46E-6 |
Oxidation study of corn masa oil |
R. VIDAL-QUINTANAR, Departamento de Investigación y Posgrado en Alimentos, Universidad de Sonora, Rosales s/n Col Centro, Hermosillo, SON, 83000, Mexico and A. López, Depto. Investigación y Posgrado en Alimentos, Universidad de Sonora, Rosales s/n Colonia Centro, Hermosill, SON, 83000, Mexico. Instant corn masa is subjected to oxidation under distribution conditions in a warm climate of México. It is very important from the consumer health point of view, to establish the shelflife of masa distributed in the north part of Mexico. The objective was to measured the oxidation of linoleic acid of corn masa in a storage study. Instant corn masa was stored in accelerate shelflife study at high temperature 45-85C and 0.45 constant water activity, to evaluate lipid oxidation of linoleic acid. Gas chromatography and chemical analysis (peroxide and anisidine values) were used to obtain the oxidation ratios over the storage time. Linoleic acid (55.1%)is the main unsatured fatty acid in corn masa, followed by oleic acid (26.9%). The propagation period of lipid oxidation measured by anisidine value reached its pick 2 to 5 days after the peroxide value had passed over its maximum value, and the flour presented at least a 10% reduction in the concentration of linoleic acid. The autocatalytic oxidation of linoleic acid in corn masa was temperature dependent, with a Q10=1.5 by each 10C temperature increases. The index of quality lost for corn flour stored at 55C was 0.48% per day, under this conditions 50% of its quality was consumed in only 104 days. Mathematical modeling estimated a shelflife of 84 days for corn masa stored at 25C. Lipid oxidation occur in the current package. Better package should be used to protect the corn masa from atmosphere oxygen moisture and light to reduce lipid oxidation.
Session 46E, International
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