Free Fatty Acid Content Research Articles

Development of novel API-based deep eutectic solvents for esterification of high free fatty acid

Low-value feedstocks containing high free fatty acid (FFA) content are incompatible with direct alkali-catalysed transesterification, and require a deacidification step through esterification to reduce its FFA level. Herein, innovative acid catalysts were developed based on deep eutectic solvents (DESs) to pretreat low-quality palm oil (12.43 % FFA). DESs were formed using Brønsted acids (5-sulfosalicylic acid and benzenesulfonic acid) and an active pharmaceutical ingredient (paracetamol) at a 3:1 molar ratio. The DESs were characterized using ATR-FTIR and Hammett acidity function (H0). DES catalyst dosage, methanol requirement, reaction time and temperature parameters were optimized, and its recyclability was evaluated. The FFA contents were reduced to below the limit of < 2 % using acidic DESs at optimized conditions. Reaction kinetics revealed that DES-catalysed reactions followed the pseudo first order rate of reaction and required the lowest activation energy of 40.91 kJ/mol. Through the Eyring-Polanyi thermodynamic study, the DES-catalysed esterification reactions were endothermic (ΔH° > 0), non-spontaneous (ΔS° < 0 and ΔG° > 0) and endergonic. COSMO-RS computational calculations reveal the viable formation of the DESs based on its moieties, and supports the good solubility of the DESs in methanol. This study demonstrates the feasible valorisation of low-value feedstocks using innovative catalysts in enabling biodiesel production.

The use of chitosan aerogels as an adsorbent for the regeneration of frying oil

One of the most commonly used food preparation methods is deep-fat frying. The improvement of the quality of used frying oil (UFO) is important because the reuse of frying oil could provide significant savings to the food industry. This study aimed to enhance the quality of used sunflower oil by using chitosan aerogels (CA), which can be considered as novel adsorbents with an increased surface area compared to chitosan powder. Aerogels are novel nanostructured materials with high porosity and large surface area. In this study, CA were produced by drying the 2% (w/v) chitosan gels using supercritical drying. In the study, 32 consecutive deep-fat frying were performed using potato slices in sunflower oil at 180 ± 5 °C. The effect of the adsorbent concentration (0.5, 1, and 2% (w/w)) and different adsorption temperatures (90, 135, and 180 °C) were studied by examining the UFO before and after the adsorption treatments. The physicochemical properties of the oil were analyzed by determining free fatty acid (FFA) content, total polar compounds (TPC), smoke point, p-anisidine value (p-AnV), and color (CIE L*, a*, b*). Moreover, the structural changes of aerogels after the adsorption process were investigated by Fourier Transform Infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). CA could reduce the % FFA values from 0.44% to 0.18% due to the ionic interaction between CA and FFA. In addition, TPC value and the smoke point increased after the treatments. The p-AnV was compensated with CA, indicating that secondary oxidation products were adsorbed. Moreover, CA caused a darker color after the adsorption treatments. Additionally, compared with magnesium silicate, the same concentrations of CA were found more effective in improving all the quality parameters of oil except for the L* values.

Biodiesel Production from Rice-Wash Water with Streptomyces fradiae Fermentation: Improved Free Fatty Acid Concentration

The lipid-producing gram-positive bacteria were isolated from soil and it was identified as Streptomyces fradiae JJ1 MK733985.1. Bacterial lipid synthesis was explored using rice washed water through the fermentation research. The exponential growth phase was reached on the fifth day of fermentation, according to the results. The ability of Streptomyces fradiae to produce microbial oil was compared to that of International Streptomyces Project-2 Medium (ISP2) medium. The results showed that RWW culture medium yielded 85.4% fatty acids and 60.3 g/L biomass, while ISP2 medium yielded 83.2% wt fatty acids and 59.5 g/L biomass. The microbial oil was transesterified into Fatty acid methyl esters (FAME), and its characteristics were studied using American Society for Testing Materials (ASTM) standards. The specific gravity was 0.864, the density was 0.863, the gross heating value was 42498 kj/kg, the cetane number was 37, and the acid value was 0.46. Streptomyces fradiae grew with an ISP2 density of 0.835, specific gravity of 0.845, gross heating value of 42326 kj/kg, and acid value of 0.43. According to the findings, Streptomyces fradiae isolated from soil can grow in RWW medium for the first time and provide the same yield as commercial media while being significantly less expensive.

