Study On Extrusion Technology Of Cistanche Deserticola-potato Composite Rice

In order to obtain nutritious composite rice with good quality,mellow taste and antioxidant properties,the twin-screw extrusion processing technology was adopted in this paper to prepare composite rice,in which crushed rice was used as the main raw materials.The effects of different extrusion parameters on the quality of composite rice were explored and the corresponding technological conditions were optimized.The specific research contents were as follows:1.Crushed rice was used as raw material,supplemented with 30% potato powder.The effects of screw speed,temperature in gelatinization zone and moisture content on texture quality(including hardness,springiness,cohesiveness,chewiness,resilience),water absorption index,water solubility index,sensory quality,solid substance of rice soup and thousand grain weight of potato composite rice were studied by single factor experiment design.It was found that when the screw speed was 140 rpm,the springiness of the product reached the maximum value.The optimum temperature in IV zone and moisture content of potato composite rice were in the range of 110-120 ? and 28-30%,respectively.2.The orthogonal test was designed based on single factor test results.Range analysis was used to find that different indexes were affected by different factors in different order.The optimum technological parameters of potato composite rice were obtained as follows: screw speed 140 rpm,temperature 115 ? in IV zone and moisture content 29%.Under these conditions,the extruded products were of good quality with the unique aroma of potatoes,whose sensory score was 84.88.3.Crushed rice and potato powder was used as the main raw materials,supplemented with Cistanche deserticola.The effects of screw speed,temperature in gelatinization zone,moisture content and addition of Cistanche deserticola on the qualities of Cistanche deserticola-potato composite rice were analyzed by single factor design.Technological parameters of Cistanche deserticola-potato composite rice were optimized by response surface methodology and data were processed by Design-Expert software.The corresponding mathematical models were fitted with the minimum hardness and the maximum springiness,the content of echinacoside and sensory score.After comprehensive analysis,the optimum process was obtained as follows: the screw speed was 139 rpm,the temperature in IV zone was 115 ?,the moisture content was 29% and the addition of Cistanche deserticola was 0.7%.Under these conditions,products with unique aroma of potatoes and Cistanche deserticola were extruded,whose taste were good.4.It was found that twin-screw extrusion or addition of Cistanche deserticola could improve the water absorption index,water solubility index and the quality of Cistanche deserticola-potato composite rice,resulting in its viscoelasticity close to that of the control group.The hardness and chewiness of extruded gelatinized products were higher than those of the control group due to the existence of starch and polysaccharides in potatoes and Cistanche deserticola.The sensory score of Cistanche deserticola-potato composite rice was as high as 89.95.At the same time,the product was endowed with functional properties,containing 93.45 mg of echinacoside in every 100 grams of composite rice.