亚临界水提取热稳定脱脂米糠蛋白

利用亚临界水在不同温度（100～200 ℃）和时间（0～30 min）条件下提取热稳定脱脂米糠（heat stable defatted rice bran，HSDRB）中的蛋白质。研究在不同提取条件下提取物中蛋白质含量、总糖含量、氨基酸组成、 分子质量分布以及色差。结果表明：在提取温度175 ℃、提取时间30 min时，提取物中蛋白质及氨基酸的含量最 高，分别为50%和48.6 mg/g HSDRB；在此条件下，氨基酸具有最高的疏水性（1.8 kJ/mol）以及最高的必需氨基酸 含量（14.8 mg/g HSDRB）；温度对提取物颜色具有显著影响，L*值与提取物中蛋白质含量呈负相关关系，而a*值 与提取物中蛋白质含量呈正相关关系；提取物中的疏水性成分主要为小分子物质。

Heat-Stable Defatted Rice Bran Protein Extracted by Subcritical Water Extraction

Protein in heat stable defatted rice bran (HSDRB) was extracted with subcritical water at various temperatures
(100–200 ℃) and various extraction durations (0–30 min). The extracts were analyzed for protein and total carbohydrate
contents, amino acid composition, molecular mass distribution and color parameters. The results showed that the highest
yields of protein and amino acids were 50% and 48.6 mg/g HSDRB, respectively at 175 ℃ for 30 min. Under these
conditions, the average hydrophobicity of amino acids and the essential amino acids content were the highest, reaching 1.84 kJ/mol and
14.8 mg/g HSDRB, respectively. The color parameters were significantly different at various temperatures. L* values were
negatively correlated with protein content while a* values were positively correlated with protein content. The hydrophilic
fraction of the extracts mainly contained low-molecular-mass substances.