Effects of Increased Pork Hot Carcass Weights. I: Chop Thickness Impact on Consumer Visual Ratings

The effect of hot carcass weight and thickness on chop size measurements

It is well documented that as hot carcass weight increases, there is a subsequent increase in the size of retail cuts (Abraham et al., 1980; Cisneros et al., 1996; Leick et al., 2011). Ultimately this size increase can result in thinner chops within a portion-control cutting setting (Dunn et al., 2000). As expected, in this study there was a hot carcass weight × chop thickness interaction for chop weight. As chop thickness increased, the chops from all weight treatments became heavier compared to chops from the thinner thicknesses. Cisneros et al. (1996), evaluated the effect of pig slaughter weight, sex, and breed type on yield. They reported as slaughter weight increased, there was also an increase in loin weight; however loin eye area was not compared across weight treatments. Similar results were reported by Leick et al. (2011), who used portion-controlled cutting on beef carcasses from different hot carcass weight treatments and reported there was an increase in longissimus muscle area as hot carcass weights increased. Additionally, those authors also reported that as longissimus muscle area increased, there was a decrease in steak thickness due to portion-controlled cutting to specified weights (Leick et al., 2011). In the current work, the use of portion-controlled cutting was not possible due to the lack of access to the proper equipment. Thus, the different thicknesses used were chosen to best represent this reduction in chop thickness commonly seen with heavier cuts with larger loin eyes associated with weight-based portion-controlled cutting.

The effect of hot carcass weight, chop thickness, and label type on chop color and marbling

The pork industry uses lean color and marbling informally to determine potential eating quality. There have been conflicting results in the studies that have assessed both instrumental color and subjective color and marbling scores of pork carcasses with increasing hot carcass weights. Studies such as Park and Lee (2011) and Durkin et al. (2012), have assessed the impact of increased hot carcass weight on color and observed no differences in L* values. In the current study, as weight increased, there was a hot carcass weight × chop thickness interaction for L* color readings. These differences were very small and do not reflect the other studies that reported greater differences in L* values due to increased weight in pigs (Virgili et al., 2003; Latorre et al., 2004; Harsh et al., 2017).

There was also label type × chop thickness interaction for a* values (redness). With the exception of chops cut to a thickness of 2.54 cm, labeled chops had greater a* values compared to unlabeled chops. Though these differences were minor, this interaction may be explained by the methods in our study. Although all chops were allowed an adequate amount of time for oxygenation (bloom) before color readings were taken (greater than 1 h), color readings were measured on all unlabeled chops before labeled chops, during the time period when the labels were being applied to the labeled treatment. We believe that the extra time needed to label packages could have allowed labeled chops a greater amount of time to bloom and possibly could explain the observed differences in a* value, as well as the label type difference main effect for b* and visual color scores. Previous work has indicated that an a* value change of greater than 0.589 is needed for consumers to detect a difference in redness (Zhu and Brewer, 1999), indicating that the differences in the current study related to labeling type would not be detectable by consumers. Another study that utilized a scanning spectrophotometer measured color differences of chicken breast samples cut to 0.5, 1.0, and 1.5 cm and reported that differences in thickness could affect L*, a*, and b* values (Sandusky and Heath, 1996), though the authors offered no potential cause. Although the current study used pork, our results are consistent with Sandusky and Heath (1996) for a* and b* values. Moreover, there were no differences detected among hot carcass weight treatment groups for visual color, but there were differences in visual color scores between chop thicknesses; however, this difference was very small, with all treatments within 0.1 units.

In addition to color, marbling has been found to be an important visual cue for consumers when purchasing fresh pork in a retail setting (Fernandez et al., 1999; Brewer et al., 2001; Rincker et al., 2008). Although there were differences found for visual marbling scores in the current study, these differences did not favor either lighter or heavier hot carcass weights. Additionally, the observed differences in marbling were very small, with at most a 0.4 unit difference between any 2 weight treatments. This is further supported by the lack of difference found among the weight treatments when evaluated for the chemical percentage of intramuscular fat content, with all weight treatments differing by no more than 0.2% (Rice et al., 2019). These results are contradictory to similar studies that have reported increased marbling scores as hot carcass weight increased (Cisneros et al., 1996; Huff-Lonergan et al., 2002; Park and Lee, 2011; Harsh et al., 2017).

