Development of Cellular High-Protein Foods: Third-Generation Yellow Pea and Red Lentil Puffed Snacks

This study aimed to evaluate how extrusion cooking conditions and microwave heating play a role in enhancing physical and thermal properties of third-generation expanded cellular snacks made from yellow pea (YP) and red lentil (RL) flours for the first time. Increasing temperature and moisture content during extrusion resulted in darker, crunchier and crispier products with higher expansion index (EI). Microwave heating after extrusion led to an increase in cell size and porosity of YP and RL products when qualitatively compared to extrusion alone. Additionally, extrusion followed by microwave heating resulted in extensive damage to starch granular structure and complete denaturation of proteins. Using microwave heating, as a fast and inexpensive process, following partial cooking with extrusion was demonstrated to greatly improve the physical and thermal properties of YP and RL snacks. Microwave heating following mild extrusion, instead of severe extrusion cooking alone, can potentially benefit the development of high quality nutritionally-dense expanded cellular snacks made from pulse flours.

Changes in Anti-nutritional Factors and Functional Properties of Extruded Composite Flour

Background: Development of complementary foods by mixing plant-based (cereals, pulses, oilseeds, and others) ingredients and employing various processing techniques is widely reported. However, information on comparison of anti-nutritional factors and functional properties of extruded and unextruded complementary flours made from a multi-mix is limited. In this regard, this study aims to investigate the influence of extrusion cooking on anti-nutritional and functional properties of newly developed extruded oats, soybean, linseed, and premix composite complementary flours.Methods: Thirteen different blending ratios of oats, soybean, linseed, and premix were generated using a constrained D-optimal design of the experiment. Each of the 13 blends was divided into two groups: extrusion cooked and unextruded composite flour sample. Anti-nutritional and functional properties were determined using standard methods for both composite flours. ANOVA was used to determine if there was a significant difference for extruded and unextruded composite flours and paired t-tests were used to check variation between extruded and unextruded.Results: The phytate content of the extruded and unextruded composite flours was 158.93–191.33 mg/100 g and 175.06–203.10 mg/100 g, respectively, whereas the tannin content of the extruded and unextruded composite flours was 8.4–22.89 mg/100 g and 23.67–36.97 mg/100 g, respectively. There was a statistically significant (p < 0.05) difference among the extruded composite flours in terms of phytate and condensed tannin content. Paired t-test has indicated a significant (p < 0.05) difference between extruded and unextruded composite flours for phytate and tannin. Water absorption capacity and bulk density have shown a significant (p < 0.05) difference among extruded and unextruded composite flours. An increase in the proportion of soybean and linseed flour was associated with an increase in phytate, tannin, and water absorption capacity of composite flours. However, bulk density was increased with an increasing proportion of oat in the blend.Conclusion: The findings revealed that extrusion cooking significantly reduced phytate and condensed tannin content and improved the functional properties of the composite complementary food flour. Further investigation is needed on other anti-nutritional factors that are not included in this report.

The Influence of the Pressure-Thermal Agglomeration Methods of Corn Bran on Their Selected Physicochemical Properties and Biogas Efficiency

The article presents the research made on the effects of methods of pressure-thermal agglomeration of corn bran, as well as the influence of processing parameters on selected physicochemical properties and biogas efficiency. Corn bran moistened to four levels of moisture content was used for the tests: 20%, 25%, 30% and 35% of dry matter. The pressure-thermal treatment was carried out with the use of a Brikol SJ25 pellet maker and a TS-45 single-screw extruder. In the tests of the extrusion-cooking process, three rotational speeds of the extruder screw were applied: 70, 90 and 110 rpm. The following characteristics were examined: efficiency of the extrusion-cooking and pelleting process, as well as the energy consumption. The water absorption index (WAI), the water solubility index (WSI), bulk density, kinetic strength, structure analysis by the ART/FTIR method, energy potential and the efficiency of cumulated biogas and cumulated methane per dry mass, as well as fresh mass and fresh organic matter and a series of microscopic pictures were completed. The analysis of the ATR/FTIR infrared spectra of the tested pelleted and extruded samples showed clear changes at the molecular level. Biogas production of extruded corn bran increased by several percent, as compared to untreated material.

Functional Properties of Extruded Corn Flour

Effect of extrusion cooking on hydration properties (water absorption index (WAI), water solubility index (WSI)), and viscosity (peak viscosity (PV), final viscosity (FV)) of corn flour was studied. The preconditioned corn flour was processed using different extrusion cooking conditions at the variable moisture content (MC), temperature (T), and screw speed (SS). Statistical analysis showed that irrespective of variable processing parameters the hydration properties were improved after extrusion cooking. WAI and WSI were increased by 70% to 268% and 5 to 198%, respectively over unextruded flour. The viscosity of extruded corn flour showed a significant (p < 0.05) decrease, indicating high paste stability of corn flour after extrusion cooking. Overall, there was 72 to 86% decrease in PV and 89 to 95% decrease in FV. The mild processing conditions (high MC, low SS, and low T) imparted better hydration properties, whereas severe processing conditions (low MC, high SS, and high T) imparted better paste stability to corn flour. Extruded corn flour with modified functional properties has the potential to be exploited in the development of various gluten-free ready-to-eat products, composite flours, bakery products, etc.