Formation Of Free Fatty Acids Research Articles

Resuspended freeze-dried Nannochloropsis as a model laboratory system for concentrated fresh Nannochloropsis in ultrasound cell disruption experiments

Microalgae have rigid, complex cell walls hindering direct lipid extraction. Cell disruption techniques are used to rupture these cellular structures to increase lipid extraction. Researchers investigating the downstream processing of microalgae do not always have access to microalgal cultivation systems to generate large amounts of fresh microalgal biomass. Using resuspended freeze-dried microalgal biomass as a model laboratory system for concentrated fresh biomass during cell disruption experiments offers greater flexibility in experimental planning and omits investment costs of microalgal cultivation equipment. So far, it however remains unclear whether freeze-dried resuspended biomass can be used as a model laboratory system to represent concentrated fresh biomass during cell disruption and lipid extraction experiments. This paper thus evaluated the suitability of resuspended freeze-dried Nannochloropsis as a model laboratory system for concentrated fresh Nannochloropsis during cell disruption. Ultrasound assisted cell disruption was used as example cell disruption technique and lipid extraction efficiency and free fatty acid content were investigated. Tap water and 3% sodium chloride are both suitable resuspension media for the resuspension of freeze-dried Nannochloropsis. Resuspension duration should be limited (< 120 min) to prevent the formation of free fatty acids. The condition of the biomass (concentrated fresh, or resuspended freeze-dried) prior to ultrasound assisted cell disruption did not influence the resulting lipid extraction efficiency. Resuspended freeze-dried Nannochloropsis biomass in tap water or 3% sodium chloride can thus be used as a model laboratory system for fresh microalgal biomass during research on ultrasound assisted lipid extraction. The generalization of the results to other cultivation conditions, cell disruption techniques, components of interest or microalgal species should be carefully assessed.

Shotgun approach reveals distinctive lipid profiles in brassica oilseeds: A high-resolution ESI-ToF-MS study

Members of Brassica seed oil are important sources of nutritionally superior edible oil. There are no comprehensive reports on complete lipidomic profile of these oilseed crops. In this study, the lipidomic profiling of edible oil from 7 different cultivated species of Brassica seed oils was performed by shotgun approach using electrospray High Resolution Time of Flight-Mass Spectrometry (ESI-ToF-MS). The mass spectrum under positive polarity revealed 1098 lipids under different lipid classes including sphingolipids, phospholipids and different storage lipids. Under negative polarity, 70 lipids including free fatty acids (FFA), cardiolipins and phospholipids were detected. Erucic acid in FFA form was found to be most abundant in both Yellow and Brown sarson. Brassica napus contains almost all forms of cardiolipins (CL). Out of 26 different species of cardiolipins detected in negative ion mode, CL 56:1 (FA 18:1) and CL 56:1 (FA 22:1) were present only in brown sarson. Similarly, CL 56:2 (FA 18:2) and CL 56:1 (FA 22:1) were present only in Yellow and Brown sarson. These findings enhance our understanding of the nutritional diversity in Brassica seed oils, emphasizing the significance of lipidomic analysis for elucidating the molecular composition of edible oils.

In Vitro and In Vivo Performance of Pickering Emulsion-Based Powders of Omega-3 Polyunsaturated Fatty Acids.

Omega-3 polyunsaturated fatty acids (n-3 PUFA) are essential nutrients for human health and have been linked to a variety of health benefits, including reducing the risk of cardiovascular diseases. In this paper, a spray-dried powder formulation based on Pickering emulsions stabilized with cellulose nanocrystals (CNC) and hydroxypropyl methylcellulose (HPMC) has been developed. The formulation was compared in vitro and in vivo to reference emulsions (conventional Self-Emulsifying Drug Delivery System, SEDDS) to formulate n-3 PUFA pharmaceutical products, specifically in free fatty acid form. The results of in vivo studies performed in fasted dogs showed that Pickering emulsions reconstituted from powders are freely available (fast absorption) with a similar level of bioavailability as reference emulsions. In the studies performed with dogs in the fed state, the higher bioavailability combined with slower absorption observed for the Pickering emulsion, compared to the reference, was proposed to be the result of the protection of the n-3 PUFAs (in free fatty acid form) against oxidation in the stomach by the solid particles stabilizing the emulsion. This observation was supported by promising results from short-term studies of chemical stability of powders with n-3 PUFA loads as high as 0.8 g oil/g powder that easily regain the original emulsion drop sizes upon reconstitution. The present work has shown that Pickering emulsions may offer a promising strategy for improving the bioavailability and stability as well as providing an opportunity to produce environmentally friendly (surfactant free) and patient-acceptable solid oral dosage forms of n-3 PUFA in the free fatty acid form.

