SBIR-STTR Award

Rice bran is an underutilized co-product of the rice processing industry and may be used as an inexpensive substrate for the production of yeast. If the proposed process is shown to be more economical than production of yeast in molasses, the rice processing industry will benefit from increased value of rice bran and the yeast production industry will benefit from lower production costs. OBJECTIVES: This Phase I project will optimize the growth in heat-stabilized, defatted rice bran (HDRB) of several strains of Saccharomyces cerevisiae yeast in an automated bio-reactor. After activating yeast from frozen stock, the conditions for growth of yeast inside the automated bioreactor will be optimized. The strain that performs best will be selected for further study in Phase II. Additional factors that will be considered in the selection of yeast strains include marketability of the strain and characteristics of the co-products of yeast fermentation. The specific Phase I objectives are: 1. Conduct and demonstrate the feasibility of producing yeast from HDRB using an automated bioreactor. 2. Optimize HDRB:water ratio and time of incubation to produce maximum amount of yeast from HDRB. 3. Optimize the temperature and pH, to produce the maximum amount of yeast from HDRB. 4. Demonstrate the maximum amount of yeast produced when conditions under objectives 2 and 3 are integrated. The Phase I work will establish the feasibility of the automation of the process. In Phase II, the work will be extended to pilot-scale testing in coordination with Riceland Foods, our commercialization partner, and in coordination with yeast manufacturers. APPROACH: Yeast fermentation in heat-stabilized defatted rice bran (HDRB ) is a promising technology to reduce the cost of production of yeast. HDRB contains the essential nutrients for the growth of yeast in a complex form and does not require the addition of nutrients as is required in the commercial scale production of yeast using food grade molasses. The HDRB contains 10.5-12.0% moisture, 18.5-20.9% protein, 1.5-2.0% lipid, 15.3-16.8% starch (from broken endosperm), 25.2-25.6% total fiber, 0.5-0.7% total phenolics, 1.73-2.28% phytic acid, and 9.0-10.4% ash. In addition, rice bran also contains vitamins (Thiamin 2.75 mg, Riboflavin 0.28 mg, Niacin 33.00 mg, Pantothenic acid 7.39 mg, Vitamin B-6 4.07 mg, Folate 63 ug, Vitamin E (alpha-tocopherol) 4.92 mg, Vitamin K (phylloquinone) 1.9 ug per 100 g) and minerals (Ca 57 mg, Fe 18.54 mg, Mg 781 mg, P 1677 mg, K 1485 mg, Na 5 mg, Zn 6.0 mg, Cu 0.7 mg, Mn 14.2 mg, Se 15.6 ug per 100g). The growth performance of yeast in HDRB in manual studies has been demonstrated by the Nutraceutical Innovations team. In this Phase I proposal, the production of yeast using HDRB will be optimized using an automated fermentation system

This project will demonstrate the applicability of using rice bran and rice bran extract as a commercial scale growth medium for yeast. Currently, the production of yeast is carried out on a high sugar starting medium composed of beet or cane molasses, both of which are in short supply and command high prices. The innovative process proposed by Nutraceutical Innovations uses as a starting medium heat-stabilized defatted rice bran (HDRB), a low cost, typically underutilized co-product from the rice milling industry. Rice bran is available in large supply (1.6 billion lbs annually in the U.S. alone)(USDA, 2003), but has little commercial value in the food industry largely because of its indigestibility and unpalatability. Although the unprocessed bran byproduct has little value ?as is,? it does serve as a rich source of nutraceutical oil, and it can be processed to remove the rice bran oil. Commercially, when the oil is extracted, the rice bran undergoes a heat stabilization step to preserve the quality of the oil. The resulting by-product after oil extraction is called heatstabilized defatted rice bran (HDRB), a potentially rich source of protein, starch, fiber, vitamins and minerals with nutraceutical health benefits. The potential commercial and health benefits of HDRB, although significant, are largely unrealized because of the lack of sound scientific investigation into the applications for HDRB as a functional food ingredient. Currently, HDRB is primarily used as a filler in animal feed, and commands a sales price of only $0.03/pound. Proteins, phenolics, and bioactive molecules are bound and unavailable. Nutraceutical Innovations, Inc. recognizes both the economic and nutritional potential of HDRB, and is