Beef Chuck, Sirloin and Round Determined Suitable for Use as Beef Finger Steaks

Product preparation

Commercially available United States Department of Agriculture (USDA) Choice beef subprimals fabricated according to the Institutional Meat Purchasing Specifications (IMPS) were obtained from a commercial beef harvest facility. The subprimals that were used in the study were obtained from carcasses that were of native beef cattle origin, finished on a conventional North American concentrate ration, and harvested under USDA inspection. Carcasses chilled at 0°C; for 24 h prior to fabrication. Beef subprimals assessed in the study were boneless strip loins (IMPS #180, longissimus lumborum), top rounds (IMPS #169A, semimembranosus [SM]), clod hearts (IMPS #114E, triceps brachii [TB]), and center-cut top sirloins (IMPS #184B, gluteus medius). The subprimals were transported from the slaughter facility under refrigeration (3.5 h; 4°C) to the University of Idaho Meat Laboratory. Twelve of each subprimal were used for the study. The vacuum-sealed subprimals were allowed to age at 0°C for 21 d post-fabrication. Following the aging period, all raw products were trimmed of external fat before further fabrication. The subprimals were cut with the grain using a mechanical meat slicer (Berkel, Louisville, Kentucky) to 1.27 cm thickness. Following the slicer, steaks were fabricated, once again with the grain, using the Strip Cutter and Tenderizer S111 (Bizerba International, Balingen, Germany) with a 1.27 cm stripping cradle to obtain beef strips of 1.27 cm × 1.27 cm × 7.62 cm in dimension. Raw finger steak strips were sorted to remove pieces containing connective tissue, cartilage, and excess fat. The finger steaks that met the dimensional requirements and visual selection were vacuum packaged, frozen at −20°C, and assigned to subsequent analysis groups including WBSF and sensory taste panels. Product remained in constant frozen storage for 6 mo, in the −20°C environment, prior to further assessments being conducted.

Preparation

A batter was formulated within guidelines commonly applied to battered meat products (Loewe, 2011). The formulated batter is presented in Table 1. Finger steaks were tempered for 24 h at 4°C prior to battering and cooking. Finger steaks were cooked in cooking oil at 188°C (Great Value Vegetable Oil, Wal-Mart Stores, Inc., Bentonville, AR) in a countertop electric fryer (Avantco F102 Dual Tank Electric Countertop Fryers, Avantco Equipment, Meridian, ID) to an internal temperature of 71°C. Fry time was determined at 2.5 min in pre-trials to meet 71°C degrees of internal temperature doneness for the finger steaks. For each muscle, initial weights (g) were recorded and used to calculate batter pick-up. The term “pick-up,” or percentage batter present, refers to the amount of coating material adhering to the product and is based on the final weight (USDA-AMS, 2014). Pick-up was calculated as:

Warner-Bratzler shear force

WBSF was used to evaluate objective tenderness of finger steak treatments. There were (n = 72) samples evaluated per treatment. Cooked finger steak samples were allowed to equilibrate to room temperature prior to shearing. Each sample was sheared perpendicular to the muscle fiber orientation using a WBSF machine (G-R Manufacturing, Manhattan, KS) at a crosshead speed of 225 mm/s. Peak shear force in kilograms of force (kgf) measurements were recorded and averaged to obtain a single shear force value for each subprimal. Additionally, shear force data were analyzed qualitatively to evaluate the proportion of pieces acceptable at USDA tenderness thresholds of 4.4 and 3.9 kg of shear force which are representative of USDA “tender” and “very tender”, respectively (ASTM, 2008).

