RIBOFLAVIN AND THIAMINE RETENTION IN FROZEN BEEF‐SOY PATTIES AND FROZEN FRIED CHICKEN HEATED BY METHODS USED IN FOOD SERVICE OPERATIONS

Abstract
Frozen beef‐soy patties, raw or char‐broiled, and frozen fried, breaded chicken parts were heated by various methods and vitamin B1 and B2 retentions determined. Heating methods used were: hot air convection followed by holding hot for 0, 1/2, 1 1/2, or 3 hr and infrared, high pressure steam, or microwave followed by hot holding for 1/2 hr. Riboflavin retentions in beef patties were above 89%, except when infrared heating was used (80%). Reheated chicken retained 87–93% of riboflavin and there was no significant difference among treatments. Thiamine retention was lowest in chicken parts reheated by convection and held hot for 3 hr (74%). Infrared heating resulted in 81–84% thiamine retention in beef or chicken while other methods retained 86–96%.