PROXIMATE, ELEMENTAL AND PHYTOCHEMICAL ANALYSIS ON UNPEELED FLOUR, STARCH, AND SHAFT OBTAINED FROM RED BEANS (PHASEOLUS VULGARIS)

This study investigated the proximate composition, elemental profile, and phytochemical constituents of unpeeled flour, starch, and shaft fractions obtained from red beans (Phaseolus vulgaris). The beans were processed into three distinct samples: unpeeled flour, extracted starch, and the residual shaft. Standard analytical procedures were employed for proximate analysis, mineral determination, and phytochemical screening. The proximate analysis revealed variations in moisture, protein, fat, fiber, ash, and carbohydrate content across the three fractions. The unpeeled flour exhibited relatively higher protein and carbohydrate contents, while the shaft fraction was rich in crude fiber and ash. The starch fraction was characterized by high carbohydrate levels and low crude fat and fiber. Elemental analysis indicated the presence of essential minerals such as calcium, magnesium, iron, zinc, potassium, and sodium in varying proportions, with the shaft showing the highest concentration of calcium and iron. Phytochemical screening confirmed the presence of alkaloids, flavonoids, tannins, saponins, and phenolic compounds, though in different concentrations among the fractions. Moisture content ranged from 9.44 % in unpeeled flour (URB) and oven-dried shaft (RBSHO) to 11.41 % in red bean shaft (RBSH), reflecting differences in water-holding capacity of the samples. Ash content, an indicator of mineral presence, was highest in red was generally low across all samples (0.97–2.15 %), consistent with beans being naturally low-fat foods. Fiber content was highest in unpeeled flour (4.23 %), highlighting its potential as a dietary fiber source, while the lowest was in RBSHO (2.82 %). Protein levels varied significantly, ranging from 7.40 % in RBS to 18.86 % in URB, suggesting that unpeeled flour retains higher nutritional quality compared to isolated starch. Carbohydrate content was highest in RBS (75.36 %), followed by RBSHO (71.87 %), reflecting starch as the primary energy fraction, while URB and RBSH had lower carbohydrate values (64.20 % and 64.36 %, respectively).