Abstract:
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 Quillaja 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.
摘要:
牡丹种子,重要的石油资源,因α-亚麻酸而备受关注。油体(OBs),天然预乳化油,在食品工业中具有巨大的应用潜力。本研究研究了提取pH和Quillaja皂苷(QS)对牡丹油体(POB)乳液理化性质的影响。从pH4.0、5.0、6.0和7.0的生牡丹乳中提取POB(命名为pH4.0-,5.0-,6.0-,和7.0-POB)。所有POB都含有外源蛋白和油质蛋白。pH4.0-和pH5.0-POB的外源蛋白为23kDa和38kDa糖蛋白,未知的蛋白质是48kDa和60kDa,在pH6.0和7.0的提取条件下,48kDa和38kDa蛋白被完全去除。外源蛋白的百分比从pH4.0-POB时的78.4%逐渐下降到pH7.0-POB时的33.88%,而油质蛋白含量增加。POB乳液的粒径和ζ电位降低,而氧化稳定性,储存稳定性,pI随着提取pH的增加而增加。QS(0.05〜0.3%)增加了所有POB乳液的负电荷,和0.1%QS显著提高了分散性,storage,和POB乳液的氧化稳定性。本研究为POBs的水性提取选择合适的条件和提高OB乳液的稳定性提供了指导。