Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/16/2010
Publication Date: 9/2/2010
Citation: Sutivisedsak, N., Moser, B.R., Sharma, B.K., Evangelista, R.L., Cheng, H.N., Lesch, W.C., Tangsrud, R.R., Biswas, A. 2011. Physical properties and fatty acid profiles of oils from black, kidney, Great Northern, and pinto beans. Journal of the American Oil Chemists' Society. 88(1):193-200. Interpretive Summary: Common beans (Phaseolus vulgaris L.) are well known as a good source of nutrients and bioactive compounds. Many of the bioactive compounds that occur in common beans partition into different oil fractions upon solvent-assisted extraction. Although a lot of studies have been recently focused on oils from seeds, e.g., sunflower, soybean, corn, cottonseed, and grapeseed, the study of oils in common beans and their nutritional benefits have usually been overlooked due to the significantly lower amount of oil in these beans. The goal of this study was to evaluate the chemical composition of bean oils, including fatty acid profile, tocopherol content, oxidative stability, and other physical properties of oils from four common, edible beans (black, dark red kidney, great northern and pinto beans). Oils from these beans were isolated & analyzed. We found that these oils have potential to be utilized as nutritional supplements that provide natural antioxidants. In addition these oils could be used as natural antioxidants for providing stability to edible oils, biodiesel, and bio- lubricants. This discovery will benefit bean growers.
Technical Abstract: Four common beans (black bean, kidney bean, great northern, and pinto) were extracted with hexane and found to contain about 2% triglyceride oils. The fatty acids found in these bean oils were mainly linolenic (41.7-46 wt %), linoleic (24.1-33.4 wt %), palmitic (10.7-12.7 wt %) and oleic (5.2-9.5 wt %). Because of the high levels of polyunsaturated fatty acids, all bean oils exhibited high iodine values up to 177 g/100 g (compared to 130 g/100g for soybean oil). Yet, the bean oils exhibited long induction periods and high oxidative stability, which can be explained by the presence of high amounts of antioxidants present. The bean oils showed low pour point (-18 to -11ºC, relative to -9ºC for soybean oil). Among the four bean oils, kidney bean oil showed the highest acid values and kinematic viscosities over a wide range of temperature.