The study was carried out to enumerate the effect of thermal process variables on the losses of some B vitamins and moisture from roasted beef and pork of various sizes in a hot air oven. The roasting temperature and time of both samples were varied from 100‐160°C and 15 min to 1 h, respectively.
Thiamin losses were between 20‐40% (0.116‐0.232 mg/100 g) in pork and between 15‐25% (0.006‐0.011 mg/100 g) in beef at the same period. The loss of riboflavin was between 10‐25% (0.019‐0.047 mg/100 g) in beef when compared with the 15‐40% (0.023‐0.061 mg/100 g) in pork. Niacin was more stable than other vitamins at all temperature‐time combinations used. The losses of niacin ranged from between 5‐10% (0.193‐0.386 mg/100 g) in beef and 10‐ 16% (0.431‐0.689 mg/100 g) in pork. Also, moisture losses from pork (22‐45%) were greater than from beef (15‐30%) during the same period of roasting.
Generally, the losses of thiamin and riboflavin appeared to be closely dependent on both heat and loss of moisture (or drip) and sample size. However, the values of niacin losses were considerably less than thiamin, riboflavin and moisture losses, and no strong dependence of niacin loss on heat was observed. The results also confirmed higher retention of these vitamins as the ratio of the mass of meat to its exposed surface area increases.