Search

L-ascorbyl palmitate (LAP) is the permitted antioxidant used in baby food, but its high commercial demand is suppressed by poor liposolubility. In this paper, a cleaner and more efficient method to synthesize the high-liposoluble and antioxidant unsaturated fatty acid ascorbyl esters (UFAAE) is proposed, based on the enzymatic catalysis using CaLB immobilized on the ordered mesoporous silicon (CaLB@OMS-C 8). The results indicated that the maximum catalytic efficiency (CE) in CaLB@OMS-C 8 could reach 20.8 M g−1 h−1, thus facilitating the high conversions of 71.8%, 74.1% and 76.8% for L-ascorbyl oleate (LAO), L-ascorbyl linoleate (LAL) and L-ascorbic acid linolenic ester (LALN), respectively. The higher yield of LALN was explained by molecular docking technology as lipase CaLB presented a high binding affinity to linolenic acid (−18.8 kJ/mol) than those to oleic acid (−9.2 kJ/mol) and linoleic acid (−15.4 kJ/mol). By using unsaturated fatty acids as acyl donors, the synthesized UFAAE exhibited a lower melting point, better liposolubility and comparable antioxidant ability compared to LAP. This method to synthesize the high-soluble and antioxidant L-ascorbyl esters by the enzymatic esterification between L-ascorbic acid and unsaturated fatty acids shows great potential as a clean and efficient approach for future industrial production. [Display omitted] • Green and clean production of ascorbyl esters by immobilized lipase was proposed. • Catalytic efficiency and thermal stability of CaLB@OMS-C 8 were largely improved. • Enzymatically produced ascorbyl esters had higher solubility and antioxidation. • Interactions of lipase and fatty acids were studied by molecular docking technique. • This paper highlights the efficiency and sustainability of enzymatic synthesis. [ABSTRACT FROM AUTHOR]

L-ascorbyl palmitate (LAP) is the permitted antioxidant used in baby food, but its high commercial demand is suppressed by poor liposolubility. In this paper, a cleaner and more efficient method to synthesize the high-liposoluble and antioxidant unsaturated fatty acid ascorbyl esters (UFAAE) is proposed, based on the enzymatic catalysis using CaLB immobilized on the ordered mesoporous silicon (CaLB@OMS-C 8). The results indicated that the maximum catalytic efficiency (CE) in CaLB@OMS-C 8 could reach 20.8 M g−1 h−1, thus facilitating the high conversions of 71.8%, 74.1% and 76.8% for L-ascorbyl oleate (LAO), L-ascorbyl linoleate (LAL) and L-ascorbic acid linolenic ester (LALN), respectively. The higher yield of LALN was explained by molecular docking technology as lipase CaLB presented a high binding affinity to linolenic acid (−18.8 kJ/mol) than those to oleic acid (−9.2 kJ/mol) and linoleic acid (−15.4 kJ/mol). By using unsaturated fatty acids as acyl donors, the synthesized UFAAE exhibited a lower melting point, better liposolubility and comparable antioxidant ability compared to LAP. This method to synthesize the high-soluble and antioxidant L-ascorbyl esters by the enzymatic esterification between L-ascorbic acid and unsaturated fatty acids shows great potential as a clean and efficient approach for future industrial production. [Display omitted] • Green and clean production of ascorbyl esters by immobilized lipase was proposed. • Catalytic efficiency and thermal stability of CaLB@OMS-C 8 were largely improved. • Enzymatically produced ascorbyl esters had higher solubility and antioxidation. • Interactions of lipase and fatty acids were studied by molecular docking technique. • This paper highlights the efficiency and sustainability of enzymatic synthesis. [ABSTRACT FROM AUTHOR]

In this work, Corn Starch (CS)-Lauric acid (LA) complexes prepared by different ultrasound times were explored for multi-scale structure and digestibility. The results showed that the average molecular weight of the CS decreased from 380.478 to 323.989 kDa and the transparency increased to 38.55 % after 30 min of ultrasound treatment. The scanning electron microscope (SEM) results revealed a rough surface and agglomeration of the prepared complexes. The complexing index of the CS-LA complexes increased by 14.03 % compared to the non-ultrasound group. The prepared CS-LA complexes formed a more ordered helical structure and a more dense V -shaped crystal structure through hydrophobic interactions and hydrogen bonding. In addition, fourier transforms infrared spectroscopy and the molecular docking revealed that the hydrogen bonds formed by CS and LA promoted the formation of an ordered structure of the polymer, retarding the diffusion of the enzyme and thus reducing the digestibility of the starch. With correlation analysis, we provided insight into the multi-scale structure-digestibility relationship in the CS-LA complexes, which provided a basis for the relationship between structure and digestibility of lipid-containing starchy foods. • Ultrasonication was helpful for the formation of CS-LA complexes to prepare RS5. • The complexes exhibited V-type crystalline structures. • Hydrogen bonds were major non-covalent linkages during CS-LA complex formation. • CS-LA complexes exhibited lower RDS and higher RS contents as compared to control. [ABSTRACT FROM AUTHOR]