Functional and thermal properties of yellow pea and red lentil extrudates produced by nitrogen gas injection assisted extrusion cooking

Abstract

BACKGROUND There are excellent opportunities for greater incorporation into our diets of pulses, which are rich in proteins and dietary fibers, if their functional properties are modified to fit a wide range of applications in the food industry. The objective of this research was to produce high protein and fiber extrudates from yellow pea and red lentil flours using conventional and N2 gas injection assisted extrusion cooking methods. The effects of process variables on extrudate functional and thermal properties were also investigated. RESULTS The cold viscosity of extrudates produced by N2 gas injection were higher than those produced by conventional extrusion, indicating that gas‐assisted extrusion does affect the end‐product pasting properties. At higher barrel temperatures (150–175 °C) extrudates did not exhibit any thermal transition in their thermograms, and thus their starches were completely gelatinized and proteins completely denatured during extrusion. In general, water solubility of extrudates produced by N2 gas injection was significantly (P < 0.05) higher than those produced by conventional extrusion. Emulsion capacity and stability of yellow pea extrudates were in the range of 44–50% and 42–47%, respectively, and the counterpart values of red lentil extrudates were very similar (in the range of 43–47% and 43–46%, respectively). CONCLUSION Nitrogen gas injection assisted extrusion cooking can be used practically in development of pulse extrudates which contain high protein and dietary fiber. This novel and innovative technique is a reliable alternative method to the conventional CO2 gas injection assisted extrusion cooking methods in the snack food and food ingredient industries. © 2019 Society of Chemical Industry

Physical and technofunctional properties of yellow pea flour and bread crumb mixtures processed with low moisture extrusion cooking

“…In contrast to the raw yellow pea flour, the peak viscosity (that is, starch gelatinization peak) and pasting temperature were not clearly seen in the pasting curves of extrudates containing 0% bread crumb, except for the highest feed moisture (Figure 4b). The lack of a hot peak indicates that all of the starch was degraded during the extrusion cooking process (Ai et al., 2016; Masatcioglu & Koksel, 2019; Menegassi, Pilosof, & Arêas, 2011). As for the 18% feed moisture extrudate in Figure 4b, the small peak around 7 min is representative of a portion of the starch granules in yellow pea flour that were still in their native state (that is, not degraded) at the end of extrusion cooking (Masatcioglu & Koksel, 2019).…”

“…The lack of a hot peak indicates that all of the starch was degraded during the extrusion cooking process (Ai et al., 2016; Masatcioglu & Koksel, 2019; Menegassi, Pilosof, & Arêas, 2011). As for the 18% feed moisture extrudate in Figure 4b, the small peak around 7 min is representative of a portion of the starch granules in yellow pea flour that were still in their native state (that is, not degraded) at the end of extrusion cooking (Masatcioglu & Koksel, 2019). Similar small peaks were also observed from the RVA curves of some extruded common bean flours (Ai et al., 2016).…”

“…2.4.1 Emulsifying capacity (EC) and emulsifying stability. Emulsifying properties (that is, EC and emulsifying stability) were determined using the method of Ahmedna, Prinyawiwatkul, and Rao (1999) as modified by Masatcioglu and Koksel (2019). Before testing, extrudates were ground and sieved (sieve size: 212 μm).…”

Low- and High-Moisture Extrusion of Pulse Proteins as Plant-Based Meat Ingredients: A Review

“…In the global food marketplace, pulse-based ingredients, mostly pea ingredients, have been used to produce pulse protein snacks. Efforts to address high consumer demand for healthier and more nutritious snacks have sparked renewed interest in extruded pea snacks (30,60,61,62). There have been several studies published on expanded snacks using pulse protein ingredients (Table II) (60,61,62).…”

“…Efforts to address high consumer demand for healthier and more nutritious snacks have sparked renewed interest in extruded pea snacks (30,60,61,62). There have been several studies published on expanded snacks using pulse protein ingredients (Table II) (60,61,62). An expanded yellow pea snack using yellow pea flour (24% protein) was successfully obtained by adjusting operating conditions (Table II) and using nitrogen gas as a blowing agent.…”