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Ultrasound-mechanical stirrer assisted extraction (UMSAE) of extraction yield, total alkaloid content (TAC) and antioxidant (DPPH) activity from Annona muricata leaves were optimized using response surface methodology. Five factors were screened using Plackett-Burman Design to investigate the variables that significantly influence the extraction yield, TAC and DPPH activity, namely solvent concentration, extraction time, ultrasound power, plant material to solvent ratio, and extraction temperature. According to statistical significance analysis, solvent concentration, ultrasound power, plant material to solvent ratio, and extraction temperature were selected for further optimization of the UMSAE extraction process using a Central Composite Design. ANOVA results exhibited that the obtained models were significant at 95 % confidence level. Satisfactory extraction yields (26.38 %) and TAC (39.73 mg AE/g) were obtained with relatively short extraction time under the optimum conditions compared with conventional Soxhlet extraction. The extract prepared under UMSAE displayed excellent DPPH activity (93.15 %). The optimized UMSAE promoted considerable yield increases 1.59-fold the yield extract, 2.32-fold TAC, and 1.19-fold antioxidant activity if compared to the Soxhlet extraction. This study provides the ideal integrated UMSAE settings for the maximum recovery of total alkaloid content with high antioxidant activity from A. muricata for possible utilization of their leaves in food applications.

Purpose This paper aims to intend to ascertain whether corporate social responsibility (CSR) can serve as an effective promotional tool for the Malaysian halal certified companies in the era of Covid-19 pandemic. Starting from being nice to do, the emergence of the Covid-19 pandemic has brought CSR to the forefront of businesses, forcing them to rapidly shift from profit maximisation to business preservation. Thus, it is practically crucial to ascertain whether CSR could be effectively used to promote halal brands in this era. Design/methodology/approach To achieve the stated aim, a survey questionnaire was developed and used to collect data from 295 participants who are familiar with the concepts of CSR and halal in Malaysia. The data collected were analysed using both descriptive and inferential statistics. Findings The findings reveal that the commitment to halal best practices, zakat and charitable donations, environmental responsibility, employee welfare and responsible dealings with clients are the most important CSR activities that can promote halal certified companies in the era of Covid-19. Whilst there is a positive relationship between halal economic responsibility and CSR as a promotional tool, such relationship is not significant. Nevertheless, the relationship between legal responsibility and CSR as a promotional tool is negative and insignificant. Research limitations/implications Limitations are inevitable in any study where a convenient sampling technique is used. Respondents from Klang Valley in Malaysia make up a large proportion of the study’s sample. This may consequently limit the generalisability of the findings of this study. Hence, future research should adequately collect data from other cities in Malaysia. Moreover, this paper does not differentiate between perceptions of Muslims and non-Muslims or between male and female; this might have an effect, as Muslims are likely to favour most of the items in the questionnaire used to collect data for this study. Thus, future research may collect sufficient data to shed more light on this issue. Originality/value The researchers have revealed that CSR is an effective promotional tool for the Malaysian halal certified companies in the era of Covid-19 pandemic. Study of this nature is rare in academic literature.

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 methyltriphenylphosphonium 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 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) toward PPL was also reported. It is worth noting that ternary DES systems would be viable lipase activators in hydrolysis reactions.

Lipids and eicosapentaenoic acid (EPA) compounds from Nannochloropsis oceanica biomass were extracted using a combination of ionic liquids (ILs) and microwave-assisted extraction (MAE). When compared to conventional Soxhlet extraction, the proposed novel approach in this paper successfully improved both the yield of total extracted lipids and the EPA content. The effect of selected extraction parameters including the weight of applied IL (tetramethyl ammonium chloride: [TMAm][Cl]) (0.5–2.5 g), reaction temperature (60–100 °C), and process time (5–30 min) on final products was evaluated using response surface methodology (RSM). The optimal values of parameters were determined and three-dimensional response surfaces were plotted from the mathematical models and discussed. The yield of total extracted lipids and the content of EPA were found 19.58 wt% (g g−1 of total biomass) and 37.919 mg g−1 of total FAME respectively, when the extraction process was accomplished in 24.69 min at 88.18 °C and with 1.65 g of ILs. Analysis of variance (ANOVA) was applied in the analysis of experimental data and the R2 of 0.9506 and 0.9517 for total lipid and EPA models, respectively, show that the experimental findings were well aligned with the predicted values. Furthermore, at similar condition, the extraction process was replicated using two other types of ILs namely [EMIM][Cl] and [EMPyrro][Br] to extract the total lipid and EPA. The results showed that [TMAm][Cl] performed better in extracting compounds from microalgae. Based on the findings, this study shows that the combination of ILs mediated in water-based MAE is an environmentally friendly, reliable, and efficacious approach to enhance the extraction of lipids and EPA from N. oceanica with considerable potential to be up-scaled for commercial applications.

