Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/3/2005
Publication Date: 5/5/2005
Citation: Hojillaevangelist, M.P., Evangelista, R.L. 2005. Effects of cooking and screw-pressing on functional properties of cuphea proteins[abstract]. American Chemical Society. p.99.
Technical Abstract: Cuphea is being developed as an alternate source of industrial oil because its oil is rich in medium chain fatty acids (MCFA), which are used in detergents, cosmetics, and lubricants. Cuphea seed also contains about 25% crude protein (dry basis), which means that protein-rich co-products will be generated by oil processing. Currently, little information is available on cuphea proteins. This investigation was conducted to determine the effects of the oil processing conditions on the functional properties of cuphea proteins and evaluate the proteins' potential for value-added uses. Flaked cuphea seeds were heated to 180 deg F in the seed cooker, held at this temperature for 0, 45, or 90 min., and then screw-pressed to extract the oil. Cooked flakes and press cake were analyzed for proximate composition and subjected to protein functionality tests. Results were compared with those of unprocessed ground, defatted cuphea seeds (control). Proteins in the control cuphea seeds had excellent emulsifying properties, but poor foaming properties. Cuphea protein had poor solubility (10%) at pH 4-7, but at pH 2 and 10, its solubility was 57 and 88%, respectively. Solubility profiles showed that simply heating the flaked seeds to 180 deg F (0 min holding) resulted in 50-60% reduction in soluble proteins. Holding for 90 min gave less than 6% soluble proteins at all pH levels. Holding for 45 min produced maximum oil yields, but also resulted in less than 10% soluble proteins at pH 2-7 and 25% soluble proteins at pH 10. The oil extraction conditions had significant detrimental effects on the solubility of cuphea seed proteins, which negatively affected the other functional properties.