The study of carrot pulps in the extrusion of high dietary fiber snack food

• Main Authors: Pan, Ei sung, 潘憶萱
• Other Authors: Jinchyan Peng
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/01267898820615548560

碩士 === 國立中興大學 === 農業機械工程學系 === 85 === waste carrot pulps was used as the additive in corn grits to produce a highdietary fiber snack food by using a single-screw extruder. The operationvariables were die temperature,screw speed,and carrot pulps content. Theresponse surface methodlogy was used to investigate the effects of operationvariables on extrudate''s physical and chemical properties, such as expansionratio, hardness, color values,β-carotene content, total dietary fiber content,water solubility index, and water absorption index.Results indicated that:1.Increasing the die temperature, screw speed, and the ratio of carrot pulpsraised the longitudinal expansion ratio, but decreased the expansion ratio.Also, increasing the ratio of carrot pulps weakened the extrudate''s structurelowered the hardness, and lifted the redness.2.The extrudate''s β-carotene content was increased with increasing the carrotpulps ratio, however, it was decreased with raising the die temperature.Lifting the die temperature and screw speed both resulted the increase of dietary fiber content. Furthermore, the increase of the die temperature resultedin an increase of the water solubility index. However, the increase of the screwspeed resulted in a decrease of the water solubility index. Water absorptionindex was independent of the screw speed and was minimun under the conditionsof 96-99℃ die temperature and 9.6% carrot pulps ratio.3.The optimum operation conditions for producing the high dietary fiber snackfood by using a single-screw extruder were as following: 98.4-103.2℃ die temperature, 1000 rpm screw speed, and 6.8-7.2% ratio of carrot pulps. The extrudate''s dietary fiber content was 14-15% under the optimum operation condition.