Storage stability of three genotypes of sunflower seeds

Abstract

tSunflower seeds (Helianthus annuus L.), due to their high oil content, are among the raw materials citedby the National Program of Biodiesel Production and Use (NPBP) with potential for the production ofbiodiesel. On the other side, seeds with high lipid content could be more sensitive to degradation thatnon-oil seeds. The objective of this project was to evaluate the stability of three genotypes of sunflowerseeds, kept in two different raffia packages under two storage conditions: a constant temperature andhumidity reference condition set at 25◦C/75% RH (Ref) and a cyclic, accelerated aging test (CW), built toreproduce the variation of temperature and humidity of a Center West production region, which was inaverage of 24◦C/71% RH, but with extreme temperatures of 17–32◦C and humidity of 24–96% RH. As allsamples evaluated had almost the same fatty acid composition up to the end of ten months´ıstorage, itwas concluded that seed can be kept without significant loss of quality in the packaging materials andstorage conditions evaluated. Cyclic accelerated aging generated different evolution profiles of the per-oxide values and moisture levels when compared to the reference condition, with constant temperatureand humidity. All seeds showed dehydration when undergoing the (CW) condition during the wintersimulation period, the driest season among the evaluated. During fall, winter and spring simulation, the(Ref) condition generated higher peroxide values than the accelerated aging test. However, in the summerperiod simulation of the cyclic aging, the peroxide values of seeds packed in uncoated raffia increasedby 32% (OL5), 9% (He250) and 90% (He 253). Laminated raffia showed a slightly higher performance thanuncoated for seed preservation. The results found in this study show that storage at constant temperatureand humidity conditions does not reproduce the sequence of degradation reactions which occurs due tothe daily cyclic variation in temperature and humidity. This highlights, the importance of carrying outstudies in laboratory conditions closer to reality for studying seed aging.