Development of Biotechnology to Produce Low-Flatulence Edible Bean Products
April 13, 2004
This project continued to attract the attention of media and consumers interest in the past year. A company in California has contacted with Dr. Chang for the use of this technology to reduce flatus in legumes. Dr. Chang appreciates the support from Northarvest Bean Growers and hopes that you would continue to support this promising project to its completion.
The Ph.D student assistant, Tammy Song, completed several experiments for this project during the past year. Tammy has developed a HPLC method for analyzing sugar composition. She has analyzed the oligosaccharides content in pinto beans after different processing treatments. The results revealed that cooking beans in tap water or different acid solutions resulted in significant decreases of the raffinose sugars. The extent of the losses increased when cooking time and acid concentration increased. Regular cooking at 100C for 30 min without acid may eliminate up to 40% of the oligosaccharides. Autoclaving (121C) in 5 % acetic acid concentration for 30 min was the most effective method among all processing conditions tested in eliminating flatulent sugars. Such treatment could eliminate two-thirds (67%) of the total oligosaccharides. Therefore, acid (vinegar or lemon juice, etc) used in flavoring bean during cooking could enhance the degradation of oligosaccharides to reduce flatulence. Tammy has submitted an abstract on Effect of soaking, cooking, and autoclaving on oligosaccharide contents of pinto bean to the 2004 IFT Annual Meeting in Las Vegas and the paper has been accepted already. Although boiling and retorting could destroy a part of flatulence oligosaacharides, the final products still retained substantial amount of flatulent sugars.
Tammy has tested the enzyme production of three fungal species, NRRL 447 Aspergillus oryzae (Ahlburg), NRRL 3 Aspergillus niger (Van Tieghem) and NRRL 4869 Aspergillus awamori, on a series of substrates and incubated for different time periods. Estimated enzyme activity among fungal species is in the order of NRRL 4869> NRRL 447> NRRL 3. The optimal temperature for the fungi 4869 is around 45-60 °C. The volume of tofu whey added to the medium of wheat bran did not contribute to the growth of the fungi, and the activity of the enzyme. The highest enzyme activity was found after the 6 days of incubation in NRRL 4869 Aspergillus awamori. Tammy still has another three fungal species and some bacteria species to test in the next few weeks.
Tammy has finished almost all the required courses and performed well in these classes. Those courses will benefit her in the research. She is expected to have more productivity in research in the following semesters. Tammy has completed the proposal defense for her thesis in this subject. We have got some pieces of good advice from her committee members who are professors of various departments at NDSU, to improve this project. We anticipate that the enzyme biotechnology would reduce 100% of the flatulence oligosaccharides and hope that the final products have good functional properties and improved nutritional value, which will help improve the image of bean products, and thereby increasing the consumption of the nutritious beans to improve human health.