The role of microbial coagulants on the physicochemical, proteolysis, microstructure and sensory properties of low-fat Edam cheese manufactured from ultrafiltered buffalo milk

This work investigates the influence of using microbial coagulants, including Rhizomucor miehei (MCR) protease and Cryphonectria parasitica (MCC) protease, on the quality characteristics of low-fat Edam cheese made from ultrafiltered buffalo milk (LFUE). Concurrently, a benchmark with calf rennet (CR) has been also performed. Throughout a 90-day ripening period, the cheeses were assessed for their physicochemical features, proteolysis, texture, free amino acid and free fatty acid content, microstructure, and sensory attributes. The study revealed that both microbial coagulants had no significant impact on the physicochemical composition and firmness of the cheeses while slightly affected the free fatty acids. Cheeses made with microbial coagulants displayed higher proteolysis, with MCR and MCC cheeses exhibiting greater levels of water-soluble nitrogen and 12% trichloroacetic acid-soluble nitrogen than CR cheese. MCR and MCC cheeses exhibited more extensive breakdown of αs- and β-caseins, as indicated by the SDS-PAGE electrophoretogram, compared to CR cheese during ripening. As for the proteolytic activity, the microbial coagulant contributed to shaping the free amino acid content, microstructure, and sensory qualities of the cheeses. Notably, MCC cheese outperformed MCR or CR cheeses in terms of free amino acid levels. MCR and MCC cheeses resulted in smooth microstructures with uniform protein networks as observed by microscopy, while CR cheese displayed rough, granular surfaces. With the highest scores for appearance, body, texture, and flavor, MCC cheese demonstrated superior sensory properties compared with MCR and CR cheeses.

Effect of Chitosan Addition on Porosity of Rice Husk Calcium Silicate Used for Free Fatty Acid Adsorbent from Palm Oil

Studies have been done on developing calcium silicate pores derived from rice husk with and without including chitosan as a template. The chitosan solution was supplemented with sodium silicate derived from rice husk, and then CaCl2 was added. The calcium silicate was calcinated at 900ºC for 4 h. The calcium silicate obtained was characterized using X-ray diffraction (XRD), fourier transform infrared (FT-IR), and Brunauer-Emmett-Teller (BET) analysis. The XRD analysis showed the presence of diffraction peaks corresponding to Wollastonite (CaSiO3) crystals, Wollastonite 2m (CaSiO3), Alite (Ca3SiO5), and larnite (Ca2SiO4). Next, the FT-IR spectrum exhibits Si-O-Si, Si-O-Ca, and Si-OH functional groups, suggesting the presence of calcium silicate material. The BET study of calcium silicate using chitosan templates revealed a pore size of 3.88 nm, a pore volume of 0.1577 cc/g, and a surface area of 81.1519 m2/g. The BET analysis results obtained differed from those of the BET analysis of calcium silicate conducted without using chitosan templates, which were 2.06 nm, 0.069 cc/g, and 13.531 m2/g, respectively. The developed mesoporous calcium silicate was employed as an adsorbent to decrease the concentrations of free fatty acids in palm oil. The acid-base titration method is used to evaluate quantities of free fatty acids. The results obtained from the computation of free fatty acid levels indicate a decline in the concentration of free fatty acids in palm oil. The concentration of free fatty acids derived from palm oil was 1.23%. Therefore, mesoporous calcium silicate-free fatty acids at a concentration of 1.06% resulted in an 86.1% reduction.

Effect of lipase addition on inhibition of starch retrogradation in rice

We investigated whether the production of the free fatty acids (FFAs) by the addition of lipase during rice cooking inhibits starch retrogradation, and to examine whether proteins are involved in this process. Rice milled with milling ratios of 90%, 80%, 70%, and 60% and alkaline-soaked raw rice (AS) were prepared to obtain samples with different protein content. The protein content decreased from 8.24% to 5.83% as the milling ratio decreased from 90% to 60%, and AS contains 4.58% of protein. The prepared rice was cooked with and without lipase, and then treated with two freeze-thaw cycles to accelerate starch retrogradation. The addition of lipase increased the FFAs content and the peroxide value form 1.65 meq/kg to 4.75 meq/kg and decreased the free thiol (SH) content in cooked rice. The degree of swelling was reduced by 0.14 during cooking with the addition of lipase in cooked rice with a milling ratio of 90%. The degree of starch retrogradation (Dr) tended to increase as the milling ratios decreased from 90% to 60% and AS showed Dr similar to milling ratio of 60%. The degree of amylose-lipid complexes formation, which is involved in the inhibition of starch retrogradation, did not change with or without lipase, suggesting that the inhibitory effect of lipase became smaller as protein decreased. These results suggest that the FFAs produced by lipase converted the free SH of the protein into disulfide bonds, which altered the swelling characteristics of the starch and eventually inhibited the starch retrogradation.

