Octanoate Research Articles

Influence of Carbohydrate Intake on Caprylic Acid (C8:0)-Induced Ketogenesis-A Systematic Review and Meta-Analysis.

The ketogenic diet is used worldwide to treat various diseases, especially drug-resistant epilepsies. Medium-chain triglycerides or medium-chain fatty acids, primarily the major ketogenic compound caprylic acid (C8; C8:0), can significantly support ketogenesis. This review examines the effects of concurrent carbohydrate intake on C8-induced ketogenesis. A systematic literature search (PubMed and Web of Science) with subsequent data extraction was performed according to PRISMA guidelines and the Cochrane Handbook. Studies investigating the metabolic response to C8-containing MCT interventions with carbohydrate intake were included. The studies did not include a ketogenic diet. Three intervention groups were created. The quality of the studies was assessed using the RoB II tool, and the meta-analysis was performed using the Cochrane RevMan software. A total of 7 trials, including 4 RCTs, met the inclusion criteria. Ketone production was lower when C8 was combined with carbohydrates compared to MCT intake alone. The lower C8 dose group (11 g) did not show a significantly lower ketogenic effect than the higher dose group (19 g). Forest plot analysis showed heterogeneous data. The data suggest a non-linear relationship between C8, carbohydrate intake and ketone production. Further studies are needed to investigate the influence of different carbohydrates on C8-induced ketogenesis. Limitations include heterogeneous intervention conditions, such as different types of dispersions, caffeine intake, limited number of studies and variability in study design.

Volatile organic compounds of camel milk and shubat across Kazakhstan's regions, seasons, and breeds

Despite extensive research in recent years on camel milk composition and health benefits, limited scientific data exists on the volatile organic compound profiles of camel milk and its fermented product, shubat. This study analyzed volatile organic compounds (VOCs) in raw camel milk and shubat from six Kazakh farms across all seasons. We found that camel milk displayed higher concentrations of aldehydes, ketones, and alcohols with the main two compounds in milk being acetone and (2-Aziridinylethyl) amine. Conversely, the majority of volatile organic compounds in shubat samples belonged to esters, but the predominant compounds by concentration were ethanol, dimethylamine, propanoic acid, and octanoic acid. Seasonality emerged as the primary driver of variation in milk, with heptanal being the most discriminative compound. Fermented milk showcased regional diversity likely driven by distinct microbial communities. Findings demonstrate the dynamic nature of camel milk's aromatic properties, which are influenced by multiple factors that contribute to its distinctive sensory characteristics.

Lipase-catalyzed synthesis and characterization of medium-long-medium (MLM) type structured triacylglycerols from peony seed oil

Structured triacylglycerols (STAGs) with medium-chain fatty acids (FAs) at sn-1,3 positions and long-chain FAs at the sn-2 position are known as medium-long-medium (MLM) type STAGs. They can not only provide energy immediately and control weight effectively, but may also provide essential or beneficial FAs to meet the human needs. In this study, MLM type STAGs were synthesized from lipase-catalyzed acidolysis of peony seed oil (PSO) with octanoic acid (OcA) and decanoic acid (DA) as medium-chain FAs in solvent-free systems. Optimal reaction conditions were 1:8 (PSO to OcA/DA), 40 °C and 24 h. The OcA content and DA content at sn-1,3 of two STAGs were 81.1% and 82.5%. The total essential FA (α-linolenic acid and linoleic acid) contents at sn-2 reached 61.5% and 57.2%, and long-chain unsaturated FA contents reached 93.3% and 87.4%. Infrared absorptions of two STAGs were weaker than those of PSO at 723 cm−1 [-(CH2)n-rocking] and 3011 cm−1 [ = CH (cis) stretching]. The end melting temperature and maximum weight loss temperature of STAG rich in DA were higher than those of STAG rich in OcA. This study is conducive to the deep processing of PSO and provides a new and promising substrate for MLM type STAG synthesis.

