Concentrations Of Medium-chain Fatty Acids Research Articles

In Vitro Predictive Model for Intestinal Lymphatic Uptake: Exploration of Additional Enhancers and Inhibitors.

Drug absorption via chylomicrons holds significant implications for both pharmacokinetics and pharmacodynamics. However, a mechanistic understanding of predicting in vivo intestinal lymphatic uptake remains largely unexplored. This study aimed to delve into the intestinal lymphatic uptake of drugs, investigating both enhancement and inhibition using various excipients through our previously established in vitro model. It also examined the applicability of the model by assessing the lymphatic uptake enhancement of a lymphotropic formulation with linoleoyl polyoxyl-6 glycerides using the same model. The model successfully differentiated among olive, sesame, and peanut oils in terms of lymphatic uptake. However, it did not distinguish between oils containing long-chain fatty acids and coconut oil. Coconut oil, known for its abundance of medium-chain fatty acids, outperformed other oils. This heightened uptake was attributed to the superior emulsification of this oil in artificial chylomicron media due to its high content of medium-chain fatty acids. Additionally, the enhanced uptake of the tested formulation with linoleoyl polyoxyl-6 glycerides underscored the practical applicability of this model in formulation optimization. Moreover, data suggested that increasing the zeta potential of Intralipid® using sodium lauryl sulfate (SLS) and decreasing it using (+/-) chloroquine led to enhanced and reduced uptake in the in vitro model, respectively. These findings indicate the potential influence of the zeta potential on intestinal lymphatic uptake in this model, though further research is needed to explore the possible translation of this mechanism in vivo.

Pickering emulsion emulsified using novel cellulose nanofibers significantly lowers the lipid release rate and cellular absorption.

A Pickering emulsion is an emulsion system stabilized by solid particles and represents a promising candidate for emulsifying lipids. Cellulose nanofibers (CNFs) have excellent ability to control the lipid release rate. This study aims to find the optimal formulation for a nanocellulose-stabilized Pickering emulsion that is the most effective in reducing the lipid release rate. The Pickering emulsion was prepared by homogenizing pretreated nanocellulose with medium-chain triglycerides using high-speed and ultrasonic homogenizers. The results show that the Pickering emulsion with 0.709% nanocellulose and 30.6% medium-chain fatty acid content yielded an average particle size of approximately 2.5 μm, which is the most stable and effective in reducing the amount of the lipids released. The nanocellulose Pickering emulsion formulation developed in this study forms a significant foundation for future research and applications regarding the use of nanotechnology and Pickering emulsions to maintain the balance between one's health and the desirable flavor of fat.

Odd- and even-numbered medium-chained fatty acids protect against glutathione depletion in very long-chain acyl-CoA dehydrogenase deficiency

Recent trials have reported the ability of triheptanoin to improve clinical outcomes for the severe symptoms associated with long-chain fatty acid oxidation disorders, including very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency.However, the milder myopathic symptoms are still challenging to treat satisfactorily. Myopathic pathogenesis is multifactorial, but oxidative stress is an important component. We have previously shown that metabolic stress increases the oxidative burden in VLCAD-deficient cell lines and can deplete the antioxidant glutathione (GSH).We investigated whether medium-chain fatty acids provide protection against GSH depletion during metabolic stress in VLCAD-deficient fibroblasts. To investigate the effect of differences in anaplerotic capacity, we included both even-(octanoate) and odd-numbered (heptanoate) medium-chain fatty acids. Overall, we show that modulation of the concentration of medium-chain fatty acids in culture media affects levels of GSH retained during metabolic stress in VLCAD-deficient cell lines but not in controls.Lowered glutamine concentration in the culture media during metabolic stress led to GSH depletion and decreased viability in VLCAD deficient cells, which could be rescued by both heptanoate and octanoate in a dose-dependent manner. Unlike GSH levels, the levels of total thiols increased after metabolic stress exposure, the size of this increase was not affected by differences in cell culture medium concentrations of glutamine, heptanoate or octanoate.Addition of a PPAR agonist further exacerbated stress-related GSH-depletion and viability loss, requiring higher concentrations of fatty acids to restore GSH levels and cell viability.Both odd- and even-numbered medium-chain fatty acids efficiently protect VLCADdeficient cells against metabolic stress-induced antioxidant depletion.