The effect of hot carcass weight and chop thickness on visual consumer ratings

Visual sensory factors are a cornerstone for the purchasing decisions consumers make at the fresh meat retail case. These visual factors include lean color, marbling, chop size, and cut thickness (Font-i-Furnols and Guerrero, 2014). As hot carcass weights increased, there were significant differences in some of these visual factors that consumers were able to detect in the current study. When consumers were asked to evaluate the overall appearance of chops and purchase intent on a line scale, for both appearance and purchase intent, consumers gave higher ratings as hot carcass weight treatment increased, indicating that consumers found the chops from the heavier carcasses to be more appealing overall and had a greater intent to purchase them. It is noteworthy that the reported differences, though different, were small in magnitude (<3.5 units). This is contradictory to a study by Sweeter et al. (2005) that assessed how increased ribeye area in beef steaks affected consumer purchasing decisions in a retail store by determining how long it took for each steak to be purchased at a local grocery store. They reported that there were no differences in the amount of time the steaks of different sizes stayed on the shelf (Sweeter et al., 2005). The authors concluded that hot carcass weight did not impact consumer purchasing decisions, unlike the current study where consumers preferred chops from heavier carcasses. Perhaps this difference between the current work and the study by Sweeter et al. (2005) is due to the related size difference in longissimus muscle area between pork and beef. It is plausible that the larger longissimus muscle in beef from heavier weight carcasses surpasses a consumer threshold for tolerance for ribeye size; whereas with the smaller longissimus muscle in pork, there is a greater relative increase in size that will be tolerated by consumers and an acceptance threshold for size that was not surpassed in the current study with the carcass weight ranges evaluated.

In addition to hot carcass weight, chop thickness impacted consumer ratings. Consumers found thicker chops to be more appealing; however, they were more willing to purchase chops with a thickness of 2.54 cm. This indicates that consumers prefer chops that are thicker, and is consistent with similar studies conducted in beef. Leick et al. (2011) asked consumers participating in their visual study with portion-controlled cut beef steaks from different hot carcass treatments, which visual trait was most important when purchasing beef steaks in a retail setting. For both top loin and sirloin steaks, consumers indicated that cut thickness was the most important trait, and the authors hypothesized that consumers felt they were getting more for their money with thicker cut steaks, even though the steaks were all cut to the same weight (Leick et al., 2011). In a follow-up, Leick et al. (2012) performed a similar study but added price as a factor. Again, when consumers were asked to rank the most important factors when purchasing beef steaks, and for all 3 cuts, color, marbling, and thickness were all ranked higher than price, and thus indicated consumers placed a greater importance on visual cues, and less on price. Additionally, they reported that consumers in the greater household income brackets selected a greater percentage of the least expensive ribeye steaks in comparison to consumers in the lower income brackets (Leick et al., 2012). This led the authors to conclude that a factor other than price impacted consumer selections of ribeye steaks. The results of the current study also reflect this, as the impact of carcass weight and chop thickness on the consumer purchase intent ratings was not dependent on knowing the price of the product (labeled vs. unlabeled), indicating consumers assessed the merit of these factors independently when determining their likelihood to purchase the product.

In addition to the appearance and purchase intent, consumers in the current study were asked a “yes” or “no” question on if the chop’s overall appearance was desirable, and if they would purchase the chop. Within all hot carcass weight treatment groups, chops cut to a thickness of 1.27 cm had the lowest percentage of consumers who indicated “yes” they were desirable. Similarly, in beef, Maples et al. (2018) used a digital survey to assess how beef steak thickness impacted consumer purchasing decisions and reported that a majority of consumers disliked thinner steaks. Although hot carcass weight did not impact the percentage of consumer who indicated “yes” they would purchase a chop, chop thickness was affected. A greater percentage of consumers indicated “yes” they would purchase chops from the middle thicknesses (1.91 and 2.54 cm), compared to chops cut both the thinnest or the thickest thickness. This indicates that when making a purchasing decision, although consumers like the appearance of the thicker chops, they can be cut too thick as well as too thin for the consumers to actually purchase them. Additionally, when asked if they would or wouldn’t purchase a chop, a greater percentage of consumer indicated “yes” they would purchase samples that were unlabeled. This could indicate that consumers were more willing to purchase chops that had no pricing information and demonstrating that price could play a greater role in consumer purchasing decisions when purchasing fresh pork what is indicated by previous authors with beef. It is noteworthy that the methods used in the current work relied on the consumers’ responses as to whether or not they would purchase the chops instead of using a victory auction or other methods commonly used to measure purchase intent where the consumers would have actually purchased the products. Therefore, the results of the current study should be interpreted as such, as it is unknown how the results related to the consumers’ purchase intent would have been impacted if they would have been required to actually purchase the products as opposed to simply indicating their willingness to purchase them.

