Shen Pengkun, Yang Ruizhi, Wu Yingying, Liu Jiao, Ding Xiuzhen, Wang Wentao, Zhao Luping
College of Food Science and Engineering, Shandong Agricultural University, Tai'an 271018, China.
Foods. 2023 Aug 11;12(16):3017. doi: 10.3390/foods12163017.
Peony seeds, an important oil resource, have been attracting much attention because of α-linolenic acid. Oil bodies (OBs), naturally pre-emulsified oils, have great potential applications in the food industry. This study investigated the effects of extraction pH and saponin (QS) on the physicochemical properties of peony oil body (POB) emulsions. POBs were extracted from raw peony milk at pH 4.0, 5.0, 6.0, and 7.0 (named pH 4.0-, 5.0-, 6.0-, and 7.0-POBs). All POBs contained extrinsic proteins and oleosins. The extrinsic proteins of pH 4.0- and pH 5.0-POB were 23 kDa and 38 kDa glycoproteins, the unknown proteins were 48 kDa and 60 kDa, while the 48 kDa and 38 kDa proteins were completely removed under the extraction condition of pH 6.0 and 7.0. The percentage of extrinsic proteins gradually decreased from 78.4% at pH 4.0-POB to 33.88% at pH 7.0-POB, while oleosin contents increased. The particle size and zeta potential of the POB emulsions decreased, whereas the oxidative stability, storage stability, and pI increased with the increasing extraction pH. QS (0.05~0.3%) increased the negative charges of all the POB emulsions, and 0.1% QS significantly improved the dispersion, storage, and the oxidative stability of the POB emulsions. This study provides guidance for selecting the proper conditions for the aqueous extraction of POBs and improving the stability of OB emulsions.
牡丹籽作为一种重要的油脂资源，因其富含α-亚麻酸而备受关注。油体是天然预乳化的油脂，在食品工业中具有巨大的潜在应用价值。本研究考察了提取pH值和皂苷（QS）对牡丹油体（POB）乳液理化性质的影响。在pH值为4.0、5.0、6.0和7.0的条件下从生牡丹乳中提取POB（分别命名为pH 4.0-、5.0-、6.0-和7.0-POB）。所有POB均含有外在蛋白和油质蛋白。pH 4.0-和pH 5.0-POB的外在蛋白为23 kDa和38 kDa的糖蛋白，未知蛋白为48 kDa和60 kDa，而在pH 6.0和7.0的提取条件下，48 kDa和38 kDa的蛋白被完全去除。外在蛋白的百分比从pH 4.0-POB的78.4%逐渐降至pH 7.0-POB的33.88%，而油质蛋白含量增加。POB乳液的粒径和zeta电位降低，而氧化稳定性、储存稳定性和pI随着提取pH值的增加而增加。QS（0.05~0.3%）增加了所有POB乳液的负电荷，0.1%的QS显著提高了POB乳液的分散性、储存性和氧化稳定性。本研究为选择合适的POB水提取条件和提高油体乳液稳定性提供了指导。