Purpose – Halal cosmetics area is progressively increasing these days. This bibliometric analysis is intended to systematically evaluate the research to brief researchers about the trend of halal cosmetics field. This paper also discloses the limitations of the studies in the area. Design/methodology/approach – This paper adopted bibliometric and network analysis to evaluate the research area. A total of 82 documents obtained from the Scopus database are extracted and analysed. Findings – The paper reports the type of documents available, the years published, authorship and geographical distribution of the published documents in the halal cosmetics area. From the keyword analysis, it is found that the most used words are halal cosmetics, halal, cosmetics, purchase intention, Malaysia, and Islamic marketing. Research limitations/implications – This bibliometric study is conducted using Scopus database; however, Scopus might possibly omit some publications, thus, authors might not report the missing studies. Halal cosmetics are still in the early years of publications, and only 82 published documents were analysed in the study. Originality/value – There is no study reported on the network analysis and bibliometric study techniques in the area of halal cosmetics.

Background: Ionic liquids (ILs) are claimed as green solvents and have demonstrated ability in the dissolution of several biomaterials and polymers, thus promoting their applications in wide scope. The aim of this study was to evaluate the yeast cells in the ionic liquid (IL), choline acetate [Cho]OAc as an eco-friendlier IL for their growth and ability of fermentation of the empty fruit bunch (EFB) biomass for ethanol production via monitoring the cell growth curve and kinetics. Methods: The Saccharomyces cerevisiae was cultured for five days on yeast extract-peptone-dextrose (YPD) agar and the sub-culturing was carried out every two weeks to evaluate the growth of yeast in [Cho]OAc at different concentrations; 5%, 10%, and 20%, where it was pre-cultivated for 24 h at 30 °C and 150 rpm in a shaking incubator as a control culture. Yeast cell number was determined by counting using a hemocytometer. Also, the kinetic growth of yeast during the fermentation of EFB was evaluated. Result: Cell concentration increased, ethanol production increased along with the optical density with the peak reached at 72 h, then declined. Enzymatic hydrolysis process followed by fermentation of EFB using [Cho][OAc] improved the yield of sugar, saccharification and ethanol around 1.938, 2.879, and 2.165 times in comparison with untreated EFB with IL. Furthermore, values of specific growth rates obtained in IL-medium and non-IL-medium are applicable for ethanol production to take place. The results showed the ability of yeast cells for fermentation even in the presence of IL. Conclusion: The results showed that the presence of the IL did not suppress the growth of the yeast cells and did not impair the fermentation productivity.

Perishability of fresh fish has become one major concern for both fish industry players as well as the consumers. If it is not properly handled and preserved, fish will be deteriorated and will lose its quality attributes. This is the point where the halalan tayyiban (lawful and wholesome) status of fish is depreciated and at the same time it affects the consumer purchase intention. This article discussed the perishability of fish, phenomenon of fish spoilage and its phases and methods which can be used to detect the deterioration. In addition, Islamic perspective on the importance of preserving the food safety, quality and halalan tayyiban status of raw fish or fish product along the processing line until reaching the consumer is also discussed according to the Maqasid al Shariah (The Objectives of Shari’ah) by using Qawaid Fiqhiyyah (Principles of Islamic Jurisprudence). The method used is the library research which includes the observation from Islamic perspectives. This is in line with achieving the highest objectives of Shariah, which is to protect the farmers, the environment, the aquaculture and the consumers. The output of the study may serve MyGAP and MS 1500:2009.

Replacement of volatile organic solvents with ionic liquids (ILs) in industrial applications is a concerned matter and a trending approach. ILs became the choice of solvents due to their merits such as low melting points (

Microalgae are an alternative source of renewable energy and high-value products for pharmaceutical, nutraceutical, etc., due to rich in carbohydrates, proteins, lipids, and high-density lipoproteins. Existing methods for cell disruption and extraction are costly and suffered from low proficiencies. Ionic liquids are proven to be an environmentally friendly substitute to conventional volatile organic solvents. They have been used in extracting different types of biomass, including microalgae. This article reviews the potential of ILs in extracting biomolecules, lipid, and omega-3, from microalgae biomass. The physicochemical properties of ILs, including viscosity, density, and melting point, their advantages and limitation, as well as toxicity and recyclability of ILs in lipid processing, are discussed.

