Search

This study investigated the presence of nitrosamines, known carcinogens, in 1320 food samples from South Korea using LC-APCI-MS/MS analysis. Results showed nitrosamines were detected in 72% of samples, with processed foods exhibiting higher levels. Sesame oil, snow white rice cake, fried chicken wings, and fried squid were identified as having the highest nitrosamine content. Daily intake estimates revealed nitrosodiethylamine (NDEA), nitrosodibutylamine (NDBA), and nitrosopyrrolidine (NPYR) as major contributors to exposure. Risk assessment, based on BMDL10 values and MOE calculations, indicated low health risks overall, but certain food groups at the 95th percentile showed MOEs below the safety threshold, warranting attention. This underscores the need for ongoing monitoring and regulation of nitrosamine levels in food products to protect public health, particularly in regions with high consumption of processed foods like South Korea. Further research and regulatory measures are crucial to minimize nitrosamine exposure and mitigate associated health risks. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the changes in imported beef loin before and after cooking, depending on cooking methods, through quality characteristics, biogenic amine (BA) content analysis, and electronic tongue system. Sous-vide (SV), characterized by the least cooking loss, exhibited the highest water content at 64.11%. Pan-grilling (PG), air-frying (AF), and IR-grilling (IR) methods showed a range of water content from 46.90 to 54.19%. In the taste results by the electronic tongue, umami and saltiness were higher in the high cooking temperature methods (PG, AF, IR, and combined sous-vide + pan-grilling [SVP]) than SV (p < 0.05). Compared to the control, total BAs concentrations decreased by 67.32% (SV), 64.90% (AF), 62.46% (IR), and 50.64% (PG), and SVP showed the largest decrease of 68.64% (p < 0.05). Therefore, SVP was considered the most effective cooking method for reducing BAs and maintaining the quality characteristics of beef loin. [ABSTRACT FROM AUTHOR]

The levels of acrylamide (AA), four polycyclic aromatic hydrocarbons (PAH4), and heterocyclic aromatic amines (HAAs) in 184 air-fried agricultural, fishery, and animal products were measured using GC–MS and UPLC-MS/MS. Among the tested samples, sea algae exhibited the highest levels of PAH4 and eight specific HAAs (HAA8), while root and tuber crops had the greatest amount of AA. Agricultural and fisheries products had higher levels of all three contaminants, while livestock products had an inverse correlation between PAH4 and HAA8. The margin of exposure in the Korean population is considered "unlikely a concern" for all samples for PAH4 and HAA8, however, that for AA in cereal, vegetable, and root and tuber crops is deemed "may be a concern", with a value < 10,000 in all age groups. These findings suggest a need to evaluate dietary AA exposure in certain food categories and further research to minimize AA formation during air frying. [ABSTRACT FROM AUTHOR]

Red bell pepper (Capsicum annuum L.) is a popular and nutritious vegetable. In this study, oven cooking (OV), air-frying (AF), and infrared grilling (IR) were used to cook red bell peppers at different temperatures (170, 180, 190, and 200 °C). Changes in the total phenolic content, ascorbic acid content, antioxidant activity, and sugar and acrylamide content in red bell peppers were evaluated before and after cooking. The total phenolic and ascorbic acid contents decreased significantly after cooking (p < 0.05). Among the three evaluated methods, OV-cooked red bell peppers exhibited the highest antioxidant activity. The acrylamide content showed the lowest levels in OV 170 °C (93.67 ± 3.22 μg/kg dw) and the highest in AF 200 °C (1985.38 ± 76.39 μg/kg dw) samples. Compared to the AF and IR methods, OV was identified as the best way to preserve the antioxidant activity of red bell peppers while reducing acrylamide production. [ABSTRACT FROM AUTHOR]

Biogenic amines are produced during fermentation and can act as harmful substances. Strains related to the fermentation of maesil extract were identified and Clavispora lusitaniae and Pichia kluyveri were selected to investigate the relationship between biogenic amines and precursors, NaCl or ethanol. Biogenic amines were analyzed by high-performance liquid chromatography. Among precursors added, arginine was most effective for the biogenic amines formation. After 24 h incubation, the content of total biogenic amines increased from 37.60 to 51.75 mL/L for C. lusitaniae and from 2.60 to 33.30 mL/L for P. kluyveri in arginine-added medium. The number of yeast decreased in both NaCl- and ethanol-YM broth added with arginine, but there was no correlation between the number of yeast and biogenic amines. These results suggested that the formation of biogenic amines by yeast was affected by various factors and their interactions rather than a single factor, such as decarboxylase activity and stress factor. [ABSTRACT FROM AUTHOR]

