Submitted to: Peanut Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/30/2004
Publication Date: 3/2/2005
Citation: Mozingo, R.W., O'Keefe, S.F., Sanders, T.H., and Hendrix, K.W. 2004. Improving shelf life of roasted and salted inshell peanuts using high oleic fatty acid chemistry. Peanut Science. 31:40-45.
Interpretive Summary: In shell roasted and salted in the shell peanuts generally have a very short shelf life and are quickly rejected by consumers due to the development of rancid flavors. These flavors develop because of the presence of high percentages of linoleic acid (two double bonds) in the oil of the peanuts. A relatively new variety of peanuts (AgraTech VC-2) with a lower percentage of linoleic acid and higher percentage of oleic acid (one double bond) was shelf life tested as both roasted and salted in the shell. This variety had an exceptionally long shelf life and indicated a significant advantage of high oleic, Virginia type peanuts for extending shelf life of roasted or salted in the shell processing
Technical Abstract: Major markets for the large-seeded virginia-type peanut (Arachis hypogaea L.) include roasted inshell and salted inshell products with short shelf life being a common consumer complaint. Unlike many other peanut products, it is not economically possible to package these inshell peanuts in nitrogen flushed, oxygen barrier bags. A number of studies have shown that roasted runner-type peanuts with high contents of oleic fatty acid have imporved oxidative stability and longer shelf life. A large-seeded, virginia-type peanut cultivar (AgraTech VC-2) with the high oleic trait has been released but no information is available on its shelf life stability. Therefore, this high oleic cultivar and the normal oleic cultivar VA98R from the 2000 and 2001 crop were used for shelf life evaluations. Peanuts were sized into the fancy inshell grade for roasted inshell and salted inshell products. Peroxide value (PV) results for the roasted inshell peanuts indicated that normal loeic fatty acid (50% range) peanuts reached a PV of 20 meq/kg by the end of 4 wk of storage. On the other hand, the high oleic fatty aci(80% range) peanuts did not reach a value of 20 meq/kg before the 2nd wk, whereas the high oleic peanuts still had not reached a PV of 20 meq/kg after 40 wk of storage. These results show a significant advantage of high oleic peanuts for extending shelf life of large-seeded, virginia-type peanuts for either roasted or salted inshell processing.