Considerable evidence supports the enhanced utilization of high-quality protein to obtain optimal health subsequences. Microalgae are a valorous source of proteins that can be employed as functional, nutritional, and remedial supplies. An effective microwave-assisted extraction method based on ionic liquids has been utilized in this study to extract proteins from microalgae Nannochloropsis oceanica biomass. The study of microwave-assisted extraction was carried out under varying conditions of temperature (30–80 °C), extraction time (5–35 min), and IL concentration (0–4.67% w/v). Among the six types of examined IL, choline acetate was an effective one for extracting total protein from microalgae biomass. The highest protein yield was obtained at 0.5 g microalgae, 2% w/v [Ch][Ac], and 40 °C for 30 min, representing 26.35% of protein yield and 65.06% of total protein extracted from the Nannochloropsis oceanica biomass. Meanwhile, conventional method of Soxhlet resulted in the protein yield of 0.63%. Only 1.56% of total Nannochloropsis oceanica protein was extracted by extraction method of Soxhlet which uses the hazardous solvent. The outcomes illustrated the superiority of [Ch][Ac]-based microwave-assisted extraction to conventional methods. This innovative procedure is recommended to have significant usage for the separation of proteins. The outcomes from this study would be beneficial in recognizing and harnessing significant microalgae biochemical from IL-based microwave-assisted extraction process to develop new and improved bioproduct technologies.

Gelatine as the product of collagen extraction from animals is widely used in the food industry. In a glance, the physical properties of gelatine from several sources such as fish, bovine and porcine are similar. Therefore, distinguishing between the sources of gelatine is a tedious task. The differentiation of the gelatine from its sources requires an approach of a chemical reaction. This paper focused on the optimisation of Maillard reaction from different sources of gelatine by Response surface methodology (RSM). The experiment was designed with several imperative parameters; temperature, time and presence of metal ion Cu2+. The response was recorded from the absorbance of reacted gelatine mixture at specific wavenumber (420 nm) through UV-Vis instrumentation. The optimal reaction condition of all type of gelatines in water bath was 95°C for 9 hrs. From solution given, only 5mM concentration of metal ion Cu2+ has an influence on the bovine gelatine compared to fish and porcine gelatine. Maillard reaction with a combination of UV-Vis spectroscopy is one of the convenient protocols for rapid authentication purpose. RSM help to optimize the reaction condition of gelatine from different sources.

Ionic liquids (ILs) are regarded as green solvents and have demonstrated ability in the solvation of lignocellulosic material, thus promoting its enzymatic hydrolysis by cellulases. In this study, ...

For this research, the utilisation of electrocoagulation (EC) toremove theciprofloxacin (CIP) and levofloxacin (LVX) from aqueous solutions was examined. The effective removal efficiencies are 93.47% for CIP and 88.00% for LVX, under optimum conditions. The adsorption isotherm models with suitable mechanisms were applied to determine the elimination of CIP and LVX utilizingtheEC method. Thefindingsshowed the adsorption of CIP and LVX on iron hydroxide flocs followed the Sips isotherm, with correlation coefficient values (R2) of 0.939 and 0.937. Threekinetic models were reviewed to determine the accurate CIP and LVX elimination methods using the EC method. The results showed that itfittedfor the second-order model, which indicated that the chemical adsorption mechanism controlled the removal of CIP and LVX. The R2 with CIP is 0.944, and LVX is 0.941. For binary system removal, efficiencies were 93.00, 90.10, and 96.30% for CIP, and 91.80, 96.10, and 92.97% for LVX, at the CIP ratio: LVX of 1:1, 1:4, and 4:1. The electrode consumption (ELC) and electrical energy consumption (EEC) were found at 0.208 g and 3.21 kWh−3 for a single operation. The operating cost was estimated at 0.613 US$ m−3.

