Pork producers are continuously reminded that pork quality is an issue that requires their attention if they expect to be competitive in the marketplace. Yet, the question remains whether pork quality differences really have an impact on consumer acceptance and value.
Measurements of pork quality are many, but we must prioritize those that are most important to producers and consumers. Then we must identify the value of those quality measures in relationship to consumers' willingness to purchase pork.
To address these challenges, a study funded by the National Pork Board (NPB) and conducted by the National Pork Producers Council (NPPC) in cooperation with Texas A&M University, Ohio State University and Total Research Corporation was undertaken in 1997. The study was implemented to understand the effect of pork lean quality attributes and consumer acceptability. The study was conducted in Boston, Chicago and Denver.
To participate, consumers had to eat pork one or more times/week and be at least 18 years old. A total of 454 consumers participated, each evaluating 12 samples. Four samples were pork loin chops, four were fresh pork inside ham chops and four were chicken breasts.
Consumers were served two samples at a time, and the samples were either a loin chop and an inside ham chop, a loin chop and a chicken breast, or a inside ham chop and a chicken breast. The loin and inside ham chops were from the same animal.
The inside ham chop is from one of the major muscles, the inside leg muscle. It is the second largest muscle from the ham (see picture, page S18). This cut is traditionally used to make cured cooked hams, but it may provide an opportunity to merchandize a new fresh ham steak.
One of the issues that we were testing was to see if the inside ham chop was similar in juiciness, flavor and tenderness to loin chops. This was the first time the inside ham chop was used in a consumer test.
The chicken breasts were purchased in each respective city so that they were representative of the available commercial chicken breast.
Each consumer received samples that varied in quality, thereby allowing us to evaluate how quality differences affected their perceptions of eating quality. Additionally, prices were varied so that we could assess how much price and quality impacted their purchase intentions.
To understand if pork quality affects consumer's perceptions of acceptability, it was important to use pork that varied greatly in quality attributes. A dry run of the study was conducted in Dallas using pork from the 1997 National Barrow Show (NBS) Sire Progeny Test to make sure that the study could be conducted as desired. Pork from NPPC's Quality Lean Growth Modeling Project was used in the rest of the study in Denver, Boston and Chicago. Only the results from these three cities are discussed here.
Quality Parameters Pork quality differences used in the study included muscle pH, intramuscular fat, lean color, lean firmness and meat tenderness. Meat tenderness was measured using the Warner-Bratzler shear force machine. Lower values mean the meat is more tender.
The Warner-Bratzler shear force method is similar to Instron tenderness measures. Instron tenderness measures also were conducted at Iowa State University. The measures were used to understand the value of tenderness for the purchase intent questions asked in the study.
Pork was ordered into three categories within a quality trait. For example, Category 1 represented the loins with the lowest pH (average value of 5.61), the lowest lipid percentage (average value of 1.00%) and highest Warner-Bratzler shear force values (3.60 kg, representing the toughest meat samples).
Categories 2 and 3 were incrementally higher for pH (5.81 and 6.17) and lipid (2.22% and 3.75%) and incrementally lower for Warner-Bratzler shear force values (2.85 kg and 2.41 kg or more tender).
These categories were used to assign pork samples to a consumer so that a consumer received samples that varied in pH, lipid content and Warner-Bratzler shear force. The same quality attributes were measured on the inside ham to understand the effect of pH, lipid content and tenderness on consumer acceptance in the fresh inside ham chop.
Because the study was conducted over a three-month period, and the animals used in the study were slaughtered on six different days, environmental factors influenced the average meat pH within a slaughter day. Therefore, meat was categorized within a slaughter day.
The loin chops, inside ham chops and chicken breasts were individually cooked to an internal temperature of 158 degreeF in convection ovens. Each cut was cut into half-inch cubes, and consumers received two samples/cut.
Consumers evaluated each sample for juiciness like/dislike, tenderness like/dislike, flavor like/dislike and overall like/dislike using a 5-point rating scale where 1 = dislike extremely and 5 = like extremely.
Consumer Responses Differ Overall, consumers liked the juiciness, the tenderness, the flavor and the overall acceptance of chicken breasts when compared to either the loin or the inside ham chops (Table 1). However, consumers rated pork cuts and chicken breasts differently depending upon the city where they lived. This is not unusual, as it is known that regional differences exist for like and dislike for pork and other meat products.
In general, consumers in Boston rated cuts lower for juiciness, tenderness, flavor and overall like than consumers in Denver and Chicago (Table 1). Additionally, pork consumers rated loin and ham chops similarly for juiciness and flavor. However, they liked the tenderness of loin chops compared to the inside ham chop, and overall, they liked loin chops compared to inside ham chops. Even though the mean values for overall like in Table 1 for loin chops and ham chops are the same, they differed because the inside ham chops varied more in consumer overall like response. In other words, they were not as consistent in overall like.