Effects of Coix Seed Oil on High Fat Diet-Induced Obesity and Dyslipidemia.

Dietary intervention is becoming more popular as a way to improve lipid metabolism and reduce the prevalence of diet-related chronic disorders. We evaluated the effects of several dietary oils on body weight, fat mass, liver weight, and tumor necrosis factor in obese mice given a high-fat diet (HFD) to discover if coix seed oil (CSO) had an anti-obesity impact. As compared to other dietary fats, CSO treatment considerably lowered body weight and liver index, successfully sup-pressed total cholesterol and triglyceride content, and raised liver lipid deposition and lipid metabolism problem induced by high fat intake. Furthermore, gas chromatography research revealed that CSO extracted by supercritical fluid, with 64% being CSO extracted by supercritical fluid, and the greatest amounts of capric acids and lauric acids being 35.28% and 22.21%, respectively. CSO contained a high content of medium-chain fatty acids and was able to modify hepatic fatty acid metabolism and lipid levels in HFD-induced obese mice. According to the results, CSO has the potential to replace dietary lipids as a promising functional lipid in the prevention of met-abolish disorders.

Molecular characterization and functional exploration of GPR84 in Chinese Giant Salamander (Andrias davidianus)

The G protein-coupled receptor 84 (GPR84) is a putative medium-chain fatty acids (MCFAs) receptor involved in immune regulation and other metabolic processes. Most available studies focused on the GPR84 characterization from mammals, neglecting vital information that could be obtained from other levels of life, such as amphibians, necessary for an apt evolutionary understanding of the orphan GPR84. Hence, this study molecularly characterized and functionally explored the GPR84 from the Chinese Giant Salamander (Andrias davidianus). Therefore, we report that the Chinese Giant Salamander (CGS), one of the world's largest amphibians, expresses a GPR84 protein having 376 amino acids, with about 70% homologous to other amphibians and around 50% to human GPR84. Investigating the relative localized expression of gpr84 mRNA in CGS using quantitative PCR revealed the highest expression in the kidney and liver. Furthermore, four medium-chain fatty acids (MCFAs) at micromolar levels activated CGS-GPR84 transfected and expressed in HEK293 cells. In HEK293 cells, four different concentrations of MCFAs inhibited forskolin-induced cAMP accumulation and resulted in a dose-dependent increase in extracellular signal-regulated kinases 1 and 2 (ERK1/2). Interestingly, MCFAs activation of GPR84 concomitantly led to the upregulation of inflammatory mediators such as Nuclear Factor Kappa B (NF-κB) and IL-6. Conclusively, this study successfully elucidated the intriguing molecular and functional properties of CGS GPR84, particularly as an immune modulator, and has positioned the findings within the existing body of knowledge for a better overall understanding of GPR84, especially in amphibians.

Ketogenic diet-induced cardiac fibrosis is independent of long-chain and medium-chain fatty acid content and mitochondrial biogenesis in mice.

Ketogenic diet-induced cardiac fibrosis is independent of long-chain and medium-chain fatty acid content and mitochondrial biogenesis in mice.

Role Medium-Chain Fatty Acids in the Lipid Metabolism of Infants.

Human breastmilk, the ideal food for healthy infants, naturally contains a high concentration of medium-chain fatty acids (MCFAs, about 15% of total fatty acids). MCFAs are an important energy source for infants due to their unique digestive and metabolic properties. MCFA-enriched oils are widely used in an infant formula, especially the formula produced for preterm infants. Recently, there has been a growing interest in the triglyceride structure of MCFAs in human milk, their metabolism, and their effects on infant health. This study summarized the MCFA composition and structure in both human milk and infant formula. Recent studies on the nutritional effects of MCFAs on infant gut microbiota have been reviewed. Special attention was given to the MCFAs digestion and metabolism in the infants. This paper aims to provide insights into the optimization of formulations to fulfill infant nutritional requirements.

Influence of cane and beet sugar for second fermentation on “fruity” aromas in Auxerrois sparkling wines

Traditional Method sparkling wine production requires a sugar addition to the base wine to initiate the second alcoholic fermentation in bottles. This study aimed to identify differences in “fruity” volatile aroma compounds (VOCs) in Traditional Method sparkling wines produced from the addition of either cane sugar or beet sugar to Auxerrois base wines. Wines underwent a second fermentation in bottles inoculated with IOC 18-2007 yeast and fermented at 15 °C. Standard chemical analysis was carried out on base wines and sparkling wines. The concentrations of fourteen “fruity” volatile aroma compounds representing five classes of compounds were analysed by Headspace-Solid-Phase Micro-Extraction-Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS). Cane and beet sugars were analysed in de-aromatised wine and distilled water to establish the concentrations of VOCs present in the sugar products prior to addition to wine. Wines were analysed on the day of inoculation and bottling and again after the second fermentation. Beet sugar significantly (Pt < 0.05) increased the concentration of linear fatty acid-derived ethyl esters (ethyl octanoate, ethyl hexanoate, and ethyl butyrate) compared to cane sugar in sparkling wine. These results are attributed to higher concentrations of medium-chain fatty acids found in beet sugar due to the duration of sugar beet storage prior to processing. Recommended future research includes monitoring aroma compounds during ageing on lees, sensory analysis, and an investigation of a wider range of sugar products permitted for use in sparkling wine production.

Recovery of bio-based medium-chain fatty acids with membrane filtration

Medium-chain fatty acids (MCFAs) are promising platform chemicals for biorefineries in the circular economy. An efficient and sustainable process for their recovery from biomass, however, remains elusive. This work aimed to develop a separation cascade for MCFA recovery from fermentation broth (FB) using membrane filtration. This technical-scale process consisted of a filter-press, thermal-pretreatment, ultrafiltration (UF), and nanofiltration (NF). While solid–liquid separation and UF were efficient, NF fluxes declined rapidly due to membrane fouling, limiting MCFA separation and concentration. Thermal pretreatment and UF membrane pore size had a negligible effect on filtration performance and diafiltration trials in NF proved ineffective. While process feasibility is presently constrained by membrane fouling in NF, characterization, and reduction of foulants could make the process readily viable. Overall, the membrane filtration cascade yielded a product, the NF retentate, with an MCFA concentration approximately 230% greater than that of the feedstock with an average overall recovery of 84%. Furthermore, although the concentration of MCFAs (C4-C8, 12.9 gL–1) may be inadequate for direct use, this product, being clarified and enriched, could serve as an improved feedstock for MCFA purification by alternative methods.

Organic acid blends improve intestinal integrity, modulate short-chain fatty acids profiles and alter microbiota of broilers under necrotic enteritis challenge.

Controlling enteric diseases of broilers is crucial. Among many additives, organic acids (OA) and their blends are gaining attention to combat diseases in the post-antibiotic era. The current study evaluated the potentials of short-chain fatty acids (SCFA) and medium-chain fatty acids (MCFA) blends and/or phenolic compounds on intestinal integrity, intestinal pH, caecal microbiota, and caecal SCFA profiles of broilers under necrotic enteritis (NE) challenge. The additives used were: (A) a blend of SCFA, MCFA, and a phenolic compound (SMP), (B) a blend of free and buffered SCFA with MCFA (SMF), and (C) a blend of free and buffered SCFA with a high concentration of MCFA (SHM). A total of 1,404 male parental chicks of Ross 308 broilers were randomly allocated to 78 floor pens on hatching day with 6 treatments replicated 13 times with 18 birds per pen. The treatments were: UCC, unchallenged control; CHC, challenged control; BAC, challenged group plus zinc bacitracin; SMP, challenged group plus additive SMP; SMF, challenged group plus additive SMF; SHM, challenged group plus additive SHM. Birds were challenged with field-strain Eimeria spp. on d 9 and Clostridium perfringens on d 14. Birds challenged with NE increased fluorescein isothiocyanate dextran (FITC-d) concentration in serum, reduced acetate and butyrate concentrations, and increased Bacteroides and C. perfringens load in the caeca (P < 0.05). Birds fed additives decreased FITC-d from gut to serum, reduced Bacteroides (d 16, P < 0.05) and numerically reduced C. perfringens load compared to CHC group. Birds fed additive SHM had higher concentrations of acetate and butyrate (d 21, P < 0.05) than CHC group but were not different from SMP and SMF groups. All the additives exhibited similar intestinal protection against NE compared to the BAC group indicated by FITC-d concentration in serum, acetate, propionate and butyrate concentrations in the caeca, and caecal bacterial loads except for the C. perfringens (P > 0.05). The SMP group had a higher load compared to BAC (P < 0.05). These findings suggest the promising effects of OA blends as alternatives to BAC to ameliorate the impact of NE challenge of broilers as indicated by improved intestinal health.

