Application of citrus dietary fibre preparations in biscuit production

摘要

Dietary fibre (DF) preparations prepared from citrus (orange and lemon) by-products were analysed for their chemical composition and functional properties. The studies indicated that citrus DF preparations were characterized by high crude DF contents (56.5% lemon, 63.4% orange) and low fat (5.1% lemon, 7.8% orange) and protein (6.4% lemon, 3.3% orange) contents. DF preparations had high water absorption capacity (10.59-12.13 kg·kg~(-1)) but low fat absorption capacity (0.07-0.10 kg·kg~(-1)). Biscuits prepared from blends with different levels (0,5,10,15%) of citrus DF preparations were also evaluated for rheological properties, physical and sensory parameters. Measurements of farinographic properties showed that water absorption capacity and dough development time increased as the amount of citrus DF increased (from 58.8% to 79.1% and from 3.4 min to 7.5 min), whereas dough stability and mixing tolerance index showed a reverse trend (decrease from 6.4 min to 4.3 min and from 56.0 BU to 36.0 BU). Physical parameters, namely, specific volume, volume index, width, thickeness, spread ratio of DF-enriched biscuits were reduced with increasing level of citrus DF preparations. Sensory evaluation revealed that the most acceptable biscuits were obtained by incorporation of 5% citrus DF preparations.