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Evaluation of antioxidant and sensory properties of selected cultivars of Colorado-grown lettuce (Lactuca sativa L.)

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dc.contributor.authorBunning, Marisa, author
dc.contributor.authorKendall, Patricia, advisor
dc.contributor.authorStushnoff, Cecil, advisor
dc.date.accessioned2024-03-13T18:50:54Z
dc.date.available2024-03-13T18:50:54Z
dc.date.issued2007
dc.description.abstractEpidemiological evidence has substantiated the health benefits associated with the consumption of vegetables, particularly leafy greens. Lettuce (Lactuca sativa L.) cultivars (varieties) have usually been selected based on shelf-life, transportability, and yield rather than nutritional or sensory traits. Information on the effects of seasonality and genetics on various characteristics of lettuce is limited. Nutritional, antioxidant, and sensory profiles of lettuce may vary considerably among cultivars and in response to environmental factors that may fluctuate widely throughout the growing season. Bitterness, an important flavor characteristic of lettuce, is generally thought to increase with higher growing season temperatures and may vary with phenolic content.
dc.description.abstractTotal phenolic content, radical scavenging capacity, vitamin C levels, and sensory properties of multiple lettuce cultivars harvested early, mid-way, and late in the growing season were assessed in this study. Each lettuce crop was grown using standard organic methods and sampled with uniform harvest and postharvest procedures. Daily temperatures and radiation were monitored to determine the impact of climatic factors.
dc.description.abstractTotal phenolic content and radical scavenging capacity were quantified in eight cultivars of lettuce grown at six different times over two growing seasons. ‘Cimmaron’ (red romaine), ‘Crisp and Green’ (green leaf), ‘Crispino’ (iceberg), ‘Green Forest’ (green romaine), ‘Lochness’ (butterhead), ‘Nevada’ (green batavia), ‘Sierra’ (redbatavia) and ‘Vulcan’ (red leaf) lettuce cultivars were analyzed for total phenolic content using the Folin-Ciocalteu assay and radical scavenging capacity was estimated with an ABTS assay. Vitamin C levels of the eight cultivars grown at two different times were determined using HPLC.
dc.description.abstractSignificant variation (P < 0.001) existed in both total phenolic content and radical scavenging capacity among the eight cultivars. With four cultivars, increases in total phenolic content were observed with higher summer temperatures but trends were not attributable to seasonality. Total phenolics varied from 13.1 mg gallic acid equivalents/gram dry weight in ‘Crispino’ to 48.2 mg GAE/gdw in ‘Vulcan’. Radical scavenging capacity ranged from 160.3 μmole TEAC/100 grams fresh weight for ‘Crispino’ to 653.8 μmole TEAC/100gfw for ‘Cimmaron’. Cultivars with red pigmentation exhibited higher levels than similar green cultivars and leaf lettuce exhibited the highest levels among the four types. Variation in vitamin C among these cultivars was not statistically significant (P > 0.05).
dc.description.abstractThirty sensory panelists rated bitterness, appearance, flavor, texture, and overall acceptability of five cultivars: ‘Crisp and Green’ (green leaf), ‘Crispino’ (crisphead), ‘Green Forest’ (romaine), ‘Lochness’ (butterhead), and ‘Vulcan’ (red leaf) lettuce. There was considerable variation in sensory ratings among the 5 cultivars (P < 0.005) but few differences within cultivars across the growing season. ‘Crispino’ received higher scores for flavor, texture, and overall acceptability and was rated less bitter than other cultivars (P < 0.01). Mean scores for all attributes remained within the acceptable range, indicating that acceptable lettuce can be grown in this region during summer months.
dc.description.abstractThese results demonstrate the diversity of antioxidant capacity among cultivars and suggest that genotype may have a significant influence on nutrient levels in this crop. As part of a food-based approach to improving nutrition, it is beneficial to identify the health-promoting potential of specific vegetable cultivars that also exhibit favorable sensory properties. Nutritional and sensory assessment of different types and colors of promising lettuce cultivars may improve the market competitiveness of Colorado-grown lettuce.
dc.format.mediumborn digital
dc.format.mediumdoctoral dissertations
dc.identifierETDF_Bunning_2007_3266401.pdf
dc.identifier.urihttps://hdl.handle.net/10217/237607
dc.languageEnglish
dc.language.isoeng
dc.publisherColorado State University. Libraries
dc.relation.ispartof2000-2019
dc.rightsCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.
dc.rights.licensePer the terms of a contractual agreement, all use of this item is limited to the non-commercial use of Colorado State University and its authorized users.
dc.subjectantioxidant
dc.subjectcultivars
dc.subjectLactuca sativa
dc.subjectlettuce
dc.titleEvaluation of antioxidant and sensory properties of selected cultivars of Colorado-grown lettuce (Lactuca sativa L.)
dc.typeText
dcterms.rights.dplaThis Item is protected by copyright and/or related rights (https://rightsstatements.org/vocab/InC/1.0/). You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
thesis.degree.disciplineFood Science and Human Nutrition
thesis.degree.grantorColorado State University
thesis.degree.levelDoctoral
thesis.degree.nameDoctor of Philosophy (Ph.D.)

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