Sustainable Enzymatic Production of Omega-3 Oil from Squid Viscera

Fish oils are widely consumed around the world to increase omega-3 fatty acid intake. Due to negative impacts on marine resources and ecosystems from an increasing demand for fish, alternative sustainable sources are under investigation. Squid viscera contains up to 10% oil by mass and is available as a byproduct from squid processing. Squid viscera oil is a source of EPA and DHA and contains the xanthophyll carotenoid astaxanthin, known for its significant anticancer, antioxidant, antidiabetic, and cardiovascular properties. In the raw form, squid viscera oil has a high free fatty acid (FFA) content, so conventional alkaline refining results in low yield and loss of astaxanthin. As a higher-yielding alternative, the current study optimized lipase-catalyzed glycerolysis of squid viscera oil to convert FFA into acylglycerol using a custom-built one-liter immobilized enzyme reactor. To monitor the reaction progress and assess its impact on the oil, we analyzed lipid classes, fatty acid composition and astaxanthin levels. Under optimized conditions, FFA was reduced from 40% to 2.7% in 10 h and 1.7% in 24 h, with no significant effect on EPA and DHA levels, and astaxanthin being retained. Squid viscera presents a safe and sustainable additional source of marine-derived EPA and DHA oil.

Antioxidant activities of lemon and mandarin peel extracts as natural preservatives in ghee (butter oil) stored at different storage temperatures

Using natural preservatives in ghee and fat-rich products has great economic importance as it can minimize adverse effects on human health and improve the marketing prospects of products. The present study aimed to use lemon (Citrus lemon L.) and mandarin (Citrus reticulata L.) peel extracts as natural preservatives instead of synthetic antioxidants of butylated hydroxyanisole (BHA) to retard the oxidation of ghee during accelerated storage at various temperatures. Antioxidant activities of lemon peel extracts (LPE), mandarin peel extracts (MPE) and BHA in ghee samples stored at different storage temperatures (T1: 5±2°C, T2: 25±2°C, T3: 60±2°C) were evaluated during the storage period (0, 20 and 40 days). The peroxide value (PV), free fatty acids (FFA), and antioxidant activity of the ghee samples were analyzed and compared with control sample (without additives). The PV and FFA content were significantly higher in the control sample than in the ghee samples treated with BHA, LPE, and MPE at all storage temperatures and during the storage period. All treatments led to a reduction in the PV and FFA content, but LPE had the most significant effect, followed by BHA and MPE, respectively. Antioxidant activity was evaluated by the 3-ethyl benzthiazoline-6-sulphonic acid (ABTS) assay; LPE had the highest antioxidant activity, followed by MPE. Compared to the control sample: BHA, LPE and MPE led to a higher reduction in the PV and FFA content of ghee samples at all storage temperatures and periods owing to their antioxidant activities. Results of incorporated samples showed that using LPE (0.1%) prevented the development of PV and FFA content of ghee samples less than using BHA (0.2%). The present study suggests that LPE (0.1%) could be used as a good natural antioxidant preservative to reduce oxidative deterioration of ghee and fat-rich products.

Fatty acids promote M1 polarization of monocyte-derived macrophages in healthy or ketotic dairy cows and a bovine macrophage cell line by impairing mTOR-mediated autophagy

