36E-87

M. B. STONE¹, P. A. Kendall¹, C. Stushnoff², E. Pilon-Smits³, and J. R. Esparza¹. (1) Dept. of Food Science and Human Nutrition, Colorado State Univ., 229 Gifford Bldg., 1571 Campus Delivery, Fort Collins, CO 80523-1571, (2) Dept. of Horticulture and Landscape Architecture, Colorado State Univ., CO, (3) Dept. of Biology, Colorado State Univ., Fort Collins, CO 80523

Minimally processed lettuce has increased in commercial importance during the last decade. The shelf life of lettuce is limited by detrimental changes that develop during harvesting, processing and storage, and adversely impact such sensory attributes as appearance, texture and color. Processing methods that extend the shelf life of minimally processed lettuce are needed. Hydrocooling is a treatment often used to remove heat from freshly harvested commodities to reduce their respiratory rate. Ascorbic acid is a reducing agent used as a browning inhibitor in some fruits and vegetables. Our objective was to evaluate the quality of green leaf lettuce untreated (control) or treated with water or 1% ascorbic acid solution applied by two hydrocooling methods (immersion and spraying). Waldmann's dark green leaf lettuce was grown for ~70 days using standard organic methods, harvested manually, rinsed 5 min in running tap water (~20° C), drained 10 min, then left untreated, or treated with tap water or 1% ascorbic acid applied by 2 min immersion or spraying (5° C). Samples were drained 5 min, sealed in polyethylene bags and stored at 5° C for up to 14 d. An untrained sensory panel evaluated the samples for appearance, color, flavor, bitterness, tartness, texture and overall acceptability after 1, 7 and 14 d storage using a 15 cm 5-point hedonic scale (15=acceptable). Treatment, storage time and treatment x storage were significant factors based on ANOVA. Ascorbic acid spraying was rated highest for overall acceptability (12.09 on d 1) and flavor (12.00 on d 1). Water spraying was the treatment which scored lowest (p < 0.05) in appearance and overall acceptability on d 14 (8.79 and 8.85, respectively). Further experimentation is needed with the application of ascorbic acid during hydrocooling to extend the shelf life of minimally processed lettuce while maintaining optimal quality.

Session 36E, Fruit & Vegetable Products: General
8:30 AM - 12:00 PM, Monday AM Room Hall I-2

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana