Impact of different roasting times and temperatures on the sensory properties of luffa (Luffa cylindrica L.) seed powder

Luffa ( Luffa cylindrica L.) seed powder is a novel ingredient generated as a by-product of harvesting the luffa fibrous network, commonly used as an exfoliator. Although luffa seeds have demonstrated nutritional potential, their sensory properties may limit consumer acceptance. The objective of this study was to evaluate the impact of different roasting temperatures and times on the sensory properties and consumer acceptance of luffa seed powder. Seeds were roasted for six or twelve minutes at 140 °C, 160 °C, or 180 °C, dried at 60 °C for five hours, ground into powder, and incorporated into yogurt at 5% (w/w). Ninety-four participants who regularly consumed seeds evaluated the samples using nine-point hedonic scales and check-all-that-apply (CATA) questions. Samples roasted for twelve minutes received significantly higher overall liking scores (ranging from 5.6 to 6.0) compared to six-minute roasted samples and the unroasted control (ranging from 4.5 to 4.7; p < 0.05). Luffa seeds roasted for twelve minutes were associated with sweet and nutty attributes, but also with aftertaste and metallic notes, which negatively affected hedonic scores. Samples roasted for six minutes were characterized by off-flavours, bitterness, and chewiness and were not significantly different from the unroasted control. These results demonstrate that roasting time, more so than temperature, significantly influences the sensory profile of luffa seed powder, with longer roasting times reducing several negative attributes and improving consumer acceptance.