Engineering Yarrowia lipolytica for sustainable ricinoleic acid production: A pathway to free fatty acid synthesis

Ricinoleic acid (C18:1-OH, RA) is a valuable hydroxy fatty acid with versatile applications. The current industrial source of RA relies on the hydrolysis of castor bean oil. However, the coexistence of the toxic compound ricin and the unstable supply of this plant have led to an exploration of promising alternatives: generating RA in heterologous plants or microorganisms. In this study, we engineered the oleaginous yeast Yarrowia lipolytica to produce RA in the form of free fatty acids (FFA). First, we overexpressed fungal Δ12 oleate hydroxylase gene (CpFAH12) from Claviceps purpurea while deleting genes related to fatty acid degradation (MEF1 and PEX10) and oleic acid desaturation (FAD2). Since Δ12 oleate hydroxylase converts oleic acid (C18:1) located at the sn-2 position of phosphatidylcholine (PC), we next focused on increasing the PC pool containing oleic acid. This objective was achieved thorough implementing metabolic engineering strategies designed to enhance the biosynthesis of PC and C18 fatty acids. To increase the PC pool, we redirected the flux towards phospholipid biosynthesis by deleting phosphatidic acid phosphatase genes (PAH1 and APP1) and diacylglycerol acyltransferase gene (DGA1), involved in the production of diacylglycerol and triacylglycerol, respectively. Furthermore, the PC biosynthesis via the CDP-DAG pathway was enhanced through the overexpression of CDS1, PSD1, CHO2, and OPI3 genes. Subsequently, to increase the oleic acid content within PC, we overexpressed the heterologous fatty acid elongase gene (MaC16E) involved in the conversion of C16 to C18 fatty acids. As RA production titer escalated, the produced RA was mainly found in the FFA form, leading to cell growth inhibition. The growth inhibition was mitigated by inducing RA secretion via Triton X-100 treatment, a process that simultaneously amplified RA production by redirecting flux towards RA synthesis. The final engineered strain JHYL-R146 produced 2.061 g/L of free RA in a medium treated with 5% Triton X-100, constituting 74% of the total FFAs produced. Generating free RA offers the added benefit of bypassing the hydrolysis stage required when employing castor bean oil as an RA source. This achievement represents the highest level of RA synthesis from glucose reported thus far, underscoring the potential of Y. lipolytica as a host for sustainable RA production.

Structural insights into ligand recognition and selectivity of the human hydroxycarboxylic acid receptor HCAR2

Hydroxycarboxylic acid receptor 2 (HCAR2) belongs to the family of class A G protein-coupled receptors with key roles in regulating lipolysis and free fatty acid formation in humans. It is deeply involved in many pathophysiological processes and serves as an attractive target for the treatment of cardiovascular, neoplastic, autoimmune, neurodegenerative, inflammatory, and metabolic diseases. Here, we report four cryo-EM structures of human HCAR2–Gi1 complexes with or without agonists, including the drugs niacin (2.69 Å) and acipimox (3.23 Å), the highly subtype-specific agonist MK-6892 (3.25 Å), and apo form (3.28 Å). Combined with molecular dynamics simulation and functional analysis, we have revealed the recognition mechanism of HCAR2 for different agonists and summarized the general pharmacophore features of HCAR2 agonists, which are based on three key residues R1113.36, S17945.52, and Y2847.43. Notably, the MK-6892–HCAR2 structure shows an extended binding pocket relative to other agonist-bound HCAR2 complexes. In addition, the key residues that determine the ligand selectivity between the HCAR2 and HCAR3 are also illuminated. Our findings provide structural insights into the ligand recognition, selectivity, activation, and G protein coupling mechanism of HCAR2, which shed light on the design of new HCAR2-targeting drugs for greater efficacy, higher selectivity, and fewer or no side effects.

The patatin-like phospholipase PfPNPLA2 is involved in the mitochondrial degradation of phosphatidylglycerol during Plasmodium falciparum blood stage development.

