Utilizing ultrasonic energy for reduction of free fatty acids in crude palm oil

Recently, biodiesel production from abundant bio-sources has drawn the attention of the academic and the industrial community. In this study, crude palm oil (CPO) containing 8.7% free fatty acid content (FFA) was used as raw material. Different common types of acid catalysts (sulfuric acid, methanesulfonic acid and hydrochloric acid) were optimized to investigate the catalytic activity of each acid in the pre-treatment of CPO by the esterification process. Ultrasonic energy was used for the reduction of FFA in CPO. FFA content was measured at different sonication intervals, and the optimum time was determined. Hydrochloric acid showed the highest catalytic activity in the reduction of FFA content in CPO, as well as in converting FFA to fatty acid methyl ester (FAME). From this work, it is reasonable to conclude that there is significant enhancement in the pre-treatment of oils by applying ultrasonic energy using long sonication time.Keywords: Biodiesel, crude palm oil, free fatty acids, ultrasonic energ

A grand avenue to integrate deep eutectic solvents into biomass processing

Deep eutectic solvents (DESs) are green solvents that are developing rapidly, used in many types of applications as well as fundamental investigations. The physicochemical properties of DESs are one of the most important factors which led to their increased interest in science and technology. DESs are thermally and chemically stable, non-flammable and have a negligible vapor pressure. Furthermore, most of the newly formulated DESs are liquids at room temperature. DESs are more economical and less expensive compared to ionic liquids. DESs are frequently prepared from renewable and non-toxic precursors, in addition, there are wide selections of biocompatible and biodegradable DESs. Hence, DESs have been used in many applications and processes such as biorefinery, lignocellulose dissolution, bioactive compound extraction and electrochemical applications. In this review, an update of the application of DESs in biomass processing as renewable sources is presented. This review aims to cover as much as possible the ongoing research and applications of DES and invite opinions to broaden the applications of DESs, rather than concentrating on the physicochemical fundamentals of new DESs. The future of these solvents is bright but require further investigations and efforts for a better understanding and future for sustainable resources

Shedding light on lipase stability in natural deep eutectic solvents

This study presents the potential role of natural deep eutectic solvents (NADESs) in a lipase-catalyzed hydrolysis reaction as both a co-solvent in an aqueous solution and as a main solvent. Ammonium salts such as choline chloride (ChCl) were paired with different hydrogen bond donors such as glycerol and malonic acid and sugars (glucose, fructose and sucrose). The hydrolysis of p-nitrophenyl palmitate by six different lipases: lipase from porcine pancreas (PR), lipase from Candida rugosa (CR), Amano lipase PS, from Burkholderia cepacia (AM), lipase from Rhizopus niveus (RN), lipase acrylic resin from Candida antartica (ARC), lipase B Candida antartica immobilized on Immobead 150, recombinant from Aspergillus oryzae (CALB), were tested in five NADESs. The results showed that NADES3 prepared from ChCl/sucrose was the most promising solvent as it enhanced the activities of both CALB and lipase from porcine pancreas to 355 % and 345 %. The kinetics investigation confirmed the higher catalytic efficiency (kcat/Km) of lipases in the 40 % of (NADES3) and compared with the aqueous form. The trend achieved by NADES may be a promising approach for applications and further perspectives as genuinely green industrial solvents

Nanocellulose and natural deep eutectic solvent as potential biocatalyst system toward enzyme immobilization

This study reports the immobilization of Candida Rugosa lipase (CRL) onto nanocellulose (NC) extracted from almond shells using p-toluenesulfonic acid (PTSA) and sulfuric acid (ASS) with sugar-based natural deep eutectic solvent (NADES1a) as a biocatalyst system. The properties of both immobilized lipases were studied and compared to the free enzyme counterpart. Under optimized conditions (2 h, 40 ºC and pH 7.0), the immobilized CRL-PTSA-NADES1a and CRL-ASS-NADES1a gave a maximum specific activity of 4.9 U mg−1 and 6.57 U mg−1, respectively, compared to the free CRL (4.52 U mg−1). Both immobilized CRL showed better thermal stability, high catalytic activity and reusability up to 7 consecutive cycles. The half- life of the immobilized lipase was 14 ∼ 16 days greater than free lipase (27 days). The Brunauer-Emmett-Teller (BET) surface area of NC-ASS (20.76 m2 g−1) is higher compared to NC-PTSA (4.81 m2 g−1). The functional groups and morphology of the free and immobilized CRL were further determined by Fourier transformed infrared (FTIR) and scanning electron microscopy (SEM). These findings revealed that the immobilized CRL onto NCs and NADES1a as green materials and solvent, respectively had higher lipase immobilization efficiency and stability for the treatment of food contaminants in oils in order to satisfy increasing commercial demands in the oil industry

3-Monochloropropane-1,2-diol (3-MCPD): a review on properties, occurrence, mechanism of formation, toxicity, analytical approach and mitigation strategy

3-Monochloropropane-1,2-diol (3-MCPD) is one of the most common food contaminants in processed oils which forms mostly during the deodorization step of edible oil refining process. It has been detected in many types of food products such as infant formula, margarine, bread and soy sauce, which could result in kidney and testicular damage. The presence of 3-MCPD contaminant have been occurring for more a decade, which warrants a maximum permissible amount of 2 µg/kg body weight in food products in national and international levels. The purpose of this review is to provide an overview in the past 12 years on its physicochemical properties, occurrence, potential precursors and formation mechanism of 3-MCPD in foodstuffs. The toxicity, its quantification methods and mitigation strategy are also reviewed with an emphasis on the applicability, efficiency and issues encountered during the analysis. This review provides an elucidation regarding 3-MCPDEs and their food safety implications