Consumer taste panel

The study was found to be exempt by the University of Idaho Institutional Review Board (IRB Protocol 21-100, Reference No. 013095). Samples were assigned, and panels set up in accordance with American Meat Science Association (AMSA) guidelines (AMSA, 2016). All panelists (N = 120) provided written, informed consent for inclusion prior to their participation in the study. Before sampling and evaluations, panelists were given verbal instructions and any necessary forms. Consumer panelists were instructed that the study was investigating beef finger steaks. It was a requirement that panelists were a minimum of 18 years old and identified as consumers of beef. Prior to sampling panelists were asked to complete a demographics survey. Three separate panels were conducted with a minimum target of 40 panel participants per panel. Within each panel, samples were assigned to panelists according to a complete block design which represented all muscle treatments equally. To minimize bias, panelists were randomly assigned 3-digit, blind-coded samples. Each panelist was provided with a ballot to evaluate each sample along with an expectorant cup, a cup of room temperature water, unsalted soda crackers (Premium Unsalted Tops Saltine Crackers, Mondelez Global LLC, East Hanover, NJ), a toothpick, and a napkin. Panelists were then asked to evaluate a finger steak sample from each subprimal treatment group based on the following traits: overall acceptability, appearance, flavor, juiciness, tenderness, color of the coating, and amount of coating using a 10-point hedonic scale where 1 = dislike extremely and 10 = like extremely. In addition, consumers were asked if they would make future purchases for the sample with options of “yes” or “no/unsure.” Order of treatment samples was randomized to account for order bias.

Trained taste panel

Samples and panels were assigned in accordance with AMSA guidelines (AMSA, 2016). However, AMSA guidelines do not account specifically for battered beef products leading to the current study having to incorporate sensory guidelines from other battered proteins to expand the knowledge on battered beef. Subjective evaluations of appearance, texture, and binding were measured using guidelines set forth in Batters and Breading in Food Processing (Loewe, 2011). Additionally, Meilgaard et al. (2006) assessments for crispiness were utilized. Reference standards were used to help illustrate attributes and can be reviewed in Table 2. Twenty-eight finger steaks from each subprimal were assessed for trained sensory evaluation. Training occurred for 4 d, twice a day, and each session was an hour long. Trained panelists (N = 7) evaluated finger steaks from each muscle based on the following traits: coating appearance, batter adhesion, crispiness, juiciness, tenderness, beef flavor intensity, and overall flavor intensity. Panelists rated the sensory attributes on a 1 to 10 scale with anchor points at each end where 1 = extremely poor appearance/poor batter adhesion/soft/dry/tough/bland/lacking flavor intensity and 10 = extremely good appearance/good batter adhesion/crispy/juicy/tender/flavor/intense flavor. The assessors used direct entry into a computerized survey (Qualtrics XM, Seattle, WA) to record their results. This allowed for performance to be monitored regularly to provide feedback until the panelists had a clear understanding of all attributes. Order of treatment samples was randomized to account for order bias.

Statistical analysis

WBSF and consumer sensory panel data were analyzed using SAS V9.4 (SAS Institute, Inc., Cary, NC). Individual subprimal cuts (strip loins, clod hearts, top sirloins, and top rounds) served as the experimental units (n = 12); thereby, 12 replications per treatment were observed. The experiment was set up as a randomized complete block design. Yield, WBSF, and consumer and trained panel responses were used as dependent variables. A generalized linear mixed model was used to fit the data where treatments were fixed effects and blocks (sensory panels days) by treatment were random effects. A binary distribution analysis was assessed for willingness to purchase responses. Differences in the estimated marginal means were compared through pair-wise comparisons. Significance was interpreted at P < 0.05.

Processing and pick-up yields

Batter “pick-up” and product yield was assessed for all muscles in the cooking process. Table 3 depicts the results for each muscle’s average weight in grams and the batter pick-up percentages. “Pick-up” and “yield” are commonly used terms when producing battered products. It can be cost-beneficial to add a high percentage of pick-up for product acceptance without loss of quality (Loewe, 2011). The term “pick-up” or percentage batter present refers to the amount of coating material adhering to the product and is based on the final weight (USDA-AMS, 2014). Variation was observed between the subprimals indicating that the top round had the highest batter pick-up percentage compared to the clod heart, which had the lowest pick-up percentage (P < 0.05). Overall, many factors can affect the coating operation, ranging from meat surface to batter viscosity and temperature, breading size, and frying temperature (Barbut, 2015). In the current study, because the top round was adhering the most batter, one could postulate a greater saleable product yield potential of that cut using the current batter procedure.

