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Hot water treatment in combination with calcium ascorbate dips increases bioactive compounds and helps to maintain fresh-cut apple quality

Citation

Aguayo, E and Requejo-Jackman, C and Stanley, R and Woolf, A, Hot water treatment in combination with calcium ascorbate dips increases bioactive compounds and helps to maintain fresh-cut apple quality, Postharvest Biology and Technology, 110 pp. 158-165. ISSN 0925-5214 (2015) [Refereed Article]

Copyright Statement

Copyright 2015 Elsevier

DOI: doi:10.1016/j.postharvbio.2015.07.001

Abstract

Fresh-cut ‘Braeburn’ apple slices were dipped into cold water (4 °C for 2 min) or hot water (HWT, 48 °C or 55 °C for 2 min) followed by dips into 0 or 6% w/v aqueous calcium ascorbate (CaAsc, 2 min, 0 °C) and stored in air up to 28 d at 4 °C. Microbial counts, changes in browning and sensory acceptance were determined to indicate changes in quality. Changes in antioxidant levels were measured using free radical scavenging activity (DPPH), reducing activity (FRAP), ascorbic acid content (AA) and polyphenolic content (by HPLC). CaAsc dips had a strong impact reducing the browning through increasing the flesh luminosity and hue angle. 6% CaAsc in fresh-cut apples extended the overall acceptability from less than 7 d to 14 d. Immediately after CaAsc treatment, AA content was 5 fold higher (0.25–1.25 g kg−1) than those not dipped into CaAsc. However, the combination of HWT treatments and CaAsc dips led to seven fold increased levels of AA inside the apple tissue (0.25–1.85 g kg−1) and consequently increased the antioxidant activity. HWT did not increase the AA content when not combined with CaAsc dips. The HWT CaAsc dip extended the overall acceptability to 21 d compared to 14 d for samples not heated but dipped into CaAsc. Shelf life was ultimately limited by sensory quality. At day 28, total plate counts were reduced from 5.3 log cfu/g (untreated slices) to 4.6 log cfu/g in the 6% CaAsc dips and further to 3.9 log cfu/g with the combination of HWT and CaAsc dip. Changes in the content of phenolic compounds with time, HWT and CaAsc dip were generally not significant except for slightly increased quercetin and phloridzin levels and decreased p-coumaric and procyanidins over time. The combination of HWT at 48 °C for 2 min followed by 6% CaAsc dip would be best for preserving the eating quality of apple slices.

Item Details

Item Type:Refereed Article
Keywords:apple, preservation, fresh-cut, quality, minimally processed, apple slices, heat treatment, shelf life, phenolic compounds, vitamin C, ascorbic acid, antioxidant
Research Division:Engineering
Research Group:Food Sciences
Research Field:Food Packaging, Preservation and Safety
Objective Division:Manufacturing
Objective Group:Processed Food Products and Beverages (excl. Dairy Products)
Objective Field:Processed Fruit and Vegetable Products (incl. Fruit Juices)
Author:Stanley, R (Dr Roger Stanley)
ID Code:106464
Year Published:2015
Web of Science® Times Cited:6
Deposited By:Tasmanian Institute of Agriculture
Deposited On:2016-02-10
Last Modified:2016-06-01
Downloads:0

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