Food Conservation and Valorization Laboratory, High Institute of Food Industries , 58 Avenue Alain Savary, El Khadra City, Tunis 1003, Tunisia.
J Agric Food Chem. 2013 Aug 14;61(32):7715-21. doi: 10.1021/jf402323u. Epub 2013 Aug 6.
Seed proteins extracted from Tunisian pumpkin seeds ( Cucurbita maxima ) were investigated for their solubility properties and sequentially extracted according to the Osborne procedure. The solubility of pumpkin proteins from seed flour was greatly influenced by pH changes and ionic strength, with higher values in the alkaline pH regions. It also depends on the seed defatting solvent. Protein solubility was decreased by using chloroform/methanol (CM) for lipid extraction instead of pentane (P). On the basis of differential solubility fractionation and depending on the defatting method, the alkali extract (AE) was the major fraction (42.1 (P), 22.3% (CM)) compared to the salt extract (8.6 (P), 7.5% (CM)). In salt, alkali, and isopropanol extracts, all essential amino acids with the exceptions of threonine and lysine met the minimum requirements for preschool children (FAO/WHO/UNU). The denaturation temperatures were 96.6 and 93.4 °C for salt and alkali extracts, respectively. Pumpkin protein extracts with unique protein profiles and higher denaturation temperatures could impart novel characteristics when used as food ingredients.
从突尼斯南瓜籽（Cucurbita maxima）中提取的种子蛋白，其溶解性特性已被研究，并且根据 Osborne 程序顺序提取。南瓜籽粉中南瓜蛋白的溶解性受 pH 值和离子强度的影响较大，在碱性 pH 区域中值较高。它还取决于种子脱脂溶剂。与戊烷 (P) 相比，使用氯仿/甲醇 (CM) 提取脂质会降低蛋白质的溶解度 (CM)。基于差异溶解性分级，并取决于脱脂方法，碱提取物 (AE) 是主要部分（42.1 (P)，22.3% (CM)），而盐提取物 (8.6 (P)，7.5% (CM)）。在盐、碱和异丙醇提取物中，除苏氨酸和赖氨酸外，所有必需氨基酸均符合学龄前儿童（粮农组织/世卫组织/联合国大学）的最低要求。盐和碱提取物的变性温度分别为 96.6 和 93.4°C。用作食品成分时，具有独特蛋白质图谱和更高变性温度的南瓜蛋白提取物可能会赋予其新的特性。