Onopordum platylepis (Murb.) Murb. as a novel source of thistle rennet: First application to the manufacture of traditional Italian raw ewe’s milk cheese

In this study, for the very first time, aqueous extracts obtained from flowers of spontaneously grown or cultivated Onopordum platylepis (Murb.) Murb. thistles were used as coagulating agents for the pilot-scale manufacture of Caciofiore, a traditional Italian raw ewe’s milk cheese. Cheese prototypes were compared to control cheeses curdled with a commercial thistle rennet obtained from flowers of Cynara cardunculus L. After 45 days of ripening under controlled conditions, both the experimental and control cheese prototypes were analyzed for: cheese yield, physico-chemical (pH, titratable acidity, aw, proximate composition), morpho-textural (color and texture), and microbiological parameters (viable cell counts and species composition assessed by Illumina sequencing), as well as volatile profile by SPME-GC–MS. Slight variations in titratable acidity, color, and texture were observed among samples. Based on the results overall collected, neither the yield nor the proximate composition was apparently affected by the type of thistle coagulant. However, the experimental cheese prototypes curdled with extracts from flowers of both spontaneous or cultivated thistles showed 10 % higher values of water-soluble nitrogen compared to the control prototypes. On the other hand, these latter showed slightly higher loads of presumptive lactococci, thermophilic cocci, coliforms, and eumycetes, but lower counts of Escherichia coli. No statistically significant differences were revealed by the metataxonomic analysis of the bacterial and fungal biota. Though most volatile organic compounds (VOCs) were consistent among the prototypes, significant variability was observed in the abundance of some key aroma compounds, such as butanoic, hexanoic, and octanoic acids, ethanol, propan-2-ol, isobutyl acetate, 2-methyl butanoic acid, and 3-methyl butanal. However, further investigations are required to attribute these differences to either the type of coagulant or the metabolic activity of the microorganisms occurring in the analyzed cheese samples. The results overall collected support the potential exploitation of O. platylepis as a novel source of thistle coagulant to produce ewe’s milk cheeses.

Caprylic Acid Inhibits High Mobility Group Box-1-Induced Mitochondrial Damage in Myocardial Tubes.

Myocardial damage significantly impacts the prognosis of patients with cancer; however, the mechanisms of myocardial damage induced by cancer and its treatment remain unknown. We previously reported that medium-chain fatty acids (MCFAs) improve cancer-induced myocardial damage but did not evaluate the differences in effect according to MCFA type. Therefore, this study investigated the role of inflammatory cytokines in cancer-induced myocardial damage and the effects of three types of MCFAs (caprylic acid [C8], capric acid [C10], and lauric acid [C12]). In a mouse model, the C8 diet showed a greater effect on improving myocardial damage compared with C10 and C12 diets. Myocardial tubes differentiated from H9C2 cardiomyoblasts demonstrated increased mitochondrial oxidative stress, decreased membrane potential and mitochondrial volume, and inhibited myocardial tube differentiation following treatment with high-mobility group box-1 (HMGB1) but not interleukin-6 and tumor necrosis factor-α cytokines. However, HMGB1 treatment combined with C8 improved HMGB1-induced mitochondrial damage, enhanced autophagy, and increased mitochondrial biogenesis and maturation. However, these effects were only partial when combined with beta-hydroxybutyrate, a C8 metabolite. Thus, HMGB1 may play an important role in cancer-related myocardial damage. C8 counteracts HMGB1's effects and improves cancer-related myocardial damage. Further clinical studies are required to investigate the effects of C8.

Theoretical and Experimental Study on the Preparation of High-Viscosity Magnetic Nanofluid by Combined Surfactants.

