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Candida antartica lipase-catalyzed esterification for efficient partial acylglycerol synthesis in solvent-free system: Substrate selectivity, molecular modelling and optimization

Zou S, Chen J, Lee YY, Wang Y, Zhang Z

Bioresour Technol, 2024 Aug 27.
PMID: 39209228 DOI: 10.1016/j.biortech.2024.131368

Partial acylglycerols are valued for their emulsifying and stabilizing properties, yet precise green synthesis remains challenging due to low yield and selectivity. This study aimed to elucidate the "lipase selectivity-substrate structure-product composition" relationship to enhance the yield of targeted partial acylglycerol. The results showed that lipase exhibited a greater selectivity towards fatty acids with shorter chain lengths and higher unsaturation. Hydroxyl donors also affected the esterification process, with the enzyme-acyl complex exhibiting selectivity towards hydroxyl donors as follows: glycerol > monoacylglycerol > diacylglycerol. Substrate ratio significantly influenced enzymatic reactions; a 10:1 ratio favored triacylglycerol formation (>80 %), while a 1:1 ratio produced > 90 % partial acylglycerols. Molecular docking simulations revealed that substrates primarily interacted with lipase through hydrogen bonding and hydrophobic interactions. A comprehensive understanding of lipase selectivity patterns could facilitate the design of more efficient reaction systems, enabling the conversion of basic lipid resources into desired high value-added products.
Effect of diacylglycerol on partial coalescence of aerated emulsions: Fat crystal-membrane interaction and air-liquid Interface interaction insights

Xie P, Zheng Y, Lee YY, Zou S, Wu Y, Lai J, et al.

Food Chem, 2024 Aug 13;461:140879.
PMID: 39154466 DOI: 10.1016/j.foodchem.2024.140879

Currently, the poor whipping capabilities of anhydrous milk fat (AMF) in aerated emulsion products are a major obstacle for their use in beverages like tea and coffee, as well as in cakes and desserts, presenting fresh hurdles for the food industry. In this study, the mechanism of action of diacylglycerols (DAGs) with different carbon chain lengths and degrees of saturation on the partial coalescence of aerated emulsions was systematically investigated from three fundamental perspectives: fat crystallization, air-liquid interface rheology, and fat globule interface properties. The optimized crystallization of long carbon chain length diacylglycerol (LCD) based on stearate enhances interactions between fat globules at the air-liquid interface (with an elastic modulus E' reaching 246.42 mN/m), leading to a significantly reduced interface membrane strength. This promotes fat crystal-membrane interactions during whipping, resulting in a thermally stable foam structure with excellent shaping capability due to enhanced partial coalescence of fat globules. Although Laurate based medium carbon chain length diacylglycerol (MCD) promoted fat crystallization and optimized interface properties, it showed weaker foam properties because it did not adequately encapsulate air bubbles during whipping. Conversely, oleate long carbon chain length diacylglycerol (OCD) proved to be ineffective in facilitating fat crystal-membrane interaction, causing foam to have a subpar appearance. Hence, drawing from the carefully examined fat crystal-membrane interaction findings, a proposed mechanism sheds light on how DAGs impact the whipping abilities of aerated emulsions. This mechanism serves as a blueprint for creating aerated emulsions with superior whipping capabilities and foam systems that are resistant to heat.
Fulltext Platelet distribution width as an useful indicator of influenza severity in children

Zou S, Mohtar SH, Othman R, Hassan RM, Liang K, Lei D, et al.

BMC Infect Dis, 2024 Jan 02;24(1):9.
PMID: 38166827 DOI: 10.1186/s12879-023-08890-w

PURPOSE: The present study aims to investigate the potential of platelet distribution width as an useful parameter to assess the severity of influenza in children.
METHODS: Baseline characteristics and laboratory results were collected and analyzed. Receiver operating characteristic (ROC) curve analysis was used to joint detection of inflammatory markers for influenza positive children, and the scatter-dot plots were used to compare the differences between severe and non-severe group.
RESULTS: Influenza B positive children had more bronchitis and pneumonia (P
Effects of liquid oils on partial coalescence and whipping capabilities of aerated emulsions: Differences between diacylglycerol and triacylglycerol

Xie P, Xie R, Lai J, Zou S, Lee YY, Tan CP, et al.

