## 4 Dealcohized Grape Pomace Applications in Bio-Based Materials
### Incorporation of Dealcholized Grape Pomace in Biodegradable Plastics  
Incorporating DGP or materials derived from grape pomace into biodegradable plastics represents an emerging strategy to improve the sustainability and functionality of packaging materials. In 2023, the Science Learning Hub [63] reported on the development of biodegradable vine net clips made from DGP, proposed as a sustainable alternative to conventional plastic clips used in vineyards. Conducted by Scion's Biopolymers and Chemicals division, the project addressed a primary environmental concern, i.e., the estimated 16.8 million plastic clips used annually in New Zealand vineyards, which are rarely collected and often accumulate as persistent microplastic waste. The bioplastic composite was formulated by blending PLA with dried grape pomace, resulting in a material with sufficient mechanical strength for vineyard use and enhanced biodegradation compared to PLA alone. According to the authors, the vine clips biodegradable more rapidly, offering an eco-friendly solution for single-use applications in vicitculture and demonstrating a tangible step forward in achieving circular bioeconomy objectives. This study demonstrates the feasibility of using DGP as a functional filler to enhance the mechanical and thermal performance of biodegradable polymer composites, supporting the design of more sustainable materials. More recently, [PERSON] et al. [64] explored the incorporation of dried and ground grape pomace into the commercial biodegradable polymer blend Mater-Bi (MB)--a mixture of PLA and poly(butylene adipate-co-butylene terephthalate) (PBAT)--to improve its properties and sustainability. The study developed and characterized biocomposites containing 10% and 20% DGP, assessing their mechanical, chemical, and degradation behavior compared to neat MB. The addition of DGP enhanced the antioxidant properties of the biocomposites and modified their rheological behavior, particularly increasing the complex viscosity at low frequencies. A modest improvement in elastic modulus and crystallinity was also observed. Soil degradation tests indicated an accelerated weight loss at higher GP content, suggesting enhanced biodegradability. NMR analysis further revealed compo sitional changes in PBAT during degradation, including an increase in terephthalatic acid content. This work highlights the potential of grape pomace as a functional filler that can boost both the performance and environmental sustainability of biodegradable plastics. Beyond DGP, other by-products obtained after dealcoholization, drying, and screening--such as GS, grape seeds, and grape seed flour--can also be used as additives or reinforcements in biopolymer films and foams. These materials are intended to enhance mechanical, antioxidant, and barrier properties while promoting environmental compatibility, and they have been investigated in the development of biodegradable plastics (Table 4). GS can be effectively used as fillers in cassava starch-based foams, integrating well without causing agglomeration or impairing foam structure. These foams are fully biodegradable within seven weeks and are suitable for packaging low-moisture food products [65]. Grape seed flour has been applied in the production of biodegradable cutlery. The resulting spoons provide a sustainable alternative to plastic utensils, combining structural strength with added nutritional and health benefits. Specifically, the flour enhances the antioxidant activity and improves the nutritional profile of the final product [66]. In another application, grape seed lignin has been incorporated into polyhydroxyalkanoate (PHA/PHB) films to improve their antioxidant capacity, gas barrier performance, and biodegradability. These films also show improved decomposition rates and yield non-toxic degradation by-products [67]. Grape pomace-derived materials consistently demonstrate rapid and complete biodegradation in soil or compost, with no formation of recalcitrant or toxic residues.