Abstract:
In this study, dry fractionation process was proposed in order to obtain protein-enriched
sunflower meal fractions. The process includes two-stage grinding using a hammer mill and a roll
mill, and fractionation of sunflower meal by sieving. Central composite design (CCD) with four
variables on three levels within response surface methodology was applied in order to estimate
the influence of grinding parameters (sieve openings diameter of the hammer mill: 2, 4, and 6 mm,
roll gap: 0.15, 0.2, and 0.25 mm, feed rate: 0.1, 0.175, and 0.25 kg/cm min, and roll speed: 400,
500, and 600 rpm) on responses (protein content, fraction yield and grinding energy consumption).
Sieve openings diameter expressed the highest impact on fraction yield while roll gap expressed the
most dominant influence on protein content in the fraction and grinding energy consumption. The
highest protein content obtained was 48.06%(dm) with fraction yield of 77.22%. A multi-response
optimization procedure was performed and optimal values were: sieve openings diameter of 2 mm,
roll gap of 0.25 mm, feed rate of 0.2 kg/cm min, and roll speed of 400 rpm, while predicted values for
a desired range of responses were: protein content 45.5%(dm), fraction yield 77.89%, and grinding
energy consumption 8.31 Wh/kg.
