长沙商贸旅游职业技术学院是经湖南省人民政府批准、教育部备案，的一所全日制公办普通高等学校，是湖南省示范性（骨干）高等职业院校、湖南省首批卓越高等职业院校建设单位。 学院的前身是创办于1956年的长沙商业职业中专学校和创办于1960年的长沙商业学校，2003年经湖南省人民政府批准，合并升格为全日制普通高等学院。 据2018年10月学校官网显示，学院占地面积47.49万平方米，总建筑面积31.18万平方米，固定资产总值5.19亿元，设有10个教学机构，有教职工495人，其中专任教师445人，有全日制高职在校生8000人。 2019年12月，被教育部、财政部列入第四类高水平专业群建设单位（C档）。
[Objective]To develop an ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)method for determining lutein and natural vitamin K(VK)homologues,including phylloquinone(VK1),menaquinone-4(MK-4),menaquinone-7(MK-7),and menaquinone-9(MK-9),in poultry eggs by optimizing ultrasound assisted enzymatic hydrolysis.[Methods]The target compound is extracted from poultry egg samples by ultrasound assisted enzymatic hydrolysis and then separated on C18(100 mm×2.1 mm,3.0 μm)column with 0.1%formic acid aqueous solution-0.1%formic acid methanol for gradient elution.Meanwhile,the samples are quantified by external standard with APCI source for detection and analysis.[Results]Under the ultrasound assisted enzymatic hydrolysis conditions of enzyme dosage of 1 500 U and hydrolysis time of 1 hour,the linear relationships of lutein and natural VK homologues are good in the range from 1.0 ng/mL to 5 000 ng/mL(R2>0.996).The detection limit is 0.8～1.5 μg/100 g,and the quantification limit is 2.0～5.0 μg/100 g.The average recovery of lutein and natural VK homologues is 80.1%～94.9%when the spiked concentration is 10,20,and 100 μg/100 g with the RSD of 1.3%～5.5%.[Conclusion]This method has high detection efficiency,sensitivity,and selectivity and can be used as a detection method for lutein and natural VK homologues in poultry eggs.
Objective: To explore the changes of phenolic substances and antioxidant activities of five edible flowers after simulated gastrointestinal digestion in vitro. Method: Five flower include osmanthus, marigold, gardenia, magnolia,hibiscus as the research material, by comparing the content of polyphenols and flavonoids and their in vitro antioxidant activities before digestion, in vitro simulated gastric digestion, and in vitro simulated intestinal digestion. Results: The contents of flavonoids, polyphenols and antioxidant activities of the five edible flowers did not increase significantly in the simulated gastric digestion stage, but showed a larger increase trend in the simulated intestinal digestion stage. Through the whole simulated gastrointestinal digestion, polyphenols increased by 127.55%（osmanthus）～461.70%（marigold）, and flavonoids increased by 46.50%（magnolia）～218.46%（marigold）. Among which, the highest content of polyphenols and flavonoids were found in marigold with the value of（8.95±0.03） mg gallic acid equivalent（GAE）/g and（83.01±0.01） mg catechin equivalent（CE）/g, respectively. Among the three antioxidant activities, the DPPH free radical scavenging ability increased by 77.0%（hibiscus）～158.05%（gardenia）, the ferric ion reducing antioxidant power increased 15.30%（osmanthus）～163.92%（gardenia）, ABTS + free radical scavenging ability increased by 142.35%（magnolia）～274.18%（gardensis）.Conclusion: Five edible flowers had good bioavailability potential and would be expected to be used as raw material sources of natural antioxidant functional foods.
