An investigation into the sensory properties of luffa [Luffa cylindrica (L.)] sap

The seeds and sap of luffa [Luffa cylindrica (L.)] are usually discarded as waste. As such, this study aimed to identify the sensory properties of luffa sap (aqueous solution) and if it can be incorporated into a food item (orange juice) for added nutritional benefits and as an alternative sweetener. A sensory trial (n = 94) asked participants to evaluate a luffa sap sample and five different orange juice samples with increasing amounts of luffa sap (control [0%], 5%, 7.5%, 10%, 12.5%). The participants evaluated the samples using 9-point hedonic scales, check-all-that-apply, and an open-ended comment question. The luffa sap was described as having a mild flavor as well as woody, earthy, and floral attributes and an aftertaste. The liking scores for the orange juice with the 5% luffa sap did not significantly differ from the control. However, as the amount of luffa sap increased above 5%, the liking scores decreased and were significantly different from the control. The orange juice with luffa sap samples (7.5% and above) was associated with off-flavors, while the orange juice with 5% luffa sap and the control were associated with the attributes (sweet, fruity, orange, tropical, citrus) that increased the participants liking. Future studies should continue to investigate the sensory properties of luffa sap and its incorporation into different food products.