Triggered by the strong antimicrobial activities of menthol and various fatty acids, eutectic mixtures based on the components are developed, producing new solvents that have possibilities to become a new antibiotic. This study aims to provide an insight into the antimicrobial activities of the new deep eutectic solvents (DESs) developed. Menthol-based DES combined with fatty acids, namely propionic acid, butanoic acid, hexanoic acid, octanoic acid, decanoic acid, and levulinic acid, were successfully obtained and their thermal profile was analyzed. The antimicrobial potential of DES systems was evaluated against both Gram positive and Gram negative bacteria. Owing to the activities of the start-up components, the results are considered promising, and this illustrates the potential of the newly obtained DESs as a new antimicrobial agent in various fields such as food, cosmetics as well as pharmaceutical.

This chapter discusses the treatment of palm oil empty fruit bunch using ionic liquids (ILs) pretreatment. By mixing IL and cellulase enzyme (IL-E) in a single pot, the empty fruit bunch (EFB) was pretreated with simultaneous fermentation. Choline acetate [Ch][Ac], which has excellent biological compatibility and renewability, has been used for pretreatment. Chemical analysis, electron scanning microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the EFB and its hydrolysate. After 24 and 48 h of enzymatic hydrolysis, sugar yield improved from 0.058 g/g EFB in the crude (untreated) sample to 0.283 and 0.62 06 g/g in the IL-E phase. EFB hydrolysate demonstrates suitability for the production of ethanol (EtOH) with a yield of 0.275 g EtOH/g EFB in the presence of [Ch][Ac] without additional nutrients, compared to the low yield without IL pretreatment.

Ionic liquids (ILs) are a large group of so-called green solvents with extensive uses in medicine, drug delivery, stabilization of proteins and enzymes, and industrial applications. Active Pharmaceutical Ingredients ionic liquids (API-ILs) are the third generation of ILs. Because of their role precision, biodegradability, and biocompatibility, this class of ILs is gaining interest. This chapter, therefore, aims to recognize the antimicrobial action of non-toxic and biocompatible antibiotics targeting API-ILs that could respond to resistant strains. The World Health Organization (WHO) has published a priority list of pathogens for antibiotic research and development. Among the pathogens are Enterobacteriaceae (Escherichia coli, Klebsiella pneumonia, Serratia spp., Enterobacter spp., Proteus spp., Providencia spp, and Morganella spp), carbapenem-resistant, 3rd generation cephalosporin-resistant, Pseudomonas aeruginosa (carbapenem-resistant), and Acinetobacter baumannii (carbapenem-resistant). The application of API-ILs could assist in overcoming the challenges correlated to the pharmaceutical industry including drug solubility and polymorphism. At present, biocidal characteristic of large cations, such as imidazolium and benzalkonium species are mostly utilized to hinder growth of yeast or bacteria. In this context, this chapter introduces a background on the applications of ILs as antimicrobial agents for microbial resistance. Their corresponding mechanism of ILs and their effect as an antimicrobial agent was investigated, as well. Since the selection of the organic cations and anions in the ILs formulation can tube the biological properties of the ILs, we aim to unveil some of the recent studies that focused on the antimicrobial activities of ILs toward some resistant strains.

This study performs a screening of potential Ionic Liquids (ILs) for the extraction of Docosahexaenoic Acid (DHA) compounds by the calculation of capacity values. For this purpose, a Conductor-Like Screening Model for Real Solvents (COSMO-RS) was employed to study the molecular structures of the ILs, and therefore, predict their extraction potential. The capacity values of 22 anions combined with 16 cations based ILs, were investigated to evaluate the effectiveness of ILs in the extraction of DHA. It was found that among the investigated ILs, a combination of tetramethyl ammonium with SO4 or Cl was the best fit for DHA extraction, followed by pyrrolidinium, imidazolium, pyridinium and piperidinium. Furthermore, it was observed that the extraction capacity and the selectivity of ILs decreased with an increase in alkyl chain length, therefore, ethyl chain-ILs, with the shortest chain lengths, were found to be most suitable for DHA extraction. The predicted results were validated through the experimentally calculated extraction yield of a DHA compound from Nannochloropsis sp. Microalgae. Five selected ILs, namely [EMIM][Cl], [BMIM][Cl], [TMAm][Cl], [EMPyr][Br] and [EMPyrro][Br], were selected from COSMO-RS for empirical extraction purposes, and the validation results pinpointed the good prediction capabilities of COSMO-RS. The findings in this study can simplify the process of selecting suitable ILs for DHA extraction and reduce the number of required empirical evaluations.

