Food Science Institute, Kansas State University, Manhattan 66506.
Food Science Institute, Kansas State University, Manhattan 66506; Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506.
J Dairy Sci. 2019 Dec;102(12):10855-10866. doi: 10.3168/jds.2019-16419. Epub 2019 Sep 20.
In recent years, using dairy phospholipids (PL) as functional ingredients has increased because PL have nutritional benefits and functional properties. In this study, a novel 2-step supercritical fluid extraction (SFE) process was used to extract whey protein phospholipid concentrate (WPPC), a dairy co-product obtained during the manufacture of whey protein isolate, for PL enrichment. In the first step, nonpolar lipids in WPPC were removed using neat supercritical carbon dioxide (S-CO) at 41.4 MPa and 60°C. In the second stage, the feasibility of using the polar solvent ethanol as a co-solvent to increase the solubility of S-CO extraction solvent was explored. A 3 × 3 × 2 factorial design with extraction pressure (35.0, 41.4, and 55.0 MPa), temperature (40 and 60°C), and concentration of ethanol (10, 15, and 20%) as independent factors was used to evaluate the extraction efficiency providing the most total PL, and the best proportion of each individual PL from the spent solids collected during S-CO SFE. All lipid fractions were analyzed using thin-layer chromatography and high-performance lipid chromatography. The total amount of PL extracted from WPPC was significantly affected by ethanol concentration; the extraction pressure and temperature were nonsignificant. The optimal SFE condition for generating a concentrated PL lipid fraction was 35.0 MPa, 40°C, and 15% ethanol concentration; the highest amount of extracted PL averaged 26.26 g/100 g of fat. Moreover, adjusting SFE condition allowed successful recovery of a high concentration of sphingomyelin, phosphatidylcholine, and phosphatidylethanolamine, giving averages of 11.07, 10.07, and 7.2 g/100 g of fat, respectively, 2 to 3 times more than conventional solvent extraction. In addition, exhausted solids obtained after the SFE process were enriched with denatured proteins (72% on dry basis) with significantly more water-holding capacity and emulsifying capacity than untreated WPPC. Overall, this 2-stage SFE process using neat S-CO and ethanol has the greatest potential to produce a PL-rich lipid fraction from WPPC.
近年来，由于磷脂（PL）具有营养价值和功能特性，因此将其作为功能性成分的使用有所增加。在这项研究中，使用了一种新颖的两步超临界流体萃取（SFE）工艺从乳清蛋白分离物生产过程中获得的乳清蛋白副产物乳清蛋白磷脂浓缩物（WPPC）中提取富含 PL 的乳磷脂。在第一步中，使用纯净的超临界二氧化碳（S-CO）在 41.4 MPa 和 60°C 的温度下除去 WPPC 中的非极性脂质。在第二阶段，探索了使用极性溶剂乙醇作为共溶剂来提高 S-CO 萃取溶剂溶解度的可行性。使用萃取压力（35.0、41.4 和 55.0 MPa）、温度（40 和 60°C）和乙醇浓度（10、15 和 20%）的 3×3×2 析因设计作为独立因素来评估提取效率，从收集的用过的 S-CO SFE 固体中提供总 PL 最多和每种 PL 比例最佳的条件。使用薄层色谱法和高效脂质色谱法分析所有脂质馏分。从 WPPC 中提取的 PL 总量受乙醇浓度的显著影响；萃取压力和温度无显著影响。产生浓缩 PL 脂质馏分的最佳 SFE 条件为 35.0 MPa、40°C 和 15%乙醇浓度；提取的 PL 量最高平均值为 26.26 g/100 g 脂肪。此外，调整 SFE 条件可成功回收高浓度的鞘磷脂、磷脂酰胆碱和磷脂酰乙醇胺，分别平均为 11.07、10.07 和 7.2 g/100 g 脂肪，是传统溶剂萃取的 2 至 3 倍。此外，SFE 工艺后获得的废固体富含变性蛋白（干基 72%），其持水能力和乳化能力明显高于未处理的 WPPC。总体而言，使用纯净 S-CO 和乙醇的两步 SFE 工艺最有可能从 WPPC 中生产富含 PL 的脂质馏分。
