RSD of peak areas isbetween6.5%and8.6%. At the spiked concentration of5.0，10.0，20.0mg/kg, the averagerecoveries of the four flavonoids ranged from80%to98%.6. First study the technological process of water chestnuts biscuit, With sensory scoreand textural properties as the standard, determine the best recipe of the water chestnutsbiscuit: wheat flour is80, the water chestnut flour is20, white sugar is12.5, soybean oil is8, yeast smallsoda is1.2, baking soda is1.5, salt is0.5.