Excessive concentrations of free fatty acids (FFA) are the main factors causing immune dysfunction and inflammation in dairy cows with ketosis. Polarization of macrophages (the process of macrophages freely switching from one phenotype to another) into M1 or M2 phenotypes is an important event during inflammation induced by environmental stimuli. In nonruminants, mammalian target of rapamycin (mTOR)-mediated autophagy (a major waste degradation process) regulates macrophage polarization. Thus, our objective was to unravel the role of mTOR-mediated autophagy on macrophage polarization in ketotic dairy cows. We performed 4 experiments: (1) In vitro differentiated monocyte-derived macrophages from healthy dairy cows or dairy cows with clinical ketosis (CK) were treated for 24 h with 100 ng/mL LPS and 100 ng/mL IFN-γ or with 10 ng/mL IL4 and 10 ng/mL IL10; (2) Immortalized bovine macrophages were treated for 24 h with 0, 0.3, 0.6, or 1.2 mM FFA, LPS, and IFN-γ, or with IL4 and IL10; (3) Macrophages were pretreated with 2 μM 4,6-dimorpholino-N-(4-nitrophenyl)-1,3,5-triazin-2-amine (MHY1485) for 30 min before treatment with LPS and IFN-γ or IL4 and IL10; (4) Macrophages were pretreated with 100 nM rapamycin (RAPA) for 2 h before treatment with LPS and IFN-γ or IL4 and IL10. Compared with healthy cows, cows with CK had a greater mean fluorescence intensity (MFI) of CD86+, but lower MFI of CD206+ and lower number of autophagosomes and autolysosomes in macrophages. Exogenous FFA treatment upregulated protein abundance of inducible nitric oxide synthase (iNOS) and the MFI of CD86, whereas it downregulated the protein abundance of arginase 1 and the MFI of CD206. In addition, FFA increased the p-p65/p65 protein abundance and tumor necrosis factor α, IL1B, and IL6 mRNA abundance, but decreased LC3-phosphatidylethanolamine conjugate protein abundance and the number of autophagosomes and autolysosomes number. Pretreatment with MHY1485 promoted macrophage M1 polarization and inhibited macrophage M2 polarization via decreased mTOR-mediated autophagy. Activation of mTOR-mediated autophagy by pretreatment with RAPA attenuated the upregulation of inflammation in M1 macrophages that was induced by FFA. These data revealed that high concentrations of FFA promote macrophage M1 polarization in ketotic dairy cows by impairing mTOR-mediated autophagy.

Physiological responses and transcriptome analysis of Hemerocallis citrina Baroni exposed to Thrips palmi feeding stress.

Thrips are serious pests of Hemerocallis citrina Baroni (daylily), affecting crop yield and quality. To defend against pests, daylily has evolved a set of sophisticated defense mechanisms. In the present study, induction of systemic resistance in Hemerocallis citrina 'Datong Huanghua' by Thrips palmi feeding was investigated at both biochemical and molecular levels. The soluble sugar content of daylily leaves was significantly lower than that in control check (CK) at all time points of feeding by T. palmi, whereas the amino acid and free fatty acid contents started to be significantly lower than those in CK after 7 days. Secondary metabolites such as tannins, flavonoids, and total phenols, which are harmful to the growth and reproduction of T. palmi, were increased significantly. The activities of defense enzymes such as peroxidase (POD), phenylalanine ammonia lyase (PAL), and polyphenol oxidase (PPO) were significantly increased, and the degree of damage to plants was reduced. The significant increase in protease inhibitor (PI) activity may lead to disrupted digestion and slower growth in T. palmi. Using RNA sequencing, 1,894 differentially expressed genes (DEGs) were identified between control and treatment groups at five timepoints. DEGs were mainly enriched in secondary metabolite synthesis, jasmonic acid (JA), salicylic acid (SA), and other defense hormone signal transduction pathways, defense enzyme synthesis, MAPK signaling, cell wall thickening, carbohydrate metabolism, photosynthesis, and other insect resistance pathways. Subsequently, 698 DEGs were predicted to be transcription factors, including bHLH and WRKY members related to biotic stress. WGCNA identified 18 hub genes in four key modules (Purple, Midnight blue, Blue, and Red) including MYB-like DNA-binding domain (TRINITY_DN2391_c0_g1, TRINITY_DN3285_c0_g1), zinc-finger of the FCS-type, C2-C2 (TRINITY_DN21050_c0_g2), and NPR1 (TRINITY_DN13045_c0_g1, TRINITY_DN855_c0_g2). The results indicate that biosynthesis of secondary metabolites, phenylalanine metabolism, PIs, and defense hormones pathways are involved in the induced resistance to T. palmi in daylily.

