Thermolabile Compounds Research Articles

Temperature mapping of milling by dual centrifugation: A systematic investigation

Using low quantities of drug compounds is often favorable in the early stages of drug development, especially for what require a large screening investigation to define the final formulation composition, such as nano- and microsuspensions. For that reason, the dual centrifugation approach has in the recent years been used due to its reproducible and fast-milling capacity with 40 samples in 2 mL vials simultaneously without the addition of cooling breaks due to a built-in cooling system. Nonetheless, heat can be dissipated into the samples during high-intensity milling, resulting in increased sample temperatures that potentially can affect thermolabile compounds and potential influence the obtained suspensions in the screening experiments if the used stabilizer has temperature dependent variations in the performance. Hence, a systematic investigation of the influence of different process parameters on the heat dissipation in samples during milling by the dual centrifugation approach was performed in the present study. It was found that the milling speed had the highest impact on the final sample temperature, but also other parameters, such as the bead loading, bead size, and placement in the centrifuge during milling had significantly influenced the final mean temperature of the milling media. Higher temperatures were obtained with higher bead loadings, i.e., 3000 mg milling beads/mL and milling speeds (1500 rpm), and when smaller milling beads, i.e., 0.1 mm, were used during production. The study further showed that higher temperatures were measured for samples located on the bottom disk during milling, and also when located on the outer placement on the sample disk. Upscale investigations showed immensely increased sample temperatures (almost up to boiling point) when samples were prepared under similar formulation parameters and milling speed as small-volume vials. Furthermore, the study indicated that the addition of drug compounds during suspension preparation decreased the final sample temperature compared to samples that only contained purified water due to energy absorption of the drug compound.

GC-MS/MS Analysis and Wound Repair Potential of Urtica dioica Essential Oil: In silico Modeling and In vivo Study in Rats.

The study aimed to assess the antioxidant and wound healing properties of Urtica dioica essential oil (UDEO) through a comprehensive evaluation involving in silico, in vitro, and in vivo analyses. The phytochemistry of UDEO was also investigated to identify trace compounds crucial. Various injection methods of the multimode inlet (MMI) in chromatography were investigated to attain lower instrumental detection limits. Subsequently, in silico studies were employed to delve deeper into the potential biological activities of the identified compounds. Standard antioxidative tests, encompassing ABTS•+ and TAC, were performed. In vivo tests centered on wound healing were implemented using rat models. The rats were randomly allocated to four groups: saline solution, vaseline vehicle, cytol centella, and 5% UDEO ointment. Wound healing progress was evaluated through a chromatic study. Gas chromatography combined with triple quadrupole mass spectrometry (GC-MS/MS) analysis revealed the presence of 97 thermolabile compounds in UDEO. Subsequent in silico studies unveiled the potential of identified compounds to inhibit COX-2, TNF-α, and IL-6, suggesting a possible enhancement of anti-inflammatory responses and healing processes. In vitro tests elucidated the notable antioxidant capacity of UDEO, a finding reinforced by wound healing data, revealing a substantial closure rate of 89% following the topical application of UDEO. Notably, fibrinogen and C-reactive protein (CRP) levels were significantly reduced, indicating minimized oxidative stress damage compared to control. Additionally, UDEO exhibited an increase in antioxidant enzyme activities compared to control. The study concludes that UDEO possesses significant antioxidant and wound-healing properties, supported by its rich phytochemical composition. The findings suggest its potential application in therapeutic interventions for oxidative stress and inflammatory conditions.

Efficient Reductive N-11C-Methylation Using Arylamines or Alkylamines and InSitu-Generated [11C]Formaldehyde From [11C]Methyl Iodide.

