This project focuses on raw grain supply to and coproducts manufactured by the grain and biorefinery processing industries. Delivering low-cost, food-safe, bio-secure, and high quality cereals and oilseeds for food, feed, fuel, and industrial uses requires a systems approach. <P> Therefore, the NC-213 objectives for the next 5-year cycle are revised to focus on three interrelated goals: <OL> <LI> To characterize quality attributes and develop systems to measure quality of cereals, oilseeds, and bioprocess coproducts<LI> To develop methods to maintain quality, capture value, and preserve food safety at key points in the harvest to end product value chain<LI> To quantify and disseminate the impact of market-chain technologies on providing high value, food-safe, and bio-secure grains for global markets and bioprocess industries.
NON-TECHNICAL SUMMARY: The ethanol and biodiesel industry will have a significant impact on the future of the grain industry in the U.S. Due to the domestic demand for corn, at least 30% more grain will be stored on U.S. farms and commercial facilities to provide feedstock to the biofuels industry. A principal challenge will be maintaining stored grain quality. In addition, the production of co-products from the ethanol process, specifically distillers dried grains with solubles (DDGS), will result in new handling, storage, transportation, marketing and utilization challenges. Also, maintaining high quality grain stocks for other food, feed and industrial uses will need to be accomplished. So this project will study the mold and mycotoxin content of DDGS and evaluate the ability and suitability of DDGS to support mold growth and mycotoxin production during transport and storage. The antifungal and antimycotoxigenic activity of benificial foodborne lactic acid and propionic acid bacteria (Lactobacillus, Propionibacterium, Streptococcus, Bacillus and others) alone, and in combination with antifungal chemicals such as propionates, sorbates, acetates and naturally occurring plant products (flaxseed and mustard) will then be studied to develop novel, new preservative methods to maintain quality and safety of stored grain and DDGS. The expected outcome will be the development new methods to preserve stored grain and DDGS. The impact will be to prevent spoilage and loss of grain and DDGS, and provide safe foods and feeds. <P> APPROACH: DDGS will be collected from ethanol producing facilities in Nebraska and analyzed for total mold content and for specific mycotoxin producing molds. Molds will be isolated, identified and evaluated for the ability to produce known mycotoxins. Mold counts, isolations and identification will be done using standard and accepted methology of plate counts on general purpose mycological agar media. Mycotoxin content of the DDGS will be determined using commercially available test kits which employ enzyme linked immuno-sorbant assay (ELISA) and immuno-afinity column (IAC) technology. The methods are both qualitative and quantative. Samples that test positive for mycotoxins will be confirmed by high performance liquid chromatography (HPLC) using methods developed at the University of Nebraska, Food Processing Center. Wet DDGS will be obtained from ethanol plants in Nebraska and will be inoculated with molds known to be capable of producing mycotoxins. The growth of the molds will be monitored by visual observation and the amount of growth over time will be estimated using a five point rating scale. Mycotoxin production will also be measured using commercially available test kits. Variables to be studied will include temperature of incubation, water activity, time and inoculum levels of the molds. The antifungal and antimycotoxigenic potential of foodborne bacteria to prevent mold growth and mycotoxin production in defined mycological media and DDGS will be studied. Bacteria will include species of Lactobacillus, Propionibacterium, Streptococcus, Bacillus and possible others. In addition, antifungal chemicals will also be studied alone and in combination with the bacteria. These chemicals will include propionates, sorbates and acetates. Naturally occurring plant products with antifungal activity such flaxseed flour and ground mustard will also be studied. These products have been shown in other studies to have antifungal properties. Combinations of antifungal bacteria and chemicals will also be studied. The bacteria will be gown in suibable broth media to produce heavy growth of the desired bacteria. This fermented media and DDGS, which will then be inoculated with various molds to determine the ability of the fermentates to inhibit or prevent mold growth and mycotoxin production. Molds to be studied will include the toxigenic species that were previously found to be capable of growing on DDGS Variables will include time, temperature, water activity, amounts of bacterial fermantates and concentration of antifungal chemicals and natural products. Appropriate statistical designs will be used based upon consultation and advice of a statistician.