Murakami Y, Yokoigawa K, Kawai F, Kawai H
Department of Food Science and Nutrition, Nara Women's University, Japan.
Biosci Biotechnol Biochem. 1996 Nov;60(11):1874-6. doi: 10.1271/bbb.60.1874.
The lipid composition of some commercial bakers' yeasts having different freeze-sensitivity in frozen dough was investigated to clarify the correlation between their lipid composition and freeze-tolerance. The total lipid content including neutral lipid, free fatty acid, sterol, and phospholipid ranged between 23.0 to 32.2 mg/100 mg protein of the yeasts tested. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidylserine were the main phospholipids found in all yeast strains, but no distinct difference in these components between freeze-tolerant and freeze-sensitive strains was observed. Palmitoleic (C16:1), oleic (C18:1), palmitic (16:0), and stearic (C18:0) acids were the major fatty acids present in total lipid and phospholipid, and unsaturation indices of fatty acid in these lipid components were almost equal by the strains. The molar ratios of sterol to phospholipid of freeze-sensitive strains were higher than those of freeze-tolerant strains. The difference in the sterol-phospholipid ratio that influences the fluidity of plasma membranes in yeast cells was supposed to reflect the difference in freeze-sensitivity of bakers' yeast.
研究了一些在冷冻面团中具有不同冻敏性的商业面包酵母的脂质组成，以阐明其脂质组成与耐冻性之间的相关性。所测试酵母的总脂质含量（包括中性脂质、游离脂肪酸、甾醇和磷脂）在23.0至32.2毫克/100毫克蛋白质之间。磷脂酰胆碱、磷脂酰乙醇胺、磷脂酰肌醇和磷脂酰丝氨酸是所有酵母菌株中发现的主要磷脂，但在耐冻菌株和冻敏菌株之间未观察到这些成分有明显差异。棕榈油酸（C16:1）、油酸（C18:1）、棕榈酸（16:0）和硬脂酸（C18:0）是总脂质和磷脂中存在的主要脂肪酸，并且这些脂质成分中脂肪酸的不饱和度指数在各菌株间几乎相等。冻敏菌株的甾醇与磷脂的摩尔比高于耐冻菌株。影响酵母细胞质膜流动性的甾醇 - 磷脂比的差异被认为反映了面包酵母冻敏性的差异。