Reductive N-11C-methylation using [11C]formaldehyde and amines has been used to prepare N-11C-methylated compounds. However, the yields of the N-11C-methylated compounds are often insufficient. In this study, we developed an efficient method for base-free reductive N-11C-methylation that is applicable to a wide variety of substrates, including arylamines bearing electron-withdrawing and electron-donating substituents. A 2-picoline borane complex, which is a stable and mild reductant, was used. Dimethyl sulfoxide was used as the primary reaction solvent, and glacial acetic acid or aqueous acetic acid was used as a cosolvent. While reductive N-11C-methylation efficiently proceeded under anhydrous conditions in most cases, the addition of water to the reductive N-11C-methylation generally increased the yield of the N-11C-methylated compounds. Substrates with hydroxy, carboxyl, nitrile, nitro, ester, amide, and phenone moieties and amine salts were applicable to the reaction. This proposed method for reductive N-11C-methylation should be applicable to a wide variety of substrates, including thermo-labile and base-sensitive compounds because the reaction was performed under relatively mild conditions (70°C) without the need for a base.

A comprehensive investigation of the use of freeze concentration appro aches for the concentration of fish protein hydrolysates

Fish protein hydrolysates (FPH) are inherently unstable in their liquid form, necessitating either freezing or dewatering for stabilization. Gentle methods such as freeze concentration can be used to remove water, this can be achieved by freezing water in solution by decreasing the bulk temperature below freezing point and separating pure ice crystals from concentrated solution. This approach serves as an alternative to techniques like evaporation and reverse osmosis for concentrating solutions that have high water content, significant nutritional value, and thermolabile compounds. This is crucial as many bioactive compounds degrade when exposed to elevated temperatures. Another notable advantage of this technology is its potential to reduce energy consumption by up to 40% when integrated into the FPH drying process. Although this technology is currently industrialized primarily for juices, it can achieve concentrations of up to 60°Brix and manage viscosities up to 400 mPa.s. Numerous studies have been dedicated to enhancing design and processes, leading to a 35% reduction in the system's capital cost and a 20% reduction in energy consumption. Moreover, freeze concentration can synergize with other concentration techniques, creating more efficient hybrid processes. This review aims to introduce freeze concentration as a superior option for preserving fish protein hydrolysates, enhancing their stability, and maintaining their nutritional and bioactive qualities.

Nanofiltration-Assisted Concentration Processes of Phenolic Fractions and Carotenoids from Natural Food Matrices

In new food formulations, carotenoids and phenolic compounds are likely to be the most sought after food ingredients according to their bioactivity, nutraceutical, nutritional value, and compatibility properties once incorporated into food formulations. Such solutes are naturally present in many plant-based sources, and some portions are directly consumed when enriching food products and formulations; however, some portions, which are contained in the parts of the plant sources not considered edible, including the leaves, peel, and seeds, among other by-products, are commonly wasted. Related to this, scientists have found a new window for obtaining these bioactive molecules, but their recovery remains a challenge. To some extent, the final purification and polishing requires highly selective performance to guarantee the desired properties and concentration. In this regard, membrane technologies, such as nanofiltration (NF), represent an alternative, owing to their highly selective properties when separating low-molecular-weight compounds. NF becomes immediately suitable when the pretreated extracts are subjected to further efficient concentration, fractionation, and polishing of phenolic fractions and carotenoids. The separation efficiency (usually higher than 97%) of NF technology is high according to the low pore size of NF membranes, but the low temperature in process separation also contributes to the separation of thermolabile compounds. Therefore, this paper reviews the ongoing cases of studies reporting the successful separation and polishing of phenolic fractions and carotenoids from distinct sources. In particular, we have focused our attention on the main interactions during the separation process and the drawbacks and advantages of using membranes for such a case study.

