菜籽预处理方法对菜籽饼品质的影响

Study on influence of different pretreatments of rapeseed on quality of rapeseed cake

以菜籽为原料,分别经3种热处理(烘烤、焙炒、微波)和3种非热处理(超声、冻融、真空冷冻干燥)再螺旋压榨后提取菜籽油,获得菜籽饼,对比不同预处理对菜籽出油率、菜籽饼的基本营养成分(粗灰分、水分及挥发性物质、粗蛋白、总磷)、蛋白氨基酸含量及其组成评价和抗营养因子(硫苷、植酸、单宁)含量的影响。结果表明,焙炒组出油率最高,为33.00%,3种热处理组的出油率均显著高于3种非热处理组;不同的预处理方法会对菜籽饼水分及挥发物、粗蛋白、总磷含量有显著影响(P<0.05),尤其是粗蛋白,焙炒组相较于烘烤组粗蛋白含量减少了19.78%,制油前预处理对粗灰分含量无显著影响(P<0.05);7种菜籽饼的氨基酸总量在405.11~491.15 mg/g;烘烤组的氨基酸总量、必需氨基酸总量、非必需氨基酸总量均最高,冻融组氨基酸总量、必需氨基酸总量、非必需氨基酸总量均最低,焙炒组的氨基酸组成最接近联合国粮农组织/世界卫生组织推荐的氨基酸模式,超声组则相差最大;3种热处理均能有效降低菜籽饼粕中植酸和硫苷含量,真空冷冻干燥预处理能显著降低植酸含量(P<0.05)。该研究为后续菜籽饼的高值化利用提供了一定的参考依据。

The rapeseed oil was extracted from rapeseed as raw material by three heat treatments(roasting,baking,and microwave) and three non-heat treatments(ultrasonication,freeze-thawing,and vacuum freeze-drying) after screw pressing to obtain rapeseed cake,comparing the effects of different pretreatments on the oil yield of rapeseed,the basic nutrients(crude ash,moisture and volatile matter,crude protein,and total phosphorus),protein amino acid content and its composition evaluation,and anti-nutritional factors of rapeseed cake(thioglycosides,phytic acid,and tannins).Results showed that the highest oil yield of 33.00% was obtained from the roasted group,and the oil yield of all three heat treatment groups was significantly higher than that of the three non-heat treatment groups.Different pretreatment methods brought significant effects(P<0.05) on the moisture and volatile matter,crude protein,and total phosphorus contents of rapeseed cake,especially crude protein,and the crude protein content of the roasted group was reduced by 19.78% compared with that of the baked group,and there was no significant effect on the crude ash content(P<0.05).The total amino acid content of the seven rapeseed cakes ranged from 405.11-491.15 mg/g.With the highest total amino acid,total essential amino acid,and total non-essential amino acid content of the baked group,and the lowest total amino acid,total essential amino acid,and total non-essential amino acid content of the freeze-thaw group,with the amino acid composition of the roasted group being the closest to the amino acid pattern recommended by Food and Agriculture Organization(FAO)/World Health Organization(WHO) and the largest difference of ultrasound group.All three heat treatments effectively reduced the phytic acid and thioglycoside contents in rapeseed cake meals,and the vacuum freeze-drying pretreatment significantly reduced the phytic acid content(P<0.05).This study provides a certain reference for the subsequent high-value utilization of rapeseed cake.