Study on Factors Affecting the Hullability, Physical and Chemical Characteristics of Sunflower Achenes Produced in Golestan Province.

In this research some characteristics of three oily sunflower varieties, Hysun33' Progress and Euroflor from four location, Aliabad, Golidagh, Kalale and Kalpush in Golestan province were evaluated for variations in linear dimensions, arithmetic mean diameter, geometric mean diameter, sphericity, surface area, true and bulk densities, porosity, 1000 seed weight, volume, moisture content, hull and kernel percent, major, intermediate and minor Size distribution, oil percent in seed, kernel and hull. Also properties of seed after dehulling such as dehulling efficiency, whole and broken kernel percent, percent of fine, unhulled seed and hull were investigated and after separation the broken kernel from whole kernel as well as extraction of oil from each fraction the qualitative tests including acidity, peroxide value, specific weight and refractive index were carried out. The results showed that the length, width, thickness, geometric mean diameter, volume and moisture content of sunflower seeds varied from 8.800 to 10.987 mm, 4.346 to 5.628 mm, 2.685 to 3.508 mm, 4.651 to 5.979 mm, 183.14 to 364.59 mm3, 5.355 to 6.184%, respectively. In all characteristics investigated the minimum and maximum values related to Golidagh Euroflor and Kalale Progress samples, respectively. The results of ANOVA showed that all of the seed gravimetrical properties such as 1000 seed Weight, bulk and true densities and porosity were significant at (p 0.01). Dehulling efficiency varied from 61.60% for small size of Aliabad Hysun33 to 92.72% for large size of Aliabad Hysun33. The results of ANOVA for all properties of extracted oils as peroxide value, specific weight and refractive index were significant at the 0.01 probability level.. Samples had significant effect (p 0.01) on hullability and its all components except broken kernel, while the achen size had significant effect (p0.01) on hullability and its all components. Dehulling efficiency was significantly (p 0.01) affected by seed size and larger achenes had higher hullability than small ones, about 21.4%. Based on obtained results and due to the effect of size achenes on hullability, samples should be separated into fractions of uniform size prior to dehulling unit operation and processing.