不同干燥方式对黄桃果粉品质的影响

Effect of drying methods on quality of yellow peach powder

以黄桃为原料,采用热风干燥(HAD)、喷雾干燥(SD)和真空冷冻干燥(VFD)3种方式制备黄桃果粉,对其进行感官评价,并就其色泽、溶解性、流动性、堆积密度、持水力和持油力等物理特性,蛋白质、总可溶性固形物、可滴定酸、维生素C、总酚等营养成分含量,微观结构,以及香气成分的种类和含量等进行深入分析。结果表明:经HAD处理的黄桃果粉色泽暗淡,黏度较大,组织状态较差。相较于SD,经VFD处理的黄桃果粉含水率[(2.69±0.02)%]、溶解时间[(46.67±0.21)s]、堆积密度[(0.21±0.11)g·mL^(-1)]和休止角[(26.07±0.25)°]显著(P<0.05)降低,水溶性指数[(98.21±0.16)%]、持水力[(2.51±0.19)g·g^(-1)]和持油力[(3.41±0.21)mL·g^(-1)]显著提高,总酚[(82.27±0.21)mg·kg^(-1)]、维生素C[(79.3±1.1)mg·kg^(-1)]和总可溶性固形物[(6.98±0.13)%]含量显著提高,且糖酸比较佳,挥发性醇、醛、酯类物质保留较多,具有更好的果味和香味。在微观结构上,经SD处理的黄桃果粉呈现球形、不规则的收缩状,而经VFD处理的黄桃果粉呈骨架状结构且多孔,易恢复到原结构,冲调性能较好。综上,真空冷冻干燥方式制得的黄桃果粉品质较佳,适宜在高质量黄桃果粉加工业中推广应用。

In order to select the suitable drying method to produce yellow peach powder,yellow peach was used as raw material,hot air drying(HAD),spray drying(SD)and vacuum freeze drying(VFD)were introduced.Sensory evaluation of yellow peach powder was conducted,and physical properties such as color,solubility,fluidity,bulk density,water holding capacity,and oil holding capacity were determined.In addition,the contents of nutrients such as protein,total soluble solids,titratable acids,vitamin C,total phenols were explored,as well as the microstructure,and the types and contents of aroma components.The results showed that the yellow peach powder produced by HAD had dark color,high viscosity and poor tissue state.Compared with the yellow peach powder produced by SD,the water content[(2.69±0.02)%],dissolution time[(46.67±0.21)s],bulk density[(0.21±0.11)g·mL^(-1)]and angle of repose[(26.07±0.25)°]of yellow peach powder produce by VFD were significantly(P<0.05)decreased,yet its water solubility index[(98.21±0.16)%],water holding capacity[(2.51±0.19)g·g^(-1)]and oil holding capacity[(3.41±0.21)mL·g^(-1)]were significantly increased,and the contents of total phenols[(82.27±0.21)mg·kg^(-1)],vitamin C[(79.3±1.1)mg·kg^(-1)]and total soluble solids[(6.98±0.13)%]were significantly improved,and the ratio of sugar to acid was better.Besides,the yellow peach powder produced by VFD retained more volatile compounds,such as alcohols,aldehydes and esters,which exhibited better fruit flavor and aroma.For microstructure,the yellow peach powder produced by SD showed spherical,irregular shrinkage,while the yellow peach powder produced by VFD showed skeleton and porous structure,which was easy to recover to the original structure.In conclusion,the yellow peach powder produced by VFD had better quality.Thus,VFD is suitable to produce high-quality yellow peach powder.