Aims: The exploration of natural products with innovative uses is dynamic and expanding rapidly. Medicinal plants have fascinated many researchers that subsequently lead to research publications highlighting plant extracts with wide range of secondary metabolites such as flavonoids, alkaloids, glycosides, quinones, terpenoids, tannins and saponins that exhibit antimicrobial activities and disease control. The concentration of these bioactive compounds in each plant species varies based on the pathosystem and environmental conditions. This study aims to uncover the various types of phytochemicals with antifungal properties. Methodology and results: Seven categories of plant-based antifungal compounds were reviewed, which are terpenoids, saponins, phenolic compounds, coumarins, alkaloids, essential oils and peptides, with examples and structures of some available compounds. The mechanism of action of each category of phytochemical was discussed. Also, the impact of some compounds was explained and elaborated. Conclusion, significance and impact of study: It is of a great importance to explore natural plant fighters against fungal infection. Those active plant components do not only have antifungal properties, but they also help in the healing process and some even exhibit anticancer activities. The development and knowledge of antifungal activities from plant extracts have the potential for applications in antifungal therapy. Since the exact description of how antifungal compounds function in the human body is still unclear more studies are required to unveil phytochemicals’ properties and to elucidate their effects on living cells.

One of the essential fatty acids with therapeutic impacts on human health is known to be omega-3 polyunsaturated fatty acids (PUFA). More lately, ionic liquids (ILs) have received significant attention among scientists in overcoming the disadvantages of traditional solvents in biomass lipid extraction. However, the large pool of cations and anions possibly accessible will lead to a growing number of innovatively synthesized ILs. Nevertheless, the exhaustive measurement of all these systems is economically impractical. The conductive screening model for real solvents (COSMO-RS) is considered a precious approach with the availability of a few models to predict the characteristics of ILs. This work introduces the estimate of capacity values at infinite dilution for a range of ILs using COSMO-RS software as part of solid-liquid extraction. This favorable outcome presented that the capacity values of the IL molecules are extremely dependent on both anions and cations. Among the 352 combinations of cation/anion tested, short alkyl chain cations coupled with inorganic anions were found to be most efficient and therefore superior in the extraction method. Sulphate-, chloride-, and bromide-based ILs were found to have higher extraction capacities in contrast with the remainders, while propanoate revealed an extraordinary capacity when combined with ethyl-based cations. Eventually, the predicted results from COSMO-RS were validated through the experimentally calculated extraction yield of alpha-linolenic acid (ALA) compound from Nannochloropsis sp. microalgae. Three selected ILs namely [EMIM][Cl], [TMAm][Cl], and [EMPyrro][Br] were selected from COSMO-RS for empirical extraction purpose and the validation results pinpointed the good prediction capability of COSMO-RS.

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. This work is licensed under a Creative Commons Attribution 4.0 International License.

Ionic liquids (ILs) - as environmentally friendly “green” solvents- have been progressively used in various reactions as reagents, solvents and co-solvents including lipase-catalysed reactions. In fact, lipase-catalysed reactions in ILs are considered as a “green”-reaction and are more advantageous than chemical methods owing to the easy recovery of the product and the mild conditions of the reactions. The use of lipase in ILs provides many technological advantages compared to conventionally used solvents, such as selectivity enhancement, enzyme stability improvement, higher conversion rate, and better recyclability and recovery system. Nevertheless, in some cases, especially in hydrophilic ILs, lipase exhibits activity reduction when compared with organic solvents. Currently, various attempts have been made to enhance the performance of lipases in ILs. The main objective of this review is to demonstrate recent developments in the technology of using ILs as reaction media for lipase. It is expected that this review might be an inspiration in ILs assisted lipase-catalysed reactions to produce value-added materials including biofuels as well as biodiesel.

Nanotechnology, particularly nanoemulsions (NEs), have gained increasing interest from researchers throughout the years. The small-sized droplet with a high surface area makes NEs important in many industries. In this review article, the components, properties, formation, and applications are summarized. The advantages and disadvantages are also described in this article. The formation of the nanosized emulsion can be divided into two types: high and low energy methods. In high energy methods, high-pressure homogenization, microfluidization, and ultrasonic emulsification are described thoroughly. Spontaneous emulsification, phase inversion temperature (PIT), phase inversion composition (PIC), and the less known D-phase emulsification (DPE) methods are emphasized in low energy methods. The applications of NEs are described in three main areas which are food, cosmetics, and drug delivery.

