Improving microbiological safety and maintaining sensory and nutritional quality of pre-cut tomato and carrot by gamma irradiation

Cs Mohácsi-Farkas, B. Nyiro-Fekete, H. Daood, I. Dalmadi, G. Kiskó

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Pre-cut tomato and carrot were irradiated with doses of 1.0, 1.5 and 2. kGy. Unirradiated control and irradiated samples were compared organoleptically by a sensory panel. Microbiological analyses were performed directly after irradiation and during post-irradiation storage for 8 days at 5. °C. Ascorbic acid contents, composition of carotenoids and tocopherols were determined. Statistically significant differences of sensory scores between unirradiated and irradiated samples were observed only in the texture of sliced carrots. Total aerobic viable cell counts have been reduced by about two log cycles with 1.5. kGy dose. Total coliforms and moulds were below the detection limit of 15. CFU/g in the irradiated samples during the refrigerated storage. Yeasts were relatively resistant part of the microbiota of pre-cut tomatoes, but 2. kGy dose reduced them below the detection limit. In pre-cut tomatoes, alpha-tocopherol and some carotenoids seemed to be the most radio-sensitive losing approximately one-third of their original concentrations at the dose of 2. kGy. At this dose tocopherols and the level of ascorbic acid decreased also one-third of the initial level in sliced carrots. Additional experiments were conducted to study the effect of irradiation and storage on the population of Listeria monocytogenes and Listeria innocua artificially inoculated on cut tomato and carrot. Cell numbers of both test organisms decreased by at least two log-cycles as an effect of 1. kGy dose. Our studies confirmed earlier findings on a temporary antilisterial effect of freshly cut carrot tissue. No re-growth of Listeria was observed during the studied storage period. The results of these studies suggest that irradiation with 1. kGy gamma rays could improve sufficiently the microbiological safety of the investigated pre-cut produce to satisfy the requirement of low microbial raw diets with acceptable nutritional quality and without diminishing significantly the organoleptic parameters of the commodities.

Original languageEnglish
Pages (from-to)79-85
Number of pages7
JournalRadiation Physics and Chemistry
Volume99
DOIs
Publication statusPublished - 2014

Fingerprint

tomatoes
safety
tocopherol
dosage
irradiation
carotenoids
ascorbic acid
commodities
diets
cycles
yeast
cells
organisms
textures
gamma rays
requirements

Keywords

  • Antioxidant vitamins
  • Low-dose irradiation
  • Microbiological safety
  • Pre-cut produce

ASJC Scopus subject areas

  • Radiation

Cite this

Improving microbiological safety and maintaining sensory and nutritional quality of pre-cut tomato and carrot by gamma irradiation. / Mohácsi-Farkas, Cs; Nyiro-Fekete, B.; Daood, H.; Dalmadi, I.; Kiskó, G.

In: Radiation Physics and Chemistry, Vol. 99, 2014, p. 79-85.

Research output: Contribution to journalArticle

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