In this study, the mechanism by which combined surfactants affect the dispersion stability of magnetic nanofluids (MNFs) was improved. Two stable lubricating oil-based magnetic nanofluids with high viscosity and one with low viscosity were prepared by chemical coprecipitation. Erucic acid and octanoic acid were used as the combined surfactants to modify the Fe3O4 nanoparticles (MNPs). The size and morphology of the particles were observed using TEM. The rheological properties were tested with a rotational rheometer. The magnetization of the lubricating oil-based magnetic nanofluids was characterized by VSM. The results indicated that the prepared magnetic nanofluids had high viscosity, high magnetism, and good stability. This study provided ideas for the preparation of a high-viscosity magnetic nanofluid. By using combined surfactants, sufficient steric repulsion energy can be provided to counteract the attraction energy of sterically protected nanoparticles, thus achieving a balance of the dispersion stability of MNF.

Screening of lactic acid bacteria with the ability to reduce goaty flavor related fatty acids in goat milk

In this study, we conducted sensory evaluation and gas chromatography–mass spectrometry analysis on fermented goat milk samples prepared by 12 strains of lactic acid bacteria (LAB) isolated from goat milk to screen for strains with the ability to reduce the goaty flavor. The bacterial counts of fermented goat milk was 7.07–9.01 log CFU/mL. The electronic nose distinguished fresh goat milk (FGM) and fermented goat milk, and the electronic tongue results showed that Leuconostoc citreum 1, 4, 20, 22, 32, and 57, Latilactobacillus curvatus 144 and 147 imparted fermented goat milk a taste different from FGM. Overall, Leuconostoc citreum 57, Leuconostoc citreum 126, Latilactobacillus curvatus 142, Latilactobacillus curvatus 143, and Latilactobacillus curvatus 147 were screened with the ability to improve the flavor of goat milk. They gave fermented goat milk a goat flavor score lower than or equal to FGM. And the fermented goat milk samples 57, 126, 142, 143, and 147 contained 25, 22, 15, 24, and 17 volatile flavor compounds, respectively, with a greater variety and content of ketones and aldehydes and lower levels of hexanoic acid, octanoic acid, and decanoic acid than FGM. However, the pH and WHC results indicated that the application of these strains as secondary cultures is necessary. Our finding provides basic research data to improve the flavor of goat milk products.

Deep-Eutectic-Solvent-in-Water Pickering Emulsions Stabilized by Starch Nanoparticles.

Deep eutectic solvents (DESs) have received extensive attention in green chemistry because of their ease of preparation, cost-effectiveness, and low toxicity. Pickering emulsions offer advantages such as long-term stability, low toxicity, and environmental friendliness. The oil phase in some Pickering emulsions is composed of solvents, and DESs can serve as a more effective alternative to these solvents. The combination of DESs and Pickering emulsions can improve the applications of green chemistry by reducing the use of harmful chemicals and enhancing sustainability. In this study, a Pickering emulsion consisting of a DES (menthol:octanoic acid = 1:1) in water was prepared and stabilized using starch nanoparticles (SNPs). The emulsion was thoroughly characterized using various techniques, including optical microscopy, transmission microscopy, laser particle size analysis, and rheological measurements. The results demonstrated that the DES-in-water Pickering emulsion stabilized by the SNPs had excellent stability and retained its structural integrity for more than 200 days at room temperature (20 °C). This prolonged stability has significant implications for many applications, particularly in the field of storage and transportation. This Pickering emulsion based on DESs and SNPs is sustainable and stable, and it has great potential to improve green chemistry practices in various fields.

Serum Medium-Chain Fatty Acids and the Risk of Incident Diabetes: Findings from the 4C Study.

