Extraction and characterization of novel fibers from Grapevine shoots: a comparative study of dry and wet pretreatment.

This study focuses on Vitis vinifera (grape), one of the world's largest crops and an ancient dietary staple. Grapevine shoots, post-pruning, are an abundant agricultural residue with little economic value, as they are mainly used as fuel or fertilizer. The prime objective of the study was the extraction and characterization of novel lignocellulosic fibers from grapevine shoots, assessing the impact of dry and wet pretreatment on their physical and mechanical properties. The results indicate that wet-pretreated fibers exhibited superior length, fineness, strength, and yield compared to dry-pretreated fibers. Additionally, wet pretreated raw material also required less time and chemical concentration than that required after dry pretreatment. In terms of further optimisation, Na₂S treatment (15 g/l) produced fibers with better length, fineness, strength, and yield, while NaOH treatment (15 g/l) gave fibers flexibility. Overall, bark fibers demonstrated better physical and mechanical properties than core fibers, while core fibers had a superior yield. Comparisons with traditional fibers including jute, flax, kenaf, hemp, ramie, sisal, and coir, revealed that grapevine bark fibers were moderately fine, strong, and elastic, positioning them as a potential sustainable alternative in textiles. In contrast, core fibers were coarser and comparable to coir and sisal, making them ideal for ropes, mats, and heavy-duty industrial applications. Therefore, distinct features of grapevine fibers make them appropriate for potential applications in yarn and composite materials. Furthermore, the valorization of this otherwise discarded agricultural waste into marketable goods would reduce greenhouse gas emissions associated with its decomposition.