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ACS Omega Oct 2023Oxytetracycline (OTC) is extensively used in veterinary medicine and for growth promotion around the globe. The indiscriminate use of OTC in food-producing animals...
Oxytetracycline (OTC) is extensively used in veterinary medicine and for growth promotion around the globe. The indiscriminate use of OTC in food-producing animals leaves residues in animal products. The presence of these residues in animal products causes economic losses and harmful effects on consumers. Different regulatory bodies set maximum residue limits (MRLs) for different tetracyclines. To avoid harmful effects, there is a need for a simple, fast, and economical method for the screening of animal products. In this study, a fast, economical, and user-friendly lateral-flow immunochromatographic (LFIC) assay based on gold nanoparticles (AuNPs) was developed to detect the presence of OTC residues in biological fluids. AuNPs provided visual results as red lines in 6-15 min. Polyclonal rabbit IgG antibodies were produced using the immunogen of OTC. These antibodies were purified by the combined ammonium sulfate-octanoic acid precipitation method. Antibodies were conjugated to AuNPs as recognition biomolecules. A LFIC strip was optimized using borate buffer spiked with different concentrations of the OTC. The visual limit of detection (LOD) in different biological samples (milk, serum, and urine) was determined using samples spiked with OTC. The LOD was found to be 15 μg/L, which is very low from the MRL (100 μg/L) set by different regulatory authorities. This LFIC strip can be used to detect OTC residues in biological fluids for point-of-care testing (POCT). These strips are easy to use, cost-effective, and portable and provide quick results without the use of laboratory instruments.
PubMed: 37810669
DOI: 10.1021/acsomega.3c04759 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Sep 2023In response to the market demand for therapeutic antibodies, the upstream cell culture scale and expression titer of antibodies have been significantly improved, while...
In response to the market demand for therapeutic antibodies, the upstream cell culture scale and expression titer of antibodies have been significantly improved, while the production efficiency of downstream purification process is relatively fall behind, and the downstream processing capacity has become a bottleneck limiting antibody production throughput. Using monoclonal antibody mab-X as experimental material, we optimized the caprylic acid (CA) precipitation process conditions of cell culture fluid and low pH virus inactivation pool, and studied two applications of using CA treatment to remove aggregates and to inactivate virus. Based on the lab scale study, we carried out a 500 L scale-up study, where CA was added to the low pH virus inactivation pool for precipitation, and the product quality and yield before and after precipitation were detected and compared. We found that CA precipitation significantly reduced HCP residuals and aggregates both before and after protein A affinity chromatography. In the aggregate spike study, CA precipitation removed about 15% of the aggregates. A virus reduction study showed complete clearance of a model retrovirus during CA precipitation of protein A purified antibody. In the scale-up study, the depth filtration harvesting, affinity chromatography, low pH virus inactivation, CA precipitation and depth filtration, and cation exchange chromatography successively carried out. The mixing time and stirring speed in the CA precipitation process significantly affected the CA precipitation effect. After CA precipitation, the HCP residue in the low pH virus inactivation solution decreased 895 times. After precipitation, the product purity and HCP residual meet the quality criteria of monoclonal antibodies. CA precipitation can reduce the chromatography step in the conventional purification process. In conclusion, CA precipitation in the downstream process can simplify the conventional purification process, fully meet the purification quality criterion of mab-X, and improve production efficiency and reduce production costs. The results of this study may promote the application of CA precipitation in the purification of monoclonal antibodies, and provide a reference for solving the bottleneck of the current purification process.
Topics: Cricetinae; Animals; Antibodies, Monoclonal; Caprylates; Cell Culture Techniques; Chromatography, Affinity; CHO Cells; Cricetulus; Chemical Precipitation
PubMed: 37805852
DOI: 10.13345/j.cjb.220882 -
Food Chemistry: X Oct 2023Niulanshan Baijiu (NLS), a notable variety of Baijiu known for its light flavor and extensive historical legacy, was subjected to a comparative analysis using two...
Unveiling innovation in aroma attribute evaluation of Niulanshan Baijiu: An advanced exploration of two different processing methods via food sensory omics and penalty analysis.