Emerging studies have revealed associations between dietary medium-chain fatty acids (MCFAs) and glucose homeostasis. However, the relationship between serum MCFAs and the incidence of diabetes, and potential interactions with genetic predisposition, remains unclear in prospective cohort studies. To investigate associations and genetic susceptibility between serum MCFAs and diabetes risk. We investigated baseline serum MCFAs (n=5) in a nested case-control study comprising incident diabetes cases (n=1,707) and matched normoglycemic control subjects (n=1,707) from the China Cardiometabolic Disease and Cancer Cohort Study. Associations between MCFAs and type 2 diabetes mellitus (T2DM) were examined, both overall and stratified by diabetes genetic susceptibility. Genetic risk scores (GRS) were calculated based on 86 T2DM-associated genetic variants. In the fully adjusted conditional logistic regression model, serum octanoic acid and nonanoic acid exhibited inverse dose-response relationships with diabetes risk, showing odds ratios (95% confidence intervals) of 0.90 (0.82-0.98) and 0.84 (0.74-0.95), respectively. Subgroup analysis demonstrated that inverse associations between MCFAs and incident diabetes were more pronounced among individuals with physical inactivity (Pinteraction = 0.042, 0.034, and 0.037, for octanoic, nonanoic and decanoic acid, respectively). Moreover, inverse associations of octanoic acid with diabetes risk were notably enhanced among individuals with high genetic risk compared to those with low genetic risk. Significant interactions were observed between octanoic acid and GRS on T2DM risk (Pinteraction = 0.003). These findings provide evidence supporting inverse associations between serum MCFAs and T2DM risk, and reveal potential interplay between genetic susceptibility and circulating octanoic acid in modulating diabetes risk.

Analysis and identification of the main antimicrobial metabolites of Lactobacillus plantarum LPZN19

BackgroundLactobacillus plantarum can produce many secondary metabolites, some of which have antibacterial effects. This study aimed to explore the main antimicrobial metabolites of Lactobacillus plantarum LPZN19. ResultsThe results of antibacterial activity after fermentation for different durations showed that the metabolites from the LPZN19 cell-free supernatant (LCFS) after 24 h had the strongest antibacterial activity, which was confirmed by the highest contents of organic acids and fatty acids in the LCFS after 24 h. Lactic acid, phenyllactic acid, malic acid, aspartic acid, dodecanoic acid and propionic acid were the main differentially abundant metabolites. LCFS was separated by semi-preparative liquid chromatography to obtain 4 antibacterial parts, mainly organic acids such as lactic acid, glycolic acid, and citric acid, and fatty acids such as stearic acid, palmitic acid, and octanoic acid. In addition, fatty glycerides and amino acids with antimicrobial activity were included. ConclusionsOur findings indicate that the main antimicrobial metabolites of L. plantarum LPZN19 include organic acids, fatty acids, fatty glycerides and some amino acids with antimicrobial activity, which not only clarifies the main antimicrobial metabolites of L. plantarum LPZN19 but also provides an effective method for rapid screening of antimicrobial substances.How to cite: Wang Y, Xu Y. Analysis and identification of the main antimicrobial metabolites of Lactobacillus plantarum LPZN19. Electron J Biotechnol 2024;71. https://doi.org/10.1016/j.ejbt.2024.05.005.

Improvement of rheological and sensory properties of Lactobacillus helveticus fermented milk by prebiotics

The fermentation characteristics and aroma-producing properties of Lactobacilli could influence the flavour quality of fermented milk, an important influencing factor of consumers' preference. In this study, fermented milk was prepared using Lactobacillus helveticus and the dynamic changes in the sensory quality of fermented milk throught fermentation were to assess the dynamic changes in sensory quality of fermented milks throughout the fermentation process, including rheological properties and flavour profiles. Styrene, linalool, octanoic acid, and 1-nonanol were considered as the key flavour components during fermentation. The quality of the fermented milk tends to be stabilized after 24-h, showing the minimal off-flavour at 48-h and optimal fermented aroma at 72-h. Three prebiotics (inulin, Galactooligosaccharides and inulin mixed with Galactooligosaccharides) were added to Lactobacillus spiralis fermented milk separately, and the results showed that inulin mixed with Galactooligosaccharides was the most effective group in improving the organoleptic quality of the fermented milk. Overall, the experimental results provide deeper insights into the release and retention of aroma compounds during fermentation and scientific reference for broadening the application of prebiotics and flavour-producing Lactobacilli in fermented milk processing.

SH-SY5Y cells undergo changes in peroxisomal metabolism when exposed to decanoic acid.