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&ndash, malonic acid (ChCl-Mal) and choline chloride&ndash, glucose&ndash, water (ChCl:Glc:W). Both co-solvents yielded 94% pectin and 52% DE after optimization at 80 &deg, C, with 60 min of sonication, pH &lt, 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 (&gt, 55%).

Enzymes are important contributors to the current industrial development as they activate the reactions through enormous pathways. In recent years, ionic liquids (ILs) have become qualified media for clean extraction, photochemistry, green processing, electrosynthesis, and pharmaceutical applications. Although many enzymes have been studied in ILs media, lipases showed exceptional stability, selectivity and production yields. This chapter briefly outlines some merit as well as the downsides of current ILs applications in lipases reactions including the production of biodiesel, esterification and other established applications.

Nowadays, palm oil mill effluent (POME) is the main water stream pollutant in Malaysia. This paper reviews to development in the methods of bioethanol production from POME by acid-base-enzyme pretreatment and hydrolysis processes. The methods currently used to treat POME are inefficient either of cost or in terms of environmental preservation. Several techniques of pretreatment of POME are discussed, where the structure of POME is breakdown and make it more accessible to the cellulase enzymes. Generally, hydrolysis process is used as a mild acid-base-enzyme for monomeric sugar production from POME. The acid-base-enzyme consists of H2SO4, NaOH and cellulase enzymes to run the hydrolysis process. In this paper, different strategies are also described for hydrolysis processes, including concentrate acid hydrolysis, dilute acid hydrolysis and enzymatic hydrolysis. In addition, the production of bioethanol by fermentation of sugars obtained from the hydrolysis process are discussed and it points out some key properties that should be targeted for cost effective and innovative pretreatment processes.

Omega-3 poly unsaturated fatty acids (PUFA) particularly eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), have many health benefits including reducing the risk of cancer and cardiovascular disease. Recently, the use of ionic liquids (ILs) in lipid extraction from microalgae provides the potential to overcome common drawbacks, offers several other benefits. To date, very limited researches are available to focus on extracting microalgae lipid and PUFA in particular by using ILs. The objective of current work is to screen the potential ILs that can be applied in EPA extraction. In this study, fast ILs screening was performed with the help of a conductor like screening model for real solvents (COSMO-RS) and the ILs with higher capacity values for use in extraction of EPA were compared. According to the results, the highest capacity for EPA extraction among 352 screened cation/anion combinations belongs to [TMAm][SO4]. It is expected to achieve a higher yield of EPA once applying this combination as the solvent in the process of extraction. ILs with small anions were observed to have higher capacities, as well possessing higher charge density compared to larger ones, and therefore, they are more preferable for extraction purposes. Moreover, shorter alkyl chain cations are preferred when using imidazolium-based IL, which agrees with experimental data.

Over the past two decades, ionic liquids (ILs) have been widely used for enzymatic conversions of substrates — especially substrates that are insoluble in common organic solvents and water — resulting in high conversion rates, high selectivity, and improved enzyme stability, wherein the ILs are recoverable and recyclable. Compared with performance in first-generation ILs, researchers recently considerably improved the technological utility of enzymes in second- and third-generation ILs composed of enzyme-benign cations and anions. Use of upgraded ILs with enzymes offers further improved activity and stability compared with research studies in the past decade, rendering IL-assisted biocatalytic processes more environmentally and economically attractive. This short review briefly presents recent developments of enzymatic reactions in ILs. The review covers approaches for and modifications of enzymes and ILs within the past 2 years for improved enzymes performance in ILs.

Dendrimers are highly branched synthetic macromolecules that offer promising prospects for utilizing them in broad applications. This study investigates the role of polyamidoamine (PAMAM) dendrimer for lipase-catalyzed reaction in aqueous solution. The hydrolysis of para-nitrophenyl palmitate (pNPP) by four different lipases was tested with PAMAM dendrimer with different generations (i.e., D0.0, D2.5, D3.0, and D4.0). The results showed that the activity of Rhizopus niveus lipase (RNL) was enhanced up to 375 % with PAMAM dendrimer (D0.0). The optimum incubation conditions such as the temperature and coupling time of the lipase with D0.0 were 40 °C and 2 h, respectively. The behavior of lipases at different pH showed that RNL was mostly active at pH 7.0. Most lipases with D0.0 were enhanced at least two-fold compared to the control samples. Kinetic study showed that the RNL affinity was enhanced in the presence of PAMAM. FTIR spectra strongly suggest that hydrogen bonding and electrostatic interactions were the main types of bonding in the RNL and PAMAM system. Additionally, the molecular docking simulation of the system was exerted to evaluate and support the related compound, (i.e., D0.0) as a ligand interacted effectively with RNL based on the experimental activity. The cytotoxicity study revealed mild toxicity of the system which could serve as a potential target in nanomedicine for many applications such as cancer therapeutics.