Potential of blended organic acids to improve performance and health of broilers infected with necrotic enteritis.

Organic acids (OA) and their blends have been shown to positively affect performance and health of broilers. However, the data in the literature are not consistent. This study examined the potential of blended short-chain fatty acids (SCFA) with medium-chain fatty acids (MCFA) as alternatives to antibiotic growth promoters (AGP) on performance, health and welfare of broilers infected with necrotic enteritis (NE). The additives used were: A) a blend of SCFA, MCFA, and a phenolic compound (SMP); B) a blend of free and buffered SCFA with MCFA (SMF); C) a blend of free and buffered SCFA with a high concentration of MCFA (SHM). A total of 1,404 Ross 308 one-day-old male parental chicks were randomly distributed into 78-floor pens with 13 replicates of 18 birds each. Six treatments were the following: T1, unchallenged control (UCC); T2, challenged control (CHC); T3, challenged group plus zinc bacitracin (BAC); T4, challenged group plus additive SMP; T5, challenged group plus additive SMF; T6, challenged group plus additive SHM. Challenged birds were gavaged with Eimeria spp. on d 9 and Clostridium perfringens EHE-NE18 on d 14. Post NE challenge and cumulatively, BWG, FCR, and nutrient digestibility of birds were compromised (P < 0.05) by NE challenge indicating a successful induction of sub-clinical NE. Additive SHM had higher BWG compared to CHC and BAC groups (P = 0.001; d 10 to 24) but not different from SMP and SMF groups (P > 0.05). All the 3 additive groups had lower FCR compared to CHC (P = 0.001; d 0 to 35), and exhibited similar jejunal lesions (d 16) compared to BAC and apparent ileal protein digestibility (d 21) compared to UCC and BAC groups (P > 0.05). Birds in additive SHM group had a higher concentration of serum IgA compared to all groups (P = 0.001) except additive SMF (P > 0.05; d 21). All the additive groups had lower footpad dermatitis and hock burns compared to CHC (P < 0.05). The findings suggest the potential of blended OA as alternatives to BAC to protect broilers from NE indicated by improved FCR, immunity, digestibility, and bird welfare.

Effects of medium chain fatty acids as a mitigation or prevention strategy against porcine epidemic diarrhea virus in swine feed.

Feed has been shown to be a vector for viral transmission. Four experiments were conducted to: 1) determine if medium chain fatty acids (MCFA) are effective mitigants when applied to feed both pre- and post-porcine epidemic diarrhea virus (PEDV) inoculation measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR), 2) evaluate varying levels and combinations of MCFA measured by qRT-PCR, and 3) evaluate selected treatments in bioassay to determine infectivity. In exp. 1, treatments were arranged in a 2 × 2 + 1 factorial with main effects of treatment (0.3% commercial formaldehyde [CF] product, Sal CURB [Kemin Industries, Inc.; Des Moines, IA], or 1% MCFA blend (Blend) of 1:1:1 C6:C8:C10 [PMI, Arden Hills, MN]) and timing of application (pre- or post-inoculation with PEDV) plus a positive control (PC; feed inoculated with PEDV and no treatment). All combinations of treatment and timing decreased detectable PEDV compared with the PC (P < 0.05). Pre-inoculation treatment elicited decreased magnitude of PEDV detection (cycle threshold value) compared with post-inoculation (P = 0.009). Magnitude of PEDV detection was decreased for CF compared with Blend (P < 0.0001). In exp. 2, pre-inoculation treatments consisted of: 1) PC, 2) 0.3% CF, 3 to 5) 0.125% to 0.33% C6:0, 6 to 8) 0.125% to 0.33% C8:0, 9 to 11) 0.125% to 0.33% C10:0, and 12 to 15) 0.125% to 0.66% C5:0. Treating feed with 0.33% C8:0 resulted in decreased (P < 0.05) PEDV detection compared with all other treatments. Increasing concentration of each individual MCFA decreased PEDV detectability (P < 0.042). In exp. 3, pre-inoculation treatments consisted of: 1) PC, 2) 0.3% CF, 3 to 7) 0.25% to 1% Blend, 8 to 10) 0.125% to 0.33% C6:0 + C8:0, 11 to 13) 0.125% to 0.33% C6:0 + C10:0, and 14 to 16) 0.125% to 0.33% C8:0 + C10:0. Treating feed with CF, 0.5% Blend, 0.75% Blend, 1% Blend, all levels of C6:0+C8:0, 0.25% C6:0 + 0.25% C10:0, 0.33% C6:0 + 0.33% C10:0, 0.25% C8:0 + 0.25% C10:0, or 0.33% C8:0 + 0.33% C10:0 elicited decreased detection of PEDV compared with PC (P < 0.05). Increasing concentration of each MCFA combination decreased PEDV detectability (linear, P < 0.012). In exp. 4, feed was treated pre-inoculation with: 1) no treatment (PC), 2) 0.3% CF, 3) 0.5% Blend, or 4) 0.3% C8:0 and analyzed via qRT-PCR and bioassay. Adding 0.5% Blend or 0.3% C8:0 resulted in decreased PEDV compared with PC and only PC resulted in a positive bioassay. Therefore, MCFA can decrease detection of PEDV in feed. Further, inclusion of lower levels of MCFA than previously evaluated are effective against PEDV.

