Oxidative evaluation of oils mixture of legumes of the Sonoran Desert with maize and soy oils during the storage

Abstract

During storage, oils from seeds of wild legumes of the Sonoran Desert have shown greater stability than oils derived from conventional sources. In this work, oxidation process was evaluated during the storage (122 day) of mixtures of oils: Mezquite Prosopis juliflora, Gatuña Mimosa grahamii, Palo fierro Olneya tesota, Vino rama Acacia constricta, Palo de brea Cercidium praecox and Palo verde Parkinsonia aculeata with oils from soy and maize. Ratios were 1:1, 2:1 and 3:1. Evaluated parameters included: Peroxides (P.V.), Iodine (I.V.), Acid (A.V.), p-Anisidine (p-A) values. Results showed that mixtures containing wild and maize oil showed 2-4 meq/Kg as initial values of iodine, while after 122 days of storage the value was 4-7 meq/Kg. Mixtures containing soy oil presented 3-6 meq-Kg initially, and 8-15 meq-Kg were detected at the end experiment. No differences were observed in I.V. and A.V. values in maize mixtures. On the contrary, mixtures containing soy oil presented increments in I.V. Also, A.V. presented a slight increment in 1:1 mixtures. p-Anisidine values presented and small increment in maize mixtures (3:1 ratio) while this increment was larger in mixtures containing soy oils and Gatuña or Palo fierro oil. These latter oils when were mixed with maize oils presented the lowest increments in all evaluated indexes.
The oils of palo fierro and blended gatuña with oil of corn didn’t present changes in their concentration in the palmitic and araquidic acid during the storage. The concentration of the oleic acid in the mezquite oils (3:1), gatuña (1:1, 2:1 and 3:1), vinorama (3:1), as well as the linoleic and erucic acids in gatuña in their three mixtures didn’t present changes neither alteration during the storage, for what you are considered the oils of palo fierro, gatuña and vinorama the most stable in the present study.