This study established a method using gas chromatography-electrostatic field Orbitrap high-resolution mass spectrometry(Orbitrap GC-MS)for the simultaneous determination of 70 organic pollutants across 4 categories:or...This study established a method using gas chromatography-electrostatic field Orbitrap high-resolution mass spectrometry(Orbitrap GC-MS)for the simultaneous determination of 70 organic pollutants across 4 categories:organochlorine pesticides(OCPs),polycyclic aromatic hydrocarbons(PAHs),polychlorinated biphenyls(PCBs),and phthalates(PAEs)in infant cereal-based supplementary foods.Techniques integrating cryogenic centrifugation and lipid and protein adsorbent(LPAS)purification were employed.The precise mass numbers of target compounds were determined by Orbitrap GC-MS in full-scan mode(Full MS),which effectively minimized matrix interferences in these foods.Method validation on rice flour samples demonstrated that the 70 compounds exhibited excellent linearity within their respective mass concentration ranges,with correlation coefficients all exceeding 0.995.The detection limits for this method ranged 0.10–1.00μg/kg,while the quantification limits varied 0.3–3.0μg/kg,meeting the established detection requirements.The average spike recovery of the 70 compounds at 3 spiked levels(5,20,and 100μg/kg)ranged 75.3%–119.3%,with relative standard deviations ranging 1.8%–10.8%.Both inter-day and intra-day precision demonstrated relative standard deviation values below 15%.This method was applied to analyze 100 samples of commercial infant cereal-based supplementary food,revealing the presence of PAEs and PAHs in 12.0%of the samples.Notably,no OCPs or PCBs were detected.The detected concentrations of benzo[a]pyrene(Ba P)and dibutyl phthalate(DBP)were(4.2±0.1)and(1.8±0.3)μg/kg,respectively.This method is straightforward,highly sensitive,and suitable for the rapid screening and confirmation of 70 organic pollutants in infant cereal-based supplementary foods.展开更多
Fungal deterioration is a barrier to the wide acceptance of fermented cereal foods from Africa.The use of protective cultures is a natural approach to controlling fungi in foods that also complies with a clean label s...Fungal deterioration is a barrier to the wide acceptance of fermented cereal foods from Africa.The use of protective cultures is a natural approach to controlling fungi in foods that also complies with a clean label strategy.This study aims to select antifungal lactic acid bacteria(LAB)previously isolated from kunu-zaki to bio-control deterioration in this cereal-based Nigerian fermented beverage.Strains of Leuconostoc citreum(1),Limosilactobacillus fermentum(6),and Weissella confusa(3)were the most active against seven test mold species,with average inhibition score of 2.25-2.88,after screening 220 LAB strains using agar overlay on millet-sorghum flour hydrolysate(MSFH)agar.The MSFH agar diffusion method revealed that antifungal activity against the seven target molds was retained in cell-free supernatants(CFSs)of selected LABs,with the strongest inhibition against A.flavus F008BA and P.citrinum 3AS1 demonstrated by L.fermentum 5KJEU5(9.06%)and W.confusa YKDIA1(24.55%),respectively.The antifungal activity of CFSs was mainly due to the occurrence of acidic compounds,with the most abundant compounds being acetic(0.30-1.96 mg/mL)and lactic(1.80-3.23 mg/mL)acids.Other compounds such as hydroxycaffeic(0.16-6.72μg/mL),3-(4-hydroxyphenyl)propionic(1.40-6.36μg/mL),3-phenyllactic(1.28-24.48μg/mL),and hydroxyferulic acids(12.25μg/mL)occurred at lower concentrations.In challenged kunu-zaki,L.fermentum 5KJEU5 prevented the growth of A.flavus F008BA and P.citrinum 3AS1 beyond 8 day at ambient temperature(25◦C).In this study,LAB from kunu-zaki displayed strong antifungal activity,showing great potential as a protective culture to prevent fungal growth and mycotoxin accumulation in cereal foods.展开更多
基金funded by National Key Research and Development Program for Young Scientists of China(2022YFF1102900)Hebei Province High-level Talent Funding Project(C20221009)。
文摘This study established a method using gas chromatography-electrostatic field Orbitrap high-resolution mass spectrometry(Orbitrap GC-MS)for the simultaneous determination of 70 organic pollutants across 4 categories:organochlorine pesticides(OCPs),polycyclic aromatic hydrocarbons(PAHs),polychlorinated biphenyls(PCBs),and phthalates(PAEs)in infant cereal-based supplementary foods.Techniques integrating cryogenic centrifugation and lipid and protein adsorbent(LPAS)purification were employed.The precise mass numbers of target compounds were determined by Orbitrap GC-MS in full-scan mode(Full MS),which effectively minimized matrix interferences in these foods.Method validation on rice flour samples demonstrated that the 70 compounds exhibited excellent linearity within their respective mass concentration ranges,with correlation coefficients all exceeding 0.995.The detection limits for this method ranged 0.10–1.00μg/kg,while the quantification limits varied 0.3–3.0μg/kg,meeting the established detection requirements.The average spike recovery of the 70 compounds at 3 spiked levels(5,20,and 100μg/kg)ranged 75.3%–119.3%,with relative standard deviations ranging 1.8%–10.8%.Both inter-day and intra-day precision demonstrated relative standard deviation values below 15%.This method was applied to analyze 100 samples of commercial infant cereal-based supplementary food,revealing the presence of PAEs and PAHs in 12.0%of the samples.Notably,no OCPs or PCBs were detected.The detected concentrations of benzo[a]pyrene(Ba P)and dibutyl phthalate(DBP)were(4.2±0.1)and(1.8±0.3)μg/kg,respectively.This method is straightforward,highly sensitive,and suitable for the rapid screening and confirmation of 70 organic pollutants in infant cereal-based supplementary foods.
基金supported by Swiss Government Excellence Scholarships for Foreign Scholars and Artists(2018-2019)Cost Action CA18101 SOURDOMICS“SOURDOugh biotechnology network towards novel,healthier and sustainable food and bIoproCesseS”is also thankfully acknowledged.
文摘Fungal deterioration is a barrier to the wide acceptance of fermented cereal foods from Africa.The use of protective cultures is a natural approach to controlling fungi in foods that also complies with a clean label strategy.This study aims to select antifungal lactic acid bacteria(LAB)previously isolated from kunu-zaki to bio-control deterioration in this cereal-based Nigerian fermented beverage.Strains of Leuconostoc citreum(1),Limosilactobacillus fermentum(6),and Weissella confusa(3)were the most active against seven test mold species,with average inhibition score of 2.25-2.88,after screening 220 LAB strains using agar overlay on millet-sorghum flour hydrolysate(MSFH)agar.The MSFH agar diffusion method revealed that antifungal activity against the seven target molds was retained in cell-free supernatants(CFSs)of selected LABs,with the strongest inhibition against A.flavus F008BA and P.citrinum 3AS1 demonstrated by L.fermentum 5KJEU5(9.06%)and W.confusa YKDIA1(24.55%),respectively.The antifungal activity of CFSs was mainly due to the occurrence of acidic compounds,with the most abundant compounds being acetic(0.30-1.96 mg/mL)and lactic(1.80-3.23 mg/mL)acids.Other compounds such as hydroxycaffeic(0.16-6.72μg/mL),3-(4-hydroxyphenyl)propionic(1.40-6.36μg/mL),3-phenyllactic(1.28-24.48μg/mL),and hydroxyferulic acids(12.25μg/mL)occurred at lower concentrations.In challenged kunu-zaki,L.fermentum 5KJEU5 prevented the growth of A.flavus F008BA and P.citrinum 3AS1 beyond 8 day at ambient temperature(25◦C).In this study,LAB from kunu-zaki displayed strong antifungal activity,showing great potential as a protective culture to prevent fungal growth and mycotoxin accumulation in cereal foods.