Natural deep eutectic solvent-assisted pectin extraction from pomelo peel using sonoreactor: experimental optimization approach

Background: Natural deep eutectic solvents (NADESs) can be used for extracting a wide range of biomaterials, such as pectin. This study introduces a new generation of natural solvents for pectin extraction which could replace the conventional solvents in the food industry. Methods: In this study, NADESs were used for pectin extraction from pomelo (Citrus grandis (L.) Osbeck) peels using a sonoreactor. Definitive screening design (DSD) was used to screen the influence of time, temperature, solid/liquid ratio, and NADES/water ratio on the pectin yield and degree of esterification (DE). Results: The primary screening revealed that the best choices for the extraction were choline chloride–malonic acid (ChCl-Mal) and choline chloride–glucose–water (ChCl:Glc:W). Both co-solvents yielded 94% pectin and 52% DE after optimization at 80 ◦C, with 60 min of sonication, pH < 3.0, and a NADES-to-water ratio of 1:4.5 (v/v). Morphological screening showed a smooth and compact surface of the pectin from ChCl-Mal where glucose-based pectin had a rough surface and lower DE. Conclusions: NADESs proved to be promising co-solvents for pectin extraction with a high degree of esterification (>55%)

Antibacterial performance enhancement using hydrophobic deep eutectic solvents: COSMO-RS prediction, experimental validation, and synergistic action with antibiotics

Microbial infection is a hazardous and challenging clinical problem that has attracted considerable attention recently, primarily owing to the noticeable rise in antimicrobial resistance. To address the medical requirements to encounter this dilemma, we present hydrophobic deep eutectic solvents (HDESs) that combine experimental research and computational prediction; conductor-like screening model for real solvents (COSMO-RS). Mentholbased HDESs were successfully obtained when mixed with fatty acids, and their thermal profiles were analyzed. The HDES systems and their synergistic effects demonstrated potent antimicrobial activity against Gram-positive and Gram-negative bacteria, with DES 4 (menthol:decanoic acid) exhibiting the highest bactericidal activity at a molar ratio of 1:5. The interaction between the HDESs and bacterial cell wall structural compounds was confirmed by field-emission scanning electron microscopy and Fourier transform infrared spectroscopy. The results revealed a favorable concurrence between the projected and empirical outcomes, indicating that DES 4 exhibited bacteriostatic properties and could be a viable substitute for managing bacterial infections of diverse origins. In addition, the synergistic effect of DES 4 and tetracycline showed promising potential. The successful integration of experimental and computational approaches in this study also sets a precedent for the rational design of future antimicrobial agents and opens new avenues for tackling other clinical challenges

Ternary glycerol-based deep eutectic solvents: physicochemical properties and enzymatic activity

The present study investigates deep eutectic solvents (DESs) as potential media for enzymatic hydrolysis. A series of ternary ammonium and phosphonium-based DESs were prepared at different molar ratios by mixing with aqueous glycerol (85%). The physicochemical properties including surface tension, conductivity, density, and viscosity were measured at a temperature range of 298.15 K – 363.15 K. The eutectic points were highly influenced by the variation of temperature. The eutectic point of the choline chloride: glycerol: water (ratio of 1: 2.55: 2.28) and methyl triphenylphosphonium bromide:glycerol: water (ratio of 1: 4.25:3.75) is 213.4 K and 255.8 K, respectively. The stability of the lipase enzyme isolated from the porcine pancreas (PPL) and Rhizopus niveus (RNL) toward hydrolysis in ternary DESs medium was investigated. The PPL showed higher activity compared to the RNL in DESs. Molecular docking simulation of the selected DES with the substrate (p-nitrophenyl palmitate) towardPPL was also reported. It is worth noting that ternary DES systems would be viable lipaseactivators in hydrolysis reactions

Nanodiamonds and natural deep eutectic solvents as potential carriers for lipase

This study investigates the use of nanodiamonds (ND) as a promising carrier for enzyme immobilization and compares the effectiveness of immobilized and native enzymes. Three different enzyme types were tested, of which Rhizopus niveus lipase (RNL) exhibited the highest relative activity, up to 350 %. Under optimized conditions (1 h, pH 7.0, 40 ◦C), the immobilized ND-RNL showed a maximum specific activity of 0.765 U mg− 1 , significantly higher than native RNL (0.505 U mg− 1 ). This study highlights a notable enhancement in immobilized lipase; furthermore, the enzyme can be recycled in the presence of a natural deep eutectic solvent (NADES), retaining 76 % of its initial activity. This aids in preserving the native conformation of the protein throughout the reusability process. A test on brine shrimp revealed that even at low concentrations, ND-RNL had minimal toxicity, indicating its low cytotoxicity. The in silico molecular dynamics simulations performed in this study offer valuable insights into the mechanism of interactions between RNL and ND, demonstrating that RNL immobilization onto NDs enhances its efficiency and stability. All told, these findings highlight the immense potential of ND-immobilized RNL as an excellent candidate for biological applications and showcase the promise of further research in this field