Development of the Oleic Acid/Linoleic Acid Ratio in High-Oleic Valencia Market Type Peanuts

Authors: LAFOUNTAIN, LISA - North Carolina State University; KLEVORN, CLAIRE - North Carolina State University; Dean, Lisa

Submitted to: North Carolina Institution of Nutrition Research Symposium
Publication Type: Proceedings
Publication Acceptance Date: 7/27/2016
Publication Date: N/A
Citation: N/A

Interpretive Summary: The fatty acid profile of a food affects the health and wellness of the consumer. Peanuts with high levels of oleic acid, a monounsaturated fatty acid are a better nutritional choice than those with normal levels. New varieties with higher oleic acid levels have been introduced, but problems with maturity, physical contamination, outcrossing and other issues prevent lots of peanuts from being totally high oleic. This study examined the variation in the fatty acids in peanuts from individual plants of the valencia market type that were reported to be high oleic. It was found that the more mature peanuts were high oleic but the immature ones were not despite being of marketable size. The conclusion was that using commercial sizing techniques would not prohibit immature valencia type peanuts from being present in the lots marketed and thus the lots would not be 100% high oleic

Technical Abstract: The major fatty acids in peanuts are oleic acid (O), a monounsaturated omega-9, and linoleic acid (L), a polyunsaturated omega-6. Peanuts containing these two fatty acids in a ratio (O/L) above 9 are known as high oleic (HO). Normal oleic (NO) peanuts are those with an O/L ratio less than 9. HO peanuts are preferred for some peanut-containing products due to monounsaturated fatty acids having a greater resistance to the onset of rancidity than polyunsaturated fatty acids. The production of L during the growth of peanuts is due to the action of a desaturase on O and is under both genetic and developmental control. Research has shown that, for Virginia and Runner market type peanuts, O was positively correlated with maturity and not size at harvest. In this study, data were collected from a high oleic Valencia market type cultivar. The FA profiles were determined for all the seeds present on 10 intact plants (n=621) harvested in New Mexico. This study found that the highest O concentration was present in mature peanuts and that large immature peanuts were found to have lower O, as was seen in the research of other market types. The physical size of the seed is somewhat correlated with maturity but this is not absolute. Peanuts of all sizes will be found in each stage of maturity. As all peanuts will not be mature at harvest due to the indeterminate flowering nature of the peanut plant, this study proves at present, no single batch will contain 100% of the high-oleic type of peanuts.