A Comparison Between Goat and Human Milk in Infant Feeding

Goat milk is an ideal replacement for cow milk. Comparing goat milk with human milk was examined in order to evaluate its nutritional values with respect to infant feeding. It was observed that goat milk characterized with higher acidity, total solids, protein, fat, ash, energy value, and mineral contents, and lower lactose and pH than human milk. The nitrogen distribution presented Evident differences in the nitrogen distribution in two species, especially in the ratios of nitrogen distribution, such as NPN/TN, WN/TN, WPN/CN and CN/TN. The amino acid profile of the two proteins considerably varied. Generally, the amino acid pattern of goat milk proteins satisfactory balance of essential amino acids content for the infant diet. The composition of fats was well-differentiated, mainly as the content of medium-chain fatty acids, which were higher in the goat milk. Human milk, on the other hand, contained higher levels of the long chain fatty acids. It could also be concluded that goat milk could be considered as a good food of high nutritive value, but when using goat's milk to feed infants, it should be diluted to reduce the protein and mineral content, alter the milk protein ratio by increasing the whey protein, and to raise the Ca: P ratio from 1.2 to 2.0. It could also be added that carbohydrates, vegetable oils and vitamins are of importance, to ensure the goat's milk is a suitable for infants' consumption.

Milk metabolites as noninvasive indicators of nutritional status of mid-lactation Holstein and Montbéliarde cows

The objective was to investigate the effects of feed restriction on concentrations of selected milk metabolites in mid-lactation Holstein and Montbéliarde cows and to explore their correlations with energy balance and classic plasma and milk indicators of nutritional status. Eight Holstein and 10 Montbéliarde cows (165 ± 21 d in milk) underwent 6 d of feed restriction during which feed allowance was reduced to meet 50% of their net energy for lactation (NEL) requirements. The experiment was divided in 4 periods: control (CON; d -3 to -1), restriction (RES; d 1 to 6), wk 1 (W1; d 7 to 13), and wk 2 (W2; d 14 to 18) after refeeding at ad libitum intake. Intake, milk production, energy balance and plasma metabolites were used to validate the feed restriction model. Concentrations of 7 milk metabolites: β-hydroxybutyrate (BHB), glucose, glucose-6-phosphate, isocitrate, glutamate, uric acid, and free amino groups were measured in morning milk samples, and fatty acids were measured in pooled p.m. and a.m. samples. Feed restriction induced a negative energy balance (-42.5 ± 4.4 MJ/d), increased plasma nonesterified fatty acids and BHB, and decreased plasma glucose concentrations. Feed restriction increased milk glucose-6-phosphate and isocitrate (+38% and +39%, respectively) and decreased milk BHB, glucose, glutamate, uric acid and free amino group concentrations (-20%, -57%, -65%, -42%, and -14%, respectively), compared with pre- restriction. Milk concentrations of medium-chain fatty acids (e.g., sum of C10 to C15) decreased and those of long chain (e.g., 18:0, cis-9 18:1) increased during restriction. Breed differences were not detected for the majority of variables. All studied milk metabolites were significantly correlated with energy balance (Spearman correlation = 0.48, 0.63, -0.31, -0.45, and 0.61 for BHB, glucose, glucose-6-phosphate, isocitrate, and glutamate, respectively). Milk glucose and glutamate showed the strongest correlations with plasma metabolites and milk FA associated with lipomobilization. These results suggest that milk metabolites may be used as noninvasive indicators of negative energy balance and metabolic status of dairy cows.

