Sensory Evaluation of Alternative Turkey Genotypes

Sensory Evaluation of Alternative Turkey Genotypes

Summary

Consumer interest is growing in specialty poultry markets, including natural and organic, which may feature alternative genotypes and production systems. Alternative turkey genotypes include “heritage breeds,” which are slow-growing standard breeds that mate naturally, and alternative production systems include outdoor access and natural feeds. Consumers buy specialty products for reasons such as nutrient/sensory attributes and animal welfare. A trial was conducted to assess the impact of alternative genotype on parts yield, meat quality, and sensory attributes. A commercial fast-growing genotype (Fast) and a slow-growing genotype (Slow) (all females) were raised for 14 weeks and 24-28 weeks, respectively. The placement dates were staggered in order to achieve a similar final body weight on the day of processing. Forty turkeys of each genotype were raised on a small commercial farm in a naturally-ventilated shed with access to outdoor yards and were provided the same diets. Turkeys were processed at a small processing facility and stored at 33ºF. Sixteen turkeys of each genotype were deboned at the UA for meat quality analyses. Nutrient content of the breast meat was analyzed, as well as tenderness, pH, water-holding capacity, and color. A trained panel conducted descriptive analyses of texture attributes of fresh breast meat and flavor attributes of the breast and thigh meat, and a consumer panel compared liking of these specialty turkeys to conventional turkeys at retail. Community outreach and a consumer event were held, where a survey was conducted.

Objectives/Performance Targets

Determine impact of genotype on meat quality and sensory attributes of turkeys in specialty poultry production

Investigate consumer perceptions about specialty turkey meat.

Accomplishments/Milestones

Two genotypes were compared in this study: conventional, fast-growing Broad Breasted White (Fast) and a slow-growing, “heritage” Standard Bronze (Slow). These birds were raised on a small commercial operation in Kansas. The fast-growing turkeys were obtained from a commercial source as day-old poults. The slow-growing turkeys were placed in May 2007 and the fast-growing turkeys in mid-July 2007. Forty turkeys of each genotype were raised for 14 and 24-28 wk, respectively, with the goal of raising the birds to a similar slaughter weight. The genotypes were raised in separate flocks and only females were used. The same feed was used for both genotypes

The turkeys were harvested in late October 2007. They were transported to a small processing plant one hour away. After processing, carcasses were transported under refrigeration to the University of Arkansas pilot processing plant where they were placed in storage at 33 F.

At 2 d postmortem, 16 carcasses of each genotype were placed on cones and cut up for parts yield analysis and deboning of breast fillets. Breast and skin samples were taken for nutrient analysis and frozen until analysis. The remaining meat was repackaged and vacuum sealed for a community outreach event and placed back in 33 F storage. pH was also measured at 2 d postmortem.

The right breast fillet was weighed after deboning and the color of the meat was measured. Breast fillets were cooked on racks in pans to an internal temperature of 165°F. The cooked fillets were reweighed to determine cook loss, an indicator of water-holding capacity. Tenderness was measured by an instrumental method.

A local nonprofit organization, Ozark Slow Food, conducted community outreach about specialty turkeys and about this project and organized a “turkey tasting” event at a local restaurant. The UA released a press release about the project and tasting event.

Ozark Slow Food developed a series of three informational pieces for the public on specialty poultry production with outdoor access, endangered farm breeds and their cultural contest as “heritage” breeds, and the “turkey tasting” consumer event. These informational pieces were posted over a period of 3 weeks to the OzarkSlowFood email listserver.

The turkey-tasting event was announced on public calendars and the local public radio station. The public radio station also interviewed UA researchers about the project, as well as a local heritage turkey producer, and the interview was broadcasted in a show called Ozarks at Large on November 2, 2007 the day before the event. The consumer turkey tasting event was also announced throughout Northwest Arkansas with posters at natural food stores and announcements by Ozark Slow Food at local events and at farmers markets. The community outreach and announcements of the event was done in the weeks before Thanksgiving.

