Impacts of Tempering and Infrared Heating of Pulse Seeds on the Functionality and Digestibility of Air‐Classified Fine Stream

ABSTRACT The objective of this study was to evaluate the functional properties and in vitro protein digestibility (IVPD) of air‐classified fine stream (i.e., protein concentrates) obtained from round pea, faba bean, and wrinkled pea that were pre‐treated by tempering and subsequent infrared (IR) heating prior to air classification. Due to the absence of effective modifications on protein and starch, the tempering did not influence the separation between these two major constituents during the air classification and exhibited negligible effects on the functional attributes and digestibility of the obtained fine stream, except for water‐holding capacity (WHC). IR pre‐treatment led to protein denaturation and starch gelatinization in round pea, faba bean, and wrinkled pea, thus showing some negative influence on the separation of protein and starch in the air classification. Although IR heating reduced the protein solubility of fine stream from 79.9%–83.4% to 24.0%–33.1% for the three pulses, this pre‐treatment did not considerably affect their particle morphologies and size distributions nor foaming and emulsifying properties. As a result of protein denaturation, IR heating enhanced WHC from 0.42–0.65 g/g to 1.82–1.98 g/g and IVPD from 78.6%–83.0% to 85.3%–86.7% for the three fine stream samples. IR heating can be utilized to pre‐treat different pulse seeds to diversify the techno‐functional attributes and enhance the digestibility of protein concentrates obtained through air classification.