They liked loin chops compared to inside ham chops, overall. However, depending on the cut, consumers in different cities rated the cuts differently. In Denver, consumers rated the chicken breast highest for acceptance of tenderness, flavor and overall like. However, Denver consumers indicated the juiciness of chicken and loin chops was similar, and they did not like the level of juiciness of inside ham chops. Additionally, they rated the inside ham chop lower for tenderness and overall like when compared to loin chops.
On the other hand, consumers in Chicago also rated the chicken breast with the highest like rating for the four sensory attributes, but they liked the inside ham chop when compared to the loin chop for tenderness, flavor and overall acceptance.
Consumers in Boston consistently rated chicken breasts higher than loin chops and loin chops higher in acceptance than ham chops for consumer sensory attributes.
What does this mean? Consumers like chicken more than either loin or inside ham chops, but these differences in consumer acceptance depend on geographic location. The inside ham chop was least preferred in Denver and Boston, but consumers in Chicago rated the inside ham chop similar to loin chops.
What does this mean for differences in quality attributes? Did quality attributes influence consumer sensory responses?
As pork quality attributes varied due to the experimental design, the categories used to segment the pork within a week were used to understand if differences in pH, lipid content and Warner-Bratzler shear force affected consumer sensory responses for pork loin and inside ham chops. If consumer sensory responses differed with the quality categories, then quality impacted consumer acceptance.
For loin chops, consumer sensory responses differed by pH category and shear category, but consumer sensory responses did not differ as intramuscular lipid percentage increased (Tables 2, 3 and 4).
Consumers liked the juiciness and the tenderness of loin chops from the high pH category more than loin chops from either pH categories 1 or 2 (Table 2). Additionally, they preferred loin chops from pH category 3 over loin chops from pH categories 1 and 2.
As Warner-Bratzler shear force values decreased or the chops were more tender, consumers indicated that they liked the juiciness, tenderness, flavor and overall acceptability of loin chops (Table 4). However, loin chops from shear categories 1 and 2 did not differ in consumer juiciness preference and loin chops from shear categories 2 and 3 did not differ in consumer flavor and overall acceptance. Similar trends were noted with inside ham chops.
As pH increased, consumers liked the juiciness, tenderness, flavor and overall acceptability of inside ham cuts (Table 2).
Consumer sensory responses were not affected by lipid category (Table 3), and as Warner-Bratzler shear force decreased, consumers liked the tenderness of inside ham chops, but other consumer sensory attributes were not affected (Table 4).
These results indicate that pH and shear force affected consumer perceptions of palatability and could be used as quality attributes to segment pork into quality categories. It isimportant to note that the pH, lipid and shear categories were defined within a day of slaughter. As pH and Warner-Bratzler shear force values can be highly affected by slaughter day and plant, it is important that classification for these attributes occur within a plant and slaughter day.
What pork quality attributes should be used? Of the quality attributes measured in the U.S. Pork Consumer Study, pH more closely segmented pork loin and inside ham chops into categories than did either lipid or Warner-Bratzler shear force. As pH is indirectly related to multiple pork quality attributes, it most likely showed the greatest ability to segment pork based on consumer eating quality attributes compared to other quality measures. This does not mean that lipid content or tenderness were not important in improving consumer acceptance. Rather, it means that pH had the greatest influence. Tenderness played a role in consumer acceptance, especially for loin chops.
To further understand the effects of pH, lipid and tenderness of consumer perceptions of pork, additional analyses were conducted to better understand what occurred when price or purchase intent was included in the consumer evaluation and when intent to purchase questions were added to the evaluation.
As pork quality attributes affected consumer acceptance and sensory attributes, what are the values of these quality attributes?
To answer this question, the consumers were asked a purchase intent question after they had evaluated and rated each pair of samples for sensory attributes. They were asked to compare the two meat samples within the pair and at a specific price, and then they were asked to indicate the likelihood that they would purchase both samples. They answered this question using a 5-point scale in which 1 and 2 meant that they were unlikely to purchase the sample, 3 corresponded to a neutral or no intent to purchase, and 4 and 5 indicated that they were likely to purchase the sample.
The price per pound for chicken was set throughout the study at $3.76. The loin chops were priced at either $1.99, $2.74, $3.49, $4.24 or $4.99, and the inside ham chops were priced at either $1.61, $2.22, $2.80, $3.43 or $4.04.
In general, consumers indicated that as price increased, their intent to purchase decreased. As price went from $2.00/lb. to $4.99/lb., the probability that they would purchase pork loin chops went from 60% to 20%. Obviously, pork consumers are very price sensitive.
