Antioxidant and antimicrobial extracts from grape stalks obtained with subcritical water. Potential use in active food packaging development

• Published in: Food chemistry 2024-09, Vol.451, p.139526-139526, Article 139526
• Main Authors: de Freitas, Pedro Augusto Vieira, Meyer, Silvia, Hernández-García, Eva, Rebaque, Diego, Vilaplana, Francisco, Chiralt, Amparo
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antioxidants - chemistry; Antioxidants - pharmacology; Escherichia coli - drug effects; Escherichia coli - growth & development; Food Packaging - instrumentation; Listeria - drug effects; Listeria - growth & development; Phenolic compounds; Plant Extracts - chemistry; Plant Extracts - pharmacology; Poly (lactic acid); Subcritical water extraction; Vitis - chemistry; Waste valorisation
• ISSN: 0308-8146; 1873-7072; 1873-7072
• DOI: 10.1016/j.foodchem.2024.139526

In order to valorise winemaking grape stalks, subcritical water extraction at 160 and 180 °C has been carried out to obtain phenolic-rich extracts useful for developing active food packaging materials. Red (R) and white (W) varieties (from Requena, Spain) were used, and thus, four kinds of extracts were obtained. These were characterised as to their composition, thermal stability and antioxidant and antibacterial activity. The extracts were incorporated at 6 wt% into polylactic acid (PLA) films and their effect on the optical and barrier properties of the films and their protective effect against sunflower oil oxidation was analysed. Carbohydrates were the major compounds (25–38%) in the extracts that contained 3.5–6.6% of phenolic compounds, the R extracts being the richest, with higher radical scavenging capacity. Every extract exhibited antibacterial effect against Escherichia coli and Listeria innocua, while PLA films with extracts preserved sunflower oil against oxidation. •Active extracts from grape stalks were obtained by subcritical water extraction.•The extracts presented radical scavenging capacity and antibacterial effect.•Poly (lactic acid) films with active extracts were prepared by thermoprocessing.•Active films showed UV light absorption and improved oxygen barrier capacity.•Mono-dose bags with extracts prevented sunflower oil oxidation.