If a consumer in the current study indicated “no” they would not purchase a chop, the survey would then prompt the consumer to give more information as to why they would not purchase. Of particular note, the percentage of consumers within each weight treatment who indicated they would not purchase a chop due to “size”, was dependent on chop thickness. For all of the carcass weight groups other than the HVY group, the greatest percentage of chops identified as a “no” for purchase due to “size” was the thinnest (1.27 cm) group. But, within the HVY treatment, thickness had no impact. In the current study, “size” was intentionally undefined as a point to not prompt consumers to think about and notice differences in and consider loin eye area when evaluating chops in the case, unless that was a common consideration for the individual consumer. Thus, in our study “size” is likely a reflection of both loin eye size as well as thickness. This is reflected as in the lighter weight treatments, the thinner chops had a greater percentage of samples that would not have been purchased due to “size”, whereas as in the HVY weight treatment, even the thinnest chops met consumer acceptance levels for “size”. These results also indicate that while in the current study we were able to produce chops that were too small, we were not able to produce chops that were too large for consumers.

However, thickness alone had a large impact on consumer intent to purchase. Both the thinnest (1.27 cm) and the thickest (3.18 cm) cut chops had the greatest percentage of consumers who indicated they would not purchase the chops due to their thickness. In the study by Leick et al. (2011), consumers gave greater ratings to thicker cut steaks, and the authors hypothesized it was due to consumers thinking they were getting more compared to thinner steaks with a greater eye area, despite all steaks being cut to the same weight (Leick et al., 2011). In the current work, both the thinnest (1.27 cm) and the thickest (3.18 cm) cut chops had fewer consumers indicate they would purchase them compared to the middle 2 thicknesses, further indicating that chops can be cut both too thin and too thick for consumer preferences. This is further supported by the consumers who indicated they would not purchase the chops due to “package weight”. As chop thickness increased, there was an increase in package weight which subsequently increased the package price. A greater proportion of consumers indicated they would not purchase the thickest and thinnest chops due to “package weight”, indicating that some of the packages were both too heavy and too light for consumers. This increase in package weight resulted in a concurrent increase in the package price. As chop thickness increased, a greater percentage of consumers indicated “no” they would not purchase due to package price. Therefore, as both package weight and price increased, it negatively impacted purchasing decisions. Though these results from the visual portion of the current study do not necessarily indicate price as the most important factor considered by consumers when purchasing pork, they do indicate that price is a consideration, and for some consumers, will be the primary reason for not purchasing the product of heavier weights. Similar results have been shown in beef. In a victory-auction scenario, Platter et al. (2005) reported consumers were willing to pay more for higher quality steaks, but the number of bids by consumers was greater for the less expensive steaks, providing evidence of the importance of price and the level of consumer-to-consumer variation in price tolerance for consumer purchasing decisions. It is noteworthy that 42.7% of consumers in the current study self-reported in the demographics survey that price was the most important factor when purchasing pork. However, results from the visual evaluation would indicate that other factors, specifically chop thickness, are as, if not more important drivers of consumer purchasing intent than price. These results are consistent with previous work who have indicated that other visual factors, including thickness, can be more important to consumer purchasing intent than price alone (Savell et al., 1989, Leick et al., 2012).

Overall, carcass weight, chop thickness, and label type affected consumer overall desirability and purchase intent for fresh pork. Consumers indicated that chops from heavier carcasses and thicker chops were more desirable. Additionally, consumers were more likely to purchase chops with a thickness of 2.54 cm, indicating that chops could become too thick as well as too thin for acceptance. As pork carcasses continue to become heavier with increased industry efficiencies, the resulting cuts will also increase in size. Results from the current work indicate that despite the associated increases in chop size, consumer desirability and purchase intent will not be negatively impacted.