Forensic profiling of smokeless powders (SLPs) by gas chromatography–mass spectrometry (GC-MS): a systematic investigation into injector conditions and their effect on the characterisation of samples

Smokeless powders (SLPs) are composed of a combination of thermolabile and non-thermolabile compounds. When analysed by GC-MS, injection conditions may therefore play a fundamental role on the characterisation of forensic samples. However, no systematic investigations have ever been carried out. This casts doubt on the optimal conditions that should be adopted in advanced profiling applications (e.g. class attribution and source association), especially when a traditional split/splitless (S/SL) injector is used. Herein, a study is reported that specifically focused on the evaluation of the liner type (Ltype) and inlet temperature (Tinj). Results showed that both could affect the exhaustiveness and repeatability of the observed chemical profiles, with Ltype being particularly sensitive despite typically not being clarified in published works. Perhaps as expected, degradation effects were observed for the most thermolabile compounds (e.g. nitroglycerin) at conditions maximising the heat transfer rates (Ltype = packed and Tinj ≥ 200 °C). However, these did not seem to be as influential as, perhaps, suggested in previous studies. Indeed, the harshest injection conditions in terms of heat transfer rate (Ltype = packed and Tinj = 260 °C) were found to lead to better performances (including better overall %RSDs and LODs) compared to the mildest ones. This suggested that implementing conditions minimising heat-induced breakdowns during injection was not necessarily a good strategy for comparison purposes. The reported findings represent a concrete step forward in the field, providing a robust body of data for the development of the next generation of SLP profiling methods.Graphical abstract

Production of octyl butyrate using psychrophilic mutant lipase from Croceibacter atlanticus LipCA lipase developed by a molecular evolution technique

Lipases are used to synthesize a variety of industrially useful compounds. Among them, psychrophilic lipase can be used to synthesize thermo-labile compounds at low temperatures. In this study, random mutagenesis was introduced into Antarctic Croceibacter atlanticus lipase gene using error-prone PCR, resulting in changes in its protein sequence. Through two rounds of mutagenesis and screening, we found that a mutant R1 showed an enhanced activity at low temperatures. Mutant R1 had five mutations (F43L, S48G, S49G, D141K, and K297R) and higher kcat/KM value than the wild type (WT) at 10 °C. We immobilized this enzyme on methacrylate divinylbenzene resin and used it to synthesize octyl butyrate, a flavor compound. The esterification reaction proceeded even at 10 °C. Mutant R1 synthesized the ester compound faster than the WT. To determine which amino acids were responsible for the increase of activity, site-directed mutagenesis was performed to introduce five back mutations into mutant R1. Three back mutants (L43F, G48S, G49S) showed significant decreases of activity at low temperatures, indicating that these amino acids were closely related to the increase in activity. This psychrophilic mutant R1 is expected to be used in low-temperature enzyme conversion reactions in the food industry.

Solvent-Assisted Laser Desorption Flexible Microtube Plasma Mass Spectrometry for Direct Analysis of Dried Samples on Paper.

The present study investigated the potential for solvent-assisted laser desorption coupled with flexible microtube plasma ionization mass spectrometry (SALD-FμTP-MS) as a rapid analytical technique for direct analysis of surface-deposited samples. Paper was used as the demonstrative substrate, and an infrared hand-held laser was employed for sample desorption, aiming to explore cost-effective sampling and analysis methods. SALD-FμTP-MS offers several advantages, particularly for biofluid analysis, including affordability, the ability to analyze low sample volumes (<10 μL), expanded chemical coverage, sample and substrate stability, and in situ analysis and high throughput potential. The optimization process involved exploring the use of viscous solvents with high boiling points as liquid matrices. This approach aimed to enhance desorption and ionization efficiencies. Ethylene glycol (EG) was identified as a suitable solvent, which not only improved sensitivity but also ensured substrate stability during analysis. Furthermore, the addition of cosolvents such as acetonitrile/water (1:1) and ethyl acetate further enhanced sensitivity and reproducibility for a standard solution containing amphetamine, imazalil, and cholesterol. Optimized conditions for reproducible and sensitive analysis were determined as 1000 ms of laser exposure time using a 1 μL solvent mixture of 60% EG and 40% acetonitrile (ACN)/water (1:1). A mixture of 60% EG and 40% ACN/water (1:1) resulted in signal enhancements and relative standard deviations of 12, 20, and 13% for the evaluated standards, respectively. The applicability of SALD-FμTP-MS was further evaluated by successfully analyzing food, water, and biological samples, highlighting the potential of SALD-FμTP-MS analysis, particularly for thermolabile and polarity diverse compounds.

