Study On The Extrusion Of Whole Purple Waxy Wheat Flour And Application

The effects of the different extrusion conditions on the physiochemical properties and antioxidant activity of whole purple waxy wheat flour were investigated. The extrusion conditions of whole purple waxy wheat flour was optimized; The effects of amount of maltodextrin, monoglyride,sodium alginate,sucrose on the dispersivity and dissolvability of the instant purple wheat powder were investigated and the optimized ingredients formula was provided.. The results were as follows:1. The effects of the different extrusion conditions on the physiochemical properties and antioxidant activity of whole purple waxy wheat flour were investigated. The expansion ratio, WSI, TDF, SDF, TPC increased and WAI decreased with the increase of barrel temperature and screw speed. SDF of the extrudate increased 26% compared to raw purple waxy wheat flour. There was the highest TPC(1.03mg/g)at 170 ℃ and 13% feed moisture. The WSI and WAI of puffed powders increased by 70% and 37% than the raw material, respectively. Increasing feed moisture content resulted in lower WSI and TPC, but higher WAI and some other properties. The total antioxidant activity significantly decreased with the increase of barrel temperature, screw speed and feed moisture content.2. The optimum extrusion conditions of whole purple waxy wheat flour were 19% feed moisture content, extrusion temperature of 160 ℃, and screw speed 300 r/min. The expansion ratio of whole purple waxy wheat flour at optimized conditions was 2.47; the WAI and WSI of puffed powders were 3.51 and 0.28. The mathematic model could exactly predict the properties of purple waxy wheat flour.3. Puffed whole purple waxy wheat flour, maltodextrin, monoglyride, sodium alginate, sugar were used as major materials to develop an instant nutritious cereal powder in this study. The suitable conditions ranges of each factor were obtained on the pre-experiments and single factor tests. Through the L(16)45 orthogonal experimental and integrated weighted scoring method, the optimal formula of the product was finally identified. The results showed that the optimal formula as follows :maltodextrin 34%,monoglyride 0.6%,sodium alginate 1.0%,sugar 17%, which could evidently improve the fast dissolvability, dispersibility and sensory evaluation of the nutritious cereal powder.