Evolution of plant water status indices during butter lettuce growth and its impact over post storage quality

BARG MÓNICA V; AGÜERO MARÍA VICTORIA; YOMMI ALEJANDRA; ROURA SARA INES

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE

Wiley InterScience

Año: 2009 vol. 89 p. 422 - 429

0022-5142

BACKGROUND: The maturity of perishable commodities has an important bearing on their storage life and quality. Lettuce is a highly perishable vegetable whose quality and shelf life are limited by dehydration. The purpose of the work was to analyze the evolution of water status indices (relative water content, water content, free water, bound water, free water to total water ratio) during lettuce growth, how these indices behaved after storage (7 days, 0-2ºC and 97-99% relative humidity) and how they impact on visual quality. RESULTS: No significant changes in weight and number of leaves were detected until 65 days after transplanting (DAT), then increments were registered up to 85 DAT, maintaining constant up to 92 DAT. Conforming development advanced, it was found, for all water status indices, a tendency to diminish differences between values of outer and inner leaves. Only at final development stages, lettuces were able to retain high indices after storage. Sensorial quality was higher in lettuces harvested at final development stages. Consequently, optimal maturity from a physiological and quality points of view coincided with optimal weight and size for harvesting. CONCLUSION: The stage of maturity at harvest, affected sensorial quality of lettuces, being lettuces harvested at last stages those that best maintained quality attributes after storage.