Plasmodium falciparum is an Apicomplexa responsible for human malaria, a major disease causing more than ½ million deaths every year, against which there is no fully efficient vaccine. The current rapid emergence of drug resistances emphasizes the need to identify novel drug targets. Increasing evidences show that lipid synthesis and trafficking are essential for parasite survival and pathogenesis, and that these pathways represent potential points of attack. Large amounts of phospholipids are needed for the generation of membrane compartments for newly divided parasites in the host cell. Parasite membrane homeostasis is achieved by an essential combination of parasite de novo lipid synthesis/recycling and massive host lipid scavenging. Latest data suggest that the mobilization and channeling of lipid resources is key for asexual parasite survival within the host red blood cell, but the molecular actors allowing lipid acquisition are poorly characterized. Enzymes remodeling lipids such as phospholipases are likely involved in these mechanisms. P. falciparum possesses an unusually large set of phospholipases, whose functions are largely unknown. Here we focused on the putative patatin-like phospholipase PfPNPLA2, for which we generated an glmS-inducible knockdown line and investigated its role during blood stages malaria. Disruption of the mitochondrial PfPNPLA2 in the asexual blood stages affected mitochondrial morphology and further induced a significant defect in parasite replication and survival, in particular under low host lipid availability. Lipidomic analyses revealed that PfPNPLA2 specifically degrades the parasite membrane lipid phosphatidylglycerol to generate lysobisphosphatidic acid. PfPNPLA2 knockdown further resulted in an increased host lipid scavenging accumulating in the form of storage lipids and free fatty acids. These results suggest that PfPNPLA2 is involved in the recycling of parasite phosphatidylglycerol to sustain optimal intraerythrocytic development when the host resources are scarce. This work strengthens our understanding of the complex lipid homeostasis pathways to acquire lipids and allow asexual parasite survival.

Influence of Different Previous Frozen Holding Periods on the Canned Fish Quality.

The combined effects of thermal processing (i.e., sterilisation treatment) and the prior frozen storage time (3 or 6 months at -18 °C) on the quality loss in canned Atlantic horse mackerel (Trachurus trachurus) were determined. Thus, the sterilisation step led to a remarkable (p < 0.05) formation in the canned fish muscle of fluorescent compounds, free fatty acids (FFAs), and trimethylamine and an increase in the L* and b* colour parameters; meanwhile, a decrease (p < 0.05) in the total ω3 FA/total ω6 FA ratio and the a* colour value were detected. The prior frozen storage period led to an increased (p < 0.05) lipid oxidation (peroxide, thiobarbituric acid reactive substance, and fluorescent compound formation) and hydrolysis (FFA formation) development and to increased L* and b* colour values in the corresponding canned samples; additionally, a lower (p < 0.05) polyene index and phospholipid content were observed in canned fish previously subjected to frozen storage. In most indices, physico-chemical changes related to quality loss were found to be higher if the previous storage period was increased. According to the marked effects of the sterilisation step and the prior frozen storage period, the optimisation of such processing conditions is recommended to maximise the quality of canned horse mackerel.

92 Implications of Processing and Handling on the Functionality of Animal Derived Products for Pet Foods

Abstract The pet food industry has been closely tied to the livestock, meat, and rendering industries by using materials left over from human food production. Rendered animal fats are an excellent source of dietary fat and provide enhanced palatability when used to enrobe dry pet food. Mechanically deboned meat, viscera, and rendered protein meals are often utilized as a primary source of highly digestible, well-balanced proteins and vitamins and minerals. Although these products can be easily transported and stored, they are susceptible to oxidative and microbial degradation. Antioxidants and antimicrobials aid in preserving the quality of these ingredients but are only part of the solution. How these ingredients are produced, stored, and handled can impact quality. It is important to remember that this raw material stream starts with livestock management practices. Specifically, changes in nutritional practices in the livestock industry can impact the characteristics of the products used for both human and pet foods, especially when considering poultry and pork products. Demands by consumers in the meat industry have resulted in the popularity of vegetarian diets. For example, decreased amounts of rendered animal protein meals in diets fed to chickens and turkeys have shifted towards more unsaturated fats, ultimately decreasing oxidative stability. Handling animal products throughout their supply chain can also affect product quality and potential usability. After harvest, raw material is often transported and processed by two or more different facilities before arriving at the pet food manufacturer. At the meat and rendering facilities, food safety hurdles along with processing aids can limit biogenic amine or free fatty acid formation. Once oxidation and microbial degradation occur, they cannot be reversed. Therefore, addressing food safety or oxidation control upstream in the supply chain is critical. Since each facility is unique in how co-products are processed and handled, understanding how different antioxidant blends and how and where these are applied all impact final product quality; this carries through to the quality and shelf life of the pet food diet these ingredients are intended for. With most pet foods targeting 18 months to 2 years of shelf life, starting with high-quality ingredients is key to achieving these goals. The human food, rendering, and pet food industries remain closely tied together. Trends within the meat and rendering industry result in the potential for these ingredients to be more susceptible to quality and functionality changes. The pet food industry must continue to monitor and evaluate changes in livestock production practices and product handling. Proactive management of these ingredients throughout the supply chain can ensure that these ingredients remain high-quality, cost-effective ingredients for pet food.

