Physicochemical characteristics of jack bean (Canavalia ensiformis (L.) DC.) milk, a non-dairy milk alternative developed using various pretreatment methods

Abstract

The endeavor to turn jack bean (Canavalia ensiformis (L.) DC.) into jack bean milk faced a challenge regarding its hard skin, which makes pretreatment of the jack bean before processing essential to soften and ease the dehulling of beans, as well as aid the grinding process. However, different pretreatment methods influence the characteristics of treated jack beans and jack bean milk as the final product. This study, thus, aimed to investigate the effect of different jack bean pretreatment methods such as soaking in NaHCO3 solution (P1), soaking in hot water (95℃) (P2), and a combination of boiling and soaking in water (P3), on the physicochemical properties of jack bean milk. Jack bean milk was prepared by subjecting jack beans to pretreatment, dehulling, wet grinding, filtering, and heating before proceeding with analyses based on proximate composition, phase behavior, color and viscosity. The results demonstrated that P2 produced the highest protein (7.01±0.11%), fat (0.10±0.00%), and ash contents (0.11±0.00%) of jack bean milk. P1 yielded higher protein and ash contents of jack bean milk than that of P3, while no significant differences in fat contents were discovered in both P1 and P3. Besides, a slight difference in carbohydrate contents was found among all treatments, ranging from 1.17 to 1.20%. The phase behavior and color analyses showed P1 and P2 to significantly generate higher colloidal stability and whiteness index value of jack bean milk than P3. In addition, jack bean milk from P2 possessed the highest viscosity value of 48.1±1.4 cP, followed by P1 (28.6±0.6 cP) and P3 (12.6±0.5 cP). Accordingly, the recent study proposes the pretreatment of soaking in hot water (95℃) to be applied in jack bean milk processing and provides new insights into how pretreatment methods affect the characteristics of plantbased milk products.