Production of low-fiber sunflower (Helianthus annuus L.) meal by micronization and air classification processes

Sunflower (Heliantus annuus L.) meal is an important by-product as a source of vegetable protein and fiber for humans and animals; however, its nutritional value is notoriously dependent on processing technology. In this study, our aim was to evaluate a processing system based on micronization and air classification of the sunflower meal as a means of greater enrichment of the protein fraction and reduction of fiber content. We also evaluated the structural characteristics of the different meal fractions through scanning electron microscopy. This system was based on a series of sortings of micronized meal, with a progressive increase in the yield of a selected fraction. Air classification of sunflower size fractions (coarse and fine) was effective (P<0.05) in separating fiber and protein from starting material. Data showed that increasing air flow setting was accompanied by a decreased (P<0.05) fiber level and an increased (P<0.05) in protein level in double-micronized meal. Performing air classification on micronized sunflower meal had the advantage that the protein and fiber enrichment or yield combination can be easily adjusted by modulating the air flow. Our finding suggests that the applied technological treatments seem to be useful to maximize the nutritional potential of sunflower meal as human food or animal feed.