This study aimed to evaluate the effects of various levels of intramuscular fat (IMF) and oleic acid (C18:1 cis-9) on retronasal aromas in Wagyu beef. Muscle samples were collected from 167 carcasses of Japanese Black. The chemical compositions were analyzed, and the cooked beef was evaluated by a trained sensory panel. Tenderness, juiciness, and fatty aroma were mainly related to the IMF content. Both sweet and Wagyu beef aromas were affected by the oleic acid and IMF contents. In marbled beef with low IMF content, both sweet and Wagyu beef aromas were stronger as the oleic acid composition increased (r = 0.401, 0.376); however, their relationships were weaker at the moderate IMF content (r = 0.278, 0.273). The effect of oleic acid on these aromas was hardly observed in beef with high IMF content (r = 0.030, 0.011). The oleic acid index [IMF content (%) × oleic acid composition (%)/100] could be fitted to the logarithmic curve for all the aromas determined (r = 0.526 to 0.565). These results indicated that the higher oleic acid composition could be better for the favorable aromas of Wagyu beef; however, the effect differs depending on the IMF content levels, and the phenomenon is relatively well explained by the oleic acid index.
Objective: The purpose of this study was to see if a portable near-infrared optical fiber spectrometer with a wavelength range of 700–1,050 nm could objectively predict the Beef Color Standard (BCS), which is visually evaluated during beef carcass grading.Methods: A total of 1,077 carcasses were procured from Japanese Black (JB) Wagyu (n = 534), crossbred (F1) (n = 367), and dairy cows (n = 176) shipped to meat markets. The cut surface between the sixth and seventh ribs was visually evaluated by grading members using the BCS. In addition, a near-infrared optical fiber spectrometer was applied to the cut surface to obtain the reflectance spectrum. Using data from 827 carcasses, a calibration model was established through a partial least squares regression analysis using the BCS value as the objective variable, while the optical data following quadratic differential processing as the explanatory variable. Using data from 250 additional animals, the calibration model and predicted BCS values were verified for accuracy.Results: The calibration model exhibited a high correlation coefficient of 0.83 and a standard error of calibration of 0.70. The predicted BCS by near-infrared evaluation rarely differed significantly from the actual BCS, and the difference was roughly distributed in the range of ±1. For verifying the accuracy of our calibration model, the correlation coefficient between the actual BCS and the predicted value for the validation sample was 0.75, and the standard error of prediction was 0.71. The probability that the error between the measured and optically predicted BCS values in the validation samples was within ±1 and ±0 was 97.6% and 54.4%, respectively.Conclusion: Using a portable near-infrared fiber optic spectrometer, we demonstrated that the BCS value of beef carcasses, particularly marbled Wagyu beef in meat markets, can be objectively evaluated with relatively high accuracy.
The genetic components for meat quality traits, such as physical characteristics and chemical traits, remain unclear. This study focused on estimating heritability for 44 meat quality traits, including chemical traits, such as general composition (moisture, crude fat, and crude protein), and fatty acid composition in Japanese Duroc populations. We collected samples from 312 commercial Duroc pigs at three different stations. Fatty acid compositions were measured in the loin eye (longissimus thoracis) muscle and subcutaneous fat. Estimates of heritability for general composition traits ranged from 0.11 to 0.87. In addition, the heritability estimates related to pork tenderness were assumed to be moderately heritable. The heritability estimates for fatty acid composition in both tissues ranged from 0.00 to 1.00. The weighted heritability estimates obtained by meta-analysis ranged from 0.01 to 0.61 for general composition traits and 0.25 to 1.00 for fatty acid composition in both tissues. Our findings suggest that most of meat quality traits in these Japanese Duroc populations are influenced by substantial genomic factors, and the influence of genetic factors on these traits could be shared across breeds. These results provide valuable genetic information needed to design a breeding program aimed at improving the pork quality of Duroc breeds.
To clarify the effects of pork lipid profiles on eating quality, we examined the relationship between sensory evaluation values and the lipid profiles of M. longissimus thoracis and subcutaneous fat. Pork loins with a broad range of intramuscular fat contents and lipid profiles were collected nationwide. In Test 1, correlations between lipid profiles and sensory evaluation values of aroma were investigated using 96 pork loins. In muscle and subcutaneous fat, sweet aroma and monounsaturated fatty acids (MUFA) exhibited a significant positive correlation. Off-flavor and polyunsaturated fatty acids (PUFA) also showed a significant positive correlation. The MUFA/PUFA (M/P) ratio was significantly positively or negatively correlated with sweet aroma or off-flavors, respectively. For most items, overall acceptability of aroma and overall acceptability were positively or negatively associated with MUFA content and M/P ratio or PUFA levels, respectively. In Test 2, 60 pork loins were classified into four levels-< 3, 3-4, 4-5, and ≥ 5-based on the M/P ratio of subcutaneous fat and their effects on eating quality were investigated. A greater M/P ratio intensified sweet aroma and overall aroma acceptability while reducing off-flavors. These results identify that the M/P ratio is an effective indicator of eating quality.
