Effect of alterations in phospholipids and free fatty acids on aroma-active compounds in instant-boiled chuck tender, sirloin and silverside beef.

Beef flavor profiles are strongly influenced by cooking methods and lipid composition. However, the effect of instant-boiling on the aroma of different beef slices was unclear. This study investigated the lipid profiles and instant-boiling volatile profiles of chuck tender (M. Supraspinatus), sirloin (M. Longissimus dorsi) and silverside (M. Biceps femoris). Quantitative lipidomics identified 336 lipid molecular species, of which 84-112 were quantitatively different among the three beef slices. Sirloin had lower phosphatidylcholine, phosphatidylinositol, phosphatidylglycerol and free fatty acids than chuck tender and silverside. The unsaturated fatty acid acyl chains in phosphatidylethanolamine differed significantly. Solid phase microextraction-gas chromatography-olfactometry-mass spectrometry (SPME-GC-O-MS) identified hexanal, octanal, nonanal, decanal, (E)-2-octenal, (E)-2-nonenal, (E)-2-undecenal, (E,E)-2,4-nonadienal, (E,E)-2,4-decadienal, 1-octen-3-ol, 2-pentylfuran and acetoin as the aroma-active compounds of instant-boiled beef. Unsaturated free fatty acids and phosphatidylglycerols with unsaturated fatty acid residues positively correlated with the aroma-active compounds and might be crucial in flavor differences among the three beef slices. These findings provide greater understanding of the lipid and instant-boiling aroma-active compound profiles in chuck tender, sirloin and silverside, and reflect the suitability of different beef slices for instant-boiling from the aroma perspective.

Development of an electrochemical sensor modified with gold nanoparticles for detecting fumonisin B1 in packaged foods.

Fumonisin B1 (FB1) is naturally present in the environment and can easily contaminate packaged foods during processing, storage and transportation, thus posing a threat to human health. We have developed an enzyme-free FB1 detector for the detection of packaged foods, which provides rapid and sensitive detection of FB1 in food. Gold nanoparticles (AuNPs; 5-10 nm) were uniformly dispersed on screen-printed electrodes, which acted as an excellent catalytic oxidizer. The surface structure of the modified electrode was characterized using scanning electron microscope and X-ray photoelectron spectroscopy. Differential pulse voltammetry demonstrated a good linear electrochemical response towards FB1 at concentrations ranging from 1 ng L-1 to 1 mg L-1 with a detection limit of 0.08 ng L-1. We employed the AuNPs-SPE sensor to detect FB1-spiked packaged meat products achieving recovery rates ranging from 89.7% to 113.3%.

Ultrasensitive analyses of zearalenone in grain samples with a catalytic oxidation platform involving gold nanomaterials.

Zearalenone (ZEN) contamination in cereals poses a serious threat to human and animal health, yet existing rapid test methods still suffer from poor stability and low sensitivity. The studied sensor reduces inspection time while enabling applications for on-site grain inspection. Specifically, a ZEN detector that can sensitively detect ZEN content in grains was developed. Ion implantation is an effective method for modifying screen-printed electrodes (SPEs). Gold nanoparticles (AuNPs; 5-10 nm) were uniformly implanted using screen-printed electrodes as a catalytic oxidation medium to generate an electrochemical sensor. The surface structure of the modified electrode was characterized using scanning electron microscopy and X-ray photoelectron spectroscopy. The results showed that differential pulse voltammetry had good linear electrochemical response to ZEN at 10 ng/kg to 10 mg/kg, with a detection limit of 1.1 ng/kg. We used AuNP-SPE sensors to detect ZEN in grain samples such as maize and oats.

Comprehensive foodomics analysis reveals key lipids affect aroma generation in beef.

Lipids are vital precursors to beef aroma compounds, but the exact lipid molecules influencing aroma generation remain unconfirmed. This study employs gas chromatography-olfactometry-mass spectrometry and absolute quantitative lipidomics to identify beef's aroma and lipid profiles and to examine lipid alterations post-thermal processing. The aim is to understand the role of lipids in aroma generation during beef's raw-to-cooked transition. Eighteen key aroma compounds were identified as significant contributors to the aroma of beef. 265 lipid molecules were quantified accurately, and we found that triglycerides containing C18:1 or C18:2 chains, such as TG(16:0_18:1_18:1), TG(16:0_18:1_18:2), TG(16:0_16:1_18:1), as well as phosphatidylcholine and phosphatidylethanolamine containing PC(16:1e_20:4), PC(16:0e_20:4), PC(18:2e_18:2), and PE(16:1e_20:4), played important roles in the generation of key aroma compounds in beef. C18:1, C18:2, C18:3, and C20:4 were key substrates for the formation of aroma compounds. In addition, lysophosphatidylcholine and lysophosphatidylethanolamine containing unsaturated fatty acid chains may serve as important aroma retainers.

Selenium maintains intestinal epithelial cells to activate M2 macrophages against deoxynivalenol injury.

