Color and pH of meat aged from Nellore young bulls fed crude glycerin associated with soybean grain in low or high starch diets
This trial aimed to evaluate the meat quality aged in seven or 14 d from Nellore young bulls fed crude glycerin (CG; 80% of glycerol) associated with soybean grain (SG) in low (LS) or high starch (HS) diets finished in feedlot. Twenty eight animals with a 20 mo and 428.57 ± 35.33 kg of initial BW were used in a randomly design in a factorial arrangement 2 x 2 x 2 (LS or HS diets, with or without oil and two aging times) with seven replicates. The diets (40:60) were: 10% of CG in DM diet replacing corn (HS); 10% of CG in DM diet replacing corn plus SG; 10% of CG in DM diet replacing soybean hulls (LS) and 10% of CG in DM diet replacing soybean hulls plus SG. After 140 d of feeding, all animals were slaughtered with a 590.21 ± 52.29 kg of BW. All carcasses were refrigerated at 0 °C for approximately 24 h. A boneless Longissimus muscle (LM) section 10 cm thick was removed from the posterior end of the wholesale rib. The LM was sliced into steaks of 2.54 cm, individually vacuum packaged and chilled at 0 - 2°C for 7 and 14 d. The color reading was conducted using the CIE L*a*b* system. The water holding capacity (WHC) was measured for the difference between the weights of the sample before and after it was subjected to a pressure of 10 kg for 5 min. Data were analyzed by the MIXED procedure of SAS, and the Tukey test used considering 5% probability. There was no interaction (P > 0.05) for any of the variables evaluated. Thus, effects were discussed independently. Similar values of lightness (L*), redness (a*), yellowness (b*), pH and WHC were observed for beef from animals fed LS or HS diets. Likewise, the inclusion of SG was not affected the meat quality traits. However, the lightness (P < 0.01) and yellowness (P < 0.01) was higher in beef aged for 14 d. The crude glycerin (10% of DM) associated with SG in LS or HS diets did not affect the meat quality traits as a pH, WHC and color of Nellore young bulls. The aging time for 14 d increases the lightness and yellowness of beef.
Keywords: glycerol, meat quality, oil