Screening In Silico Lipase Inhibitory Activity of Various Coumarin Compounds for the Treatment of Obesity

Currently, obesity is one of the most common diseases and accounts for a high rate in many countries. Pancreatic lipase (PL) is the major enzyme secreted by the pancreas that has a direct effect on the formation of monoglycerides and free fatty acids. Inhibition of pancreatic lipase enzyme helps to break down fat, reduce kCal, and lose weight. Coumarins are a group of compounds that are active in obesity. Therefore, our study aimed to evaluate and screen coumarin compounds effective in inhibiting lipase enzyme by molecular docking method. As a result, we obtained eight compounds showing lower binding energy values than the positive control Orlistat and satisfying drug-like properties when evaluating the Lipinski rule of five. After that, these compounds continued to analyze pharmacokinetic and toxicological properties (ADMET) to obtain three compounds with the best results: Peucenidin, Edultin, and Xanthalin with good intestinal absorption, well distributed to tissues, metabolized by the liver, hepatic metabolism, renal excretion, and low toxicity. Therefore, further in vivo and in vitro studies are needed to develop drugs for the treatment of obesity.&#x0D;

Screening techniques for monitoring the sub-visible particle formation of free fatty acids in biopharmaceuticals

Free fatty acid (FFA) particles that originate from the enzymatic hydrolysis of polysorbate (PS) via co-purified host cell proteins generally appear abruptly in drug products during real-time (long-term) storage. Efforts were taken to understand the kinetics of FFA particle formation, aiming for a mitigation strategy. However, it is rather challenging particularly in the sub-visible particle (SVP) range, due to either the insufficient sensitivity of the analytical techniques used or the interference of the formulation matrices of proteinaceous drug products. In this study, we examined the feasibility of Raman microscopy, backgrounded membrane imaging (BMI) and total holographic characterization (THC) on the detection of FFA sub-visible particles (SVPs). The results indicate that THC is the most sensitive technique to track their occurrence during the course of PS hydrolysis. Moreover, with this technique we are able to distinguish different stages of FFA particle formation in the medium. In addition, a real time stability study of a biopharmaceutical was analyzed, demonstrating the viability of THC to monitor SVPs in a real sample and correlate it to the visible particles (VPs) occurrence.

Image classification of degraded polysorbate, protein and silicone oil sub-visible particles detected by flow-imaging microscopy in biopharmaceuticals using a convolutional neural network model

Degradation of polysorbates in biopharmaceutical formulations can induce the formation of sub-visible particles (SvPs) in the form of free-fatty acids (FFAs) and potentially protein aggregates. Flow-imaging microscopy (FIM) is one of the most common techniques for enumerating and characterizing the SvPs, allowing for collection of image data of the SvPs in the size ranges of two to several hundred micrometers. The vast amounts of data obtained with FIM do not allow for rapid manual characterization by an experienced analyst and can be ambiguous. In this work, we present the application of a custom convolutional neural network (CNN) for classification of SvP images of FFAs, proteinaceous particles and silicon oil droplets, by FIM. The network was then used to predict the composition of artificially pooled test samples of unknown and labeled data with varying compositions. Minor misclassifications were observed between the FFAs and proteinaceous particles, considered tolerable for application to pharmaceutical development. The network is considered to be suitable for fast and robust classification of the most common SvPs found during FIM analysis.