Intent to purchase also was affected by the city where the evaluation was conducted. Consumers in Chicago showed the lowest intent to purchase compared to consumers in the other two cities.
Quality factors did affect intent to purchase. In general, as pH increased, intent to purchase increased. But, in low pH meat, higher levels of intramuscular fat increased the intent to purchase. Additionally, as pork loins became tougher, the intent to purchase decreased, but this relationship also was dependent on the pH of the meat.
What is the value of pH and tenderness? As pH increased, consumers were willing to pay more for pork loin chops as long as they were from pork loins that were tender (a 4 kg or less Instron value; Table 5). This shows that the intent to purchase pork loin chops was affected by both pH and tenderness. If the pork loin chops were tougher (5 kg or greater in Instron value), the meat pH did not affect their purchase intent. Therefore, consumers were not willing to pay as much for tougher meat, regardless of meat pH.
In general, consumers in all three cities were willing to pay an additional $0.50/lb. for a 1 kg improvement in tenderness when tenderness was changed from a 5 kg to a 4 kg of Instron value. Pork with Instron values up to 4 kg would be considered tender meat. When Instron values were below 4 kg, improvement in tenderness did not affect purchase intent.
Therefore, when pork is tender, further improvements in tenderness did not have value.
Still, the value of improving tenderness from 5 kg to 4 kg was affected by pH and city as Table 5 shows. Chicago's more price-sensitive consumers were not willing to pay as much for pork loin as in the other cities.
For consumers in the three cities, the values of changing 1 kg in Instron value at three levels of pH showed that improving tenderness had more value for loin chops with higher pH. This may be because consumers had lower intent to purchase low pH meat to begin with, and when tenderness was increased, they were willing to pay slightly more for it.
The initial price level used to examine the effect of changing Instron values by 1 kg affected the outcome of what consumers were willing to pay for improved tenderness. If the pork loin chops were priced at $2.50 to $3.50, consumers were willing to pay $0.36 to $0.90/lb. for a 1 kg improvement in Instron value for pork with a pH of 5.3. For pork loins with pH values of 5.55, they were willing to pay $0.90/lb. for a 1 kg improvement in Instron value, but they were willing to pay $1.20 to $1.50/kg for a 1 kg improvement in Instron value for pork loins with a pH of 5.80.
We hypothesize that consumers' willingness to pay more for pork with a higher pH, lower Instron values and a lower initial price was because this was the pork that they preferred and they were willing to pay more for it.
However, when pork chops were initially priced at $3.50 to $4.99, consumers were less willing to pay for improvements in tenderness ($.36/kg for loins with pH of 5.3; $.51/kg for loins with pH of 5.55; and $0.63 to $0.75 for loins with pH of 5.80).
The value of quality, either pH or tenderness, is dependent on the initial price. When initial price is high, consumers are less willing to pay for improvements in tenderness.
What is the value of pH and intramuscular fat? A value difference existed for intramuscular fat or marbling, but it was affected by the pH of the loin chop. The value for intramuscular fat was present for meat with a low pH. Consumers indicated that for meat that had a low pH of 5.3, they were willing to pay an additional $0.22/lb. for each 1% increase in intramuscular fat.
These results indicate that pH played a role in purchase intent, but consumer's intent to purchase decreased in pork loin chops with a low pH.
The probability of purchase intent of low pH meat could be improved by increasing intramuscular fat and tenderness.
Does the inside ham chop have a future? Consumers indicated the lowest intent to purchase the inside ham chop when compared to the loin chop or chicken breast. Of 1,674 observations, 737 people indicated a low intent to purchase the inside ham chop and only 566 indicated an intent to purchase the pork cut.
As pH increased, price decreased and tenderness increased, the intent to purchase the inside ham chop also increased. In order to get a 50% probability that a consumer would purchase the inside ham chop over a chicken breast, the inside ham would have to have a pH of at least 5.6 and be priced at $2.60 when chicken was priced at $3.76.
What did we learn? In summary, pH affected consumer's perception of pork eating quality, and it also affected consumer's intent to purchase.
However, the story is not that simple; pH, in combination with tenderness and the amount of intramuscular fat, affect consumers' eating quality perceptions and their intent to purchase.
Consumers are not willing to pay very much for pork that has a low pH. But, if the low pH pork is more tender or has more intramuscular fat, their acceptance and intent to purchase does increase. Based on this evidence, quality affects consumer's perceptions of eating quality and intent to purchase. To improve pork's competitiveness, quality has to be considered.
Packers are developing databases that record the meat quality of a herd, especially loin ultimate pH. This information may be used in selecting future market hog suppliers.
Processors may use these results to sort carcasses with higher pH levels for case-ready, fresh products and/or flavored products. The enhanced flavor and tenderness could make high quality pork products that are very competitive with fresh chicken products.