Direct Rub Inoculation of Fungal Flora Changes Fatty Acid Composition and Volatile Flavors in Dry-Aged Beef: A Preliminary Study.

Abstract

Simple SummaryDry-aged beef naturally develops a crust of desirable fungi and bacteria over the aging process. However, this natural growth process is expensive and time-consuming. The process of direct fungal adhesion may accelerate aging and improve the flavor and fatty acid profile of dry-aged beef. We compared the fungal growth and meat quality of dry-aged beef inoculated by natural fungal adherence and dry-aged beef inoculated by direct application of fungi (direct adhesion) to assess the differences in appearance, volatile flavors, and fatty acid composition. After 26 days of aging, dry-aged beef that received direct fungal application exhibited increased surface mold, volatile compound intensity, and oleic acid composition compared with the dry-aged beef that did not receive direct inoculation. Thus, we report an improved method of manufacturing dry-aged beef with high quality that has the potential to enhance the “melt-in-the-mouth” feeling and flavors.Here, we established a method to produce dry-aged beef (DAB) by rub inoculation with fungal flora on the prepared DAB surface. Portions of Holstein steers’ rumps were prepared by direct rub inoculation of fungal flora or without treatment (conventional DAB) and dry-aged for 26 days in an aging room at 2.9 °C and 90% relative humidity. We compared the fungal covering and meat quality, including fatty acid composition and volatile aromatic compounds, of fungal-inoculated DAB with those of the conventional DAB. The fungal-inoculated DAB was almost entirely covered with white mold, in contrast to the conventional DAB. Moreover, the proportion of oleic acid and the concentration of nine volatile compounds significantly increased in the raw meat of fungal-inoculated DAB compared with those in the conventional DAB (p < 0.05). These results suggested that direct rub inoculation of fungal flora from prepared DAB may accelerate DAB production and efficiently enhance the “melt-in-the-mouth” feeling and flavors of DAB.