Song Zhang,Jian Xiong,Wenyong Lou,Zhengxiang Ning,Denghui Zhang,Jiguo Yang
This study was designed to synthesize triglycerol monolaurate (TGML) with Lipozyme 435 as the catalyst, and explore its effects on the growth of Aspergillus parasiticus ( A. parasiticus ) and Aspergillus flavus ( A. flavus ) and the secretion of aflatoxin b1. The highest content of TGML (49.76%) was obtained at a molar ratio of triglycerol to lauric acid of 1.08, a reaction temperature of 84.93°C, a reaction time of 6 h and an enzyme dosage of 1.32%. After purification by molecular distillation combined with the washes with ethyl acetate and water, the purity of TGML reached 98.3%. Through characterization by electrospray-ionization mass spectrometry, infrared spectrum and nuclear magnetic resonance, the structure of TGML was identified as a linear triglycerol combined with lauroyl at the end. Finally, the inhibitory effects of TGML on the growths of A. parasiticus and A. flavus and the secretion of aflatoxin b1 were evaluated by measuring the colony diameter, the inhibition rate of mycelial growth and the content of mycotoxin in the media. The results indicated that TGML had a stronger inhibitory effects on colony growth and mycelial development of both toxic molds compared to sodium benzoate and potassium sorbate, and the secretions of toxins from A. parasiticus and A. flavus were completely suppressed when adding TGML at 10 and 5 mM, respectively. Based on the above results, TGML may be used as a substitute for traditional antifungal agents in the food industry.
Duan Zhou,Mouming Zhao,Jiankang Wang,Muniba Faiza,Xuefeng Chen,Junjie Cui,Ning Liu,Daoming Li
Punicic acid (PA)-enriched diacylglycerol (DAG) possesses both the beneficial effects of PA and DAG. However, few studies have focused on the preparation of PA-enriched DAG. Here, we report a novel and highly efficient method for the preparation of PA-enriched DAG through Lipozyme 435-catalyzed ethanolysis of pomegranate seed oil (PSO). Firstly, PSO was obtained through microwave-assisted extraction. Subsequently, four lipases were screened for their capability in the preparation of PA-enriched DAG through ethanolysis of PSO (containing 82.98% PA), and Lipozyme 435 was selected. Under the optimal conditions, the resultant mixture containing 32.86% DAG was obtained. Interestingly, Lipozyme 435 maintained superior operational stability after ten successive cycles. A scale-up reaction was then conducted under the optimized conditions and the purified product containing 51.83% DAG (containing 81.95% PA) was obtained. The final product with a low peroxide value (1.45 mmol/kg) and undetectable acid value reached edible quality. This is the first study for the preparation of PA-enriched DAG through ethanolysis and Lipozyme 435 exhibited superior capability and recyclability. Compared with other approaches for DAG preparation, this approach favored shorter reaction time and better quality of the product. This study provides useful information for further studies involving DAG preparation and modification of PSO.
Arbutin, salidroside, polydatin, and phlorizin are typically natural bioactive phenolic glycosides. To improve the liposolubility and bioavailability, highly liposoluble derivatives including 6′-O-lauryl arbutin, 6′-O-lauryl salidroside, 6″-O-lauryl polydatin, and 6″-O-lauryl phlorizin were efficiently synthesized by enzymatic acylation in a green solvent 2-MeTHF. Their reaction conversions reached 84.4, 99.5, 99.8, and 89.1%, respectively, when catalyzed by Lipozyme 435 at 20 mg/mL at 50 °C. As expected, the derivatives had high log P (1.66–2.37) and retained good antioxidant activity, making them potential alternatives to butylated hydroxytoluene (BHT) and tert-butyl-hydroquinone (TBHQ) in lipid systems. Then, the intestinal permeability characteristics and metabolism of phenolic glycosides and their derivatives were investigated based on Caco-2 monolayers. The permeability of polydatin and phlorizin was mainly through active transport, but that of arbutin and salidroside involved both passive diffusion and active uptake. The acylated derivatives suffered from severe CES-mediated hydrolysis but exhibited a larger transported amount than phenolic glycosides.
危险品化学品经营许可证（带存储）