Triacylglycerol containing medium-chain fatty acids (MCFA-TAG): The gap between human milk and infant formulas

The high concentration of medium-chain fatty acids (MCFAs) in human milk has special benefits for infants. The study compared the characteristic of triacylglycerol containing MCFAs (MCFA-TAG) in human milk and infant formulas with different fat sources including plant oil, cows' milk and goats' milk (POF, CMF and GMF, respectively). Significant differences were observed in both the concentration and composition of the MCFA-TAG. The MCFAs naturally present in human milk were medium-and-long chain triacylglycerols (MLCTs), especially the TAG with one MCFA and two long-chain fatty acids (MLL type), whereas POF contained higher proportions of the TAG with three MCFAs (MMM type) and GMF contained higher proportions of the TAG with two MCFAs and one LCFA (MML type) than that in human milk. The results indicated that deeper research is needed to narrow the gap in MCFA-TAGs between human milk and infant formulas.

Relationship between the fatty acid profile of hair and energy availability of lactating primiparous cows.

We hypothesised that a relationship would exist between hair fatty acids, especially C12:0, C14:0 and C16:0, and parameters of energy metabolism such as energy intake, energy mobilisation, and energy requirement for maintenance and milk performance. For this study, 11 primiparous German Holstein cows were available from which hair samples at weeks 6 and 8 of lactation were analysed. The average body weight of these animals was 558 ± 27 kg at calving and milk yield at 100-days in milk was 3,537 ± 529 kg. Feed intake and milk yield were measured daily. Body weight and back fat thickness were measured at calving and in weeks 2, 4, and 8 of lactation. Energy balance and energy utilisation were calculated until week 6 of lactation. Spearman's correlation coefficients were found to be significantly positive for the relationship between the percentage of C12:0 and C14:0 fatty acids in the hair in lactation week 8 and energy intake in weeks 5 and 6 (0.62 &lt; r &lt; 0.65, P &lt; 0.05). If the animals are grouped according to their energy utilisation between weeks 1 and 6 into two groups higher (n = 6) or lower (n = 5) than the median, animals of the high energy utilising group had a higher energy intake. These animals had also higher percentages of the C12:0 fatty acid in their hair fat (week 6: 4.9% vs. 3.1%, P &lt; 0.05; week 8: 4.3% vs. 2.9%, P = 0.05). Our hypothesis is supported, and this study justifies further investigation of the content of medium-chain fatty acids in hair samples as biomarkers for the metabolic status of a cow during early lactation.

Lipid compositional changes and oxidation status of ultra-high temperature treated Milk