Medium-chain fatty acids (MCFAs), particularly decanoic acid (C10) and octanoic acid (C8), have garnered attention in recent years for their potential antiepileptic properties. A previous study from our laboratory demonstrated that C10 targets the PPARγ nuclear receptor, increasing the activity of the antioxidant enzyme catalase and thereby possibly modulating peroxisomal content. Here, we examined markers of peroxisomal content and activity in response to C10 and C8 exposure in neuronal-like SH-SY5Y cells. SH-SY5Y were treated with 250 mM C10 or C8 for a period of 6 days. Following this, biochemical markers of peroxisomal content and function were assessed, including acyl-coA oxidase activity, peroxisomal gene expression and peroxisomal VLCFA β-oxidation. Our findings revealed that C10 treatment augments acyl-CoA oxidase 1 (ACOx1) activity by 129% in comparison to control cells. An exploration into genes related to peroxisomal biosynthesis showed 23% increased expression of PEX11α upon C10 exposure, implying peroxisomal proliferation. Furthermore, it was observed that C10 exposure not only elevated ACOx1 activity but also enhanced peroxisomal β-oxidation of docosanoic acid (C22). Our findings bolster the premise that C10 functions as a peroxisome proliferator, influencing peroxisomal content and function. Further investigations are required to fully understand the mechanistic details as to how this may be beneficial in epilepsy and the potential implications with regards to peroxisomal disease.

Process intensification in microwave assisted lipase catalysed solvent-free synthesis of n-nonyl caprylate

Microwave-assisted solvent free synthesis is a frequently applied mainstream tool in various enzymatic processes. Microwaves are a non-contact heat source which reduces the thermal gradient and helps to accelerate energy transfer. Microwave irradiation along with solvent free synthesis has great efficiency and efficacy in product synthesis and purification. In the present investigation, synthesis of n-nonyl caprylate was achieved by using immobilized lipases specifically Lypozyme TLIM, Novozym 435 and Lypozyme RM IM. Novozym 435 (Cal-B) was the best among these catalysts. Highest conversion of 76.8 % was achieved with following parameters: 180 min, 50 °C, 400 rpm, 50 W, 8.36 g/L catalyst loading, and 1:1 mol ratio of caprylic acid to n-nonanol. The confirmation of the product was done by GC-MS analysis.

Effects of massive desiccation of olive waste residues on air quality

New industries are proliferating in the recovery of agri-food wastes, such as those involved in the revaluation of alperujo, generated in the production of olive oil. Despite the potential environmental benefits, their activity is not exempt from new forms of emissions, aggravated by the massification of waste treatments.This work reports a six-month field campaign carried out in an alperujo desiccation plant which can serve as a proxy for these emerging industries in the Mediterranean countries. The study focused on air quality parameters, covering criteria pollutants, metals and microbiological load of particulate matter and the characterization of volatile organic compounds (VOCs).The results show a slight contribution of the factory to the NOx levels in the surroundings (3.0–12.5 μg/m3). Statistically significant effects were not observed for ozone, CO, SO2, or PM10. Concerning the levels of metals, concentrations were low and calculated health risk indexes indicated safe conditions in the area. The most abundant elements were Na (6.5 × 102 ng/m3), K (4.0 × 102 ng/m3), Al (2.7 × 102 ng/m3), Zn (2.1 × 102 ng/m3), Ca (2.16 × 102 ng/m3), Fe (3.6 × 101 ng/m3) and Mg (3.2 × 101 ng/m3).Bacterial counts, with a mean value of 15.9 CFU/m3, showed a seasonal shift, mainly explained by weather (air moisture and temperature) and PM2.5 concentration. The genomic analysis showed Cutibacterium as the dominant genus during the cold months while Bacillus predominated in the warm season.The VOCs with higher average concentrations were acetic acid (130 μg/m3), nonanoic acid (124 μg/m3), benzoic acid (29.7 μg/m3), octanoic acid (19.9 μg/m3) and nonanal (4.70 μg/m3), with the rest of compounds in concentrations below 4 μg/m3. Odorant pollutants with the greatest contribution to olfactory nuisance were aldehydes (from pentanaldehyde to decanaldehyde), acetic acid and phenol.Although the observable effects of the waste treatments were low, several parameters showed an influence on the environment which should be assessed to foresee and prevent long-term consequences.