Selenium (Se) is indispensable in alleviating various types of intestinal injuries. Here, we thoroughly investigated the protective effect of Se on the regulation of the epithelial cell-M2 macrophages pathway in deoxynivalenol (DON)-induced intestinal damage. In the present study, Se has positive impacts on gut health by improving gut barrier function and reducing the levels of serum DON in vivo. Furthermore, our study revealed that Se supplementation increased the abundances of GPX4, p-PI3K, and AKT, decreased the levels of 4-HNE and inhibited ferroptosis. Moreover, when mice were treated with DON and Fer-1(ferroptosis inhibitor), ferroptosis was suppressed and PI3K/AKT pathway was activated. These results indicated that GPX4-PI3K/AKT-ferroptosis was a predominant pathway in DON-induced intestinal inflammation. Interestingly, we discovered that both the number of M2 anti-inflammatory macrophages and the levels of CSF-1 decreased while the pro-inflammatory cytokine IL-6 increased in the intestine and MODE-K cells supernatant. Therefore, Se supplementation activated the CSF-1-M2 macrophages axis, resulting in a decrease in IL-6 expression and an enhancement of the intestinal anti-inflammatory capacity. This study provides novel insights into how intestinal epithelial cells regulate the CSF-1-M2 macrophage pathway, which is essential in maintaining intestinal homeostasis confer to environmental hazardous stimuli.

Selenomethionine protects the liver from dietary deoxynivalenol exposure via Nrf2/PPARγ-GPX4-ferroptosis pathway in mice.

Deoxynivalenol (DON) is a significant Fusarium toxin that has gained global attention due to its high frequency of contamination in food and feed. It was reported to have hepatotoxicity, immunotoxicity, and reproduction toxicity in organs. On the other hand, Selenomethionine (SeMet) was proven to have anti-oxidation, tissue repairing, immunity improvement, and antifungal mycotoxin infection functions. However, the molecular mechanism by which SeMet alleviates DON damage is not yet clear. C57BL/6 mice were randomly divided into three groups, Se-A and Se-A+DON were fed with a diet containing 0.2 mg/kg Se whereas Se-S+DON were fed with a diet of 1.0 mg/kg Se. After feeding for four weeks, the mice were gavaged for 21 days with DON (2.0 mg/kg BW) or ultrapure water once per day. In the present study, we showed that SeMet significantly decreased the lipid peroxidation product malondialdehyde, and increased activities of antioxidant enzymes superoxide dismutase and total antioxidant capacity after DON exposure. In addition, our investigation revealed that SeMet regulated pathways related to lipid synthesis and metabolisms, and effectively mitigated DON-induced liver damage. Moreover, we have discovered that SeMet downregulation of N-acylethanolamine and HexCer accumulation induced hepatic lipotoxicity. Further study showed that SeMet supplementation increased protein levels of glutathione peroxidase 4 (GPX4), peroxisome proliferator-activated receptor γ (PPARγ), nuclear erythroid 2-related factor 2 (Nrf2), and upregulated target proteins, indicating suppression of oxidative stress in the liver. Meanwhile, we found that SeMet significantly reduced the DON-induced protein abundances of Bcl2, Beclin1, LC3B and proteins related to ferroptosis (Lpcat3, and Slc3a2), and downregulation of Slc7a11. In conclusion, SeMet protected the liver from damage by enhancing the Nrf2/PPARγ-GPX4-ferroptosis pathway, inhibiting lipid accumulation and hepatic lipotoxicity. The findings of this study indicated that SeMet has a positive impact on liver health by improving antioxidant capacity and relieving lipotoxicity in toxin pollution.

Clinical Characteristics and Eosinophils in Young SARS-CoV-2-Positive Chinese Travelers Returning to Shanghai.

Background: The COVID-19 outbreak, which was first reported in Wuhan, China, in December 2019, began to spread throughout the world, and now involves over 200 countries. Methods: A total of 37 overseas young and middle-aged people, who tested as SARS-CoV-2 positive upon their return to Shanghai, were enrolled for an analysis of their clinical symptoms, blood routine indexes, and lung CT images. Results: The clinical symptoms were characterized by fever (51.4%), dry cough (13.5%), expectoration (27.0%), hypodynamia (21.6%), pharyngalia (10.8%), pharynoxerosis (8.1%), rhinobyon (13.5%), rhinorrhea (8.1%), muscular soreness (16.2%), and diarrhea (2.7%). In 16.2% of cases, no symptoms were reported. Fever was the most common symptom (51.40%). The pneumonic changes referred to the latticed ground glass imaging and similar white lung imaging accompanied by consolidated shadows. The rate of pneumonia was high (81.10%). We found that the exclusive percent of eosinophils was abnormally low. By analyzing the correlation of eosinophils, fever, and pneumonia, we found that the percentage of eosinophils was low in the COVID-19 patients afflicted with fever or pneumonia (P < 0.01). Additionally, pneumonia and fever were negatively correlated with the percentage of eosinophils and eosinophils/neutrophils ratio (P < 0.01, respectively), but not associated with pneumonia severity (P > 0.05). Fever was not correlated with pneumonia (P > 0.05). Conclusion: A low percentage of eosinophils may be considered as a biomarker of pneumonia of COVID-19, but not as a biomarker of pneumonia severity.