不同干燥技术对核桃粕蛋白粉品质特性及微观结构的影响

以核桃粕为原料,采用热风干燥、热泵干燥、真空冷冻干燥和喷雾干燥4种干燥技术制备核桃粕蛋白粉,考察不同干燥技术对核桃粕蛋白粉品质特性及微观结构的影响.结果 表明:热风和热泵干燥制备的核桃粕蛋白粉吸水率较低,易贮藏,但色泽和品质较差,呈现大小不一的不规则块状结构,且表面结构租糙;真空冷冻干燥获得的核桃粕蛋白粉集粉率、蛋白质...

Effects of Different Drying Technologies on the Quality Characteristics and Microstructure of Walnut Meal Protein Powder

Walnut meal protein powder was processed from walnut meal by four drying technologies:hot air drying(HA),heat pump drying(HP),vacuum freeze drying(VF)and spray drying(SD).The aim of this study was to investigate the effect of different drying technologies on the quality characteristics and microstructure of walnut meal protein powder.The results showed that the walnut meal protein powders processed by HA and HP had lower hygroscopicity and consequently better storability compared to those processed by the other drying methods,but their color and quality were poorer,and their microstructure exhibited irregular blocky shapes of varying size with rough surfaces.The product dried by VF,with the highest yield of 29.18%,had the highest protein,essential amino acid and total amino acid contents of 87.70%,24.61 g/100 g and 86.11 g/100 g,respectively,as well as the lowest moisture of 3.05%,but it had poor color,lamellar microstructure with smooth surfaces,and large particle size.The product dried by SD,with the lowest yield,had the highest sensory score,L^*value,moisture content,specific surface area and hygroscopicity of 75 points,90.63,3.91%,271.47 m²/kg and 2.16%,respectively.In addition,it had good nutritional quality,the lowest wettability(settlement time of 139.33 s),and the smallest and uniform particle size,and its microstructure was maintained well.Taking into consideration the quality characteristics and microstructure of walnut meal protein powder,and the drying efficiency and cost,SD was the method of choice for preparing walnut meal protein powder.