Geng Zhihua, Zhu Lichun, Wang Jun, Yu Xianlong, Li Mengqing, Yang Wenxin, Hu Bin, Zhang Qian, Yang Xuhai
College of Mechanical and Electrical Engineering, Shihezi University, Shihezi, China.
College of Food Science and Engineering, Northwest A&F University, Yangling, China.
Front Nutr. 2023 Feb 8;10:1106009. doi: 10.3389/fnut.2023.1106009. eCollection 2023.
Sea buckthorn berries are important ingredients in Chinese medicine and food processing; however, their high moisture content can reduce their shelf life. Effective drying is crucial for extending their shelf life. In the present study, we investigated the effects of hot-air drying (HAD), infrared drying (IRD), infrared-assisted hot-air drying (IR-HAD), pulsed-vacuum drying (PVD), and vacuum freeze-drying (VFD) on the drying kinetics, microstructure, physicochemical properties (color, non-enzyme browning index, and rehydration ratio), and total phenol, total flavonoid, and ascorbic acid contents of sea buckthorn berries. The results showed that the IR-HAD time was the shortest, followed by the HAD, IRD, and PVD times, whereas the VFD time was the longest. The value of the color parameter * decreased from 53.44 in fresh sea buckthorn berries to 44.18 (VFD), 42.60 (PVD), 37.58 (IRD), 36.39 (HAD), and 36.00 (IR-HAD) in dried berries. The browning index also showed the same trend as the color change. Vacuum freeze-dried berries had the lowest browning index (0.24 Abs/g d.m.) followed by that of pulsed-vacuum-(0.28 Abs/g d.m.), infrared- (0.35 Abs/g d.m.), hot-air-(0.42 Abs/g d.m.), and infrared-assisted hot-air-dried berries (0.59 Abs/g d.m.). The ascorbic acid content of sea buckthorn berries decreased by 45.39, 53.81, 74.23, 77.09, and 79.93% after VFD, PVD, IRD, IR-HAD, and HAD, respectively. The vacuum freeze-dried and pulsed-vacuum-dried sea buckthorn berries had better physicochemical properties than those dried by HAD, IRD, and IR-HAD. Overall, VFD and PVD had the highest ascorbic acid and total phenolic contents, good rehydration ability, and bright color. Nonetheless, considering the high cost of VFD, we suggest that PVD is an optimal drying technology for sea buckthorn berries, with the potential for industrial application.
沙棘果是中药和食品加工中的重要原料；然而，其高水分含量会缩短其保质期。有效的干燥对于延长其保质期至关重要。在本研究中，我们研究了热风干燥（HAD）、红外干燥（IRD）、红外辅助热风干燥（IR-HAD）、脉冲真空干燥（PVD）和真空冷冻干燥（VFD）对沙棘果干燥动力学、微观结构、理化性质（颜色、非酶褐变指数和复水率）以及总酚、总黄酮和抗坏血酸含量的影响。结果表明，IR-HAD时间最短，其次是HAD、IRD和PVD时间，而VFD时间最长。颜色参数*的值从新鲜沙棘果中的53.44降至干沙棘果中的44.18（VFD）、42.60（PVD）、37.58（IRD）、36.39（HAD）和36.00（IR-HAD）。褐变指数也呈现与颜色变化相同的趋势。真空冷冻干燥的沙棘果褐变指数最低（0.24 Abs/g干物质），其次是脉冲真空干燥的（0.28 Abs/g干物质）、红外干燥的（0.35 Abs/g干物质）、热风干燥的（0.42 Abs/g干物质）和红外辅助热风干燥的沙棘果（0.59 Abs/g干物质）。沙棘果经VFD、PVD、IRD、IR-HAD和HAD干燥后，抗坏血酸含量分别下降了45.39%、53.81%、74.23%、77.09%和79.93%。真空冷冻干燥和脉冲真空干燥的沙棘果比HAD、IRD和IR-HAD干燥的沙棘果具有更好的理化性质。总体而言，VFD和PVD的抗坏血酸和总酚含量最高，复水能力良好，颜色鲜艳。尽管如此，考虑到VFD成本高昂，我们建议PVD是沙棘果的最佳干燥技术，具有工业应用潜力。