developing novel, value added processing methods for HDRB from which extracts can be derived, allowing for the development of new food ingredients with health benefits. The process under development has direct applicability to the yeast production industry, and if successfully commercialized, promises significant economic benefits over the current process. The proposed process utilizes the HDRB to produce co-products that will have significant value in the market, and provide health benefits to the consumer. Purpose: The overall objective of the Phase II effort is to develop and test a cost-competitive process for producing yeast and co-products using HDRB extracts as a growth medium. Successful completion of the project objectives will produce a minimum of 30-logs of growth of up to 4 strains of yeast in HDRB extracts, and at least two coproducts with viability for use as beneficial food additives. The broad vision of Nutraceutical Innovations is to develop a spectrum of commercially valuable products from HDRB using the patent pending total systems approach. The conceived commercial opportunities range from relatively low risk products and processes with ready markets (e.g. licensing the patent pending process that uses HDRB as the energy and nutrient source for the production of yeast) to potentially promising but untested product concepts (e.g. anti-cancer therapeutics from fermentation extracts). OBJECTIVES: The overall objective of the Phase II effort is to build on the results of the research conducted in Phase I, and to develop and test (at pilot scale) a cost-competitive process for producing yeast and co-products using HDRB as a growth medium. Specifically, the objectives are as follows: 1. Optimize the growth of yeast for pilot-scale production. Milestone 1: Optimized conditions will produce a minimum of 30-logs of growth of up to 4 strains of yeast in HDRB at pilot-scale. 2. Evaluate marketable co-products derived from the production of yeast in HDRB. Milestone 2: A prepetition is filed with the Food and Drug Administration for approval of at least two co-products as beneficial food additives. APPROACH: TASK 1: Optimize the production of yeast at pilot-scale (Months 1-9)Parameters that will be optimized include incubation time, incubation temperature, water content and pH. The goals of pilot-scale production will be to demonstrate scalability of the process to commercial partners in the yeast production industry and to product adequate quantities of HDRB co-products for characterization and toxicity studies. TASK 2: Conduct comprehensive analysis of extracts and residues (Months 9-15) Extracts and residues from Task 1 will undergo comprehensive analysis for type and concentration of phenolics, general nutrition content(lipid, carbohydrate, dietary fiber, protein, calories) minerals, elements, vitamins (water and fat soluble), types of carbohydrates, fatty acid composition, and others including trans fat, glutamic and all amino acids. Antioxidant activity will also be determined by DPPH. This information can be provided to the FDA as part of a Food Additive Petition and will be the basis for labeling requirements for any of the co-products that result from this project. The stability of the freeze dried extracts will be determined over a 6 month time period. TASK 3: Evaluate mutagenicity and in vitro toxicity of the co-products with the greatest commercial viability (Months 15-21) The mutagenicity effect of the co-products will be assayed by Ames et al. (1975) with slight modification. In order to determine that the co-products are non-cyto toxic, and bioavailable, it is necessary that the extract pass through and be absorbable chiefly through the intestinal and blood environments without causing adverse effects to the human system. Hence, toxicity to normal cells representative of colon, intestine and blood will be examined. TASK 4: Submit a prepetition to the FDA for approval of the co-products as beneficial food ingredients (Months 22-24) The data collected in Tasks 1-3 will be collected into a prepetition and presented to the FDA for approval of the products as food additives. Because all of the ingredients used in the production process are GRAS, we do not expect that there will be any concerns with toxicity of the products and we expect the FDA to assign a low level of concern to the yeast production process and the co-product food additives. Nutraceutical Innovations expects to be in a position to garner the necessary funding for full commercialization of the products by the end of Phase II