2013 Meeting Abstract - Growing location of Lariat pinto beans and effect on lipoxygenase activity and grassy flavors

Poster Presentation
Ingredients & Innovations

14-P

Growing location of Lariat pinto beans and effect on lipoxygenase activity and grassy flavors
C. Simons (1), C. HALL (1), J. Osorno (1)
(1) North Dakota State University, Fargo, ND, U.S.A.

Reducing grassy flavors such as hexanal and hexanol in edible beans can improve opportunities for their use as food ingredients. Growing environment can have a significant impact on lipoxygenase, total lipids and amount of unsaturated fatty acids synthesized in seeds. This will in turn affect production of grassy flavors during processing and storage. Lipoxygenase activity, total hexane extractable lipids and fatty acid profile of pinto beans (Lariat variety) grown at three different locations during the 2011 crop season in North Dakota (Hatton, Johnstown and Forest River) were investigated. To evaluate changes in hexanal and hexanol concentrations, samples were stored at 30°C for one to four weeks in an incubator. Lipoxygenase activity in beans from Hatton was significantly higher than in beans from other locations, which was likely due to exposure to higher drought conditions during growing season. The amount of peroxides produced was 245.08 µM for beans from Hatton, while beans from Johnstown had the lowest (99.30 µM). Total lipids in beans from Hatton (1.32%) were significantly lower than beans from Johnstown and Forest River (1.48%). Linolenic acid in beans from Hatton was significantly higher (51.9%) compared to beans from Johnstown and Forest River (49.3%). Hexanal concentration in beans from each location was stable during storage; however, hexanol concentration progressively decreased from week one to four. Hexanol concentration in beans from Hatton was the lowest. The amount of grassy flavors produced in edible beans will therefore likely to be more influenced by the total lipids present than its lipoxygenase activity. Reduction in hexanol concentration during storage indicates potential for reduction in grassy flavors during storage and hence need to establish a minimum storage period for bean flours before distribution.