菜籽油复合脱色剂脱色工艺优化及其品质分析

摘要

运用紫外可见光分光光度计对油脂进行全波长扫描后,确定油脂脱色率测定波长.以537和612 nm波长下脱色率为指标,分别研究复合脱色剂脱色工艺中的脱色剂用量、脱色剂配比、脱色温度、脱色时间和搅拌速率5个单因素对脱色效果的影响,在单因素基础上,选取脱色剂用量、脱色温度和脱色时间,进行三因素三水平响应面法进行试验优化,并进行方差分析和模型拟合,在脱色剂用量3.4％、脱色温度100℃、脱色时间27 min时,脱色油复合脱色率达97.02％.对脱色油的基本理化指标进行测定后,分析可知,复合脱色剂脱色油酸价和磷含量明显低于活性白土脱色油,而前者维生素E含量、甾醇含量、脱色率和色泽等指标则高于后者,且后者油脂品质可达到国标一级菜籽油水平.%The detection wavelength of rapeseed oil decolorization ratio was confirmed after the oils and fats was be full wave scanned by ultraviolet-visible spectrophotometer.Decolorization ratios under the wave length of 537 and 612 nm were selected as the experiment indicators,and the effects of the 5 single-factors (decolorant amount,proportion of decolorizing agent,decolorization temperature,decolorization time and agitation rate) on the decoloration process by compound decolorant studies,respectively.On the basis of single-factor experiments,three factors (the decolorant amount,decolorization temperature and decolorization time) were chosen to conduct 3-variable 3-level response surface methodology (RSM) to optimize the decoloration process,and conducted the analysis of variance and model fitting.The highest composite decoloring rate(97.02％) was obtained when the decolorant amount was 3.4％,the decolorization temperature was 100 ℃ and decolorization time was 27 min.After basic physical and chemical indexes of the bleached oils were tested,the results showed that acid value (AV) and phosphorus content of the rapeseed oil bleached by compound decolorant were obviously much lower than the oil bleached by activated clay,while the content of Vitamin E,sterols and the decolorization ratio and color and lustre ect.indexes of the former oil were higher than the latter,but the oil-fat quality of the latter could reach the national standards level first class for rapeseed oil.