分子蒸馏对沙棘果油中8种塑化剂组分脱除及综合品质的影响

Effect of Molecular Distillation on the Removal of 8 Phthalic Acid Esters and the Quality of Sea Buckthorn(Hippophae rhamnoides L.) Pulp Oil

沙棘果油因富含多种有益活性成分而成为价格高昂的食用植物油,但受生长环境、采摘方式、储存方法等因素的影响,其塑化剂含量存在超标风险。利用两级分子蒸馏工艺对沙棘果毛油中8 种邻苯二甲酸酯类塑化剂(phthalic acid esters,PAEs)进行脱除,并对脱除前后沙棘果油的脂肪酸组成及活性成分含量进行检测分析,研究分子蒸馏对沙棘果毛油中PAEs脱除效果以及活性成分保留的影响。结果显示,本实验所取沙棘果毛油样品中邻苯二甲酸二正丁酯(di-butyl phthalate,DBP)和邻苯二甲酸二(2-乙基)己酯(bis(2-ethylhexyl) phthalate,DEHP)含量分别为1.626、10.933 mg/kg,明显超出GB 9685—2016《食品安全国家标准食品接触材料及制品用添加剂使用标准》限量(DBP含量不超过0.3 mg/kg、DEHP含量不超过1.5 mg/kg)。经一级分子蒸馏,DBP含量从1.626 mg/kg降至0.071 mg/kg,明显低于GB 9685—2016限量;经两级分子蒸馏,DEHP含量从10.933 mg/kg降低至0.668 mg/kg,明显低于GB 9685—2016限量,DBP、DEHP、邻苯二甲酸二异壬酯(diisononyl phthalate,DINP)及8 种塑化剂含量总和的脱除率分别为98%、94%、85%和93%,VE、甾醇、黄酮类成分的保留率分别为14%、32%、46%,脂肪酸组成没有明显变化,基本无反式脂肪酸形成,游离脂肪酸质量分数明显降低。两级分子蒸馏工艺是脱除食用植物油中高含量PAEs的有效方法,但会造成油脂中VE、甾醇、黄酮类成分的较大损失。因此,为避免活性成分损失,在保证油脂中DBP和DEHP脱除达到GB 9685—2016限量时,可采用一级分子蒸馏,此时VE、甾醇、黄酮的保留率可分别提高至35%、55%、63%。

Sea buckthorn (Hippophae rhamnoides L.) pulp oil (SPO) is an expensive edible vegetable oil due to its beneficial bioactive ingredients, but this oil may pose a risk of phthalic acid esters (PAEs) exceeding the legal limits, depending on various factors such as growing environment, picking methods, and storage methods. In the present study, two-stage molecular distillation (MD) was used to remove 8 PAEs from SPO. Fatty acid composition and the contents of VE, phytosterol, and flavonoids in SPO were detected before and after MD to evaluate the effect of MD on the removal of PAEs and the retention of bioactive constituents. The results showed the contents of di-butyl phthalate (DBP)(1.626 mg/kg) and bis(2-ethylhexyl) phthalate (DEHP)(10.933 mg/kg) in raw sea buckthorn pulp oil (R-SPO) greatly exceeded the limits (0.3 and 1.5 mg/kg respectively) specified in China’s national standard for the use of food contact materials and food additives. The content of DBP decreased from 1.626 to 0.071 mg/kg during the first stage of MD, which was far below the legal limit, and the content of DEHP reduced from 10.933 to 0.668 mg/kg during the whole MD process. The removal rates of DBP, DEHP, DINP and the sum of these PAEs and five others were 98%, 94%, 85% and 93%, respectively;after two-stage MD, the retention rates of VE, sterol and flavonoids were 14%, 32%, and 46% respectively. Fatty acid composition of SPO did not change obviously, almost no trans-fatty acids were produced, whereas the proportion of free fatty acids decreased visibly. These results indicated that the two-stage molecular distillation process was an effective method to remove high concentrations of PAEs from edible vegetable oils, but it could result in large losses of nutrients such as VE, sterol and flavonoids. One-stage molecular distillation could reduce the contents of DBP and DEHP in edible vegetable oil to less than the legal limits while avoiding losses of nutrients, increasing the retention rates of VE, sterol and flavonoids up to 35%, 55% and 63%, respectively.