Determination of Objective Analysis of Juiciness among Multiple Beef Muscles and Quality Grades

Abstract

ObjectivesThe purpose of this study was to use a developed objective juiciness analyses including corresponding tenderness measurements to determine the juiciness among multiple beef muscles of various quality grades.Materials and MethodsTreatments were obtained from 5 different beef sub-primals: Strip loins (IMPS #180), inside rounds (IMPS #169), bottom rounds (IMPS #171B), shoulder clods (IMPS #114), and chuck rolls (IMPS #116). Sub-primals were also represented by 3 different USDA quality grades: Prime, Low Choice and Select; (n = 10/quality grade). All sub-primals were vacuum packaged, aged for 21dthen fabricated into 2.5 cm thick steaks from respective cuts: Adductor (AD), Biceps femoris (BF), Chuck Eye (CE), Infraspinatus (IF), Semimembranosus (SM), Serratus ventralis (SV), Longissimus lumborum (LD), and Triceps brachii (TB). The steaks were frozen (–20°C) until subsequent analyses. Several objective measures of juiciness and tenderness were evaluated on raw and cooked samples. Analysis techniques measured on raw samples included: pH and percentage fat, moisture, protein and collagen. Cooked techniques evaluated included: Warner-Bratzler shear force (WBSF), slice shear force (SSF), cook loss, and pressed juice percentage (PJP). For cooked analysis, each steak was cooked on a clam-shell grill to a medium degree of doneness (71°C), and the fiber orientation (45 or 90°) was determined before sampling. Analysis of PJP was evaluated using a compression-based juiciness method. Following SSF, a 1cm thick PJP slice was removed parallel with predetermined muscle fiber orientation (45 or 90°) and compressed on filter paper at 8 g for 30s. Data were analyzed using the GLIMMIX procedure of SAS (SAS Inst. Inc., Cary, NC; ɑ = 0.05). Subprimal was experimental unit, and muscle, quality grade, muscle × quality grade were used as fixed effects. Carcass was used as a random effect.ResultsA muscle × quality grade interaction (P 0.05) to IF in the Select grade. Within Prime and Low Choice, moisture was greatest (P 0.05) to AD. The pH was lowest (P 0.05) to Choice TB, LD and Select TB. A muscle × grade interaction (P < 0.05) was found for SSF. The BF across all quality grades was the toughest (P < 0.05). The SV was the most tender (P < 0.05) in Prime, however few differences were found in all other quality grades between muscles of AD, IF, LD, and SV. Quality grade and muscle affected (P < 0.05) WBSF and PJP. As quality grade increased, WBSF values decreased (P < 0.05). The SV and CE were more tender (P < 0.05) than AD, TB, and IF. The PJP was less (P < 0.05) for Prime and Choice than Select, while TB and SM were greater (P < 0.05) than IF and AD for the same trait.ConclusionObjective juiciness and tenderness measures among different beef cuts and quality grades cooked to the same degree of doneness indicated that there is a difference in the amount of juice that is released from various beef muscles.