An Kejing, Fu Manqin, Zhang Hao, Tang Daobang, Xu Yujuan, Xiao Gengsheng
Sericulture and Agri-Food Research Institute Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture/Guangdong Key Laboratory of Agricultural Products Processing, Dong Guanzhuang Yiheng RD, Tianhe District, Guangzhou, 510610 People's Republic of China.
J Food Sci Technol. 2019 Feb;56(2):783-791. doi: 10.1007/s13197-018-3538-7. Epub 2019 Jan 4.
Blueberry belongs to the genus , which is rich in a variety of biologically active components beneficial to the human body. Drying of blueberry is a slow and energy-intensive process because of its waxy skin, which has low permeability to moisture. Therefore, chemical pretreatment of ethyl oleate (AEEO) was adopted to accelerate moisture diffusivity. The results showed that the drying rate of blueberries was increased significantly by AEEO treatment, and the drying time can be shortened by 17.17-40.70%. After AEEO dipping, the effective diffusion coefficient increased from 5.461 × 10 to 1.067 × 10 m/s at 60 °C. Six semi-theoretical thin-layer models were used to estimate the curves of air-drying of blueberry, and Wang-Singh model was found to perform better than other models. Besides, the rehydration and retention of nutritional contents were also improved by AEEO dipping. The total phenolics, total flavonoids, total anthocyanin content, and ABTS*+ scavenging activity of blueberry were increased by 37.74%, 21.01%, 47.83%, and 30.75%, respectively. The result of SEM observation and cell-membrane permeability indicated that AEEO could break down the wax layer of blueberry, change the crystal structure of wax layer, and increase cell permeability, which resulted in shorter drying time and higher quality of blueberry.
蓝莓属于该属，富含多种对人体有益的生物活性成分。由于蓝莓表皮蜡质化，水分渗透率低，其干燥过程缓慢且耗能。因此，采用油酸乙酯（AEEO）化学预处理来加速水分扩散率。结果表明，AEEO处理显著提高了蓝莓的干燥速率，干燥时间可缩短17.17 - 40.70%。在60℃下，经AEEO浸渍后，有效扩散系数从5.461×10增加到1.067×10米²/秒。使用六个半理论薄层模型来估算蓝莓风干曲线，发现Wang-Singh模型比其他模型表现更好。此外，AEEO浸渍还改善了蓝莓的复水性和营养成分保留率。蓝莓的总酚、总黄酮、总花青素含量和ABTS⁺清除活性分别提高了37.74%、21.01%、47.83%和30.75%。扫描电子显微镜观察结果和细胞膜通透性表明，AEEO可分解蓝莓蜡层，改变蜡层晶体结构，增加细胞通透性，从而缩短干燥时间并提高蓝莓品质。
