Determination of thermal process requirements for baked soybeans canned in brine and tomato sauce: A comparative study of the methods of process calculation

Thermal process schedules were evolved for baked soybean canned in 2.5% brine (pH 5.66) and in tomato sauce (pH 4.98). The cold point of plain A 21/2 cans filled with brine and tomato sauce were found to be on central axis 2.0 cm and 4.0 cm above the base of the cans. The corrected process time (Pt) to achieve sterilization value (F 0 ) corresponding to 6.0 min for A 21/2 can size at 121.1°C in still vertical retorts calculated by improved general and lethal rate paper methods were found to be 35.6 min and 36.8 min, respectively for baked beans canned in brine and 40.8 min, and 40.4 min, respectively for baked beans canned in tomato sauce. Process times were also calculated by six different formula methods. The process times to achieve F 0 value of 6.0 for baked soybean in brine were found to be 34.6 min by Ball's method; 33.7 min by Stumbo's method; 35.7 min by Steele et al method; 38.05 min by Steele and Boards method; 37.7 min and 38.4 min by Pham's methods. The corresponding process time for baked soybean packed with tomato sauce were 37.8 min; 37.8 min; 38.9 min; 37.3 min; 39.9 min and 40.4 min, respectively. Pham's method gave highest process times for both types of canned products. Process time obtained by the method of Steele et al was found similar to the value obtained by the improved general method for baked soybean in brine medium.