Vol. 115 (2002): Proceedings of the Florida State Horticultural Society
Handling & Processing

Evaluation of different oxygen, carbon dioxide and nitrogen combinations employed to extend the shelf life of fresh-cut collard greens

Celso L. Moretti
Embrapa Vegetables
front cover of vol 115, 2002

Published 2002-12-01

Keywords

  • brassica oleracea,
  • brix,
  • chlorophyll,
  • modified atmosphere,
  • quality,
  • postharvest,
  • vitamin c
  • ...More
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Abstract

Collard greens (Brassica oleracea var. acephala) "Manteiga" were harvested in commercial fields in Brasilia, Brazil, aiming to evaluate different oxygen, carbon dioxide and nitrogen combinations to extend the shelf life of the fresh cut product. After harvest, leaves were taken to the postharvest laboratory, selected for external blemishes and minimally processed (3 mm thick) inside a cold room (13±2C). After processing, fresh cut collard greens were stored under two controlled atmosphere (CA) conditions (3% O[sub2], 4% CO[sub2] ; 5% O[sub2] ,5% CO[sub2] - balance N[sub2]), and normal air (control), at 5 C (95% RH), for six days. Daily, minimally processed collard greens were evaluated for total vitamin C, total chlorophyll, total soluble solids content, and titratable acidity. Total vitamin C content decreased for all treatments during the storage period. Storage under CA conditions delayed total vitamin C degradation for both atmospheres studied. At the end of the storage period, fresh cut collard greens stored under 3% O[sub2], 4% CO[sub2] showed around 25% and 56% more vitamin C than the material stored under 5% O[sub2], 5% CO[sub2] and control, respectively. Total chlorophyll content decreased during the storage period. At the end of the experiment, fresh cut collard greens stored under 3% O[sub2], 4% CO[sub2] showed 24% and 45% more total chlorophyll than the product stored under 5% O[sub2], 5% CO[sub2] and control, respectively. CA storage delayed organic acid degradation. At the sixth day, fresh cut collard greens stored under 3% O[sub2], 4% CO[sub2] had around 44% more organic acids than control. Total soluble solids content were not significantly affected.