BackgroundMilk fat is one of the complex fat and most sensitive biochemical compounds towards auto-oxidation. To enhance the shelf life, milk is subjected to Ultra-high Temperature (UHT) treatment followed by aseptic packaging. During the storage, several chemical and biochemical changes take place in lipid fraction of UHT milk. In current investigation, the effect of UHT treatment and storage was determined by making a comparison in fatty acid profile, triglyceride composition, organic acids and lipid oxidation of the thermally treated and stored milk with raw milk, which was not reported in earlier investigations.MethodsRaw milk samples were collected from the bulk storage facility of a dairy industry. The same milk was routed to UHT treatment and aseptically packaged samples were collected. The fatty acid profile, triglyceride composition, organic acids and lipid oxidation was determined in raw and UHT treated milk at 0, 30, 60 and 90 days. Fatty acid and triglyceride profile was determined on GC-MS while organic acids were determined by HPLC. For the measurement of induction period, professional Rancimat was used. Lipid oxidation was characterized through free fatty acids, peroxide value, anisidine value and conjugated dienes.ResultsCompositional attributes of milk remain unchanged during the entire length of storage. Concentrations of short-chain fatty acids in raw and UHT milk were 10.49% and 9.62%. UHT treatment resulted in 8.3% loss of short-chain fatty acids. Up to 30 days, storage did not have any significant effect on fatty acid profile of UHT milk. Concentration of medium-chain fatty acids in raw and UHT treated milk was 54.98% and 51.87%. After 30, 60 and 90 days of storage, concentration of medium chain fatty acids was found 51.23%, 47.23% and 42.82%, respectively. Concentration of C18:1 and C18:2 in raw and UHT milk was 26.86% and 25.43%, respectively. The loss of C18:1 and C18:2 in UHT treatment was 5.32%. After 30, 60 and 90 days of storage, the concentrations of C18:1 and C18:2 were 24.6%, 21.06% and 18.66%, respectively. Storage period of 30 days was found non-significant, while noticeable variations were found in triglyceride profile of 60 and 90 days old samples of UHT milk. UHT treatment and storage period significantly affected the concentration of organic acids in milk. After UHT treatment, concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid increased by 3.45, 0.66, 3.57, 0.68, 2.24, 2.16 and 1.63 mg/100 g. Effect of storage period on the production of organic acids in UHT milk was non-significant up to 30 days. After 60 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 3.79, 0.75, 4.69, 0.78, 2.83, 3.03 and 2.38 mg/100 g. After 90 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 7.3, 2.18, 9.96, 3.58, 11.37, 5.22 and 5.96%. Free fatty acids content of raw, UHT treated and 90 days old milk were 0.08%, 0.11% and 0.19%. UHT treated version of milk showed similar peroxide value. While, the storage remarkably affected the peroxide value. After 30, 60 and 90 days, peroxide value was 0.42, 0.62 and 1.18 (MeqO2/kg). Induction period of raw, UHT and stored milk was strongly correlated with peroxide value and fatty acid profile. Mean value of lipase activity in raw milk was 0.73 ± 0.06 μmoles/ml. UHT treatment significantly decreased the lipase activity. The lipase activity of milk immediately after the UHT treatment was 0.18 ± 0.02 μmoles/ml. Lipase activity of UHT milk after 30, 60 and 90 days of room temperature storage was 0.44 ± 0.03, 0.95 ± 0.07 and 1.14 ± 0.09 μmoles/ml. Color, flavor and smell score decreased through the storage of UHT milk for 90 days.ConclusionThe results of this investigation revealed that fatty acid and triglyceride profile changed after 60 and 90 days of storage. Production of organic acids led to the drop of pH and sensory characteristics in UHT milk during the long-term storage. Induction period can be successfully used for the determination of anticipatory shelf life of UHT milk.

Increasing medium chain fatty acids production in Yarrowia lipolytica by metabolic engineering

BackgroundOleaginous yeast Yarrowia lipolytica is an organism of choice for the development of biofuel and oleochemicals. It has become a chassis for metabolic engineering in order to produce targeted lipids. Understanding the function of key-enzymes involved in lipid metabolism is essential to design better routes for enhanced lipid production and for strains producing lipids of interest. Because medium chain fatty acids (MCFA) are valuable compounds for biokerosene production, we previously generated strains capable of producing MCFA up to 12% of total lipid content (Rigouin et al. in ACS Synth Biol 6:1870–1879, 2017). In order to improve accumulation and content of C14 fatty acid (FA), the elongation, degradation and accumulation of these MCFA in Yarrowia lipolytica were studied.ResultsWe brought evidence of the role of YALI0F0654 (YlELO1) protein in the elongation of exogenous or de novo synthesized C14 FA into C16 FA and C18 FA. YlELO1 deletion into a αFAS_I1220W expressing strain leads to the sole production of C14 FA. However, because this strain does not provide the FA essential for its growth, it requires being cultivated with essential fatty acids and C14 FA yield is limited. To promote MCFA accumulation in Y. lipolytica without compromising the growth, we overexpressed a plant diglyceride acyltransferase specific for MCFA and reached an accumulation of MCFA up to 45% of total lipid content.ConclusionWe characterized the role of YlELO1 in Y. lipolytica by proving its involvement in Medium chain fatty acids elongation. We showed that MCFA content can be increased in Yarrowia lipolytica by promoting their accumulation into a stable storage form (triacylglycerides) to limit their elongation and their degradation.

