The most common reaction for biodiesel production is catalysed by acid, base or enzyme catalysts. When transesterification is completed, the reaction mixture contains various impurities such as soap, ...catalyst, free glycerol and alcohol that have to be removed to meet the biodiesel international standard specifications. In this work, biodiesel was produced by lipase catalysed transesterification from edible sunflower oil and methanol as substrates. The purification of crude biodiesel was carried out by decantation followed by ultrafiltration membrane technology. Four different membranes, polyethersulfone, polyacrylonitrile, polypropylene and regenerated cellulose were selected and used for biodiesel ultrafiltration. Based on permeate flux and glycerol content in the permeate membrane performance was evaluated. The obtained results showed that two out of four tested membranes have potential for biodiesel purification. Polyacrylonitrile membrane showed the best performance resulting in lowest glycerol content in permeate (0.006% (w/w)). Additionally, polyacrylonitrile membrane was successfully reused six times without significant loss of performance. Furthermore, the membrane blocking mechanisms were analysed for all membranes by Hermina’s model. Consequently, complete cake layer formation was identified as the most dominant blocking effect.
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•Biodiesel produced by lipase catalysed transesterification was purified by ultrafiltration.•Four different ultrafiltration membranes were tested and compared.•Polyacrylonitrile membrane showed the best performance.•The most dominant blocking effect according Hermina’s model was complete cake layer formation.
Microreactors have become an efficient tool for many enzymatic reactions because the laminar fluid flow within the microchannel enables precise process control, rapid mixing, and short residence ...time. This paper provides a systematic overview of the application of reaction kinetics and the mathematical modeling of enzymatic processes in microreactors. Rapid heat and mass transfer and a high surface-to-volume ratio are usually the reasons why reactions in microchannels proceed faster and with higher yields and productivity compared to conventional macroreactors. Since there are no radial diffusion limitations, microreactors are also an effective tool for determining the kinetic parameters of enzyme-catalyzed reactions. By eliminating the mass transfer effect on the reaction rate, the kinetics estimated in the microreactor are closer to the intrinsic kinetics of the reaction. In this review, the advantages and disadvantages of using microreactors are highlighted and the potential of their application is discussed. Advances in microreactors result in process intensification and more efficient biocatalytic processes in line with the advantages offered by the application of microreactors, such as (i) higher yields, (ii) a cleaner and improved product profile, (iii) scale-independent synthesis, (iv) increased safety, and (v) the constant quality of the output product through (vi) accelerated process development. Furthermore, microreactors are an excellent tool for kinetic studies under specified mass transfer conditions, enhancing the capabilities of other methods.
Theobroma cacao L. seeds, commonly known as cocoa beans, are the foundation for cocoa and chocolate production. Following harvest, these beans undergo a multi-step processing chain including ...fermentation, drying, roasting, and grinding. This process yields cocoa solids, cocoa butter, and cocoa powder—all fundamental ingredients in the food and beverage industry. Beyond its sensory appeal (flavor, aroma, and texture), cocoa has garnered significant interest for its potential health benefits attributed to a rich profile of bioactive compounds. Cocoa is a well-documented source of polyphenolics, specifically flavanols, alongside methylxanthines, phytosterols, and dietary fibers. These constituents have been associated with a diverse range of bioactivities, including antioxidant, anti-carcinogenic, anti-diabetic, anti-inflammatory, anti-obesity, and anti-allergenic properties, potentially contributing to overall health maintenance. Efficient extraction techniques are crucial for maximizing the recovery of these valuable bioactive components from cocoa plant material. Modern methods are continuously being explored to optimize this process. This review focuses on the established health benefits associated with the bioactive compounds present in cocoa. Additionally, it will explore and discuss contemporary approaches for the extraction of these bioactive compounds from this plant source.
In the last twenty years, the application of microreactors in chemical and biochemical industrial processes has increased significantly. The use of microreactor systems ensures efficient process ...intensification due to the excellent heat and mass transfer within the microchannels. Monitoring the concentrations in the microchannels is critical for a better understanding of the physical and chemical processes occurring in micromixers and microreactors. Therefore, there is a growing interest in performing in-line and on-line analyses of chemical and/or biochemical processes. This creates tremendous opportunities for the incorporation of spectroscopic detection techniques into production and processing lines in various industries. In this work, an overview of current applications of ultraviolet–visible, infrared, Raman spectroscopy, NMR, MALDI-TOF-MS, and ESI-MS for monitoring (bio)catalytic processes in continuously operated microreactor systems is presented. The manuscript includes a description of the advantages and disadvantages of the analytical methods listed, with particular emphasis on the chemometric methods used for spectroscopic data analysis.
The implementation of a suitable and ecologically friendly solid waste management plan is accepted as an essential need. Given that organic matter constitutes the majority of solid waste, composting ...has gained popularity as an alternative way of organic refuse recycling. Compost quality is defined by its stability and maturity, both of which must be assessed by measuring a large number of physical–chemical parameters, microbiological variables, and enzymatic activities. These procedures are complex and time-consuming, making it difficult to assess compost quality correctly. Spectroscopy methods could be used as an efficient alternative. In this work, general information about composting processes and near-infrared spectroscopy (NIRS) is given. A discussion and comparison of the different approaches of coupling NIRS and chemometric tools for the monitoring and/or control of composting processes are presented in this work.
