Sustainable herbal teas from fig (Ficus carica L.) waste leaves: volatile fingerprinting, sensory descriptors, and consumer acceptability

Herbal teas made from agricultural waste or by-products are gaining attention as eco-friendly alternatives to support circular economy practices. Fig (Ficus carica L.) leaves are well known for their biological activities. The research aims to investigate the possibility of using fig waste leaves to produce healthy and sustainable herbal teas. Different drying technologies have been used, including air drying (AD) and microwave drying (MWD), and consumer acceptability was tested and related to the sensory features and volatile odor compounds. Sensory descriptive analysis and hedonic consumer tests were carried out. Odor volatiles were analyzed by headspace-solid-phase microextraction-mass spectrometry-gas chromatography (HS-SPME-GC-MS). The teas were also evaluated for their phenolic content and antioxidant capacity. Results indicate that MWD increases the total phenolic compound amount by 20%, reduces C6 alcohols and aldehydes responsible for green and herbaceous sensory notes, and increases pentanal, octanal, nonanal, ketones (especially 6 methyl-5-hepten-2-one) and terpenes, such as beta-cyclocitral, which are related to the fruity and honey odors; this leads to a more appreciated color and taste. This study demonstrated that dehydrated fig waste leaves, especially those processed through the eco-friendly microwave drying method, can be utilized to produce herbal teas with favorable sensory and nutritional properties. This approach aligns with sustainability objectives and presents a promising strategy for diversifying the herbal tea market while promoting the valorization of agricultural wastes.