Cellulose nanocrystals (CNCs) were obtained from grape pomace through chemical and physical pretreatments. Bleached cellulose pulp was subjected to acid hydrolysis (AH) for 30 or 60 min and an ultrasound treatment to obtain CNCs (AH_30Sand AH_60S). Compositional analyses of untreated (UGP) and pretreated (PGP) grape pomace showed the effectiveness of pretreatment in removing non-cellulosic components, recovering 80.1% cellulose in PGP (compared to 19.3% of UGP). Scanning and transmission electron microscopies were used to evaluate the CNCs morphology. AH in combination with ultrasound treatment led to needle-shaped structures and apparently more dispersed suspensions. Crystallinity index and thermal stability were studied by X-ray diffraction and thermogravimetric analysis, respectively. The AH_60S sample presented high aspect ratio, crystallinity and thermal stability. CNCs toxicity was evaluated by exposing Caco-2 cells to CNCs suspension and evaluating their viability. Results showed that CNCs are non-toxic, opening the opportunity for their use on food and pharmaceutical applications.

通过化学和物理预处理从葡萄果渣中获得纤维素纳米晶体（CNC）。对漂白的纤维素纸浆进行酸水解（AH）30或60分钟，然后进行超声波处理，以得到_CNCs（AH _30S和AH _60S）。未经处理（UGP）和经过预处理（PGP）的葡萄渣的成分分析表明，预处理在去除非纤维素成分方面是有效的，可回收PGP中80.1％的纤维素（相对于UGP的19.3％）。扫描和透射电子显微镜用于评估CNC的形态。AH与超声治疗相结合导致了针状结构和明显分散的悬浮液。通过X射线衍射和热重分析分别研究了结晶度指数和热稳定性。AH _60S样品具有高的长径比，结晶度和热稳定性。通过将Caco-2细胞暴露于CNCs悬浮液并评估其生存能力来评估CNCs的毒性。结果表明，CNC是无毒的，为它们在食品和药品应用中的使用提供了机会。