Momordica cochinchinensis Spreng. (gac) fruit carotenoids reevaluated

Momordica cochinchinensis Spreng., Cucurbitaceae, is indigenous to Southeast Asia and consumed there for dietary as well as medicinal uses. In Viet Nam, this plant is called “gac”, and the seed membrane (seed pulp or aril) of the ripe fruit is widely used as a rice colorant due to its intense red color from its high carotenoid content. Because of conflicting reports on the carotenoid concentrations in gac fruit, we analyzed samples of seed membrane and mesocarp obtained from Viet Nam by HPLC/PDA for carotenoids and tocopherols. On average in three fruits, total carotenoid concentrations (±standard deviation) were 497 (±154) μg/g fresh material with lycopene dominating and exceeding beta-carotene concentrations by a factor of approximately five (408 μg/g versus 83 μg/g). These values agree with recent data from Japan, but are lower than those from a recent study in the US. A sample of pulp mixed with mesocarp had significantly lower concentrations of total carotenoids. The alpha-tocopherol concentration in the pulp was 76 μg/g. In light of its nutritional value, in particular regarding the remarkably high concentration of lycopene, more systematic analyses of the factors affecting the nutrient composition of gac fruit are needed.