Niulanshan Baijiu (NLS), a notable variety of Baijiu known for its light flavor and extensive historical legacy, was subjected to a comparative analysis using two different processes: Hunzheng Xucha (HX) and Qingzheng Qingcha (QQ). The study combined sensory-oriented flavor analysis and penalty analysis to assess the differences between the two processes. Aroma compounds in NLS were extracted using liquid-liquid extraction and headspace solid phase microextraction. Gas chromatography-olfactometry-mass spectrometry was employed to identify 46 aroma-active compounds, including the first-time discovery of ethyl isohexanoate and 2,4-nonadienal in NLS. Quantification of 35 compounds with odor activity value (OAV) ≥ 1 was achieved using internal standard curve methods. Sensory assessments by a cohort of 111 participants highlighted the preference for HX-NLS in terms of flavor, while QQ-NLS exhibited a sour-Chen aroma that required improvement. The study further revealed the significant impact of acetic acid, butyric acid, hexanoic acid, octanoic acid, and 3-methylbutanal on the sour-Chen aroma in liquor.
PubMed: 37780286
DOI: 10.1016/j.fochx.2023.100852 -
Foods (Basel, Switzerland) Sep 2023Soy sauce, as a traditional seasoning, is widely favoured by Chinese and other Asian people for its unique colour, smell, and taste. In this study, a salt-tolerance...
Soy sauce, as a traditional seasoning, is widely favoured by Chinese and other Asian people for its unique colour, smell, and taste. In this study, a salt-tolerance strain HF-130 was obtained via three rounds of ARTP (Atmospheric and Room Temperature Plasma) mutagenesis and high-salt based screening. The ethanol production of mutant HF-130 was increased by 98.8% in very high gravity fermentation. Furthermore, gene was overexpressed in strain HF-130, generating ester-producing strain HF-130-ATF1. The ethyl acetate concentration of strain HF-130-ATF1 was increased by 130% compared to the strain HF-130. Finally, the soy sauce fermentation performance of and HF-130-ATF1 was compared with , HF-130, HF-130-ATF1, and Torulopsis and HF-130. Results showed ethyl acetate and isoamyl acetate concentrations in co-fermentation of and HF-130-ATF1 were increased by 2.8-fold and 3.3-fold, respectively. In addition, the concentrations of ethyl propionate, ethyl caprylate, phenylethyl acetate, ethyl caprate, isobutyl acetate, isoamyl alcohol, phenylethyl alcohol, and phenylacetaldehyde were also improved. Notably, other three important flavour components, trimethylsilyl decyl ester, 2-methylbutanol, and octanoic acid were also detected in the co-fermentation of and HF-130-ATF1, but not detected in the control strain . This work is of great significance for improving the traditional soy sauce fermentation mode, and thus improving the flavour formation of soy sauce.
PubMed: 37761157
DOI: 10.3390/foods12183449 -
Biofilm Dec 2023Antibiotic therapy is the primary treatment for bovine mastitis, but the drawbacks of this strategy include poor cure rate and economic losses from the need to discard...
Antibiotic therapy is the primary treatment for bovine mastitis, but the drawbacks of this strategy include poor cure rate and economic losses from the need to discard milk with antibiotic residues. Unfortunately, few other treatment options are currently available for mastitis. Failure of antibiotic treatments is often attributed to formation of bacterial biofilms and abscesses in the mammary gland tissue, which lead to chronic infections that are difficult to eradicate and drive recurrent disease. A major mastitis-causing pathogen (MCP) associated with biofilms in bovine mastitis is . In this study, we demonstrate that octanoic acid has broad-spectrum microbicidal activity against MCPs and effectively inhibits biofilm formation in milk (>50% inhibition at 3.13 mM). Octanoic acid effectively clears biofilms (95% eradication at 1 minimum bactericidal concentration, MBC) and infrequently induces small colony variants (SCVs) that may cause recurrent mastitis. Additionally, octanoic acid rapidly kills persistent biofilm cells and cells with antibiotic tolerance (within 4 h). In contrast, antibiotics treated at >100 MBC cannot eradicate biofilms but do induce SCVs and antibiotic-tolerant cells. These effects may accelerate the transition from biofilm to chronic infection. Thus, octanoic acid exhibits bactericidal action against biofilms, and it is less likely than antibiotic therapy to induce persistent cells and pathogen tolerance. Moreover, octanoic acid acts additively with antibiotics against , and it attenuates tetracycline-induced virulence factor gene expression in cells. According to these data, octanoic acid may prevent the pathological progression of bovine mastitis and offer a new strategy for treating the condition.
PubMed: 37635811
DOI: 10.1016/j.bioflm.2023.100149 -
Bioresource Technology Nov 2023Polyhydroxyalkanoates (PHAs) are biological polyesters, viewed as a replacement for petrochemical plastic. However, they suffer from suboptimal physical and mechanical...
Polyhydroxyalkanoates (PHAs) are biological polyesters, viewed as a replacement for petrochemical plastic. However, they suffer from suboptimal physical and mechanical properties. Here, it was shown that a metabolically versatile Pseudomonas umsongensis GO16 can synthesise a blend of short chain length (scl) and medium chain length (mcl)-PHA. A defined mix of butyric (BA) and octanoic acid (OA) in different ratios was used. The PHA monomer composition varied depending on the feeding strategy. When OA and BA were fed at 80:20 ratio it showed 14, 8, 77 and 1 mol% of (R)-3-hydroxybutyrate, (R)-3-hydroxyhexanoate, (R)-3-hydroxyoctanoate and (R)-3-hydroxydecanoate respectively. The polymer characterisation clearly shows that polyhydroxybutyrate (PHB) and mcl-PHA are produced individually. The two polymers are blended on the PHA granule level, as demonstrated by fluorescence microscopy and yeast two-hybrid assay. The resulting blend has a specific viscoelasticity compared to PHB and PHO. Mcl-PHA acts as a plasticiser and reduces PHB brittleness.
Topics: Polyhydroxyalkanoates; Pseudomonas; Polyesters
PubMed: 37572888
DOI: 10.1016/j.biortech.2023.129668 -
Foods (Basel, Switzerland) Jul 2023Given the substantial world coffee production, tons of coffee fruit cascara rich in bioactive compounds are discarded annually. Using this by-product to produce...
Given the substantial world coffee production, tons of coffee fruit cascara rich in bioactive compounds are discarded annually. Using this by-product to produce potentially healthy and acceptable foods is a sustainable practice that aggregates value to coffee production and may help improve people's lives. This study aimed to elaborate kombuchas from coffee cascara tea, evaluate their microbial profile, and monitor the changes in the volatile profile during fermentation, together with sensory attributes and acceptance by consumers from Rio de Janeiro ( = 113). Arabica coffee cascaras from Brazil and Nicaragua were used to make infusions, to which black tea kombucha, a Symbiotic Culture of Bacteria and Yeasts (SCOBY), and sucrose were added. Fermentation of plain black tea kombucha was also monitored for comparison. The volatile profile was analyzed after 0, 3, 6, and 9 days of fermentation via headspace solid phase microextraction GC-MS. A total of 81 compounds were identified considering all beverages, 59 in coffee cascara kombuchas and 59 in the black tea kombucha, with 37 common compounds for both. An increase mainly in acids and esters occurred during fermentation. Despite the similarity to black tea kombucha, some aldehydes, esters, alcohols, and ketones in coffee cascara kombucha were not identified in black tea kombucha. Potential impact compounds in CC were linalool, decanal, nonanal, octanal, dodecanal, ethanol, 2-ethylhexanol, ethyl acetate, ethyl butyrate, ethyl acetate, β-damascenone, γ-nonalactone, linalool oxide, phenylethyl alcohol, geranyl acetone, phenylacetaldehyde, isoamyl alcohol, acetic acid, octanoic acid, isovaleric acid, ethyl isobutyrate, ethyl hexanoate, and limonene. The mean acceptance scores for cascara kombuchas varied between 5.7 ± 0.53 and 7.4 ± 0.53 on a nine-point hedonic scale, with coffee cascara from three-day Nicaragua kombucha showing the highest score, associated with sweetness and berry, honey, woody, and herbal aromas and flavors. The present results indicate that coffee cascara is a promising by-product for elaboration of fermented beverages, exhibiting exotic and singular fingerprinting that can be explored for applications in the food industry.
PubMed: 37509803
DOI: 10.3390/foods12142710 -
Appetite Oct 2023Older adults are advised to increase their protein intake to maintain their muscle mass. However, protein is considered the most satiating macronutrient and this... (Randomized Controlled Trial)
Randomized Controlled Trial
Older adults are advised to increase their protein intake to maintain their muscle mass. However, protein is considered the most satiating macronutrient and this recommendation may cause a decrease in total energy intake. To date, satiety studies comparing all three macronutrients have been undertaken in young adults, and it is unclear if the same response is seen in older adults. The objective of this study was to compare the effect of preloads high in protein, fat, and carbohydrate but equal in energy (∼300 kcal) and volume (250 ml) on energy intake, perceived appetite, and gastric emptying in younger and older adults. Twenty older and 20 younger adults completed a single-blinded randomised crossover trial involving three study visits. Participants consumed a standard breakfast, followed by a preload milkshake high in either carbohydrate, fat, or protein. Three hours after the preload, participants were offered an ad libitum meal to assess food intake. Visual analogue scales were used to measure perceived appetite and gastric emptying was measured via the C-octanoic acid breath test. There was no significant effect of preload type or age on energy intake either at the ad libitum meal, self-recorded food intake for the rest of the test day or subjective appetite ratings. There was a significant effect of preload type on gastric emptying latency phase and ascension time, and an effect of age on gastric emptying latency and lag phase such that older adults had faster emptying. In conclusion, energy intake, and perceived appetite were not affected by macronutrient content of the preloads in both younger and older adults, but gastric emptying times differed.