Impact of carbonization on oak wood δ18O: A preliminary study

The carbonization process induces significant physical, elemental, and structural transformations of wood. In this study, the modification of δ18O in wood during the carbonization process was investigated in conjunction with elemental analysis, infrared spectroscopy (FTIR), and Rock-Eval thermal analysis, to explore the connection between the chemical composition of the materials and the alterations in δ18O. Quercus petraea wood samples were experimentally burned at temperatures ranging from 200 °C to 1000 °C under inert (pyrolysis) and oxidative atmospheres. The results reveal that the modification of δ18O values in charred wood can be described as a sequential two-step process. The initial step, occurring below 300 °C, involves the volatilization and preferential degradation of thermolabile compounds, leading to an increase of +1.6‰ in δ18O. The subsequent step, below 700 °C, results in a decrease in δ18O values of –21.6‰, primarily driven by the thermal degradation of cellulose and lignin, as well as the increase of aromaticity and reorganization. The components and the δ18O of wood undergo distinct changes in combustion mode, due to different carbonization kinetics as evidenced by FTIR and elemental analysis. To assess the intensity of the carbonization process, influenced by temperature, oxygen availability, and wood characteristics, the H/C atomic ratio, a good indicator of aromaticity, is used. A non-linear regression model was established, relating δ18O to the H/C atomic ratio, thereby demonstrating that δ18O values undergo changes as wood aromatization progresses, independent of the carbonization conditions. The second order model has a mean confidence interval of 1.9‰ and a prediction interval of 8.1‰. This work provides a fundamental understanding of the connection between the chemical composition of woody materials, alterations in δ18O, and the carbonization process, offering valuable insights for further studies and applications related to oxygen-related information that may be preserved in charcoals.

Quality and energy efficiency evaluation of Rosmarinus officinalis L. by intermittent and continuous microwave drying: Polyphenol composition, bioactive compounds quantification, antioxidant properties, physical characteristics, and energy consumption

AbstractImproper drying is one of the major causes of beneficial bioactive compounds' degradation in bio‐crops together with high energy consumption. Preservation of the compounds is crucial in retaining the bioactivities of the herbs with diverse industrial applications. Continuous microwave drying (CMD), despite being effective and efficient, has not merged with the industry as process intensification due to the challenges of overheating. This study investigates the application of intermittent microwave drying (IMD) on rosemary and its compounds, to address the issues of overheating and the subsequent loss of bioactive compounds resulting from CMD. This technology is implemented through the application of microwaves in a periodic on/off manner. Although CMD had the shortest drying duration (&gt;20 min) and the highest drying rate (0.431 kg H2O/kg DB min), IMD had the highest effective diffusivities (1.292 × 10−10 m2/s) indicating better moisture kinetics and evaporation. CMD exhibited favorable physical characteristics of shrinkage (83.40%), bulk density (669.23 kg/m3), and rehydration capacity (34%). However, both methods displayed high antioxidant activity (90.36%–93.78% inhibition). Higher compound concentrations of Carnosic acid (4.85 mg/g), Carnosol (6.86 mg/g), and Rosmarinic acid (14.36 mg/g) were achieved using IMD. Lastly, IMD had a higher energy efficiency (1.70%) than CMD due to drying by residual heat generation and redistribution.Practical applicationDrying is a crucial first post‐harvest process to preserve aromatic and medicinal herbs and plants for downstream processing. However, the sensitive and diverse nature of bioactive compounds makes it practically impossible to implement one drying technology to process all. Microwave technology is highly favored by researchers as well as industries to replace traditional convective hot air drying due to its effectiveness and higher efficiency. Nevertheless, the overheating issue from the continuous microwave is still a challenge while processing delicate herbs and their bioactive compounds. Especially, herbs like rosemary which possesses thermolabile compounds. The current study implements microwave technology periodically to benefit from sustainable drying via microwave without overheating and subsequent loss of bioactive compounds. The outcome of this study demonstrated the effectiveness of the intermittent microwave technology which proved to be more energy efficient than continuous microwave while retaining higher bioactive compound concentration in rosemary leaves.