Warner-Bratzler shear force

Mean WBSF differences were observed between treatments where the strip loin was more tender than all other muscle treatments (Table 4; P < 0.05). The top round had the highest average WBSF mean of 3.73 kgf. To be considered “tender” and “very tender,” shear force values must be below the USDA thresholds of 4.4 and 3.9 kgf, respectively (ASTM, 2008, ASTM, 2011). Table 3 demonstrates that all treatment means were considered “very tender” based on USDA thresholds. Previous research has grouped muscles into tenderness classifications of tender, intermediate and tough. These levels are based on thresholds for tenderness identified by Shackelford et al. (1991) and Huffman et al. (1996). Muscles deemed tough had a WBSF value of >4.6 kgf, tender muscles had a WBSF value of <3.9 kgf, and intermediate muscles had WBSF values between 3.9 and 4.6 kgf. The previous research of Shackelford et al. (1991) and Huffman et al. (1996) classified the TB and the SM muscles as intermediate tenderness while the gluteus medius muscle was classified as tough. In contrast, the muscles in the current research were all deemed very tender. The 2015 National Beef Tenderness Survey (Martinez et al., 2017) noted top round steaks had higher WBSF values compared to other loin muscles and advised processors and merchandisers to increase post-fabrication aging times to improve consumer acceptance of beef steaks.

Consumer sensory analysis

Consumer sensory panelists were recruited in the state of Idaho. Consumer demographics are reported in Table 5. The consumer group of 53 men and 63 women were between 18 and 91 years. Moreover, the data presented in Table 5 indicated that almost half of the panelists eat beef 2 to 4 times per week. Consumer sensory panel results (Table 6) indicated a difference in overall acceptability (P < 0.01), flavor (P < 0.01), tenderness (P < 0.01), and juiciness (P < 0.01) between treatments. As could have been anticipated, the strip loin outperformed the other cuts in tenderness, juiciness, and overall acceptability.

Previous research has demonstrated fairly comprehensive rankings of beef muscles demonstrating the relative overall superiority in palatability of the Longissimus lumborum (strip loin) over the clod heart, top round, and top sirloin muscle cuts (McKeith et al., 1985; Carmack et al., 1995; Rhee et al., 2004; Hunt et al., 2014). In the categories of tenderness and acceptability, the clod heart and top sirloin were second highest compared to the strip loin. Clod heart, top sirloin and strip loin consumer assessment results showed a superior flavor to that of top round. Flavor is often affected by the amount of intramuscular fat, or marbling, within a cut. Intramuscular fat has a significant impact on marketing and palatability of fresh meat, particularly beef (Corbin et al., 2015; Lonergan et al., 2019). The top round treatment resulted in less acceptable flavor than the other cuts of meat. The investigators hypothesize that the top round flavor rating was due to the fact that the SM muscle, the primary muscle in the top round, is characterized as fast-twitch glycolytic muscle, with relatively low marbling and high collagen content (Jurie et al., 2007). Moreover, Voges et al. (2007) rated different retail cuts for palatability attributes and reported that the top round was liked less with respect to overall liking and tenderness than other meat contents, which is similar to the results from the previous study. The mechanical tenderness evaluation (WBSF) of the treatments complements the consumer tenderness assessment.

Coating and appearance differed between treatments. The strip loin treatment had the preferred coating over all other treatments (P < 0.05). Similarly, the mean appearance values of the strip loin treatment were greater than that of the clod heart and top sirloin (P < 0.05). The top round was observed to have no difference in mean appearance acceptance values from any of the other treatments (P > 0.05). Color and appearance parameters play an important role in the evaluation of fried foods (Cao et al., 2020). Color of fried foods will directly affect consumer acceptance (Cao et al., 2020). The color of the food surface is the first quality parameter evaluated by consumers and is critical in the acceptance of the product (Pedreschi et al., 2005). A study performed by Pedreschi et al. (2005) evaluated potato chips according to their sensory quality as determined by color and saw that consumers prefer a golden-brown color, not a burnt color. Controlling frying temperature, time and heat led to a golden-brown surface color preferred by consumers. Barbut (2012) found the same effect in coated chicken breast fillets. The strip loin in the current study had the greatest mean color and coating acceptability even though all products were the same size and prepared in the same manner. Overall beef eating quality is predominantly dependent upon all 3 factors: tenderness, juiciness, and flavor, as well as the interaction among these traits (O’Quinn et al., 2018). However, a steak may be deemed acceptable by consumers due primarily to the outstanding level of a single trait despite the lower or even unacceptable levels of one or both of the other traits (O’Quinn et al., 2018). It is possible that this trait compensation theory was also applied by consumers to color scores; however, more research would be needed to come to this conclusion.