Production of biodiesel from waste cooking oil using a novel surface-functionalized CaMoO4/ TiO2 solid catalyst

This study involves the synthesis of a mesoporous CaMoO4/TiO2 solid catalyst through the impregnation method. The catalyst, known for its novelty, efficiency, and recyclability, was thoroughly characterized using various techniques, including Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDAX), Thermogravimetric Analysis (TGA), Brunauer-Emmett-Teller (BET), and Barrett-Joyner-Halenda (BJH) studies. Waste cooking oil is analysed using FTIR spectroscopy for its free fatty acid content. In addition, the specific catalytic activities are investigated under a variety of reaction conditions. A yield of 95.6 % is achieved under the standard trans esterification reaction operating parameters such as catalyst loading of 4 wt %, methanol to waste cooking oil molar ratio of 15:1 (v/v), reaction duration of 70 min, reaction temperature of 55 °C, stirring speed of 270 rpm, and temperature of calcination as 650 °C. The reaction kinetics (pseudo first order) is also studied. Solid catalysts can also be reused up to five successive times. Biodiesel is characterized by FTIR and 1H NMR studies to examine the presence of functional and methyl ester groups respectively, and the extracted biofuel met the specifications of ASTM D 6751 norms for standard diesel fuel.

Exploring physiological variables and lipid fraction characteristics in chia nutlets: Correlations with biophysical techniques across varieties with varying germinative power and vigor

Understanding aging in seeds is vital for conservation and long-term preservation. This study examined the physiological and lipid characteristics of three chia varieties (WN, MNI, MNII) using conventional and biophysical methods to establish correlations and explore aging mechanisms. Variables assessed included thousand seed weight, moisture content (MC), and germination parameters, such as normal germination power (NGP), hypocotyl and radicle length, vigor, viability, as well as lipid characteristics, and thermal parameters. Physiological differences were prominent, especially in the MNII, with longer mean germination times (MGT = 2.11 d) and reduced NGP (63.24%). The WN variety exhibited superior germination (NGP = 95.9%), while MNI had an NGP of 93.2% and the highest vigor. Lipid analysis revealed significant differences, particularly in free fatty acid content (FFA). The oxidative status and tocopherol content were evaluated, with high germination in WN being associated with the combination of tocopherol isomers. The thermal analysis highlighted the predictive potential of ΔH for seed health and viability. Spectral analysis distinguished nutlets and oils, showcasing unique vibrational patterns. The correlation analysis revealed significant relationships crucial for conservation. MGT showed positive correlations with moisture content, electrical conductivity, and FFA, but negative correlations with germinated nutlets (GN) and normal seedlings (NS). MC positively correlated with FFA, abnormal seedlings (AS), and deteriorated nutlets, yet negatively correlated with GN and NS. Electrical conductivity emerged as a germination indicator, positively correlating with FFA and deteriorated nutlets, and negatively with GN and NS. δ-tocopherol content positively correlated with successful germination and NS, but negatively with AS. Thus, this research provides relevant knowledge on the conservation of chia nutlets by offering information on seed deterioration markers that can be obtained by FT-IR and DSC. This is particularly valuable for studying germplasm with a limited sample size, common in gene banks.

Production and testing of mahua oil-based biodiesel synthesized through heterogeneous catalyst using experimental and numerical method.

A two-step treatment of mahua oil was conducted to synthesize mahua biodiesel using heterogeneous biomass-based catalyst derived from mahua shell. Mahua oil having higher free fatty acid (FFA) content (about 19%) was esterified to reduce the FFA content up to 1%. The esterification process was carried out using 200mL mahua oil, 5:1 molar ratio (methanol:oil), and 2.25 weight% of H2SO4 at a temperature of 60°C for 3h. Post esterification, a set of 16 experiments were created using a Box-Behnken design (BBD)-based response surface methodology (RSM) approach to conduct the transesterification of the esterified oil. Molar ratio, catalyst loading, reaction temperature, and reaction time were the four input variables chosen for the design of experiments. The optimized conditions for maximum biodiesel yield (87.7%) were found to be 14.88 molar ratio, 3.578% catalyst loading, 69.7°C reaction temperature, and 81.9min reaction time. The Diesel RK engine simulation tool which was experimentally validated for baseline diesel fuel was used for numerical simulation of mahua biodiesel. The performance, combustion, and emission behavior of mahua biodiesel analyzed using numerical simulation presented the sustainability of mahua biodiesel as an alternate fuel.

Effects of one-hour daily outdoor access on milk yield and composition and behaviors of tethered dairy cows.

