Dept. of Food and Nutrition, Sookmyung Women's Univ., Seoul, 04310, Korea.
Dept. of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Inst. of Agriculture and Life Science, Seoul National Univ., Seoul, 08826, Korea.
J Food Sci. 2019 Oct;84(10):2944-2954. doi: 10.1111/1750-3841.14813. Epub 2019 Sep 25.
The objective of this study was to isolate and identify the microorganisms, especially yeasts and molds, related to the improvement of beef quality during dry-aging of beef through microbiome analysis, and to examine the possibility of using them as starter culture strains to improve the efficiency of dry-aging beef production. Beef sirloins were dry-aged for 28 days using different wind speeds (0, 2.5, and 5 m/s) at 1 to 3 °C and 75% relative humidity, and microbial compositions were confirmed by microbiome analysis. Mold and yeast samples were plated on potato dextrose agar supplemented with 10% tartaric acid, and the isolated colonies were identified by DNA sequencing. The isolates were subjected to microbial characterization (morphological characterization, growth condition, and enzyme activity). Microbiome analysis showed that the dominant microorganisms were molds and yeasts identified as Pilaira anomala SMFM201611 and Debaryomyces hansenii SMFM201707. Pilaira anomala SMFM201611 and D. hansenii SMFM201707 were inoculated into 24 sirloins of the lowest grade. All samples were dry-aged for 0, 14, 21, and 28 days and analyzed for microbial growth, pH, shear force, ultrastructure, and flavor compounds (free amino acids and free fatty acids). Inoculation with P. anomala SMFM201611 and D. hansenii SMFM201707 improved tenderness and cause the breakdown of myofibrils by proteolysis. Both microorganisms also produced free amino acids and fatty acids through proteolytic and lipolytic activities. These results indicate that P. anomala SMFM201611 and D. hansenii SMFM201707 isolated and identified from dry-aged beef can improve the quality of low-grade beef during dry-aging. PRACTICAL APPLICATION: During dry-aging, mold and yeast improve the quality of dry-aged beef. Pilaira anomala SMFM201611 and Debaryomyces hansenii SMFM201707 isolated from dry-aged beef can improve tenderness by breaking down myofibrils. Both microorganisms improve flavor by producing free fatty acids and amino acids, and the taste and aroma characteristics of low-grade beef may be improved during the dry-aging process.
本研究的目的是通过微生物组分析分离和鉴定与牛肉干化过程中牛肉品质改善相关的微生物，特别是酵母和霉菌，并研究将其用作发酵剂菌株以提高牛肉干化生产效率的可能性。将牛里脊肉在 1 至 3°C 和 75%相对湿度下用不同的风速（0、2.5 和 5 m/s）干化 28 天，并通过微生物组分析确认微生物组成。将霉菌和酵母样本接种到添加了 10%酒石酸的土豆葡萄糖琼脂上，并通过 DNA 测序鉴定分离的菌落。对分离株进行微生物特性（形态特征、生长条件和酶活性）分析。微生物组分析表明，优势微生物为霉菌和酵母，鉴定为 Pilaira anomala SMFM201611 和 Debaryomyces hansenii SMFM201707。将 Pilaira anomala SMFM201611 和 D. hansenii SMFM201707 接种到 24 块最低等级的牛里脊肉中。所有样本均在 0、14、21 和 28 天进行干化，并分析微生物生长、pH 值、剪切力、超微结构和风味化合物（游离氨基酸和游离脂肪酸）。接种 P. anomala SMFM201611 和 D. hansenii SMFM201707 可改善嫩度并通过蛋白水解导致肌原纤维分解。两种微生物还通过蛋白水解和脂肪水解活性产生游离氨基酸和脂肪酸。这些结果表明，从干化牛肉中分离和鉴定的 Pilaira anomala SMFM201611 和 Debaryomyces hansenii SMFM201707 可以在干化过程中提高低等级牛肉的质量。实际应用：在干化过程中，霉菌和酵母可以改善干化牛肉的质量。从干化牛肉中分离出的 Pilaira anomala SMFM201611 和 Debaryomyces hansenii SMFM201707 可以通过分解肌原纤维来提高嫩度。两种微生物通过产生游离脂肪酸和氨基酸来改善风味，并且在干化过程中可能会改善低等级牛肉的口感和香气特征。
