College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Southwest University, College of Food Science, Chongqing, 400700, China.
Food Res Int. 2022 Dec;162(Pt B):112104. doi: 10.1016/j.foodres.2022.112104. Epub 2022 Nov 2.
Drying is essential for preserving fresh bee pollen. However, the effects of different drying techniques on lipid quality are unknown. This study aimed to compare the effects of four drying methods (freeze-drying (FD), infrared drying (IRD), hot-air drying (HAD), and pulsed vacuum drying (PVD)) on the drying kinetics, lipid oxidation, lipid profiles, and lipid metabolic pathways of bee pollen. IRD and HAD had the fastest drying rates but the highest degree of lipid oxidation. Lipidomics analysis of the bee pollen identified 1541 lipid metabolites from 20 subclasses. Glycerophospholipids were the most abundant, followed by glycerides, glycolipids, and sphingolipids. Drying not only reduced the lipid content, but also altered the structure of the triglyceride (TG) and fatty acid (FA), which might be caused by degradation and oxidation. Principal components analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) showed that IRD and HAD had the greatest effects on lipid metabolites, whereas FD had the smallest influence. Lipid oxidation during drying was correlated with differential lipids and three main metabolic pathways, including glycerophospholipid, linoleic acid, and glycerolipid metabolic pathways, in which phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidic acid (PA), and lyso-phosphatidylcholine (LPC) were the key lipids. Our results provide comprehensive lipid profiles and potential mechanisms of lipid oxidation during bee pollen drying.
干燥对于保持新鲜蜂花粉至关重要。然而，不同干燥技术对脂质质量的影响尚不清楚。本研究旨在比较四种干燥方法（冷冻干燥（FD）、红外干燥（IRD）、热空气干燥（HAD）和脉冲真空干燥（PVD））对蜂花粉干燥动力学、脂质氧化、脂质谱和脂质代谢途径的影响。IRD 和 HAD 具有最快的干燥速率，但脂质氧化程度最高。通过对蜂花粉的脂质组学分析，从 20 个亚类中鉴定出 1541 种脂质代谢物。甘油磷脂含量最丰富，其次是甘油酯、糖脂和鞘脂。干燥不仅降低了脂质含量，还改变了甘油三酯（TG）和脂肪酸（FA）的结构，这可能是由于降解和氧化引起的。主成分分析（PCA）和正交偏最小二乘判别分析（OPLS-DA）表明，IRD 和 HAD 对脂质代谢物的影响最大，而 FD 的影响最小。干燥过程中的脂质氧化与差异脂质和三个主要代谢途径相关，包括甘油磷脂、亚油酸和甘油酯代谢途径，其中磷脂乙醇胺（PE）、磷脂酰胆碱（PC）、磷脂酰丝氨酸（PS）、磷脂酸（PA）和溶血磷脂酰胆碱（LPC）是关键脂质。我们的研究结果提供了全面的脂质谱和蜂花粉干燥过程中脂质氧化的潜在机制。
