Isolation of protein from winged bean (Psophocarpus tetragonolobus) and long bean (Vigna unguiculata subsp. sesquipedalisis) / Ahmad Hilmi Basharal Hafi

The demand for food of plant origin will continue to keep up with the world rapidly growing population. The potentially plant to generate high protein output is desirable to overcome the shortage of animal-based protein. This study was carried out to identify an alternatives plant-based protein. The winged bean (Psophocarpus tetragonolobus) and long bean (Vigna unguiculata subsp. sesquipedalis) are said as a rich protein source plant and widely consumed in Malaysia. Therefore, these two species, were used as a subject study. The objectives of this research are to isolate protein from winged bean (Psophocarpus tetragonolobus) and long bean (Vigna unguiculata subsp. sesquipedalis) and also to compare protein extraction from long bean and winged bean. Albumin was used as indicator to compare present of protein between long bean and winged bean. Protein was extracted by using alkaline method. Technically there are six major steps involved which are sample pre-treatment, extraction, centrifugation, Biuret test, spectrophotometer, and precipitation of protein. Samples were treated in 25°C and 35°C with three different volume-weight ratios (35:1. 40:1 and 45:1). The result obtained from this study showed that the protein not successfully extracted using alkaline method and proven by Biuret test and precipitation of protein, even though spectrophotometric analysis showed certain number of absorption reading but too low. Albumin give the positive result for protein compared to distilled water (control) and the sample used.