Application of different drying techniques to fresh-cut salad waste to obtain food ingredients rich in antioxidants and with high solvent loading capacity. (March 2018)

• Record Type: Journal Article
• Authors: Plazzotta, Stella; Calligaris, Sonia; Manzocco, Lara
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 89(2018)
• Page Start: 276
• Page End: 283
• Publication Date: 2018-03
• Subjects: Drying techniques -- Fibre -- Polyphenol -- Antioxidant activity -- Food ingredients; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2017.10.056
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: Wastes from iceberg salad fresh-cut processing were submitted to air-drying, freeze-drying, and supercritical-CO2 -drying with or without ethanol as co-solvent. Drying was combined with grinding to obtain flours. Samples were analysed for macro- and micro-appearance, particle size, dietary fibre, polyphenol content, antioxidant activity, water vapour sorption, water and oil holding capacity. Air-drying produced a collapsed brown material allowing a flour rich in fibre (>260 g/kg) and polyphenols (3.05 mg GAE/gdw ) with antioxidant activity (6.04 OD −3 /min/gdw ) to be obtained. Freeze-drying maintained vegetable structure and colour while partly retaining polyphenols (1.23 mg GAE/gdw ). Supercritical-CO2 -drying with ethanol as co-solvent, produced an expanded material able to entrap huge amounts of water and oil (43.2 and 35.2 g of water and oil for g of dry sample). Air-dried salad waste derivatives could be used as functional food ingredients, while supercritical-CO2 -dried ones can be exploited as bulking agents and absorbers of oil spills or edible oils. Highlights: Air-drying allows salad flours rich in fibre and antioxidants to be obtained. Freeze-drying partly maintains fresh salad structure, colour and polyphenols. Supercritical-CO2 -drying with ethanol as co-solvent produces highly porous flours.