In this study, a new starch has been isolated from acorn (Quercus ilex) fruits. The chemical composition of acorn flour showed its richness in carbohydrates (64.43%), proteins (8%), and fat (10%). The extraction yield of acorn starch was about 34.5%. Thus, the composition of extracted acorn starch and its physical and functional properties were studied. Acorn starch had high purity represented by low proportions of proteins (0.92%) and lipids (0.51%) with a pH of 5.3. The swelling power was 20.76 g/g, while the solubility was about 64.22% at 90°C which suggests that acorn starch has potential for use in food industries. The FT-IR spectra of isolated native starches have shown the main bands characterizing the starch. However, X-ray diffractograms exhibited an A- and B-type diffraction pattern. Furthermore, the effect of acorn starch incorporation at different levels (0.5%, 1%, 1.5%, and 2%) on the quality parameters of a fermented dairy product was investigated at the beginning of storage. The results demonstrated that the most suitable dose of acorn starch to be incorporated in the fermented dairy product was lower than 1%. This low concentration reduced syneresis, improved functional properties, and enhanced the viscosity of the fermented dairy product.

中文翻译：

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突尼斯栎类淀粉的提取，表征及其对发酵乳制品品质的影响。

在这项研究中，从橡子中分离出了一种新淀粉（Quercus ilex） 水果。橡子粉的化学成分显示其富含碳水化合物（64.43％），蛋白质（8％）和脂肪（10％）。橡子淀粉的提取率约为34.5％。因此，研究了提取的橡子淀粉的组成及其物理和功能特性。橡子淀粉具有高纯度，其蛋白质（0.92％）和脂质（0.51％）的比例低，pH值为5.3。溶胀力为20.76g / g，而在90℃下的溶解度为约64.22％，这表明橡子淀粉具有在食品工业中使用的潜力。分离的天然淀粉的FT-IR光谱显示出表征淀粉的主要谱带。但是，X射线衍射图显示出A型和B型衍射图。此外，橡子淀粉掺入的影响程度不同（0.5％，1％，1.5％，在储存之初就对发酵乳制品的质量参数进行了2％的研究。结果表明，要掺入发酵乳制品中的最合适的橡子淀粉剂量低于1％。这种低浓度降低了脱水收缩，改善了功能特性，并提高了发酵乳制品的粘度。