Antioxidant activity of selected plants extract for palm oil stability via accelerated and deep frying study

Antioxidants are organic compounds that help to prevent lipid oxidation and improve the shelf-life of edible oils and fats. Currently, synthetic antioxidants were used as oil stabilizing agent. However, synthetic antioxidants have been causing various health risks. As a result, natural antioxidants such as most parts of olive plant, green tea, sesame, medicinal plants were plays an important role to retard lipid oxidation. The palm oil was continuously frying at 180 °C for 6 days using Lepidium sativum (0.2%w/v) and Aframomum corrorima (0.3%w/v) seeds extracts as antioxidant. The physicochemical properties of oil in the herbal extract additive group significantly maintained the oil quality during frying compared to the normal control and the food sample containing group. The L. sativum extract had a greater oil stability compared to A. corrorima extract. However, the frying oil without herbal extract significantly increase the physicochemical properties of oil such as iodine value, acid value, free fatty acid, total polar compounds, density, moisture content, pH etc. during repetitive frying. The antioxidant activity of the plant extract was outstanding, with an IC50 value in the range of 75–149.9 μg/mL when compared to the standard butyl hydroxy anisole, which had an IC50 value in the range of 74.9 ± 0.06–96.7 ± 0.75 μg/mL. The total phenolic and flavonoid content of the extract for L. sativum was 128.6 ± 0.00 mg GAE/g, 127.0 ± 0.00 mg QE/g, and 130.16 ± 0.001 mg GAE/g, 105.76 ± 0.02 mg QE/g, respectively. The significant effect of the plant extract on the degradation of oil and the formation of free fatty acids was confirmed by Fourier transform infrared spectroscopy. The result of these study revealed that the ethanolic crude extract of L. sativum and A. corrorima had a potential natural antioxidant to prevent the degradation of palm oil.

Effect of Spoilage by Lipolytic Fungi Strains on Free Fatty Acids (FFA) Formation in Fermented and Dry Cocoa Beans

Aim: High free fatty acids (FFA) content of cocoa beans is high lead to alter quality of butter fraction and chocolate manufactured. During primary post-harvest processing, cocoa beans harbor lipase producing mold speciess could trigger the accumulation of FFA. This study investigated the improvement of the quality of raw cocoa material sourced from Côte d’Ivoire regarding its high FFA concentration.&#x0D; Methods: Fermented and dry cocoa were sampled on-farm level in some main cocoa producing regions of Côte d'Ivoire. Contaminating mold strains were isolated using Sabouraud chloramphenicol agar incubated at 25°C for 7 days. Morphological identification of mold isolates was preformed from younger fungal culture. Biochemical study about lipolytic properties of mold isolates was carried out using Cazpeck-Dox Agar medium enriched with olive oil as carbon source and rhodamine B as indicator of lipase activity. Extraction, PCR amplification using a specific transcribed spacer primer (ITS4/ITS5) and sequencing of DNA were performed for fungal species molecular identification.&#x0D; Results: Approximately 154 mold isolates belonging to 8 genera were found in tested cocoa beans. Only Rhizopus oryzae, Absidia corymbifera, Mucor heimalis, Aspergillus niger, A. tubingensis, A. aculeatus, A. flavus, A. tamari, A. fumigatus, Nigrospora sphaerica, Curvularia geniculate and Penicillium chrysogenum species produced greater lipolytic properties. A. corymbifera, A. niger, A. fumigatus and R. orysae were the most frequent and predominant species. Cocoa beans inoculated with R. oryzae, A. corymbifera or A. niger recorded higher FFA content above 1.75%.&#x0D; Conclusion: Reducing of the mold species growth during cocoa primary post-harvest processing could sustainably produce raw cocoa material with less FFA.

Free Fatty Acid Formation Points in Palm Oil Processing and the Impact on Oil Quality