Optimization of Ultrasound-Assisted Cold-Brew Method for Developing Roselle (Hibiscus sabdariffa L.)-Based Tisane with High Antioxidant Activity

Edible flowers, including roselle, contain a varied composition of phenolic compounds that may inhibit the oxidative stress mechanism. Roselle-based tisane with appealing sensory properties is commonly consumed worldwide. However, the conventional hot-brew method may ruin the stability of thermolabile phenolic compounds during the tisane preparation. Hence, this study aimed to develop a new alternative brewing method linked with the new cold-brew method, which involves a lower temperature and applying ultrasound to maximize the extraction of phenolic compounds and to avoid degradation during the tisane preparation. The brewing factors, including particle size (10, 20, 30 mesh), temperature (4, 15, 26 °C), time (10, 20, 30 min), and ultrasound amplitude (20, 60, 100% of the maximum amplitude) have been optimized simultaneously using Box–Behnken design in conjunction with response surface methodology. Seven major phenolic compounds were identified by HPLC-DAD and classified into hydroxycinnamic acid derivatives (HCA) and flavonoids. The optimum extraction condition to reach the highest level of the studied phenolic compounds was set to brew roselle with particle size of 30 ± 3.25 mesh at 26 ± 1.32 °C for 18 ± 2.00 min applying 78 ± 5.64% ultrasound amplitude. This method successfully extracted almost all HCA and flavonoid during the first cycle with less than 10% CV and provided higher antioxidant activity in terms of DPPH (IC50 9.77 ± 0.01 µg mL−1), ABTS (IC50 8.05 ± 0.02 µg mL−1), and FRAP (IC50 10.34 ± 0.03 µg mL−1) than the roselle tisane prepared using the conventional method. Additionally, the resulting cold-brew product was stable for up to five days of storage.

The impact of extract of mistletoe on tumour cells and hemostasis of human plasma

Background: The plant Viscum album (Mistletoe) is a known source of biologically active substances, used in traditional medicine in Europe and Asia.Aim: The goal was to study cytotoxic/cytostatic effect of mistletoe extract on tumour and normal cells and its influences on certain proteins of the blood coagulation system.Setting: Mistletoe was collected in Ukraine in November 2020.Methods: Water extract of V. album, both leaves and stems, was obtained and fractionated; it was characterised using high-performance liquid chromatography (HPLC) and mass spectrometry and tested on cancer cells and blood plasma.Results: Extract demonstrated the presence of viscotoxins and carbohydrates and thermolabile compounds that enhance the activity of thrombin and factor X in plasma in the presence of calcium ions and increased the activated partial thromboplastin time (APTT) by 2.7 times. The cytotoxic/cytostatic action of the mistletoe fractions, the total extract and the fraction 10 000 Da were higher in relation to Lewis lung carcinoma (LLC) cells than with Vero cells. The IC50 of total extract for LLC cells was 35% (p 0.05) lower than that for Vero cells (1.12 ± 0.2 and 1.71 ± 0.15 mg/ml). Thus, the IC50 of the fraction 10 000 Da for LLC cells was more than by 44% (p 0.05) lower than that for Vero cells (2.07 ± 0.26 and 3.67 ± 0.41 mg/ml).Conclusion: It was shown that both extracts exhibited a cytotoxic/cytostatic effect, more pronounced against tumour cells than normal cells and enhanced the clotting of blood plasma by thermolabile compounds by facilitating plasma coagulation.Contribution: This research makes it possible to study mistletoe as a light and cheap anticancer therapy plant and cure blood coagulopathy or construct antibleeding bandages.