Ionic liquids (ILs) have been found to be highly promising for lignocellulosic biomass pretreatment, due to their excellent abilities to dissolve biopolymers. However, they have found to inactivate enzymes. In previous studies, Cholinium-based ILs showed great compatibility with cellulases and thus were introduced for a combined-system. This study aims to find the optimum condition in order to achieve the maximum pretreatment-hydrolysis of empty fruit bunches (EFB). Definitive screening design (DSD) was employed with seven factors that are thought to impact the process including pretreatment temperature, pretreatment time, hydrolysis time, enzyme loading, particle size, biomass loading, and IL/buffer ratio. DSD offered several solutions for optimization in which they were experimentally tested. The maximum sugar concentration (77 g/L) was obtained at 90 °C, 70–116 min of treatment, 36–42 h of hydrolysis, 40–62 Unit/g cellulase loading, 34–35 %, w/v) biomass loading, 220–450 μ particle size, and 10 % (v/v) IL to buffer ratio, respectively. The subsequent optimization by response surface methodology (RSM) revealed the temperature for treatment can drop to 75 °C while fixing the pretreatment time at 100 min. Around 75 unit/g of cellulase and >22.0 % (w/v) of the biomass could be loaded to achieve a minimum of 70.0 ± 7.83 g/L of sugar, equivalent to 0.38 ± 0.08 g glucose/g and 0.48 ± 0.05 g total reducing sugar/g dry EFB. The locally produced cellulase (PKC-Cel) from Trichoderma reesei exhibited promising results in the single-step process and can be used as an efficient approach to be optimized for fermentation to bioethanol production.

Ionic liquids (ILs) have been increasingly exploited as solvents and/or reagents in many applications due to their “green” properties as well as their tunable physicochemical and biological properties. One of them is the pretreatment of lignocellulosic biomass prior to enzymatic hydrolysis for bioenergy and biomaterials production. Generally, the process composed of an IL pretreatment/recovered followed by enzymatic hydrolysis of lignocellulosic biomass. Another approach was developed in which simultaneous pretreatment and saccharification of biomass in ILs were performed. However, the use of ILs in this integrated process, in which enzymatic hydrolysis is done in the presence of IL applied for biomass pretreatment, can easily inactivate the enzymes. Cellulases, one of the most important hydrolytic enzymes used to catalyze the polysaccharide, showed good levels of stability in many ILs. In addition, various approaches were made including synthesis of enzyme-compatible ILs, screening ILs-tolerant enzymes and media engineering to improve cellulases performance. In this review paper, recent advances of the hydrolysis of lignocellulosic biomass in a single-step process in ILs will be highlighted. Various cellulase stabilization approaches and the design of enzyme compatible biomass-dissolving ILs are also discussed. We strongly believe that IL-compatible cellulase systems would eliminate the need to recover the regenerated biomass and lead to a simple, in situ saccharification of cellulosic materials, which would be beneficial in developing integrated bioprocesses.

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.

As a biocompatible and designer solvents, ionic liquids (ILs) are extensively used for enzymatic conversion of substrates, particularly those that are insoluble or sparingly soluble in water and common organic solvents. More than a decade ago, the first-generation ILs involved in enzymatic reactions generally comprised an imidazolium cation and non-coordinating anions, such as tetrafluoroborate and hexafluorophosphate. Recently, focus has shifted to more environmentally acceptable second- and third-generation ILs comprising enzyme compatible cations (e.g., cholinium salts) and anions, such as amines and amino acids. A wide range of such ILs have been derived from readily available renewable resources and used in biocatalytic reactions. Compared with first-generation ILs, the use of enzymes in second- and third-generation ILs provides better activity and stability, and they are also attractive from both an environmental and an economic viewpoint. In this review, we report the recent advances of enzymatic reactions in second- and third-generation ILs. The intention of this review is not to cover first-generation ILs, but rather to update and overview the potential approaches developed within the last ten years for enzymatic reactions in second- and third-generation ILs.