Food Chem, 2025 Feb 12;475:143385.
PMID: 39952178 DOI: 10.1016/j.foodchem.2025.143385

Liquid oils are typically used to dilute solid fat in aerated emulsions, yet the structure of lipid components determines their functional properties. This study investigates the mechanism of liquid diacylglycerol (DAG) and triacylglycerol (TAG) on the whipping capabilities of aerated emulsions from the perspective of fat crystal- membrane interactions. Although there were no significant differences in thermodynamic properties, DAG significantly delayed the reduction in lamella thickness of fat crystals compared to TAG, thereby maintaining the density of the fat crystal network at high liquid oil levels. Additionally, the extra hydroxyl group in DAG, compared to TAG, enabled DAG-rich fat globules to occupy the air-liquid interface more rapidly, thereby significantly enhancing the occurrence and development of partial coalescence during whipping. Therefore, the whipping capabilities of aerated emulsions rich in DAG were greatly improved. This study enhances understanding of structural lipids in aerated emulsions and offers new insights into improving whipping capabilities.
Redefining shortening: Systematically characterizing traditional and new enriched diacylglycerol shortening and exploring their impact on processing applications

Xie P, Wang F, Zhou J, Lee YY, Zhang Y, Zou S, et al.

Food Chem, 2025 Feb 28;466:142196.
PMID: 39612838 DOI: 10.1016/j.foodchem.2024.142196

Compared to lard-based shortenings, diacylglycerol (DAG)-based shortenings have demonstrated beneficial effects, such as lowering blood lipids, and reducing postprandial blood glucose levels. In this study, different chain-length DAG oils were blended with lower melting point peanut oil DAG oil (PO-DAG-oil). The blend ratios for the three types of DAG-based shortenings were determined based on the solid fat content (SFC) of lard. Subsequently, 1 % of various emulsifiers were added, and the crystallization properties, rheological and textural characteristics, polymorphism, microstructure, water-absorbing capacity, and plasticity of the four shortening systems were examined. The emulsifiers found to be suitable for lard shortening, long chain fatty acid DAG (LCD-shortening), medium chain fatty acid DAG (MCD-shortening), and medium and long chain fatty acid DAG (MLCD-shortening) were Span60, PGFE, PGFE, and MAG, respectively. Cakes baked using DAG-based shortenings exhibited superior textural properties compared to those made with lard-based shortenings, supporting the application of high-melting-point DAG oils in shortening formulations.
Lipase-catalyzed esterification for efficient acylglycerols synthesis in a solvent-free system: Process optimization, mass transfer insights and kinetic modeling

Zou S, Zhang Z, Lee YY, Ai H, Zhang Y, Wang Y

Food Chem, 2025 May 15;474:143151.
PMID: 39891972 DOI: 10.1016/j.foodchem.2025.143151

Acylglycerols are widely used in the food industry due to their antimicrobial, emulsifying and nutritional properties. This study investigated the key reaction parameters, mass transfer mechanisms, and kinetic features of lipase-catalyzed esterification in a solvent-free system. Taguchi method was further employed to explore the relationship between "reaction parameter - yield composition". The results revealed that the maximum selectivity were achieved fror MAG (57.72 %), DAG (82.67 %) and TAG (79.29 %) under different enzymatic conditions. Fatty acid-to-glycerol molar ratio had the greatest impact on DAG selectivity, contributing 38.08 % of total impact level. Mass transfer analysis showed that external mass transfer limitation could be effectively overcome at stirring speeds above 600 rpm. Kinetic analysis confirmed that the reaction followed the Ping-Pong BiBi mechanism with alcohol and acid inhibition (SSE = 0.000643). This work provided a theoretical basis for developing more efficient and selective catalytic processes, aiding in quality control, reactor design, and industrial scale-up.