Development of an Effective Chain Elongation Process From Acidified Food Waste and Ethanol Into n-Caproate.

Introduction: Medium chain fatty acids (MCFAs), such as n-caproate, are potential valuable platform chemicals. MCFAs can be produced from low-grade organic residues by anaerobic reactor microbiomes through two subsequent biological processes: hydrolysis combined with acidogenesis and chain elongation. Continuous chain elongation with organic residues becomes effective when the targeted MCFA(s) are produced at high concentrations and rates, while excessive ethanol oxidation and base consumption are limited. The objective of this study was to develop an effective continuous chain elongation process with hydrolyzed and acidified food waste and additional ethanol.Results: We fed acidified food waste (AFW) and ethanol to an anaerobic reactor while operating the reactor at long (4 d) and at short (1 d) hydraulic retention time (HRT). At long HRT, n-caproate was continuously produced (5.5 g/L/d) at an average concentration of 23.4 g/L. The highest n-caproate concentration was 25.7 g/L which is the highest reported n-caproate concentration in a chain elongation process to date. Compared to short HRT (7.1 g/L n-caproate at 5.6 g/L/d), long HRT resulted in 6.2 times less excessive ethanol oxidation. This led to a two times lower ethanol consumption and a two times lower base consumption per produced MCFA at long HRT compared to short HRT.Conclusions: Chain elongation from AFW and ethanol is more effective at long HRT than at short HRT not only because it results in a higher concentration of MCFAs but also because it leads to a more efficient use of ethanol and base. The HRT did not influence the n-caproate production rate. The obtained n-caproate concentration is more than twice as high as the maximum solubility of n-caproic acid in water which is beneficial for its separation from the fermentation broth. This study does not only set the record on the highest n-caproate concentration observed in a chain elongation process to date, it notably demonstrates that such high concentrations can be obtained from AFW under practical circumstances in a continuous process.

Embelin and its derivatives unravel the signaling, proinflammatory and antiatherogenic properties of GPR84 receptor

GPR84 is an orphan G-protein coupled receptor, expressed on monocytes, macrophages and neutrophils and is significantly upregulated by inflammatory stimuli. The physiological role of GPR84 remains largely unknown. Medium chain fatty acids (MCFA) activate the receptor and have been proposed to be its endogenous ligands, although the high concentrations of MCFAs required for receptor activation generally exceed normal physiological levels. We identified the natural product embelin as a highly potent and selective surrogate GPR84 agonist (originally disclosed in patent application WO2007027661A2, 2007) and synthesized close structural analogs with widely varying receptor activities. These tools were used to perform a comprehensive study of GPR84 signaling and function in recombinant cells and in primary human macrophages and neutrophils. Activation of recombinant GPR84 by embelin in HEK293 cells results in Gi/o as well as G12/13-Rho signaling. In human macrophages, GPR84 initiates PTX sensitive Erk1/2 and Akt phosphorylation, PI-3 kinase activation, calcium flux, and release of prostaglandin E2. In addition, GPR84 signaling in macrophages elicits Gi Gβγ-mediated augmentation of intracellular cAMP, rather than the decrease expected from Giα engagement. GPR84 activation drives human neutrophil chemotaxis and primes them for amplification of oxidative burst induced by FMLP and C5A. Loss of GPR84 is associated with attenuated LPS-induced release of proinflammatory mediators IL-6, KC-GROα, VEGF, MIP-2 and NGAL from peritoneal exudates. While initiating numerous proinflammatory activities in macrophages and neutrophils, GPR84 also possesses GPR109A-like antiatherosclerotic properties in macrophages. Macrophage receptor activation leads to upregulation of cholesterol transporters ABCA1 and ABCG1 and stimulates reverse cholesterol transport. These data suggest that GPR84 may be a target of therapeutic value and that distinct modes of receptor modulation (inhibition vs. stimulation) may be required for inflammatory and atherosclerotic indications.