Evaluating the Processing Potential of Specialty Crops and Enhancing the Food Safety of Oklahoma Produced And/or Processed Horticultural Products

<p>NON-TECHNICAL SUMMARY:<br/> This project will Identify and investigate the winemaking potential of grape and other fruit crops in Oklahoma. This will create new markets and expand existing markets for high-value horticultural crops such as grapes, small fruits, and pecans. This in turn will improve the economic viability of small to medium-sized farming operations in the state and the region. This project will also improve the nutraceutical content and/or quality of value-added horticultural crop products and capture value from horticulturalcrop processing waste streams in the form of high-value, health-promoting nutraceutical compounds. This will create new products and thus new income streams for small-scale fruit and vegetable processors such as fresh-cut operations, wineries, and so on. Finally, this project will improve the safety of minimally-processed fruits and
vegetables by developing and testing new processing practices and treatments to reduce the risk of contamination of produce by disease-causing microorganisms.
<p>APPROACH:<br/> Objective 1 -- Identify and investigate the winemaking potential of grape and other fruit crops in Oklahoma: Oklahoma's grape and wine industry is growing rapidly but still faces a number of challenges, particularly with consistent grape supply and wine quality. A wine grape variety trial vineyard consisting primarily of V. vinifera cultivars was established at the Cimarron Valley Research Station in Perkins, OK in 2001 to help address these issues. The cultivars in the vineyard are both on rootstock and own-rooted. Standard viticultural data (e.g. yield, cluster size, berry size, berry pH, berry titratable acidity, etc.) have been collected since 2004. A research enology laboratory was established at the Robert M. Kerr Food and Agrigculutral Products Center on the campus of Oklahoma State University in Stillwater in 2007 and various winemaking studies
have been conducted which involved the evaluation of specific grape and blackberry cultivars, the use of micro-oxygenation to improve wine quality, and the examination of health-promoting compounds in grape and fruit wines. We will continue to conduct similar studies looking at the winemaking quality of grapes from the Perkins Research Station and elsewhere in Oklahoma. The proposed studies will involve examining the effect of various wine-making techniques designed to compensate for some of the challenges typically faced by Oklahoma winemakers such as less than optimal grape chemistry. Research into topics such as evaluation of skin contact time and phenolic compound manipulation during grape fermentation will significantly strengthen Oklahoma's grape and wine industry. This will build upon previous studies evaluating micro-oxygenation and will involve, for example, the direct
addition of phenolic and pigment extracts to wines before and after fermentation. We will also study the winemaking potential of lesser-used grape cultivars including American and hybrid grapes. These grapes are better suited to Oklahoma's climate in terms of cold-hardiness and disease resistance. But they face some resistance in the industry due to the perception that they produce wines of lesser quality than do traditional European grape varieties. Objective 2 -- Improve the nutraceutical content and/or quality of processed specialty crop products; capture value from specialty crop processing waste streams in the form of nutraceutical compounds: In recent years, energy bars, beverages, cereals, even margarine and candy have all been fortified with functional ingredients ranging from herbs to probiotic bacterial cultures. Many of these foods contain various natural antioxidants.
This trend presents an opportunity for Oklahoma's horticultural product producers and processors to produce crops high in nutraceutical components and to create new processed foods and food ingredients marketed in whole or in part on the basis of their health-functional properties. On-going studies are looking at extracting valuable nutraceutical and/or antimicrobial compounds, mainly phenolic compounds and essential oils, from horticultural product processing waste streams using both solvent extraction and distillation methods. Previous work by others suggests that these waste streams may contain valuable components. We are currently investigating the potential value of winery waste as a source of antioxidant compounds that could be used as food ingredients by screening various extracts using the Oxygen Radical Absorbance Capacity (ORAC) assay. Objective 3 -- Enhance the safety of
processed fruits and vegetables with an emphasis on minimally-processed products; capture value from specialty crop processing waste streams in the form of antimicrobial compounds: The public's desire for fresher, more convenient food is driving processors to maximize the quality and shelf-life of the minimally processed food products they produce. Insuring the safety of these minimally processed foods is vital since these foods typically lack traditional "kill steps" such as heating. It is often necessary to develop specific processing treatments for a given product to preserve food quality and maintain food safety. In minimally processed foods, safety and quality can rarely be assured by a single treatment. Therefore, multiple steps that individually constitute barriers to microbial growth are often employed. Often these barriers, taken together, create a greater impediment to
microbial growth than might be expected from their individual effects. Several key processing treatments exist within the context of developing multiple barriers to quality loss and microbial growth in minimally processed foods. One of these is chemical and/or physical treatments applied to the product such as a chlorine dip. Treatment with other antimicrobial agents or inoculation with competitive non-pathogenic microorganisms may be employed. Physical treatments such as the application of ultraviolet light, pulsed electric fields, and ultra high pressure have also been tested with varying degrees of effectiveness. We expect to continue work examining possible treatments including novel technologies such as electrostatic spray application to apply natural microbial inhibitors such as essential oils to minimally-processed produce. While it is clear that processing techniques and
treatments can help keep foods safe, the 2011 outbreak of Listeria monocytogenes infections associated with cantaloupe demonstrated that ensuring the safety of minimally processed horticultural products must begin in the field and be continued all along the processing and distribution chain. We expect that continued study of interactions between horticultural practices and processing interventions will be beneficial. Accordingly, we plan to conduct studies investigating intervention strategies, with an emphasis on natural antimicrobial treatments such as essential oils and other plant extracts. This will continue work already conducted on evaluating the antimicrobial effects of winery waste stream extracts via in-vitro bacterial pathogen inhibition studies. The best processing scheme for any given type of minimally processed food will often mandate research into at least several of the
areas detailed above. Research into techniques applicable to minimally processed foods may prove especially useful for Oklahoma's small processors, who are typically seeking to find a niche and fill a regional demand.