30A-32 |
Influence of two different corn diets on the oxidative susceptibility of pork as measured by TBARS and hexanal content |
L. N. FERNANDO1, E. P. Berg2, and I. U. Gruen1. (1) Dept. of Food Science, Univ. of Missouri, 256 Eckles Hall - Stringer Wing, Columbia, MO 65211, (2) Dept. of Animal Science, Univ. of Missouri, S138B Animal Sciences, Columbia, MO 65211 Diets containing high amounts of unsaturated fats increase the unsaturation of pork fat, which may affect the oxidative stability of the ground pork. Thiobarbituric acid reactive substances (TBARS) is the most commonly used method to determine the oxidative state of meat, but hexanal analysis is considered a good alternative. The objective of this study was to evaluate the quality of ground pork from swine fed a corn diet high in monounsaturated fat during storage at 1ºC in simulated retail display, and to test automated headspace solid-phase microextraction (Auto-HS-SPME) for the determination of hexanal in raw ground pork. Twenty-one (21) and 15 animals were raised on a normal corn diet and a corn diet high in monounsaturated fat, respectively. Samples of ground pork shoulder from each animal were stored at 1ºC in simulated retail display. Samples were analyzed on days 0, 3, 5, 7 and 9 for color, odor, TBARS and hexanal. Color and odor were evaluated using a 5-point scale, TBARS were determined by distillation and the hexanal content was determined by Auto-HS-SPME coupled with gas chromatography. Results showed no significant difference between the two treatments for color, odor, TBARS and hexanal content, although there was a significant (P<0.001) increase in both color and odor for both treatments for days 5,7 and 9 compared to day 0. TBARS were significantly (P<0.001) higher on days 7 and 9 compared to day 0, while hexanal content was significantly (P<0.001) higher on day 9 as compared to day 0. TBARS and hexanal were correlated with R2 values of 0.992 and 0.804 for the treatment and control groups respectively. These results suggest that the color, odor and oxidative state of ground pork were not affected by feeding swine a corn diet high in monounsaturated fat. Automated HS-SPME coupled with gas chromatography provided a rapid and convenient method for monitoring the hexanal content of raw ground meat.
Session 30A, Food Chemistry: Lipids
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