Plant-based meat analogues are food products made from vegetarian or vegan ingredients that are intended to mimic taste, texture and appearance of meat. They are becoming increasingly popular as ...people look for more sustainable and healthy protein sources. Furthermore, plant-based foods are marketed as foods with a low carbon footprint and represent a contribution of the consumers and the food industry to a cleaner and a climate-change-free Earth. Production processes of plant-based meat analogues often include technologies such as 3D printing, extrusion or shear cell where the ingredients have to be carefully picked because of their influence on structural and textural properties of the final product, and, in consequence, consumer perception and acceptance of the plant-based product. This review paper gives an extensive overview of meat analogue components, which affect the texture and the structure of the final product, discusses the complex interaction of those ingredients and reflects on numerous studies that have been performed in that area, but also emphasizes the need for future research and optimization of the mixture used in plant-based meat analogue production, as well as for optimization of the production process.
The aim of this work was to analyze and compare the adsorption and desorption processes of carbohydrates (glucose as a model molecule), polyphenols (gallic acid as a model molecule), and proteins ...(bovine serum albumin, BSA as a model molecule) on alginate microcapsules. The adsorption and desorption processes were described by mathematical models (pseudo-first-order, pseudo-second-order, and Weber-Morris intraparticle diffusion model for adsorption, and first-order, Korsmeyer-Peppas, and the Higuchi model for desorption) in order to determine the dominant mechanisms responsible for both processes. By comparing the values of adsorption rate (
) and initial adsorption rate (
) based on the pseudo-first-order model, the lowest values were recorded for BSA (
= 0.124 ± 0.030 min
), followed by glucose (
= 0.203 ± 0.041 min
), while the model-obtained values for gallic acid were not considered significant at
< 0.05. For glucose and gallic acid, the limiting step of the adsorption process is the chemical sorption of substances, and the rate of adsorption does not depend on the adsorbate concentration, but depends on the capacity of the hydrogel adsorbent. Based on the desorption rates determined by the Korsmeyer-Peppas model (
), the highest values were recorded for gallic acid (
= 3.66236 ± 0.20776 g beads/mg gallic acid per min), followed by glucose (
= 2.55760 ± 0.16960 g beads/mg glucose per min) and BSA (
= 0.78881 ± 0.11872 g beads/mg BSA per min). The desorption process from alginate hydrogel microcapsules is characterized by the pseudo Fickian diffusion mechanism.
Spirulina platensis microalga has become recognized as a promising source of highly nutritious food components to feed the growing global population. Because of its high protein content, abundance of ...essential amino acids, and excellent digestion, it is employed in human nutrition and there is growing interest in analyzing bioactive compound present in Spirulina platensis microalga. In this work, a portable near-infrared (NIR) spectrometer was used for the monitoring of physicochemical properties (extraction yield (EY), total polyphenols concentration (TPC), total proteins concentration (TP), antioxidant activity measured by (i) the DPPH method (DPPH) and (ii) FRAP method (FRAP)) of Spirulina platensis aqueous extracts. The ultrasound-assisted aqueous extraction (ultrasonic bath with an ultrasound frequency of 35 kHz) of bioactive molecules from Spirulina platensis was performed throughout 30 independent experiments. NIR spectra were recorded in the wavelength range of 900–1700 nm. Raw NIR spectra were subjected to the physicochemical properties applying Principal Component Analysis (PCA), partial least square (PLS), and artificial neural network (ANN) modeling. Results show that ANN models developed for the prediction of TPC and DPPH can be utilized for extraction process control (RER > 10), while the other three models can be employed for screening (RER > 4). Generally, the obtained results indicate significant potential for using portable NIR spectroscopy for the analysis of Spirulina platensis aqueous extracts.
Grape pomace is a fibrous food with satisfactory quantities of residual sugars. It meets the desirable characteristics for conservation in the form of silage for later use in animal feed, mainly for ...ruminant herbivores. Fresh grape pomace was subdivided into three treatment groups: grape pomace as a control, grape pomace treated with an inoculum of lactic acid bacteria, and grape pomace treated with zeolite. The treatments were performed in micro-silos over 90 days. There was a significant change (p < 0.05) in the chemical characteristics, content of biologically active compounds, and fermentative characteristics during the silage of all treatments. After 30, 60 and 90 days of ensiling, silages treated with inoculum and zeolite had better fermentation quality indicated by significantly (p < 0.05) lower pH and ammonia-nitrogen contents compared with those of the control. Also, the additives have decreased the total polyphenols and tannins for 97% in average which confirmed that lactic acid bacteria and zeolite positively effect on the degradation of polyphenols and tannins in grape pomace silage. The Flieg score was calculated and the values were above 80% what refers to excellent silage. In conclusion, our results suggest that inoculant and zeolite supplementation improves the quality of grape pomace silage for later use in animal feed.
The reusability of by-products in the food industry is consistent with sustainable and greener production; therefore, the aim of this paper was to evaluate the applicability of multiple linear ...regression (MLR), piecewise linear regression (PLR) and artificial neural network models (ANN) to the prediction of grape-skin compost's physicochemical properties (moisture, dry matter, organic matter, ash content, carbon content, nitrogen content, C/N ratio, total colour change of compost samples, pH, conductivity, total dissolved solids and total colour change of compost extract samples) during in-vessel composting based on the initial composting conditions (air-flow rate, moisture content and day of sampling). Based on the coefficient of determination for prediction, the adjusted coefficient of determination for calibration, the root-mean-square error of prediction (RMSEP), the standard error of prediction (SEP), the ratio of prediction to deviation (RPD) and the ratio of the error range (RER), it can be concluded that all developed MLR and PLR models are acceptable for process screening. Furthermore, the ANN model developed for predicting moisture and dry-matter content can be used for quality control (RER >11). The obtained results show the great potential of multivariate modelling for analysis of the physicochemical properties of compost during composting, confirming the high applicability of modelling in greener production processes.
