Abstract

The objective of this study was to examine the effects of oxidation on the Semi-tendinosus (ST) and Vastus lateralis (VL) muscles of Thai native cattle (Kamphaeng Saen beef cattle). The muscle samples ST and VL (n = 6) were collected from three cows and sliced into 3 cm steaks. These steaks were stored at 50°C for seven days and analyzed for proximate and myoglobin content on day 0. The pH, expressible drip, cooking loss, surface color L*(lightness), a* (redness/greenness), and b*(yellowness/blueness), hardness and values of Thiobarbituric Acid Reactive Substances (TBARS) were monitored from day 0 to day 7 of storage. The results indicated that the vastus lateralis muscle was more susceptible to lipid oxidation in terms of TBARS compared to the ST muscle, which was linked to its higher percentage of myoglobin on days 5 and 7 of storage. Additionally, a decline in the redness/greenness of surface color (a* value) of the vastus lateralis muscle was observed on days 5 and 7, concomitantly with an increase in myoglobin and TBARS content, indicating discoloration. These changes were attributed to the differences in anatomical position and physical activity of these muscles. These findings suggest that muscle source can influence the rate of deterioration and discoloration during chilled storage.