Extraction of Faloak Stem Bark (Sterculia quadrifida R. Br) Using Microwave-Assisted Extraction Method And LC-HRMS Profiling of the Extract

The extraction of bioactive plants is an essential step in isolating the targeted bioactive compounds. Microwave-assisted extraction (MAE) offers a green technology extraction that can minimize energy, time, and solvent and is a suitable method for extracting thermolabile plant bioactive compounds. The study aims to find out the optimal time and temperature for isolating the total phenolic content (TPC), total flavonoid (TF), and antioxidant activity (AO) of faloak stem bark (FSB) (Sterculia quadrifida R. Br) and to profile the phytochemicals in the FSB extract using sophisticated of LC-HRMS (Liquid Chromatography High-Resolution Mass Spectrometry). The research used the Randomized Block Design (RBD) method with two factors. The factors were the extraction time (5, 15, and 25 min) and temperature variation (50, 60, and 70°C). The data of observed parameters were calculated using Analysis of Variance (ANOVA) and followed by a further test with a 95% confidence interval. The results showed an interaction between temperature and time of extraction on TPC, TF, and AO activity. The best MAE condition for extracting FSB was achieved at 60°C for 25 min. The FSB extract had a TPC of 81.2 mg GAE/g, TF of 70.30 mg QE/g, and AO activity of 67.8%. LC-HRMS revealed the newly identified phenolic compounds such as methyl cinnamate, vanillin, apocynin, scopoletin, L(-)-pipecolinic acid, arecoline, δ-valerolactam, 3,4-dihydroxybenzaldehyde, 4-hydroxybenzaldehyde; flavonoids such as epicatechin and rutin and some fatty acids and its derivatives. Future research could focus on developing new therapies for promoting human health using extract FSB.

Comparison of high pressure and thermal pasteurization on the quality parameters of strawberry products: a review.

Strawberry (Fragaria ananassa) is rich in bioactive compounds with high antioxidant activity. High pressure processing (HPP) is an efficient alternative to preserve these bioactive compounds in terms of microbial inactivation and shelf-life stability. This review compares the effects of pasteurization methods using high pressure or thermal pasteurization (TP) on the quality parameters of various strawberry-based products. To summarize, most of the high pressure-treated products are microbiologically stable and showed minimum degradation of thermolabile compounds than TP-treated ones. However, some studies reported that high pressure did not have an advantage over TP especially in the preservation of phenolic phytochemicals during storage. The insufficient enzyme inactivation and high residual activity of enzymes after high pressure treatment could cause anthocyanins degradation thus affecting the product quality. Overall, this review could be valuable to potential processors in evaluating the effective commercialization of high pressure-treated strawberry products.

Thermal and nonthermal sonication: Extraction of bioactive compounds from beet leaves and microbiological quality of extracts

AbstractThis work aimed to optimize a nonthermal (NT) ultrasound‐assisted aqueous extraction (aq‐UAE) to maximize the recovery of polyphenols, betaxanthins, and betacyanins. Extraction yields, thermal profiles and microbiological quality of the extract were compared with a previoulsy optimized thermal aq‐UAE. Extraction yields resulted 68%–121% higher in NT‐aqUAE. Polyphenols and betaxanthins were the most affected by high temperatures of thermal process showing decreses after 8 min of thermosonication at temperatures &gt;50°C. Temperature during NT‐aqUAE waslower than 30ºC avoiding the detrimental effects of heat. Microbial counts decreased 2‐log cycles after thermosonication and the remaining microbial load did not resist the storage conditions. Conversely, no significant decreases were detected after NTaq‐UAE. However, sublethal damage was observed as microbial counts presented a higher lag phase than control during refrigerated storage. Although NTaq‐UAE process allows for higher phytochemical extraction yields than thermal aq‐UAE, it does not contribute to controlling the microbial load of extracts.Practical applicationNonthermal ultrasound‐assisted aqueous extraction of bioactive compounds from beet leaves was optimized in this work. This process improved the extraction yield of polyphenols and betalains compared with the thermal counterpart as thermolabile compounds degradation was avoided with the limitation on thermal increments. The developed process resulted simple and reasonably efficient for producing extracts rich in polyphenols and betalain pigments that hold potential to be used as natural additives. Additionally, evaluation of microbiological quality of extracts obtained by thermal and nonthermal optimized UAE processes allow to establish that thermal aq‐UAE improved microbiological quality and stability of extracts while nonthermal one would require an additional treatment of the extract to improve its microbiological quality. Developed processes are effective postharvest strategies to the valorisation of horticultural by products such as beet leaves and increase biomass utilization improving the sustainability of the agri‐food chain.

