Chemical evaluation of winged beans (Psophocarpus Tetragonolobus), Pitanga cherries (Eugenia uniflora) and orchid fruit (Orchid fruit myristica)

Abstract

The proximate, mineral and sugar compositions of winged beans (Psophocarpus tetragonolobus), Pitanga Cherries (Eugenia uniflora) and Orchid Fruit (Orchid fruit myristica) and physico-chemical properties of their oils were determined using standard methods. All the samples were found to be rich in proteins (winged beans 33.83 %, pitanga cherries 14.71 % and orchid fruit 17.96 %). Each of the samples also had a considerably high amount of carbohydrate (22.30 %, 38.55% and 26.45 % in winged beans, pitanga cherries and orchid fruit, respectively). Orchid fruit had a significantly higher (P < 0.05) fat content of 34.36 % as compared to 17.51 % found in winged beans, and 15.62 % in pitanga cherries. Winged beans had the highest crude fiber (12.23 %) while orchid fruit had 6.03%and pitanga cherries had 9.77%. Winged bean and orchid fruit had similar (P > 0.05) water content, which is significantly different from pitanga cherries. Iron, cadmium, lead and manganese were absent in all the samples. Copper and calcium were absent in pitanga cherries. Pitanga cherries had the highest composition (g/100g) of sugar, winged beans ranked next, while orchid fruit had low sugar content. The peroxide values of the oil of the various samples ranged between 11.41 and 12.91 meq/kg, while the saponification values ranged between 182.58 and 191.05 mgKOH/g. The unsaponifiable matter was very low in pitanga cherries compared with winged beans and orchid fruit. The acid value rangedbetween 0.71 and 2.82 mg/KOH/g while iodine value ranged between 91.15 and 144.57. The refractive index ranged between 1.465 and 1.474 in all the samples. Based on the results of this study, winged beans could be useful in the formulation of infant formula, pitanga cherries in the production of fruit jam and as a flavour in food drinks, because of its sugar contents, while orchid fruit—which has very high oil content—could be used as a spice.