Analysis of the Fatty Acid Profile in Cream, Buttermilk Fractions, and Anhydrous Milk Fat: Influence of Physicochemical and Microbiological Parameters on the Fatty Acid Profile

This study analyzes the impact of physicochemical parameters on the microbiological and fatty acid profiles of cream, buttermilk, and anhydrous milk fat. Using gas chromatography coupled with mass spectrometry (GC-MS), the fatty acids present in these dairy products were qualitatively determined, highlighting the differences associated with the processing stages. Specifically, the distribution of short-chain, medium-chain, and long-chain fatty acids, such as butyric, caproic, caprylic, capric, lauric, myristic, palmitic, stearic, oleic, and linoleic acids, were analyzed, assessing their nutritional implications. The microbiological composition of the samples was also analyzed using MALDI-ToF MS. The presence of lipolytic bacteria, such as Serratia monocytogenes, which can negatively impact the oxidative stability of fats, was detected. The results show that both environmental and processing conditions significantly affect the quantity and quality of fatty acids, thereby influencing the overall dietary value of dairy products. These findings offer insight into developing improved dairy product formulations that may lead to enhancement of their health benefits.

The characteristic VOCs of different parts of Artocarpus heterophyllus fruit based on HS-SPME-GC-MS and PTR-TOF-MS

Insight investigation on both edible pulps and inedible parts involving inflorescence axis and shreds of Artocarpus heterophyllus Lam were carried out, a total of 98 VOCs and 201 masses were identified by the combination of HS-SPME-GC-MS and PTR-TOF-MS. Among them, according to the consistency of OAV and results of VIP > 1, p < 0.05, compounds methyl isovalerate (A2), 3-methylbutyl acetate (A5) and octanoic acid, ethyl ester (A21) were recognized as aroma markers to distinguish the pulps, shreds and inflorescence axis. Meanwhile, the inflorescence axis (IC50: 1.82 mg/mL) and shreds (IC50: 16.74 mg/mL) exhibited more excellent antioxidant potency than pulps (IC50: 17.43 mg/mL) in vitro. These findings validated the feasibility of coupling HS-SPME-GC-MS and PTR-TOF-MS for rapid detection of characteristic VOCs of this plant, and offered new prospect of fragrance utilization and waste management of the edible and inedible parts of A. heterophyllus fruit.

Medium-chain triglycerides combined with DHA improve cognitive function by inhibiting neurocyte apoptosis of the brain in SAMP8 mice

Medium-chain triglycerides (MCTs) and docosahexaenoic acid (DHA, Cn-3, 22:6) are essential in improving cognitive function and protecting neurocytes. This study explored the effects of the combined intervention of MCTs and DHA on inhibiting neurocyte apoptosis of the brain and improving cognitive function in senescence-accelerated mouse-prone 8 (SAMP8). Four-month-old male SAMP8 mice were randomly divided into four treatment groups (12 mice/group): DHA, MCT, DHA + MCT, and control groups, which intervened for seven months. Twelve age-matched male senescence-accelerated mouse resistant 1 (SAMR1) was used as the natural aging group. TUNEL assay and HE staining were used to assess neurocyte apoptosis and damage in the brain of mice. Moreover, the cognitive function was analyzed using the Morris water maze (MWM) and open field (OF) tests. The results showed that the cognitive function of 11-month-old SAMP8 mice decreased with age, and further pathological examination revealed the damaged neurocyte structure, karyopyknosis, cell atrophy, and even apoptosis. MCTs combined with DHA supplementation could increase octanoic acid (C8:0), decanoic acid (C10:0), and DHA levels in the serum, inhibit neurocyte apoptosis, improve neurocyte damage, moreover delay age-related cognitive decline after seven-month treatment. Furthermore, combining MCTs and DHA was significantly more beneficial than MCTs or DHA alone. In conclusion, MCTs combined with DHA could delay cognitive decline by inhibiting neurocyte apoptosis of the brain in SAMP8 mice.