The turkey tasting event sponsored by Ozark Slow Food was held at Basil’s Restaurant in Rogers, AR on November 3, 2007, which was 5 d postmortem to the slaughter of the turkeys. Meat was prepared according to recipes chosen by the restaurant chefs but all meat was cooked to 165 F. The objective of the event was to give consumers the opportunity to learn about specialty turkey production, try various types of turkey and to gather information about why they would purchase specialty turkey. Materials were provided, talks were given about Slow Food, turkeys, and written/visual materials were provided. Consumers tasted the following 3 types of turkey: the slow-growing “heritage” turkey raised free-range (Slow), and the conventional fast-growing turkey raised free-range (Fast). The third treatment was a frozen retail turkey (Retail). The retail turkey was purchased at a local grocery store and thawed at 33 F. It was cut up at the UA processing plant like the other treatments. The retail turkey contained additional ingredients (water, sodium, spices, etc.) from injection as is common in retail turkeys in the US. These turkeys are fast-growing birds from indoor production systems and the inclusion of this treatment helped elaborate differences between specialty and conventional turkey products. Attendees were asked to complete a consumer survey.
Two events were actually held, including a pre-event that featured the 3 types of turkey. The main event was a meal that featured 3 types of turkey, along with traditional holiday dishes. The UA donated the turkey for the event and a per person price was charged to cover costs of additional food ingredients and labor for Basil’s Restaurant.

Because the product is sold as a refrigerated product (not frozen) with a 21 d shelf life, the turkey meat was never frozen during the research.

After the consumer event, a descriptive analysis was conducted on Slow and Fast turkeys by a trained panel at the University of Arkansas on carcasses that were roasted whole. At 8 d postmortem the panel described the flavor attributes and at 9 d they described textural attributes

At 10 d postmortem, a consumer test (40 panelists) was conducted on the breast and thigh meat from the Slow and Fast, with the additional treatment of retail turkey. Four turkeys of each type Retail, Fast, and Slow (12 total) were cooked for consumer analysis. At 11 d postmortem, the procedure was repeated with an additional 40 panelists (80 panelists total). Whole turkeys were roasted as describe above, and breast and thigh meat cut into bite-size cubes. They were asked to evaluate their overall liking of the product, liking of appearance, texture, and flavor, and appropriateness of color, tenderness, juiciness, and flavor. They were also asked to indicate the likelihood that they would buy the product and if they would pay more for the product than for their usual poultry product. Nine-point hedonic scales were used to assess overall liking and liking of appearance, texture, and of flavor and Just-About-Right (JAR) scales were used to assess the appropriateness of color, tenderness, juiciness, flavor. Consumer panelists were recruited via a panelist database housed at the University of Arkansas Food Science Department, and selection of panelists was based on consumption patterns of white and dark poultry meat and on the consumption of natural and/or organic poultry products.

Impacts and Contributions/Outcomes

The carcasses of the Fast turkeys were larger than those of the Slow (P < 0.05). The breast yield was higher (P < 0.05) for the Fast compared to the Slow, while the leg yield was higher for the Slow (P < 0.05). The breast meat of the Slow had lower pH and was less pale and more red than Fast (P < 0.05). Other meat quality data is under analysis.

Community outreach about specialty turkey was far-reaching. Thousands of people visit the Fayetteville farmers market each Saturday. OzarkSlowFood listserver has 120 participants and Ozarks at Large is broadcasted on the local public radio station KUAF. Thirty-seven people attended the consumer events. General comments about the event were positive. A blind straw poll vote revealed that consumer preferences in the following order Retail, Fast, and Slow turkeys. Data from the consumer survey is under analysis.

The descriptive panel found few differences in the flavor of breast meat, although the Fast had more intense cooked meat flavor and the Slow had more intense aftertaste of blood/metal (P < 0.05). The panel found more differences in texture. The Slow was more hard, cohesive, and fibrous than the Fast (P < 0.05). However, in an instrumental study, the Slow was more tender than the Fast (P < 0.05). In most categories of the consumer trials, the Retail and Fast were preferred over the Slow, including appearance and texture. For the breast meat, the overall liking was higher for Retail than Fast and Slow (P < 0.05), and the liking of flavor was higher for Retail than the Slow (P < 0.05).

These data indicate differences in meat quality and sensory attributes, especially in terms of texture, with consumers preferring the conventional turkeys over the specialty.

Results will be shared at a national meeting (Poultry Science Association) July 2008.

Collaborators: