Plant-derived essential oils have excellent antifungal effects and can be used for the preservation of fresh foods such as fruits and vegetables, but the detailed mechanism has not been fully elucidated. In this study...Plant-derived essential oils have excellent antifungal effects and can be used for the preservation of fresh foods such as fruits and vegetables, but the detailed mechanism has not been fully elucidated. In this study, we investigated the inhibitory effects of trans-cinnamaldehyde on Penicillium italicum, a common pollution fungus in citrus, and explored the antifungal mechanism of trans-cinnamaldehyde by detecting fungal oxidative damage, mitochondrial metabolism, and cell apoptosis. These results showed that transcinnamaldehyde made the carboxylic acid cycle deregulated by altering the related enzyme activities(succinate dehydrogenase, malate dehydrogenase) and mid product. Moreover, the level of reactive oxygen species rose sharply while the redox level was out of regulation. The mitochondrial membrane potential collapsed, leading to the leakage of cytochrome c, and then triggering the activation of apoptotic protease, which was further confirmed by the significant increase in caspase-3 activity from(3.6 ± 0.6) U to(8.8 ± 1.1) U(P < 0.05). The cytochrome c in mitochondria was detected by confocal Raman microspectroscopy, the characteristic intensity index(I750/I2944) was decreased, indicating that the cytochrome c in mitochondria was reduced and leakage. Besides, the strong negative correlation between Raman intensity and the amount of cytochrome c leakage was established with the correlation coefficient of-0.981 7. This study revealed that destroying the integrity of the mitochondrial membrane, activating the mitochondrial-mediated apoptosis pathway was the in-depth antifungal mechanism of trans-cinnamaldehyde;and Raman spectroscopy technology provided new ideas to study this process with high sensitivity determination of cytochrome c.展开更多
The risk of the illegal addition of anti-inflammatory and analgesic chemical drugs in anti-rheumatic health foods should not be ignored.Market supervision and rapid on-site detection technology need to be strengthened...The risk of the illegal addition of anti-inflammatory and analgesic chemical drugs in anti-rheumatic health foods should not be ignored.Market supervision and rapid on-site detection technology need to be strengthened.Thin-layer chromatography-surface-enhanced Raman spectroscopy(TLC-SERS),which has the advantages of simple operation,fast separation,and qualitative and quantitative detection,was used in this study.And these eleven chemical drugs(acetaminophen,acetylsalicylic acid,aminophenazone,dexamethasone,diclofenac sodium,hydrocortisone,indometacin,naproxen,phenylbutazone,piroxicam,prednisone 21-acetate)that may be added to anti-rheumatic health foods have been simultaneously identified by TLC-SERS combined with chemometrics method.The characteristic signals of the separated drug spots were collected by SERS,which were optimized by the gold colloidal nanoparticles’volume and integration time.Then SERS was subjected to principal component analysis(PCA)to reduce dimensionality and combined with the pattern recognition methods in chemometrics,such as PCA-Linear Discriminant Analysis(LDA),PCA-K Nearest Neighbor and PCA-Support Vector Machine,and eleven drug components were judged and identified.Moreover,the predictive performances of different models were also analyzed and compared.The results showed that the TLC plate and four organic solvents of petroleum ether,chloroform,ethyl acetate and acetic acid were selected as the developing agent.The dropping amount of gold colloidal nanoparticles and the integration time were set and optimized.The limit of detection of the simultaneous detection method of SERS was 10-100 mg/L.Furthermore,SERS was preprocessed by Gap-Segment 2nd Derivative,and then the PCA-LDA model was established,and the model’s prediction accuracy can reach 100%.The method is simple,rapid,sensitive and accurate,and has low experimental instruments and equipment requirements.It is suitable for the on-site simultaneous detection of various anti-inflammatory and analgesic chemical drugs in health foods.It can also provide guarantee and support for the establishment of appropriate rapid detection methods and the development of supervision technology.展开更多
Nitroimidazoles are a family of veterinary drugs containing a 5-nitroimidazole ring structure,which are commonly used antibiotics.In view of their potential genotoxicity and possible coexistence in actual samples,it i...Nitroimidazoles are a family of veterinary drugs containing a 5-nitroimidazole ring structure,which are commonly used antibiotics.In view of their potential genotoxicity and possible coexistence in actual samples,it is necessary to establish a rapid and effective method for the simultaneous determination of multiple nitroimidazoles.In this study,a rapid thin-layer chromatography combined with surface-enhanced Raman spectroscopy(TLC-SER)detection method for 14 nitroimidazole compounds has been established.The theoretical Raman spectra of the nitroimidazoles were calculated using the B3LYP/6-311+G(d)basis set in density functional theory(DFT)and the theoretical Raman spectra of TNZ,NBZ,ONZ,SCZ,DMZ,MNI,2-HMZ,4-HMZ,CMNI,IPZ,MNZ-OH and HMDMZ have been obtained for the first time.SERS detection was carried out on a gold nanoparticles(AuNPs)substrate,which exhibited strong SERS signals and a limit of detection limit of 0.1 mg/L.By optimizing the conditions used for the developing agent in TLC,12 nitroimidazoles were successfully separated,while MNZ and RNZ still could not be separated.When combined with the chemometrics analysis method,the TLC-SERS method can realize the simultaneous detection of 14 nitroimidazoles.Actual pork samples were spiked with nitroimidazoles with a recovery rate of 80%-110%and RSD of 0.74%-16.70%,which showed that SERS and TLC-SERS methods are also effective for detection in actual samples.The detection time of this method is<10 min,which is suitable for the rapid detection of nitroimidazoles,especially for the rapid qualitative identification of nitroimidazoles in situ.展开更多
The cuticle is the outermost protective film of eggs, whose quality will affect internal freshness. At present, the undamaged detection of eggs freshness relies on hyperspectral imaging technology, which is relatively...The cuticle is the outermost protective film of eggs, whose quality will affect internal freshness. At present, the undamaged detection of eggs freshness relies on hyperspectral imaging technology, which is relatively complicated. In this study, a novel simple approach for evaluating internal freshness of eggs was further explored by detecting the quality of egg cuticle. Malachite green selected as the alternative dye for quality evaluation of adhesive film, the correlation analysis was carried out by collecting the physical and chemical indexes of eggs with different degrees of freshness. It is found that there was a strong positive correlation between the quality of all parts of the cuticle and internal freshness (p < 0.01), and the Pearson correlation coefficient was over 0.85. The Haugh unit and pH of albumen were most strongly correlated with cuticle quality at the top, with the correlation coefficient of 0.919 and −0.906, respectively. The cuticle quality of eggs with contents got worse than that of eggs without contents, and the holes increased when they were stored for 28 days. In this way, malachite green staining method can be used to identify the freshness of egg cuticle, and the quality of egg cuticle can be used to distinguish eggs with different freshness. This study provided a new direction for the study of egg freshness and assisted to distinguish the quality and safety of eggs nondestructively.展开更多
基金supported by China Postdoctoral Science Foundation (2020M680064)National Natural Science Foundation of China (32172326)the Postdoctoral Research Startup Fee of Jiangnan University (1025219032200190)。
文摘Plant-derived essential oils have excellent antifungal effects and can be used for the preservation of fresh foods such as fruits and vegetables, but the detailed mechanism has not been fully elucidated. In this study, we investigated the inhibitory effects of trans-cinnamaldehyde on Penicillium italicum, a common pollution fungus in citrus, and explored the antifungal mechanism of trans-cinnamaldehyde by detecting fungal oxidative damage, mitochondrial metabolism, and cell apoptosis. These results showed that transcinnamaldehyde made the carboxylic acid cycle deregulated by altering the related enzyme activities(succinate dehydrogenase, malate dehydrogenase) and mid product. Moreover, the level of reactive oxygen species rose sharply while the redox level was out of regulation. The mitochondrial membrane potential collapsed, leading to the leakage of cytochrome c, and then triggering the activation of apoptotic protease, which was further confirmed by the significant increase in caspase-3 activity from(3.6 ± 0.6) U to(8.8 ± 1.1) U(P < 0.05). The cytochrome c in mitochondria was detected by confocal Raman microspectroscopy, the characteristic intensity index(I750/I2944) was decreased, indicating that the cytochrome c in mitochondria was reduced and leakage. Besides, the strong negative correlation between Raman intensity and the amount of cytochrome c leakage was established with the correlation coefficient of-0.981 7. This study revealed that destroying the integrity of the mitochondrial membrane, activating the mitochondrial-mediated apoptosis pathway was the in-depth antifungal mechanism of trans-cinnamaldehyde;and Raman spectroscopy technology provided new ideas to study this process with high sensitivity determination of cytochrome c.
基金supported by the China Postdoctoral Science Foundation(2020M680064)the Postdoctoral Research Startup Fee of Jiangnan University(1025219032200190)+1 种基金the National Natural Science Foundation of China(32172326)the Open Project of Engineering Research Center of Dairy Quality and Safety Control Technology of Ministry of Education of China(R202101).
文摘The risk of the illegal addition of anti-inflammatory and analgesic chemical drugs in anti-rheumatic health foods should not be ignored.Market supervision and rapid on-site detection technology need to be strengthened.Thin-layer chromatography-surface-enhanced Raman spectroscopy(TLC-SERS),which has the advantages of simple operation,fast separation,and qualitative and quantitative detection,was used in this study.And these eleven chemical drugs(acetaminophen,acetylsalicylic acid,aminophenazone,dexamethasone,diclofenac sodium,hydrocortisone,indometacin,naproxen,phenylbutazone,piroxicam,prednisone 21-acetate)that may be added to anti-rheumatic health foods have been simultaneously identified by TLC-SERS combined with chemometrics method.The characteristic signals of the separated drug spots were collected by SERS,which were optimized by the gold colloidal nanoparticles’volume and integration time.Then SERS was subjected to principal component analysis(PCA)to reduce dimensionality and combined with the pattern recognition methods in chemometrics,such as PCA-Linear Discriminant Analysis(LDA),PCA-K Nearest Neighbor and PCA-Support Vector Machine,and eleven drug components were judged and identified.Moreover,the predictive performances of different models were also analyzed and compared.The results showed that the TLC plate and four organic solvents of petroleum ether,chloroform,ethyl acetate and acetic acid were selected as the developing agent.The dropping amount of gold colloidal nanoparticles and the integration time were set and optimized.The limit of detection of the simultaneous detection method of SERS was 10-100 mg/L.Furthermore,SERS was preprocessed by Gap-Segment 2nd Derivative,and then the PCA-LDA model was established,and the model’s prediction accuracy can reach 100%.The method is simple,rapid,sensitive and accurate,and has low experimental instruments and equipment requirements.It is suitable for the on-site simultaneous detection of various anti-inflammatory and analgesic chemical drugs in health foods.It can also provide guarantee and support for the establishment of appropriate rapid detection methods and the development of supervision technology.
基金supported by National Natural Science Foundation of China(32172326)National Key R&D Program of China(2018YFC1602300,2020YFC1606800)+2 种基金Modern agriculture in Jiangsu Province-key and general projects(BE2019362)Science and technology planning project of Jiangsu market supervision and Administration Bureau(KJ204132,KJ21125006)Suzhou science and technology development plan(SS2019016).
文摘Nitroimidazoles are a family of veterinary drugs containing a 5-nitroimidazole ring structure,which are commonly used antibiotics.In view of their potential genotoxicity and possible coexistence in actual samples,it is necessary to establish a rapid and effective method for the simultaneous determination of multiple nitroimidazoles.In this study,a rapid thin-layer chromatography combined with surface-enhanced Raman spectroscopy(TLC-SER)detection method for 14 nitroimidazole compounds has been established.The theoretical Raman spectra of the nitroimidazoles were calculated using the B3LYP/6-311+G(d)basis set in density functional theory(DFT)and the theoretical Raman spectra of TNZ,NBZ,ONZ,SCZ,DMZ,MNI,2-HMZ,4-HMZ,CMNI,IPZ,MNZ-OH and HMDMZ have been obtained for the first time.SERS detection was carried out on a gold nanoparticles(AuNPs)substrate,which exhibited strong SERS signals and a limit of detection limit of 0.1 mg/L.By optimizing the conditions used for the developing agent in TLC,12 nitroimidazoles were successfully separated,while MNZ and RNZ still could not be separated.When combined with the chemometrics analysis method,the TLC-SERS method can realize the simultaneous detection of 14 nitroimidazoles.Actual pork samples were spiked with nitroimidazoles with a recovery rate of 80%-110%and RSD of 0.74%-16.70%,which showed that SERS and TLC-SERS methods are also effective for detection in actual samples.The detection time of this method is<10 min,which is suitable for the rapid detection of nitroimidazoles,especially for the rapid qualitative identification of nitroimidazoles in situ.
基金supported by the Science and Technology Planning Project of Jiangsu Market Supervision and Administration Bureau(KJ21125006)the China Postdoctoral Science Foundation(2020M680064)+1 种基金the Open Project of Engineering Research Center of Dairy Quality and Safety Control Technology of Ministry of Education of China(R202101)the Postdoctoral Research Startup Fee of Jiangnan University(1025219032200190).
文摘The cuticle is the outermost protective film of eggs, whose quality will affect internal freshness. At present, the undamaged detection of eggs freshness relies on hyperspectral imaging technology, which is relatively complicated. In this study, a novel simple approach for evaluating internal freshness of eggs was further explored by detecting the quality of egg cuticle. Malachite green selected as the alternative dye for quality evaluation of adhesive film, the correlation analysis was carried out by collecting the physical and chemical indexes of eggs with different degrees of freshness. It is found that there was a strong positive correlation between the quality of all parts of the cuticle and internal freshness (p < 0.01), and the Pearson correlation coefficient was over 0.85. The Haugh unit and pH of albumen were most strongly correlated with cuticle quality at the top, with the correlation coefficient of 0.919 and −0.906, respectively. The cuticle quality of eggs with contents got worse than that of eggs without contents, and the holes increased when they were stored for 28 days. In this way, malachite green staining method can be used to identify the freshness of egg cuticle, and the quality of egg cuticle can be used to distinguish eggs with different freshness. This study provided a new direction for the study of egg freshness and assisted to distinguish the quality and safety of eggs nondestructively.