We investigated the effects of outdoor access for one-hour per day (ODA) on milk yield and composition and behaviors of tethered dairy cows. Eleven all-day tethered dairy cows were treated with ODA for two weeks. To evaluate the effect of ODA on milk yield, we first calculated the average daily milk yield of each cow for three days during two weeks before the ODA, three days before the ODA, three days at the end of the ODA, and three days during two weeks after the ODA. We then compared the milk yield change during the ODA with that for two weeks before and two weeks after the ODA. The effects of ODA on milk compositions and behaviors were evaluated by comparing the average values for each composition and behavior for the three days before the ODA and the last three days of the ODA. The decrease of milk yield during the two weeks of ODA was significantly higher than that during the two weeks before ODA (p<0.01). The milk fat rate was significantly higher during ODA than before ODA (p<0.05). Lactose rate was significantly lower during ODA than before ODA (p<0.05). The concentrations of milk urea nitrogen, ketone bodies, and free fatty acids in the milk were significantly higher during ODA than before ODA (p<0.05). The mean total duration per day of lying during ODA was significantly lower than that before ODA (p<0.05). The walking steps per one-hour outdoor access were 158.4±54.7. The social behavior during the one-hour outdoor access of the 11 cows was 53 times/h/herd. Our results suggested that ODA promotes the expression of normal behavior in dairy cows, but even one hour of ODA decreases milk production in cows, which may drop producers' profits without some financial supplementation.

Effects of different production systems on health, zootechnical and metabolic parameters in Holstein calves in the extreme south of Brazil

The aim of this study was to evaluate the incidence of diseases as well as metabolic and zootechnical parameters in Holstein calves maintained in individual or collective housing systems in the extreme south of Brazil. One hundred calves were included immediately after birth and monitored for 90 days. Animals were randomly divided into two groups: individual stalls group (ISG; n=50) and collective stalls group (CSG; n=50). ISG calves were individually housed in 1.2m² wood pens and received 6 L of milk/day and concentrate food and water ad libitum for 90 days. Calves in the CSG were housed in groups of up to 25 animals, in a total of two stalls containing one animal per 3 m2. CSG calves received up to 8 L of milk/day at 0-15 days, milk ad libitum at 15-40 days, 7.2 L of milk. /day at 40-60 days, and gradual weaning at 60-90 days with concentrate food and water ad libitum, using an automatic feeder. In both groups, Zootechnical parameters (weight, thoracic perimeter, height at the withers, and rump width) were measured weekly during the first 28 days and once every 15 days until weaning. Blood samples were retrieved weekly during the first 28 days. Metabolic parameters evaluated in this study were total calcium, beta-hydroxybutyrate (BHBA), free fatty acids (FFA), and glucose. The animals were monitored daily for clinical signs of diseases diarrhea and respiratory symptoms. General morbidity was higher in CSG 92% compared to ISG 74% (p&lt;0.05). We observed increased diarrhea-related morbidity and a higher rate of recurrence in the ISG (50% and 60%, respectively; p&lt;0.05) compared to those in the CSG (both 20%, p&lt;0.05 between groups). The morbidity due to bronchopneumonia was higher in the CSG (92%) than in the ISG (74%, p&lt;0.05). Recurrence of bronchopneumonia and mortality were similar between groups (p&gt;0.05). Glucose, FFA, and BHBA concentrations were higher in the ISG (p&lt;0.05) and total calcium higher in CSG (p&lt;0.05). Finally, the weight and thoracic perimeter were higher in the CSG than those in the ISG, whereas the height and, rump width, at the withers was higher in the ISG than that in the CSG (p&lt;0.05). In conclusion, animals raised in a collective system with automatic feeders exhibited less diarrhea and increased serum calcium as well as improved zootechnical development, although they had a higher incidence of bronchopneumonia.

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 (&amp;lt; 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.

Meta-analysis of the effects of gamma irradiation on chicken meat and meat product quality.

