Effect of Superheated Steam- and Hot Air-Assisted Processing on Functional and Nutritional Properties of Yellow Peas

The effect of processing temperature of hot air (HA) and superheated steam (SS) on functional and nutritional properties of yellow pea (Pisum sativum L.) kernels such as moisture content, hydration capacity, cooking characteristics, dehulling efficiency, microstructure, starch gelatinization, and protein content were studied. Three processing temperatures (120, 135, and 150 °C) for both HA and SS were used, while keeping the velocity of air and steam at 1 m/s. Both processing methods (HA and SS) exhibited a significant effect (p < 0.05) on the selected functional properties. Dehulling efficiency of HA-processed peas ranged from 83.5 to 88.2%, whereas for SS-processed peas, it ranged between 85.4 and 89.9%, within the processing temperature range. An increase of 19.1, 20.0, and 35.0% in porosity was observed in SS-processed yellow pea when compared to those processed with HA, at 120, 135, and 150 °C, respectively. At 150 °C, peas processed with HA demonstrated a greater reduction in protein content by 2.38%, whereas a protein reduction of 0.75% with SS was achieved. The study also explored optimization of initial moisture content (26, 40, and 54%) of yellow peas for selected SS temperatures (120, 135, and 150 °C) in order to minimize soaking time prior to cooking. Results showed a pronounced reduction in the peak extrusion force of cooked peas with an initial moisture content of (54%) and processed in SS, for 5 and 10 min cooking times, ensuring a cooked texture (force ratio < 0.5) Based on these results, it is inferred that SS has potential to minimize the overall cooking time of yellow peas without compromising functional and nutritional properties.