title: Total phenolics, antioxidant properties and quality of fresh-cut onions (Allium cepa L.) treated with mild-heat.
abstract: This study investigated the effect of mild-heat on fresh-cut onion slices by treating in hot water (50, 60, 70°C) for 1 min. Total phenolics (TP), antioxidant properties, colour, and weight loss of slices were evaluated during 4°C storage at 7-day intervals (21 days total). The 60°C heat treatment resulted in a significant increase in TP, from 44.92 to 52.32 mg GAE/100g. Except for 50 and 70°C treatments, TP in control and 60°C treated fresh-cut onions decreased during storage. The antioxidant properties of fresh-cut onions were 1.31, 0.99, and 62.49 μM TE/g using ABTS, DPPH, and ORAC assays, respectively. The mild-heat treatments did not affect ABTS and DPPH antioxidant activities and the colour of fresh-cut onions. The storage time had mixed effect on the antioxidant properties (ABTS decreased; DPPH and ORAC remained fairly stable). The 50°C samples exhibited the lowest weight loss during 21-day storage.
authors.affiliation: Department of Food Science & Human Nutrition, Michigan State University, East Lansing, MI 48824, USA. siddiq@msu.edu
authors.forename: M
authors.initials: M
authors.lastname: Siddiq
authors.forename: S
authors.initials: S
authors.lastname: Roidoung
authors.forename: D S
authors.initials: DS
authors.lastname: Sogi
authors.forename: K D
authors.initials: KD
authors.lastname: Dolan
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D005511:Food Handling / Q000379:methods*; D061353:Food Storage; D006358:Hot Temperature; D019697:Onions / Q000737:chemistry*; D010636:Phenols / Q000032:analysis*; D010936:Plant Extracts / Q000032:analysis*; D011786:Quality Control
chemical_list: D000975:Antioxidants; D010636:Phenols; D010936:Plant Extracts