Effect of High Pressure and Irradiation Treatments on Hydration Characteristics of Navy Beans

Raghupathy Ramaswamy, Department of Food Science and Technology, The Ohio State University, 2015 Fyffe Road, Columbus, OH 43210-1007
V. M. Balasubramaniam, Department of Food Science and Technology, The Ohio State University, 2015 Fyffe Road, Columbus, OH 43210-1007.*Corresponding author.
S.K. Sastry, Department of Food, Agricultural and Biological Engineering. The Ohio State University. 590 Woody Hayes Drive, Columbus, OH 43210-1057

Abstract

The effects of high-pressure (33, 400 and 700 MPa for 3 min at 24 and 55°C) and irradiation (2 and 5 kGy) pre-treatments on hydration behavior of navy beans were studied by soaking the treated beans in water (1:2, w/w) at 24 and 55°C. Beans hydrated at 55°C and allowed to cool by natural convection served as the control. Treating beans under moderate pressure (33 MPa) resulted in high initial moisture uptake (0.59 to 1.02 kg/kg dry mass) and reduced loss of soluble materials. The final moisture content after three hours of soaking was the highest in irradiated beans (5 kGy) followed by HPP (33 MPa; 3 min; 55°C). Within the experimental range of the study, Peleg’s model was found to satisfactorily describe the rate of water absorption of navy beans. Peleg's constant K₁ had an inverse correlation with soaking temperature whereas K₂ increased with increases in temperature and pressure.