Background: The level of free fatty acids (FFAs) is an important oil quality index that is consistently measured at mills and refineries to ensure that palm oil is within specification limits. FFAs can accumulate at any point throughout the process, for example, during fresh fruit bunch (FFB) harvesting or during the mill process before sterilisation. Another key contributor to FFA build-up is loose fruit (LF), which is collected following FFB harvesting and is commonly processed together with FFB into crude palm oil (CPO) at the mill. The aim of this study was to identify pivotal points of FFA formation during the process of crude palm oil production. Results: The present study shows that the highest FFA accumulation occurred during the conveying process at the mill before sterilisation due to significant fruit damage. The rapid formation of FFA occurred during the first 15 min of oil palm fruit bruising. A minimum temperature of 60 °C for one hour was needed to deactivate the lipase activity, which is responsible for FFA formation. Blending high-FFA CPO with standard CPO affected indices of palm oil quality, such as the deteriorated peroxide value (PV) and anisidine value (AV), and particularly worsened the bleachability index (DOBI). Conclusions: This study suggests that the conveyor system in the mill could be the prime area to focus on in terms of FFA reduction, along with minimising bruising events. In addition, loose fruits (LF) with high FFA content should be processed separately from FFB, and high-FFA CPO derived from LF should not be mixed with standard CPO.

Diabetic Ketoacidosis Induced ‘Terrible Triad’ Associated With Seizures And Acute Renal Failure: A Rare Case Report

We report a case of diabetic ketoacidosis with a severely elevated triglyceride level (25,585 mg/dL) complicated by acute pancreatitis, renal involvement, and generalized seizures. The proposed mechanism is triglyceride excess due to increased lipolysis, resulting in the formation of excess free fatty acids. A 17-year-old male patient came to the emergency department with abdominal pain, headaches for 2 days, lethargy, and Kussmaul breathing. Diabetic ketoacidosis with several complications was diagnosed. The objective of this case report is to present and describe the clinical features, laboratory investigations, case management, and natural course of hypertriglyceridemia in DKA.

Free Fatty Acids and Cocoa Butter Quality Traits: Causes and Impact on Consumers’ Health

Cocoa butter (CB) technological quality and financial value depend widely on the free fatty acids (FFA) content. Cocoa butter has to contain less than 1.75% free fatty acids (FFA, based on oleic acid) to be in compliance with the EU directive 2000/36/EC (2000) and needs to be free from off-flavours and rancidity from a sensory (taste, odour, colour) and technological point of view. Free fatty acids are carboxylic acids, generated from triglycerides via the hydrolysis of their ester bounds by enzymatic and/or chemical reactions. The present work reviews free fatty acids formation mechanisms in cocoa beans, the free fatty acids levels assay as well as possible reduction methods. Furthermore, the impact of high free fatty acids content on the technological and chemical qualities and on the health of consumer of cocoa derived products were described. The results highlighted that the free fatty acids formation in cocoa beans was ascribed to the endogenous and exogenous lipases activities. Excreted exogenous lipases by contaminated molds during poor post-harvest processing are most active for free fatty acids generation in cocoa beans. In addition, the germination, poor storage conditions such as high water activity and moisture content provoke high free fatty acids content in cocoa butter. Although alkalization, deodorization and other refining treatments are efficient methods for reduction of free fatty acids content, chocolate manufacturers recorded high losses in cocoa butter. It is important to eliminate the free fatty acids content of cocoa butter because excessive consumption of high- free fatty acids cocoa product induces pathologies.

Substrates of Opposite Polarities and Downstream Processing for Efficient Production of the Biosurfactant Mannosylerythritol Lipids from Moesziomyces spp.

Biosurfactants can replace fossil-driven surfactants with positive environmental impacts, owing to their low eco-toxicity and high biodegradability. However, their large-scale production and application are restricted by high production costs. Such costs can be reduced using renewable raw materials and facilitated downstream processing. Here, a novel strategy for mannosylerythritol lipid (MEL) production explores the combination of hydrophilic and hydrophobic carbon sources sideways with a novel downstream processing strategy, based on nanofiltration technology. Co-substrate MEL production by Moesziomyces antarcticus was threefold higher than using D-glucose with low levels of residual lipids. The use of waste frying oil instead of soybean oil (SBO) in co-substrate strategy resulted in similar MEL production. Moesziomyces antarcticus cultivations, using 3.9 M of total carbon in substrates, yields 7.3, 18.1, and 20.1 g/L of MEL, and 2.1, 10.0, and 5.1 g/L of residual lipids, for D-glucose, SBO, and a combination of D-Glucose and SBO, respectively. Such approach makes it possible to reduce the amount of oil used, offset by the equivalent molar increase in D-glucose, improving sustainability and decreasing residual unconsumed oil substrates, facilitating downstream processing. Moesziomyces spp. also produces lipases that broken down the oil and, thus, residual unconsumed oils are in the form of free fatty-acids or monoacylglycerol, which are smaller molecules than MEL. Therefore, nanofiltration of ethyl acetate extracts from co-substrate-based culture broths allows to improve MEL purity (ratio of MEL per total MEL and residual lipids) from 66 to 93% using 3-diavolumes.