Topics: Young Adult; Humans; Aged; Satiation; Appetite; Energy Intake; Nutrients; Eating; Carbohydrates; Cross-Over Studies
PubMed: 37507052
DOI: 10.1016/j.appet.2023.106982 -
Scientific Reports Jul 2023There is great interest on medium chain fatty acids (MCFA) for cardiovascular health. We explored the effects of MCFA on the expression of lipid metabolism and...
There is great interest on medium chain fatty acids (MCFA) for cardiovascular health. We explored the effects of MCFA on the expression of lipid metabolism and inflammatory genes in macrophages, and the extent to which they were mediated by the nuclear receptor peroxisome proliferator-activated receptor beta/delta (PPAR β/δ). J774A.1 murine macrophages were exposed to octanoate or decanoate as MCFA, a long-chain fatty acid control (palmitate), or the PPAR β/δ agonist GW501516, with or without lipopolysaccharide (LPS) stimulation, and with or without an siRNA-induced knockdown of PPAR β/δ. MCFA increased the expression of Plin2, encoding a lipid-droplet associated protein with anti-inflammatory effects in macrophages, in a partially PPAR β/δ-dependent manner. Both MCFA stimulated expression of the cholesterol efflux pump ABCA1, more pronouncedly under LPS stimulation and in the absence of PPAR β/δ. Octanoate stimulated the expression of Pltp, encoding a phospholipid transfer protein that aids ABCA1 in cellular lipid efflux. Only palmitate increased expression of the proinflammatory genes Il6, Tnf, Nos2 and Mmp9. Non-stimulated macrophages exposed to MCFA showed less internalization of fluorescently labeled lipoproteins. MCFA influenced the transcriptional responses of macrophages favoring cholesterol efflux and a less inflammatory response compared to palmitate. These effects were partially mediated by PPAR β/δ.
Topics: Mice; Animals; PPAR delta; PPAR-beta; Caprylates; Cell Line; Lipopolysaccharides; Macrophages; Fatty Acids; Cholesterol; Palmitates
PubMed: 37463952
DOI: 10.1038/s41598-023-38700-x -
Molecules (Basel, Switzerland) Jun 2023Chilled Tan mutton is currently the mainstream of Tan mutton production and consumption in China, but the reports on chilled meat quality evaluation and shelf-life...
Chilled Tan mutton is currently the mainstream of Tan mutton production and consumption in China, but the reports on chilled meat quality evaluation and shelf-life discrimination by volatiles are limited. This study aimed to investigate the changes of volatile compounds in chilled Tan mutton at four storage stages (1d, 3d, 5d, 7d) in order to differentiate the various storage stages. An analysis protocol was established for the characterization and discrimination of the volatiles in chilled Tan mutton based on high capacity sorptive extraction-thermal desorption-gas coupled with chromatography-mass spectrometry (HiSorb-TD-GC-MS), electronic nose (E-nose), and multivariate statistical analysis. A total of 96 volatile compounds were identified by HiSorb-TD-GC-MS, in which six compounds with relative odor activity value >1 were screened as the key characteristic volatiles in chilled Tan mutton. Four storage stages were discriminated by partial least squares discriminant analysis, and nine differential volatile compounds showed a variable importance for the projection score >1, including octanoic acid, methyl ester, decanoic acid, methyl ester, acetic acid, heptanoic acid, methyl ester, propanoic acid, 2-hydroxy-, methyl ester, (ñ)-, hexanoic acid, propanoic acid, butanoic acid, and nonanoic acid. With the volcano plot analysis, hexadecanoic acid, methyl ester, was the common volatile marker candidate to discriminate chilled stages of Tan mutton. Meanwhile, E-nose could discriminate chilled Tan mutton at different storage stages rapidly and efficiently using linear discriminant analysis. Furthermore, E-nose sensors could obtain comprehensive volatile profile information, especially in esters, acids, and alcohols, which could confirm the potential of E-nose for meat odor recognition. Thus, this analysis protocol could characterize and discriminate the volatiles in chilled Tan mutton during storage.
Topics: Gas Chromatography-Mass Spectrometry; Electronic Nose; Volatile Organic Compounds; Meat; Acetic Acid; Esters
PubMed: 37446654
DOI: 10.3390/molecules28134993