The pretreatment of empty fruit bunch (EFB) was conducted using an integrated system of IL and cellulases (IL-E), with simultaneous fermentation in one vessel. The cellulase mixture (PKC-Cel) was derived from Trichoderma reesei by solid-state fermentation. Choline acetate [Cho]OAc was utilized for the pretreatment due to its biocompatibility and biodegradability. The treated EFB and its hydrolysate were characterized by the Fourier transform infrared spectroscopy, scanning electron microscopy, and chemical analysis. The results showed that there were significant structural changes in EFB after the treatment in IL-E system. The sugar yield after enzymatic hydrolysis by the PKC-Cel was increased from 0.058 g/g of EFB in the crude sample (untreated) to 0.283 and 0.62 ± 06 g/g in IL-E system after 24 and 48 h of treatment, respectively. The EFB hydrolysate showed the eligibility for ethanol production without any supplements where ethanol yield was 0.275 g ethanol/g EFB in the presence of the IL, while lower yield obtained without IL-pretreatment. Moreover, it was demonstrated that furfural and phenolic compounds were not at the level of suppressing the fermentation process. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13205-018-1253-8) contains supplementary material, which is available to authorized users.

Ionic liquids (ILs) are developing as potential solvents in lignocellulose solvation, which enables cellulase accessibility into the substrate. Nevertheless, ILs could result in enzyme deactivation because of the high polarity. Therefore, developing a system of ILs-compatible cellulase (IL-E) to promote lignocellulose conversion into sugars is a challenge in ILs applications. This study used an IL-E to attain high conversion yield of sugars from oil palm empty fruit bunch (EFB). Cellulase (Tr-Cel) from Trichoderma reesei was stable in the ILs, 1-ethyl-3-methyl imidazolium diethyl phosphate [EMIM]DEP and choline acetate [Cho]OAc. The inhibition and deactivation of cellulase were evaluated using the model substrate, carboxymethyl cellulose (CMC) and EFB as a lignocellulosic material to assess the hydrolytic activity. The enzyme kinetics revealed that [Cho]OAc acted as a noncompetitive inhibitor. Additionally, [EMIM]DEP may not be considered as an inhibitor as it increases the Vmax and does not significantly affect the KM. In both cases, the study proved that IL did not result in a severe loss of cellulase activity, which is a promising outcome for one-pot hydrolysis of lignocellulosic materials.

Lignocellulosic biomasses, exhibit resistance to enzymatic hydrolysis due to the presence of lignin and hemicellulose. Ionic liquids proved their applicability in lignin degradation, however, ionic liquid removal has to be performed to proceed to hydrolysis. Therefore, this study reports an in situ hydrolysis of empty fruit bunches (EFB) that combined an ionic liquid (IL) pretreatment and enzymatic hydrolysis. For enzyme production, palm kernel cake (PKC) was used as the primary media for microbial cellulase (PKC-Cel) from Trichoderma reesei (RUTC30). The obtained enzyme exhibited a promising stability in several ionic liquids. Among few, in choline acetate [Cho]OAc, PKC-Cel retained 63.16 % of the initial activity after 6 h and lost only 10 % of its activity in 10 % IL/buffer mixture. Upon the confirmation of the PKC-Cel stability, EFB was subjected to IL-pretreatment followed by hydrolysis in a single step without further removal of the IL. The findings revealed that choline acetate [Cho]OAc and choline butyrate [Cho]Bu were among the best ILs used in the study since 0.332 ± 0.05 g glucose/g and 0.565 ± 0.08 g total reducing sugar/g EFB were obtained after 24 h of enzymatic hydrolysis. Compared to the untreated EFB, the amount of reducing sugar obtained after enzymatic hydrolysis increased by three-fold in the case of [Cho]OAc and [Cho]Bu, two-fold with [EMIM]OAc and phosphate-based ILs whereas the lowest concentration was obtained in [TBPH]OAc. Pretreatment of EFB with [Cho]OAc and [Cho]Bu showed significant differences in the morphology of EFB samples when observed with SEM. Analysis of the lignin, hemicellulose and hemicellulose showed that the total lignin content from the raw EFB was reduced from 37.8 ± 0.6 to 25.81 ± 0.35 % (w/w) upon employment of [Cho]OAc in the compatible system. The PKC-Cel from T. reesei (RUTC30) exhibited promising characteristics that need to be investigated further towards a single-step process for bioethanol production.