PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

The Elateriospermum tapos seed extract is one of the major contributors to the therapeutic effects as remedy drink for chronic diseases, such as hypertension, diabetes and obesity by the locals in East Malaysia. It is believed that the component in the seed, such as protein, plays an essential role due to its nutraceutical properties. Hence, we report the extraction of protein from the seed of E. tapos that has the potential biological activities. The protein was initially extracted using salt solution, which was similar to the local practice and maximal values of extraction yield (44 mg/g) was performed based on the extraction parameters; pH 8, sample to buffer ratio, 1:50 (w/v), 2 h at 80°C. Sodium dedocyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) profile showed that 7S globulin was the dominant protein in the E. tapos seed protein isolate (ETSPI), whereas Fourier Transform Infrared (FTIR) analysis showed that the extracted protein consisted of α-helical secondary structure. This protein could be digested up to 72.5% in vitro. In the biological activity evaluation, the results showed that ETSPI exhibited angiotensin converting enzyme (ACE) inhibitory (56.6%/100 µg), lipase inhibitory (26.7%/100 µg), α-amylase inhibitory (31.2%/100 µg), free radical scavenging (33.4%/mg) and metal reducing activities (0.97 mM FeSO₄/mg), which suggests that this protein has the potential in the aforementioned therapeutic effects.