MATHEMATICAL MODELING OF THE EXTRACTION PROCESS IN THE ACOUSTIC EXTRACTOR

One of the most promising physical methods of extraction processes intensification is ultrasound. Dissemination of sound waves in the device occurs by periodic rarefaction and compression of the liquid with the corresponding frequency to the frequency of sound wave oscillations and with a rarefaction amplitude equal to the compression amplitude. Effects of mixing and heating of the liquid, pulsation, collapse of cavitation bubbles is occurred during the operation of the ultrasonic generator. Extraction under the ultrasound influence has its advantages. The equipment has the possibility of continuous operation and is suitable for mass extraction of medicinal products from plants; the extraction time is reduced; the process takes place at a low temperature, which is very important for the thermolabile pharmaceutical ingredients. Sound waves are mechanical vibrations in solids, liquids, and gases that have frequencies higher than 20 kHz. Sound waves moves in any matter, they are associated with cycles of compression and expansion during movement in the medium, in contrast with electromagnetic waves. It is possible to reduce the extraction operating temperature of thermolabile compounds using ultrasound. In addition, any solvent can be used during ultrasonic extraction. Ultrasonic extraction can be used to extract biologically active substances such as essential oils, lipids, and dietary supplements from plants. To calculate the process of extraction of biologically active substances in an acoustic extractor, it is necessary to develop a mathematical model for establishing diffusion coefficients and extraction time.

Upcycling Fish By-Products into Bioactive Fish Oil: The Suitability of Microwave-Assisted Extraction

The seafood industry is often left out of the food waste discussion, but this sector is no exception, as it generates large amounts of various by-products. This study aimed to explore the potential of the microwave-assisted extraction (MAE) technique to obtain high-quality oil from fish by-products. The independent variables, which were time (1-30 min), microwave power (50-1000 W), and solid/liquid ratio (70-120 g/L) were combined in a 20-run experimental design coupled with the response surface methodology (RSM) for process optimization. The obtained oil yield values were fitted to a quadratic equation to build the theoretical models, which were statistically validated based on statistical criteria and used to predict the optimal MAE condition. The oil yields were significantly affected by the three independent variables through linear, quadratic, and/or interactive effects. Compared to a conventional Soxhlet extraction (SE), the optimal MAE conditions allowed between 60 and 100% of oil to be recovered in less than 19 min and with less solvent consumption. The fatty acid profiles of the oils obtained through SE and optimized MAE were characterized by gas chromatography with flame ionizing detection (GC-FID) after a derivatization process. These oils were constituted mainly of health, beneficial unsaturated fatty acids, such as oleic, docosahexaenoic (DHA), linoleic, and eicosapentaenoic (EPA) acids, which were not affected (p > 0.05) by the extraction methods. Interestingly, the oils obtained through MAE showed the best microbial growth inhibition results may have been due to thermolabile compounds, preserved via this unconventional non-thermal method. The oils also exhibited anti-inflammatory effects via nitric oxide production inhibition and cytotoxic potential especially, against breast and gastric adenocarcinoma cells. However, the threshold of toxicity should be further investigated. Overall, this work emerges as a future-oriented approach to upcycling fish by-products into high-quality oils that can be used in the formulation of pet food and other products.

