UMR 1253, INRA, Science et Technologie du Lait et de l'Œuf, 65 rue de Saint Brieuc, F-35042 Rennes, France.
J Agric Food Chem. 2011 Dec 14;59(23):12443-52. doi: 10.1021/jf2027268. Epub 2011 Nov 10.
Ragusano is a pasta filata cheese produced from raw milk in Sicily. The proteolysis was extensively analyzed after stretching (day 0), at 4 and 7 months of ripening through soluble nitrogen, urea-PAGE, and peptide identification by tandem mass spectrometry. After stretching, 123 peptides were identified: 72 arising from β-casein, 34 from α(s1)-casein, and 17 from α(s2)-casein. The main protein splitting corresponded to the action of plasmin, chymosin, cathepsin D, cell envelope proteinase, and peptidase activities of lactic acid bacteria. Unlike other types of cheeses, <10% residual β- and α(s)-caseins remained intact at 7 months, indicating original network organization based on large casein fragments. The number of identified soluble peptides also dramatically decreased after 4 and 7 months of ripening, to 47 and 25, respectively. Among them, bioactive peptides were found, that is, mineral carrier, antihypertensive, and immunomodulating peptides and phosphopeptides.
拉古萨诺干酪是一种源自西西里岛的新鲜牛奶乳源的意大利乳清干酪。在拉伸（第 0 天）后，通过可溶性氮、尿素-PAGE 和串联质谱法鉴定肽，对其进行了广泛的蛋白水解分析，在 4 个月和 7 个月的成熟过程中也进行了分析。拉伸后，共鉴定出 123 种肽：72 种来自 β-酪蛋白，34 种来自 α(s1)-酪蛋白，17 种来自 α(s2)-酪蛋白。主要的蛋白裂解对应于纤溶酶、凝乳酶、组织蛋白酶 D、细胞包膜蛋白酶和乳酸菌肽酶活性的作用。与其他类型的奶酪不同，在 7 个月时，β-和 α(s)-酪蛋白的 <10%残留量保持完整，表明基于大的酪蛋白片段的原始网络组织。在成熟 4 个月和 7 个月后，可溶肽的数量也分别急剧减少到 47 种和 25 种。其中发现了生物活性肽，即矿物质载体、降压和免疫调节肽和磷酸肽。