Differential Effects of Three Medium-Chain Fatty Acids on Mitochondrial Quality Control and Skeletal Muscle Maturation.

Nutritional interventions are one focus of sarcopenia treatment. As medium-chain fatty acids (MCFAs) are oxidized in the mitochondria and produce energy through oxidative phosphorylation (OXPHOS), they are key parts of nutritional interventions. We investigated the in vitro effects of three types of MCFA, caprylic acid (C8), capric acid (C10), and lauric acid (C12), in skeletal muscle cells. Compared with C10 and C12, C8 promoted mitophagy through the phosphatase and tensin homolog (PTEN)-induced kinase 1-Parkin pathway and increased the expression of peroxisome proliferator-activated receptor gamma coactivator 1-α and dynamin-related protein 1 to reduce mitochondrial oxidative stress and promote OXPHOS. Furthermore, the expression of myogenic differentiation 1 and myosin heavy chain increased in myotubes, thus promoting muscle differentiation and maturation. These results suggest that C8 improves mitochondrial quality and promotes skeletal muscle maturation; in contrast, C10 and C12 poorly promoted mitochondrial quality control and oxidative stress and suppressed energy production. Future animal experiments are required to establish the usefulness of C8 for nutritional interventions for sarcopenia.

Octanoic acid kills Lucilia sericata (Diptera: Calliphoridae) by affecting two major defence systems: cuticular free fatty acids and immunocompetent cells

This work examines the insecticidal activity of octanoic acid (C8:0), a short-chain fatty acid detected in entomopathogenic fungus – Conidiobolus coronatus medium, against Lucilia sericata larvae and adults. The LD50 value was calculated as 3.04±0.26 µg/mg (3040 mg/kg) of insect body mass, which places the compound in category 5 of acute toxicity (slightly hazardous). The presented research also describes its probable mechanism, with a particular focus on changes in two main insect defense mechanisms: (1) the composition of the cuticle (GC–MS analysis) and (2) immunocompetent cells (microscopic analysis of cultured hemocytes). More precisely, octanoic acid application resulted in changes in cuticular free fatty acid (FFA) profiles in both adults and larvae; generally, treatment increased short-chain FFAs, and a decrease of middle- and long-chain FFAs. Both in vivo and in vitro applications of octanoic acid resulted in vacuolisation, disintegration, and destruction of nets formed by plasmatocytes. As the compound has also previously been found to be toxic against Galleria mellonella, it appears to have lethal potential against insects in both the Orders Diptera and Lepidoptera, indicating it may have strong entomopathogenic potential. It is worth noting that octanoic acid is approved as a food additive with well-documented insecticidal activity, and hence may be a valuable component in the design of new insecticides that are safe for both humans and the environment.

Ultrasound-induced modifications of beef flavor characteristics during postmortem aging

To investigate the effect of ultrasound treatment on the flavor profile of beef during postmortem aging, a comprehensive analysis of beef flavor was conducted at 0, 7, and 12 d of aging using sensory evaluation and electronic nose. Furthermore, the key volatile flavor compounds were identified using gas chromatography-mass spectrometry (GC–MS), and the odor activity value (OAV) was further evaluated. In addition, the primary pathway involved in flavor formation during beef aging after ultrasound treatment was explored. The results indicated that ultrasound enhanced the flavor profile of beef during postmortem aging by modifying the OAV of hexanal, heptanal, octanal, nonanal, decanal, (Z)-2-nonenal, dodecanal, pentanal, 1-octen-3-ol, octanoic acid, and 2-pentylfuran. Lipid oxidation was a crucial pathway through which ultrasound promoted the generation of volatile flavor compounds in beef, confirmed by the improved oxidation level of fatty acids, particularly monounsaturated ones. The study indicates that ultrasound technology can be regarded as an effective method for enhancing the beef flavor profile during postmortem aging.