Antioxidant and Antimicrobial Effect of Biodegradable Films Containing Pitaya (Stenocereus thurberi) Extracts during the Refrigerated Storage of Fish.

This study focused on the quality loss inhibition of fish muscle during refrigerated storage. Two parallel experiments were carried out that were focused on the employment of pitaya (Stenocereus thurberi) extracts in biodegradable packing films. On the one hand, a pitaya-gelatin film was employed for hake (Merluccius merluccius) muscle storage. On the other hand, a pitaya-polylactic acid (PLA) film was used for Atlantic mackerel (Scomber scombrus) muscle storage. In both experiments, fish-packing systems were stored at 4 °C for 8 days. Quality loss was determined by lipid damage and microbial activity development. The presence of the pitaya extract led to an inhibitory effect (p < 0.05) on peroxide, fluorescent compound, and free fatty acid (FFA) values in the gelatin-hake system and to a lower (p < 0.05) formation of thiobarbituric acid reactive substances, fluorescent compounds, and FFAs in the PLA-mackerel system. Additionally, the inclusion of pitaya extracts in the packing films slowed down (p < 0.05) the growth of aerobes, anaerobes, psychrotrophs, and proteolytic bacteria in the case of the pitaya-gelatin films and of aerobes, anaerobes, and proteolytic bacteria in the case of pitaya-PLA films. The current preservative effects are explained on the basis of the preservative compound presence (betalains and phenolic compounds) in the pitaya extracts.

Effect of Rigor Stage and Pressurisation on Lipid Damage, Total Volatile Amine Formation and Autolysis Development in Palm Ruff Stored on Ice

The effect of the rigor stage (pre or post) and previous high-pressure processing (HPP; 450 and 550 MPa for 3 min) was checked during the storage on ice of farmed palm ruff (Seriolella violacea). Fish processed in pre-rigor conditions led to higher and lower levels (p < 0.05) of moisture and lipid contents in chilled fish, respectively, when compared to their counterpart samples processed in the post-rigor stage. Pre-rigor fish showed a higher (p < 0.05) quality level than post-rigor samples according to the assessment of the K value (59.0-92.1 and 70.3-96.3 ranges, respectively), fluorescent compounds (0.29-1.11 and 0.37-1.90 ranges, respectively), free fatty acids (FFA) (15.1-188.0 and 33.8-232.5 g·kg-1 lipids ranges, respectively), and total volatile amines (216.3-387.6 and 217.7-412.2 g·kg-1 muscle ranges, respectively). Pressure-treated fish showed higher (p < 0.05) quality retention than non-treated samples according to the formation of fluorescent compounds (0.29-0.86 and 0.85-1.90 ranges, respectively), FFA (15.1-50.6 and 58.9-223.5 g·kg-1 lipids ranges, respectively), and total volatile amines (216.3-250.3 and 351.1-412.2 g·kg-1 muscle ranges, respectively) and the evolution of the K value (59.0-77.2 and 86.9-96.3 ranges, respectively). The use of pre-rigor fish and previous HPP is recommended for the commercialisation of the current species as a fresh product.

The Effects of Modified Atmosphere Packaging on the Quality Properties of Water Buffalo Milk's Concentrated Cream.

Concentrated cream (CC) is a dairy product containing more than 60% milk fat. CC has a very short shelf life because it is made from unripe cream. The present study aims to determine how packaging with reducing gas (H2) and nitrogen (N2) affects the quality properties and shelf life of CC. For this purpose, lipolysis, oxidation, color, microbiological, and free fatty acid development and the fatty acid composition of modified atmosphere packaged (MAP) CC samples were studied for 28 days. For MAP1, 96% N2 + 4% H2 was used, and for MAP2, 100% N2 and air was used for the control group. During storage, MAP1 samples remained at lower lipolysis (ADV and FFA) and oxidation levels than MAP2 and the control group. The MAP1 and MAP2 methods preserved the color of the samples and reduced the microbial growth rate. A lower formation of free fatty acids was observed in the samples packed with MAP1 and MAP2 than in the control group. The results showed that hydrogen gas positively affected the quality and storage time of samples.