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United States Department of Agriculture

Agricultural Research Service

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Research Project: Innovative Ultraviolet-B Processing to Enhance Health Promoting Bioactive Components in Specialty Crops

Location: Healthy Processed Foods Research

2010 Annual Report


1a.Objectives (from AD-416)
(1) Establish which specialty crops respond best to UV-B treatment for the enhancement of their health-promoting properties (e.g. phenolics, antioxidants) and determine dose-response. (2) Establish the localized and distal effects of UV-B treatment on plant tissues (e.g. skin vs. interior). (3) Determine the effect of postharvest conditions on the synthesis of phenolic compounds with and without UV-B treatment and analyze the stability of these compounds during normal storage. Determine the effects of these treatments on sensory quality and nutritional value. (4) Verify enhanced bioavailability of phenolic compounds following UV-B treatment using in-vitro and in-vivo methods.


1b.Approach (from AD-416)
Recently harvested produce, including whole and precut fruits and vegetables such as whole grapes, whole berries, cherry tomatoes, baby carrots, broccoli florets, and apples will be exposed to UV-B treatments at different doses. Effectiveness of the treatments will be evaluated and subsequently optimized based on increased phenolic compound concentrations, antioxidant capacity, and PAL activity. Increases in specific compounds, such as trans-resveratrol, anthocyanins, quercetin glycosides, tocopherols, and carotenoids will be determined through HPLC analysis. The potential impact or improvement resulting from UV-treatment on quality factors (color, firmness, acidity/sweetness ratio, ascorbic acid, etc.), sensory attributes, respiration rate (under controlled atmosphere, temperature, and %RH) and shelf-life will also be evaluated for the most promising samples. Changes in the bioavailability of phenolic compounds from UV-B treated fruits and vegetables will be verified using both in-vitro and in-vivo methods. Document AFRI Reimbursable.Log 39208. Formerly 5325-41000-060-16R; April, 2010.


3.Progress Report

This agreement supports in-house project objectives on adding value to foods through novel processing. Whole carrots exhibited an 85% increase in antioxidant compounds and carrot peels exhibited a 22% increase after UV-B treatment. Strawberries showed a significant but slight increase in antioxidants. Whole grapes, blueberries, and industrial pomaces from baby carrot manufacture, cold-break tomato paste process, wine grape processing, and cold-press olive oil extraction did not benefit from UV-B exposure. Ultraviolet B processing can be used on select specialty crops to enhance nutritional value.


Last Modified: 8/30/2014
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