Irradiation is one of the most effective microbial decontamination treatments for eliminating foodborne pathogens and enhancing chicken meat safety. The effect of gamma irradiation on the overall quality of chicken meat and its products must be observed to provide a comprehensive explanation to the public. This meta-analysis examined the effects of gamma irradiation on the oxidation parameters, microbial activity, physicochemical characteristics, sensory parameters, and nutrient quality of chicken meat and meat products. We conducted a literature search using various search engines (Scopus®, PubMed®, and Google Scholar®) with "irradiation," "gamma," "chicken," and "meat" as keywords. Gamma irradiation treatment was set as a fixed effect, and the difference between experiments was set as a random effect. This study used a mixed-model methodology. After evaluation, we selected 43 articles (86 studies) for inclusion in the database. Gamma irradiation significantly increased (p < 0.01) thiobarbituric acid-reactive substance levels on days 0, 7, and 14 of storage. Gamma irradiation reduced total aerobic bacteria, coliforms, Salmonella, yeast, and mold activity (p < 0.01). According to our meta-analysis, 21.75 kGy was the best dose for reducing total aerobic bacteria. On day 0, gamma irradiation did not affect the color parameters (L*, a*, b*). However, a significant difference (p < 0.01) was noted for a* and b* parameters between the control and irradiation treatments at 7 and 14 days. Although irradiation treatment was less consistent in sensory parameters, overall acceptability decreased on days 0, 7, and 14 after storage (p < 0.05). Regarding nutrient composition, gamma irradiation reduced moisture content and free fatty acid (FFA) content (p < 0.05). Although irradiation significantly reduces the microbial population, it increases the oxidation of chicken meat and its products. Irradiation decreases FFA content and overall acceptability, but it does not affect flavor, tenderness, juiciness, or cooking loss. Gamma irradiation positively reduces the microbial activity in chicken meat and its products but increases the oxidation parameters. Although gamma irradiation does not alter the flavor, tenderness, juiciness, or cooking loss, gamma irradiation can reduce the FFA content and overall acceptability.

Lipolysis and fat oxidation decrease during postprandial lactatemia

Circulating glycerol ([glycerol]) and free fatty acid ([FFA]) concentrations decrease and lactate concentration ([lactate]) increases in response to oral glucose consumption, but the effect of increased [lactate] on the rate of lipolysis is not known. We hypothesized that whole-body lipolytic (i.e., glycerol rate of appearance, Ra) and fat oxidation (FOx) rates would decrease following oral glucose consumption and inversely correlate with an increase in [lactate] above baseline levels (i.e., lactatemia) during both enteric (0–30 min) and systemic (60–120 min) phases of the postprandial lactate shuttle (PLS). Young, healthy men and women (n=15) reported to the lab following a 12-hour overnight fast and had the forearm vein catheterized for primed continuous infusion of [1,1,2,3,3-2H]glycerol. The contralateral hand vein was warmed and catheterized for arterialized blood sampling. After a 90-min equilibration period, participants underwent a 75 g oral glucose tolerance test (OGTT). Glycerol Ra was significantly lower at 5 min (1.92 ± 0.12 μmol·kg−1·min−1) and 30–120 min during the OGTT compared to baseline (2.06 ± 0.12 μmol·kg−1·min−1). [Glycerol] was significantly lower from baseline (69.19 ± 2.50 μM) at 30 min (50.58 ± 3.01 μM) after glucose consumption, then continued to decline thereafter. Similarly, [FFA] was significantly lower from baseline (464.71 ± 27.01 μM) at 30 min (247.14 ± 32.78 μM), then continued to decline. FOx was significantly lower from baseline (0.89 ± 0.05 kcal∙min−1) at 60 min (0.58 ± 0.05 kcal∙min−1) and remained steady from then on. Concurrently, [lactate] increased from baseline (0.59 ± 0.06 mM) and was significantly higher at 5 min (0.71 ± 0.06 mM) after glucose consumption, peaked at 15 min (1.09 ± 0.01 mM), reached a nadir at 30 min, then continued to rise thereafter. There was an overall inverse correlation (r = -0.71, p = 0.07) between glycerol Ra and [lactate] during the OGTT that was also present during the enteric phase (r = -0.45, p = 0.55). Similarly, there was overall an inverse correlation between FOx and [lactate] (r = -0.57, p = 0.17), but it was not present during the enteric phase (r = 0.93, p = 0.07). However, the correlations of both glycerol Ra and FOx with [lactate] approached linearity during the systemic phase (r = 0.99, p = 0.06). The reduction in glycerol Ra at 5 min indicates a rapid decrease in the rate of lipolysis following oral glucose consumption. The correlations suggest that lactatemia may influence both glycerol Ra and FOx by exerting an inhibitory effect, particularly during the systemic phase of the PLS. However, the lag in the decrease in FOx and opposing responses of glycerol Ra and [lactate] at 5 min suggests that lactatemia may have a greater role in inhibiting whole-body lipolysis in the postprandial period. Supported by NIH grant R01 AG059715 to GAB. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Valorization of waste seashells for neutralization of sunflower oil

