以活菌数、水分含量、感官品质、消化特性、贮藏稳定性、干燥能耗和得率为指标,探究发酵豆乳粉的最佳干燥方式.结果表明:真空冷冻干燥处理的发酵豆乳粉具有较高的乳酸菌活菌数、抗性淀粉含量和贮藏稳定性,并具有较好的色泽、外观和冲调性,但其能耗高,生产效率较低;喷雾干燥处理的发酵豆乳粉具有较好的色泽、外观和冲调性,且水分含量低,其乳酸菌活菌数和贮藏稳定性略低于真空冷冻干燥,但贮藏6个月后的活菌数仍能保持在7.31 lg CFU/g,且其干燥速度快,能耗小,适于发酵豆乳粉的规模化生产;与其他两种方式相比,45 ℃热风干燥处理的发酵豆乳粉冲调性和贮藏稳定性最差.综上,考虑到生产效率、能耗优势和产品质量,建议在发酵豆乳粉生产中采用喷雾干燥技术.
Effect of different drying methods on the quality of fermented soymilk powder
The optimal drying method for fermented soymilk powder was investigated using indicators such as the number of viable lactic acid bacteria moisture content,sensory quality,digestive properties,storage stabil-ity,drying energy consumption and yield.The Results showed that vacuum freeze-drying group had a higher number of viable lactic acid bacteria,higher resistant starch content and better storage stability,as well as bet-ter color,appearance and reconstitution properties,but it had high energy consumption and low production ef-ficiency.Spray drying group had better color,appearance and reconstitution properties,and low moisture content.Although its number of viable lactic acid bacteria and storage stability were slightly lower than vacu-um freeze-drying group,the viable lactic acid bacteria count remained at 7.31 lg CFU/g after 6 months of storage.Additionally,spray drying group had a fast drying speed and low energy consumption,making it suit-able for large-scale production of fermented soymilk powder.Compared to the other two methods,hot air dr-ying group at 45 ℃ had the worst reconstitution properties and storage stability.In conclusion,considering production efficiency,energy consumption and product quality,spray drying technology is recommended for the production of fermented soymilk powder.