Wu Limin, Wei Mengmeng, Lu Ninghai, Liu Benguo
School of Plant Protection and Environment, Henan Institute of Science and Technology, Xinxiang 453003, China.
School of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China.
Foods. 2025 Aug 10;14(16):2779. doi: 10.3390/foods14162779.
Pepper seeds, a key byproduct of pepper processing, are rich in high-quality plant proteins. This study investigated the structural and functional properties of pepper seed protein isolate (PSPI) and optimized the ultrasonic homogenization process for PSPI-based nanoemulsions using response surface methodology (RSM), followed by stability evaluation. The results showed that glutamic acid is the dominant amino acid in PSPI, with a molecular weight range of 10-55 kDa. Some protein subunits were interconnected via disulfide bonds. Functionally, PSPI had lower water-/oil-holding capacities but superior emulsifying activity compared to soy protein isolate (SPI). RSM optimization determined the optimal nanoemulsion parameters within experimental constraints: PSPI 0.53%, ultrasonic power 500 W, and ultrasonic time 130 s, yielding a nanoemulsion with a droplet size of 319 ± 2 nm, consistent with the theoretical prediction (318 nm). The nanoemulsion demonstrated stability under neutral-to-alkaline conditions (pH 7.0-9.0), high ionic strength (Na concentration ≤ 100 mM), and elevated temperatures (40-100 °C), without phase separation or aggregation. This work supports pepper seed protein utilization and provides insights for plant protein nanoemulsion production.
辣椒籽是辣椒加工的一种关键副产品，富含优质植物蛋白。本研究调查了辣椒籽分离蛋白（PSPI）的结构和功能特性，并采用响应面法（RSM）优化了基于PSPI的纳米乳液的超声均质过程，随后进行了稳定性评估。结果表明，谷氨酸是PSPI中的主要氨基酸，分子量范围为10 - 55 kDa。一些蛋白质亚基通过二硫键相互连接。在功能方面，与大豆分离蛋白（SPI）相比，PSPI的持水/油能力较低，但乳化活性较高。RSM优化在实验范围内确定了最佳纳米乳液参数：PSPI 0.53%、超声功率500 W和超声时间130 s，得到的纳米乳液液滴尺寸为319±2 nm，与理论预测值（318 nm）一致。该纳米乳液在中性至碱性条件（pH 7.0 - 9.0）、高离子强度（Na浓度≤100 mM）和高温（40 - 100°C）下表现出稳定性，无相分离或聚集现象。本研究为辣椒籽蛋白的利用提供了支持，并为植物蛋白纳米乳液的生产提供了见解。