In this study, an investigation was conducted to explore the potential of utilizing calcium oxide (CaO) derived from carbonized seashells for the purpose of acid removal. Consequently, the objective of this research is to develop an alternative bio-material to be employed in the neutralization process. The CaO produced was compared to the conventional utilization of caustic (NaOH) based on various parameters related to oil quality. It was observed that the removal rates of free fatty acid content using CaO and NaOH were 61% and 85% respectively. Furthermore, it was determined that the use of CaO did not result any adverse effects on the composition of sterols and fatty acids during the neutralization process. On the contrary, the preservation of total sterol content was superior in comparison to NaOH. The neutralization loss observed with CaO was comparable to that of NaOH. Consequently, CaO demonstrates promise as an alkaline substitute for acid removal in vegetable oils. Additionally, it is well-suited for implementation under minimal process conditions, which have become increasingly popular in recent years.

Impaired Long-Chain Fatty Acid Metabolism in Carnitine Palmitoyltransferase II Knockout Mouse Leads to Chronic Pancreatitis

Background: To support high rates of protein synthesis, pancreatic acinar cells must generate large quantities of ATP. Mitochondrial dysfunction and impaired energy metabolism play a significant role in the development of pancreatitis. Patients with elevated plasma triglycerides are at increased risk for development of severe acute pancreatitis. Carnitine palmitoyltransferase II (CPT2) is required for importing and thus metabolizing long-chain fatty acids (LCFAs) in mitochondria. To inhibit LCFA metabolism, we utilized the CPT2acinarKO mouse to probe the consequences of impaired LCFA import on pancreatic function. Hypothesis: Loss of CPT2 causes an accumulation of long-chain acylcarnitines and disruption of the tissue acylcarnitine/free carnitine ratio which is thought to alter cellular function. Given acinar cells’ high metabolic requirement, impaired LCFA utilization would reduce energy production, secretory function, and alter pancreatic lipid composition. Methods: We generated mice lacking CPT2 specifically in acinar cells (CPT2acinarKO) by crossing tamoxifen-inducible, Elastase-Cre mice with CPT2 floxed mice. Mice were fed a high fat (60% kcal fat), low fat (10% kcal fat), or chow (14% kcal fat) diet for 12 weeks. Analysis of fat accumulation, edema, and fibrosis was performed with H&amp;E and picrosirius staining. Mass Spec. lipid profiling was performed in pancreas and serum. Acinar cells were isolated from wildtype, CPT2 floxed, and CPT2acinarKO mice to assess secretory function, ATP levels, and necrosis via lactate dehydrogenase (LDH) release. Results: Histologic examination revealed CPT2acinarKO mice on all three diets displayed pancreatic fat accumulation. Strikingly, CPT2acinarKO mice fed a chow or low fat diet developed chronic pancreatitis with a 25% loss in pancreatic weight, immune cell infiltration, edema, and fibrosis. As anticipated, long-chain acylcarnitines were significantly elevated in CPT2acinarKO pancreas. Assessment of secretion in 2 weeks post tamoxifen cells revealed significantly reduced maximal (10 pM) and supramaximal (1 nM) cholecystokinin (CCK) stimulated amylase release as a percent of total cellular amylase. Acini isolated at 4 weeks post tamoxifen revealed significantly increased basal secretion and reduced maximal and supramaximal CCK stimulated amylase release. When normalized to cellular DNA, secretion was similar between CPT2acinarKO and CPT2 floxed acinar cells indicating CPT2acinarKO cells had reduced amylase levels. Wildtype acinar cells treated with unsaturated and saturated free fatty acid concentrations as low as 100 μM for 3 hours caused significant necrosis. CPT2acinarKO pancreas had significantly decreased ATP levels indicative of mitochondrial dysfunction. Conclusion: Loss of CPT2 in the pancreatic acinar cells impairs LCFA import, reduces ATP levels, disrupts the secretory pathway, promoting chronic pancreatitis. In contrast to other CPT2 knockout models, pancreatitis occurs independent of high fat feeding in CPT2acinarKO mice. Further investigation is needed to identify metabolic alterations leading to acinar damage and mitochondrial dysfunction following the loss of CPT2. UW-Madison Comprehensive Diabetes Center Pilot Grant. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.