Shrimp paste, a type of traditional Chinese food prepared from shrimp fermented with salt, contains biogenic amines (BAs). In this study, the BA content, salinity, and pH of eight commercial low-salt shrimp pastes were analyzed. In addition, the influences of various cooking conditions on the BA content of it were evaluated by HPLC. The total BA amount per product ranged between 32.39 and 1051.16 mg/kg. The salinity and pH were found significantly inversely correlated with the total BA amount. Of the cooking methods tested, after microwave heating and stir-frying, the total BA amount of shrimp paste, which showed the highest BA amount among 8 samples, declined from 1051.16 to 598.48 and 650.49 mg/kg, respectively; however, boiling or steaming showed no significant effects on the total BA amount. These results indicated possible health risk of low-salt shrimp paste whereas the risk could be reduced by choosing appropriate cooking method. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) constitute carcinogens. In this study, the risk of PAHs being consumed through meat and edible oils was assessed using a total diet study. Results were monitored by applying the toxic equivalency factor of benzo[a]pyrene; among each category, this factor was highest in grilled beef chitterlings (1.35 μg/kg), grilled Wiener sausages (1.20 μg/kg), fried chicken wings (0.70 μg/kg), and stir-fried perilla oil (1.29 μg/kg). The chronic daily intake was calculated, and risk characterization was estimated by applying the margin of exposure using the benchmark dose approach. Most samples analyzed in our study were denoted as having no concern; however, the intake group of stir-fried beef chitterlings, pan-fried pink sausage, deep-fried pork loin, and grilled duck was regarded as possible concern, and grilled chicken was assessed as having low concern. PAH changes must be monitored on a regular basis. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) were analyzed using gas chromatography–mass spectrometry in 115 dairy products and beverages, including alcoholic, grain, carbonated, and functional drinks; fruit and vegetable juices; coffee; and tea, purchased from 10 local city markets in South Korea. The sample groups were divided into non-fatty and fatty groups, pretreated with the ultrasound-assisted extraction method and saponification method, respectively. The limit of detection, limit of quantification, and accuracy were 0.038–0.185 μg/kg, 0.114–0.560 μg/kg, and 87.64–112.25%, respectively. The measurement uncertainty was ≤ 6.38% for eight PAHs (PAH8). PAH8 was detected in 41 of the 115 samples, ranging from 0.041 to 7.793 µg/kg. The risk assessment revealed that the margin of exposure for PAH8 ranged from 3.60 × 104 to 7.84 × 1011 in the mean intake groups and from 3.60 × 104 to 5.33 × 1011 in the P97.5 intake groups. [ABSTRACT FROM AUTHOR]

A Gram-stain-negative, strictly aerobic, cream yellow colored, non-motile, rod-shaped bacterial strain, designated MAH-1T was isolated from rhizospheric soil of Coriandrum sativum. A polyphasic taxonomic study was performed on the isolated strain. Optimal growth occurred at 28–30 °C, pH 6.5 and 0% NaCl. The strain showed activity for both catalase and oxidase tests. Cell growth occurs on R2A agar, nutrient agar and Luria–Bertani agar. Cells were able to hydrolyze starch, aesculin, gelatin, and Tween 20. Alignment of 16S rRNA gene sequences indicated that strain MAH-1T was associated with the genus Flavobacterium and was most closely related to Flavobacterium longum YIT 12745T (94.5% sequence similarity) and Flavobacterium caeni LM5T (93.0%). Strain MAH-1T had a genome size of 3,975,600 bp. Genome contained 67 contigs encoded by 3,522 protein-coding genes with 38 tRNA and 6 rRNA genes. The genomic DNA G + C contents of strain MAH-1T was 47.1 mol %. The genomic ANI and dDDH values between strain MAH-1T and one of the close relatives F. caeni LM5T were 72.2 and 18.8%, respectively. The major fatty acids were C15:0 iso, C16:0 iso and C15:0 anteiso. The predominant respiratory quinone was menaquinone 6 (MK-6). Based on physiological, biochemical and phylogenetic data for this isolate, it was confirmed that strain MAH-1T was affiliated to the genus Flavobacterium and represented a novel species, for which the name Flavobacterium agri sp. nov. is proposed. The type strain is MAH-1T (= KACC 19300T = CGMCC 1.16617T). [ABSTRACT FROM AUTHOR]

A total of 5 subfractions were obtained from methanol extracts of N. sublateritium mycelia via systemic extraction using n-hexane, chloroform, ethyl acetate, n-butanol, and water. The trolox equivalent antioxidant capacity of the chloroform subfraction was 649.40 μmol/g of sample. The highest ferric reducing/antioxidant power (FRAP) assay value was found in the chloroform subfraction (299.24 μmol of FeSO·7HO/g). The chloroform and ethyl acetate subfractions exhibited the highest total phenolic compound contents, with ferulic acid equivalents of 31.66 and 48.57 mg/g, respectively. The phenolic acids in the subfractions were further identified using liquid chromatography-tandem mass spectrometry. The 5 phenolic acids of 4-hydroxybenzoic acid, α-resorcylic acid, 4-coumaric acid, salicylic acid, and gentisic acid were found to be the major phenolics in the mushroom. [ABSTRACT FROM AUTHOR]

Key message: We report the production of taxadiene by transformation of N. benthamiana with a taxadiene synthase gene. The production was significantly increased by an elicitor treatment or metabolic pathway shunting. Abstract: Paclitaxel (Taxol) was first isolated from the bark of the pacific yew tree as an anticancer agent and has been used extensively to treat various types of cancer. Taxadiene, the first committed product of paclitaxel synthesis is cyclized from geranylgeranyl diphosphate (GGPP), and further complex hydroxylation and acylation processes of the unique taxane core skeleton produce paclitaxel. To accomplish de novo production of taxadiene, we transformed Nicotiana benthamiana with a taxadiene synthase ( TS) gene. The introduced TS gene under the transcriptional control of the CaMV 35S promoter was constitutively expressed in N. benthamiana, and the de novo production of taxadiene was confirmed by mass spectroscopy profiling. Transformed N. benthamiana homozygous lines produced 11-27 μg taxadiene/g of dry weight. The highest taxadiene production line TSS-8 was further treated with an elicitor, methyl jasmonate, and metabolic pathway shunting by suppression of the phytoene synthase gene expression which resulted in accumulation of increased taxadiene accumulation by 1.4- or 1.9-fold, respectively. In summary, we report that the production of taxadiene in N. benthamiana was possible by the ectopic expression of the TS gene, and higher accumulation of taxadiene could be achieved by elicitor treatment or metabolic pathway shunting of the terpenoid pathway. [ABSTRACT FROM AUTHOR]