Effect of Soaking and Cooking Ratios on the Physicochemical, Foaming, and Emulsifying Properties of Cowpea (Vigna Unguiculata) Aquafaba and Its Comparison with Selected Legume Aquafaba

Lee, Wen Hui (2026) Effect of Soaking and Cooking Ratios on the Physicochemical, Foaming, and Emulsifying Properties of Cowpea (Vigna Unguiculata) Aquafaba and Its Comparison with Selected Legume Aquafaba. Final Year Project (Bachelor), Tunku Abdul Rahman University of Management and Technology.

Text Lee Wen Hui_Full Text.pdf Restricted to Registered users only Download (4MB)

Abstract

Growing sustainability concerns have increased interest in aquafaba as a value-added food-by-product; however, studies on cowpea aquafaba (CWPA) remains limited, particularly regarding processing conditions. This study aims to determine the effects of cowpea-to-water soaking ratio (C:W) and soaked cowpea-to-water cooking ratio (SC:W) on the physicochemical, foaming, and emulsifying properties of CWPA, and compared its performance with selected legume aquafaba. Cowpeas were soaked at C:W ratios of 1:3, 1:4, and 1:5, followed by boiling-cooking at SC:W ratios of 1:2, 1:3, and 1:4. Soaked cowpeas were analyzed for water absorption capacity (WAC) and texture. Extracted CWPA was characterized for physical, physicochemical, chemical, and foaming, and emulsifying properties. The results showed that the increased SC:W ratios significantly increased yield and total soluble protein content (TSP), but significantly reduced titratable acidity, total soluble solids content (TSS), viscosity, foaming stability (FS), and emulsifying activity index (EAI) at p < 0.05. The optimal C:W and SC:W ratios were achieved at 1:4 and 1:2, respectively, producing WAC of 101.2 ± 1.56 % and hardness of 14293.09 ± 176.60 g for CWP as well as CWPA with yield of 282.25%, L* value of 22.7, a* value of 3.63 ± 0.23, b* value of 1.87 ± 0.12, C* value of 4.07 ± 0.29, h° value of 26.97 ± 0.47, density of 986.61 kg/m3, pH of 6.22, TA of 1.49%, TSS of 3.1 °Brix, viscosity of 3.54 mPa·s, TSP of 14.58 mg/100 mL, foaming capacity (FC) of 200.00%, FS of 81.44%, EAI of 775.16 m2/g, and emulsifying stability index (ESI) of 21.06 min. Compared to chickpea (CPA), red kidney bean (RKBA), and lima bean (LBA) aquafaba, CWPA demonstrated a significantly (p < 0.05) higher density, FS, and EAI than those of RKBA and LBA, although slightly lower than CPA. Overall, the study proves that both soaking and cooking ratios play a crucial role in enhancing the functional performance of cowpea aquafaba, supporting its potential as an alternative plant-based ingredient. Further studies are recommended to evaluate CWPA performance in real food systems to validate its functionality and suitability in various food applications.