Kinetics and Mechanisms of Saccharomyces boulardii Release from Optimized Whey Protein-Agavin-Alginate Beads under Simulated Gastrointestinal Conditions.

Encapsulation is a process in which a base material is encapsulated in a wall material that can protect it against external factors and/or improve its bioavailability. Among the different encapsulation techniques, ionic gelation stands out as being useful for thermolabile compounds. The aim of this work was to encapsulate Saccharomyces boulardii by ionic gelation using agavins (A) and whey protein (WP) as wall materials and to evaluate the morphostructural changes that occur during in vitro gastrointestinal digestion. Encapsulations at different levels of A and WP were analyzed using microscopic, spectroscopic and thermal techniques. Encapsulation efficiency and cell viability were evaluated. S. boulardii encapsulated at 5% A: 3.75% WP (AWB6) showed 88.5% cell survival after the simulated gastrointestinal digestion; the bead showed a significantly different microstructure from the controls. The mixture of A and WP increased in the survival of S. boulardii respect to those encapsulated with alginate, A or WP alone. The binary material mixture simultaneously allowed a controlled release of S. boulardii by mostly diffusive Fickian mechanisms and swelling. The cell-release time was found to control the increment of the Damköhler number when A and WP were substrates for S. boulardii, in this way allowing greater protection against gastrointestinal conditions.

Extraction of Citrus deliciosa Tenore petitgrain (leaf) essential oil by steam distillation under different operating pressures

ABSTRACT This work aimed to evaluate the effect of system absolute pressure on the yield and composition of petitgrain essential oil of Citrus deliciosa Tenore, extracted by steam distillation. The extractions were carried out at the absolute pressures of 760, 610, 460, and 310 Torr, for 1 h. The chemical composition of the essential oil was determined by GC/MS and GC-FID. According to the results, the reduction of pressure reduced essential oil yield, from 0.6% v/w at 760 Torr to 0.3% v/w at 310 Torr. Regarding the chemical composition, there was an increase in methyl N-methylanthranilate content with the reduction of system pressure, from 88.3 wt.% at 760 Torr to 97.6 wt.% at 310 Torr. However, it was observed a reduction in extraction efficiency due to the lower steam temperature. On the other hand, lower temperatures may imply a smaller degradation of thermolabile compounds. This process may be an alternative to other deterpenation techniques because it couples in a sole stage the extraction and purification/separation of essential oil components.

A Review on Extraction of Bioactive Compounds from Moringa oleifera Leaves: Their Principle, Advantages, and Disadvantages

Moringa oleifera, belongs to the Moringaceae family, is an indigenous plant and native to the North India region. It has been used for centuries as traditional medicine and nutritional supplement. Moringa olefeira leaves contain high phenolics and flavonoid compounds as major constituents such as kaempferol, quercetin, caffeoylquinic acid, coumaroylquinic acid, and feruloylquinic acid. The extraction techniques play a critical role in the extraction outcome such as crude extracts yield, type and quantity of compound extracted. To date, there is a wide range of technologies for crude plant extraction such as ultrasoundassisted extraction, microwave-assisted extraction Soxhlet extraction, and dipping (maceration) technique. These extraction techniques employ various types of solvent which could enhance the efficiency of extraction and quality of the compound extracted. Hence, this review aims to describe and compare the conventional and novel extraction techniques methods of Moringa oleifera leaves based on the total phenolics content, flavonoid content, and antioxidant activity. The difference based on the extraction process principle, advantages, and disadvantages were further evaluated to show the suitability, environmentally friendly, the economic feasibility of the various extraction methods. From this review, ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) have minimized the processing time, which is useful for extracting thermolabile compounds, such as phenol compounds. In conclusion, novel extraction techniques could be effectively enhancing the total phenolic compound, flavonoid content, and antioxidant activities of crude extracts, which provides a theoretical basis for upgrading to alarge-scale applicationin the future.