Meat Science and Technology

Nutritional and Eating Quality of Locally Produced, Forage-Finished Beef

Forage-finished beef has unique nutritional qualities that are positively associated with human health. Compared to grain-finished beef, foragefinished beef contains lower amounts of intramuscular fat, higher amounts of omega-3 fatty acids and unsaturated fatty acids, and a higher intramuscular content of conjugated linoleic acid (CLA). It thus appears that foragefinished beef produced in Hawai‘i has the potential to be marketed as a natural, health-promoting food, particularly for those people seeking animal products that are raised in natural conditions without administration of growth-promoting agents or much intervention on the animals’ dietary intake.

Forage-finished beef, however, is generally known to be less tender and less palatable than grainfinished
beef, suggesting a need to improve the eating quality of forage-finished beef. Interestingly, our recent studies demonstrated that almost half of the steaks from Hawai‘i forage-finished beef were as tender as the choicest steaks from grain-finished-beef. These results indicate that understanding the factors affecting the tenderness of forage-finished beef will be crucial in improving the palatability of locally produced forage-finished beef.

Objectives:

• To examine the tenderness of forage-finished beef produced in Hawai‘i
• To investigate the intrinsic and extrinsic factors affecting the tenderness of forage-finished beef produced in Hawai‘i.
• To measure CLA content and polyunsaturated fatty acid composition in forage-finished beef produced in Hawai‘i.
  
  

Progress

• Number of samples collected: 176 ribeye steaks from 12th rib
• Tenderness measured (2 wk aged): 124
• Proximate analysis (moisture, fat, and ash) completed: 124

Preliminary Results

Figure 1 shows the distribution of the shear values of 122 samples analyzed. The shear values ranged from 2.29 kg to 9.72 kg with a mean value at 5.30 kg. According to a study by Miller et al. (JAS 2001, 79:3062–3068), shear values of 3.4, 4.0, and 4.3 kg would result in 99, 94, and 86% of consumer satisfaction for beef tenderness. About a quarter of our samples had shear values below 4.3 kg, suggesting that only 25% of the forage-finished beef produced in Hawai‘i would provide enough tenderness for consumer satisfaction.

Figure 2 shows the distribution of intramuscular fat content of 90 samples analyzed. The fat content ranged from 0.95% to 14.1% with the mean at 4.88%. Intramuscular fat content of Choice grade is usually above 6%, and about 20% of our samples had more than 6% of intramuscular fat content, indicating that about 20% of the forage-finished beef can be graded as Choice if the cattle are below 3 yrs old.

Figure 3 shows the relationship between the intramuscular fat content and shear value. No significant relationship was observed between these two parameters.

Future Work

Report Summary

This study was designed to investigate the nutritional and eating quality of locally produced, foragefinished beef using about 200 ribeye steak samples collected from two local slaughterhouses. Currently, 176 samples have been collected, and measurement of shear force values and proximate analysis were completed on 124 samples.