Agricultural Engineering Research Department, Khorasan Razavi Agricultural and Natural Resources Research and Education Center, AREEO, Mashhad P.O. Box 91735-488, Iran.
College of Food Science and Technology, Nanjing Agricultural University, 14 1 Weigang Road, Nanjing 211306, China.
Molecules. 2022 Dec 3;27(23):8509. doi: 10.3390/molecules27238509.
For the food sector, onion rejects are an appealing source of value-added byproducts. Bioactive compounds were recovered from yellow onion rejects using a pulse electric field process at 6000 v and 60 pulses. The onion extract was encapsulated with whey protein isolate (WPI), pectin (P), and sodium caseinate (SC) with a mass ratio of 1:5 (extract/wall material, w/w). A Simplex lattice with augmented axial points in the mixture design was applied for the optimization of wall material for the encapsulation of onion reject extract by freeze-drying (FD). The optimal wall materials were 47.6 g/100 g (SC), 10.0 g/100 g (P), and 42.4 g/100 g (WPI), with encapsulation yield (EY) of 85.1%, total phenolic content (TPC) of 48.7 mg gallic acid equivalent/g DW, total flavonoid content (TFC) of 92.0 mg quercetin equivalent/g DW, and DPPH capacity of 76.1%, respectively. The morphological properties of the optimal encapsulate demonstrated spherical particles with a rough surface. At optimal conditions, the minimum inhibitory concentration (MIC) of the extract (mean diameter of inhibition zone: 18.8 mm) was shown as antifungal activity against Aspergillus niger.
对于食品行业来说，洋葱废料是有吸引力的增值副产物来源。采用脉冲电场法在 6000V 和 60 个脉冲下从黄洋葱废料中回收生物活性化合物。洋葱提取物用乳清蛋白分离物（WPI）、果胶（P）和酪蛋白酸钠（SC）包埋，质量比为 1:5（提取物/壁材，w/w）。在混合物设计中应用了带有扩充轴向点的单纯形格子来优化冷冻干燥（FD）包埋洋葱废料提取物的壁材。最佳壁材为 47.6 g/100 g（SC）、10.0 g/100 g（P）和 42.4 g/100 g（WPI），包埋产率（EY）为 85.1%，总酚含量（TPC）为 48.7 mg 没食子酸当量/g DW，总黄酮含量（TFC）为 92.0 mg 槲皮素当量/g DW，DPPH 容量为 76.1%。最佳包埋物的形态特性表现为具有粗糙表面的球形颗粒。在最佳条件下，提取物（抑菌圈平均直径：18.8mm）的最小抑菌浓度（MIC）显示出对黑曲霉的抗真菌活性。
