Characterization of lignans in Schisandra chinensis oil with a single analysis process by UPLC-Q/TOF-MS.

Schisandra chinensis is a medicinal and edible plant that contains various bioactive compounds. Among these, lignans are the major functional compounds. Nevertheless, detailed information about lignans in Schisandra chinensis oil remains scarce. A powerful UPLC-Q/TOF-MS method was established for the rapid identification of the lignan constituents of Schisandra chinensis oils. The results showed that 21 lignans have been unambiguously identified, and four lignans have been tentatively identified in the Schisandra chinensis oils. In addition, semi-quantitative analysis indicated that the total lignan content in the Schisandra chinensis oils was distributed from 67.73 ± 0.06 to 87.61 ± 1.83 mg/g. Schisandrin and schisandrin B were the most abundant lignans in the Schisandra chinensis oils, their content ranging from 15.85 ± 0.09 to 20.57 ± 0.38 mg/g. Additionally, this study provided a systematic characterization of lignans in Schisandra chinensis oil and indicated that the oil might be used as lignan-related functional foods.

Ultrasound irradiation promoted enzymatic alcoholysis for synthesis of monoglyceryl phenolic acids in a solvent-free system.

Monoglyceryl phenolic acids (MPAs) were known as the natural hydrophilic antioxidants which could be used in different fields such as food, pharmaceutical, cosmetic etc. A novel enzymatic route of MPAs synthesis by the alcoholysis of phenolic acid ethyl esters with glycerol under ultrasound irradiation in solvent free system was developed. Optimization of reaction parameters shows that a high conversion of above 97.4% can be obtained under the following conditions: phenolic acid ethyl esters to glycerol molar ratio of 1:10, with 6% catalyst (Novozym 435), at 60°C and 200rpm, with ultrasound input of 250W, at 20kHz frequency. Compared to the conventional stirring method, the activation energy for phenolic acid ethyl esters conversion was decreased from 65.0kJ/mol to 32.1kJ/mol under ultrasound promotion; the apparent kinetic constant (Vm/Km) increased above 1.2-folds; the lipase amount decreased to 50%; the time required for the maximum conversion reduced up to 3-folds without damaging the lipase activity, which is the fastest report for enzymatic synthesis of MPAs.

Facile preparation of magnetic carbon nanotubes-immobilized lipase for highly efficient synthesis of 1,3-dioleoyl-2-palmitoylglycerol-rich human milk fat substitutes.

In this study, Candida lipolytica lipase (CLL) was immobilized on magnetic multi-walled carbon nanotubes (mMWCNTs) via hydrophobic and cation-exchange interaction. The resultant immobilized CLL showed much better thermal stability, biocatalyst activity and easier recycling than the free form. A method for efficient enzymatic acidolysis of tripalmitin (PPP) with oleic acid (OA), to produce OPO-rich TAGs, was developed, using the immobilized CLL as the biocatalyst. Under optimized conditions (2% water, 20mg/ml enzyme, 1:6 PPP/OA, 50°C, 2h), the content of OPO in the final product reached 46.5%. CLL@mMWCNTs had a better activity and manipulative stability than commercial lipases. More importantly, the feasibility of CLL@mMWCNTs was also validated in the practical production of OPO-rich TAGs, using lard and restructured palm oil as the raw material. These results suggest that CLL@mMWCNTs is a promising biocatalyst for the OPO-rich TAGs production and will be helpful for the infant formula industry.