Changes in Insoluble and Soluble Dietary Fiber of White Asparagus (Asparagus officinalis L.) during Different Conditions of Storage

Abstract

Changes occurring in the content and composition of dietary fiber of white asparagus during storage in different conditions were studied (room temperature; 2 °C in polyethylene bags; 2 °C and 95% relative humidity). The neutral sugars and uronic acid composition of dietary fiber was determined by gas chromatography and by a spectrophotometric method. In the insoluble dietary fiber, glucose was found in a major amount followed by galactose, xylose, arabinose, mannose, rhamnose, and fucose. In the soluble dietary fiber, galactose was the predominant neutral sugar followed by arabinose, mannose, glucose, and rhamnose. The content of uronic acids was significantly higher in the soluble dietary fiber than in the insoluble one. The modifications observed in dietary fiber of the asparagus stored at room temperature are more rapid and pronounced than those in the refrigerated conditions, which prolong the conservation. Statistical analysis indicated that the changes were significantly affected by the type of storage and time. Keywords: Dietary fiber; asparagus; changes; storage