There was a significant response in consumers’ willingness to purchase (P < 0.01). Affirmative purchases for the muscles in a battered application were reported in Figure 1. The strip loin treatment was the most likely to be purchased based on consumer responses (83% Yes response, P < 0.05). All other treatments were not significantly different in consumer affirmative purchase responses.

Figure 1.

Affirmative purchase response by cut in a battered beef finger steak application. Treatments with different adjacent superscripts (^{a, b}) differ (P < 0.05).

The researchers wanted to also consider the fact that the science of assessing one’s texture preferences are becoming more of a consideration among the meat science community (Miller et al., 2022). These considerations may need to be more of a factor in research assessing overall consumer acceptance of battered meat products in the future.

Trained sensory analysis

Trained taste panelists (n = 7) were recruited in the state of Idaho. Trained sensory panel scores are reported in Table 7. Panelists evaluated samples for color appearance, batter adhesion, crispiness, juiciness, tenderness, and flavor intensity. Acceptance of fried food is directly affected by the color appearance and often determines their selection or rejection of fried food as demonstrated by studies performed on potato chips (Segnini et al., 1999; Mendoza et al., 2007). Consumers tend to associate visual appearance with the taste and crispiness preferences, enjoyment level, safety, health, and storage conditions among other physicochemical properties (Segnini et al., 1999; Mendoza et al., 2007). Another essential feature of fried food is ensuring that the adhesion of the batter to the product throughout the cooking process. Lack of adhesion can negatively impact product perception. In addition, although it may be a difficult sensory impression to quantify, crispiness is certainly one, if not the most, critical coating characteristic (Loewe, 2011). For the present study, no differences were observed among the trained sensory panelists for coating appearance (P = 0.46), batter adhesion (P = 0.34), or crispiness (P = 0.23). These findings demonstrate that the products tested were prepared in a consistent and controlled manner and that differences observed by the trained panelists were the result of the beef cuts assessed.

The traits of tenderness, juiciness, and flavor have long been considered the most important palatability traits affecting beef eating quality (O’Quinn et al., 2018). A muscle profiling study performed by Sullivan and Calkins (2011) found the TB muscle to possess palatability attributes suitable for retail steak fabrication. The results of the current study support that the clod heart was comparable in juiciness to the strip loin (P > 0.05) and superior to top round and top sirloin. The strip loin, clod heart, and top sirloin were more tender than the top round (P < 0.05). Nyquist et al. (2018) evaluated the palatability of beef chuck, loin, and round muscles and found through trained sensory panels that round muscles were less juicy and tender and had less flavor intensity in comparison to the longissimus lumborum and chuck muscles. Previously, it was stated that muscles from the round are less desirable due to lower tenderness influenced by fiber type and an increased level of connective tissue (Anderson et al., 2012). Carmack et al. (1995) ranked 12 muscles for flavor intensity, and with the exception of the TB (clod heart), the hindquarter muscles of the carcass, excluding the SM, exhibited the most-intense beef flavor. By contrast the current study results showed no significant difference for beef flavor intensity (P = 0.12) and overall flavor intensity (P = 0.53). Voges et al. (2007) advised that, because of their WBSF values and consumer ratings, round retail cuts still require more attention to ensure acceptable tenderness. The WBSF results of the current study are concomitant with results of the trained sensory panel tenderness assessment.