No abstract

This study performed the first environmental and dietary exposure assessment to explore plant uptake of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) from agricultural soil and irrigation water in the Nakdong River delta, South Korea. Annual average concentrations of total PFOA and PFOS ranged from 0.026 to 0.112 µg L -1 (irrigation water), and from 0.818 to 1.364 µg kg -1 (soil), respectively. PFOA and PFOS hotspots were identified downstream of the Nakdong River, and were influenced by seasonal climatic variations. The observed average biennial concentration of the sum of PFOA and PFOS decreased in irrigation water, from 0.112 µg L -1 in 2013 to 0.026 µg L -1 in 2015, suggests that the 2013 Persistent Organic Pollutants Control Act may have helped to reduce levels of PFAS at this location. This study calculated some of the highest plant uptake factors reported to date, with values ranging from 0.962 in green onions to < 0.004 in plums. Leafy vegetables and rice are important components of the Korean diet; these groups had the largest contribution to the estimated dietary intake of PFOA and PFOS, which was calculated at 0.449 and 0.140 ng kgbw -1 day -1 , respectively. This corresponded to 66.4% for PFOA and 7.9% for PFOS of the EFSA reference dose (RfD). The dietary intake of PFOA and PFOS from crops alone did not exceed the RfD. However, when the estimated daily intake (EDI) from other sources such as tap water, meat, fish, dairy and beverages were included in the exposure risk assessment, both of the EDIs to PFOA and PFOS exceeded the RfDs, indicating there may be a risk to human health. This study concludes that consumption of crops might, therefore, be a significant and underappreciated pathway for human exposure to PFAS.

The cyclic lipopeptide produced from Bacillus pumilus strain HY1 was isolated from Korean soybean sauce cheonggukjang. The chemical structures of the surfactin isomers were analyzed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). The five potential surfactin isoforms were detected with protonated masses of m/z 994.7, 1008.7, 1022.7, 1036.7, and 1050.7 and different structures in combination with Na+, K+, and Ca2+ ions. ESI-MS/MS analysis revealed that the isolated surfactin possessed the precise amino acid sequence LLVDLL and hydroxyl fatty acids with 12 to 16 carbons. The surfactin content during cheonggukjang fermentation increased from 0.3 to 51.2 mg/kg over 60 h of fermentation. The mixture of five surfactin isoforms of cheonggukjang inhibited the growth of two cancer cell lines. The growth of both MCF-7 and Caco-2 cells was strongly inhibited with 100 μg/μL of surfactin. This study is the first-time report of five surfactin isomers of Bacillus pumilus strain HY1 during Korean soybean sauce cheonggukjang fermentation, which has cytotoxic properties.

Elaeagnus multiflora Thunb. (cherry silverberry, CS) is an underutilized fruit with notable phytochemical profile and biological activities. However, there are few studies on cancer inhibitory effect using fermented CS fruits. This study aimed to develop fermented CS fruits using lactic acid bacteria and investigate its anticolorectal cancer (CRC) property and phenolic composition. SW480 CRC cells were treated with aqueous extracts of CS fermented by single and coculture of Lactobacillus plantarum and L. casei. The extracts of fermented CS exhibited greater antiproliferative activity and anticlonogenicity in comparison with the unfermented extract and the control. Among the extracts of CS fruits, the ones fermented by the coculture (LPLC) showed the most potent tumor suppression property, at 25 to 50 µg/mL, by induction of cell cycle arrest at the S and G2/M phases, downregulating cyclins and its dependent kinases while increasing tumor suppressor proteins p27 and p53. LPLC also exerted its tumor suppression effect by inhibiting the chemotactic motility and invasiveness of SW480 cells, downregulating matrix metalloproteinase‐9, and PI3K/AKT/mTOR pathways and upregulating TIMP‐9, and E‐cadherin. HPLC‐PDA analysis revealed that the levels of major flavonoids in CS extracts, namely, catechin, epigallocatechin, epicatechin, epigallocatechin gallate, rutin, naringin, and quercetin, were enhanced by fermentation with L. plantarum and L. casei in coculture. Overall, this study showed that the extracts of fermented CS have augmented and multifaceted anticancer property and can be utilized in the development of functional food or ingredient for the prevention of CRC. Practical Application Elaeagnus multiflora, commonly known as cherry silverberry, has been proven to contain bioactive components and possesses high functionality. However, due to limited shelf‐life as a fresh commodity, development of novel product is essential. Fermentation is a beneficial process employed in the food industry to enhance the shelf stability, nutritional, sensory, and functional properties of food products. The present study has explored the possibility of adding value to an underutilized fruit, cherry silverberry, through the process of fermentation, making it as a potential source of functional food and ingredient for the prevention of colorectal cancer.

This study presents a numerical approach to predict the flow resistance coefficient in a segment ball valve. If more than a few valves are installed in a pipe system, the flow resistance coefficient should be considered in selecting the valves. Thus, the design of a segment ball valve incorporating the prediction of the flow resistance coefficient is suggested in this study. A segment ball valve incorporates the advantages of a ball valve and a butterfly valve. To predict the flow resistance coefficient of a segment ball valve, two approximate methods are introduced: second-order response surface method (RSM) and kriging interpolation method. The metamodels, built by EXCEL program and determined from the two models, were compared with the true numerical model. This study proposes the most suitable approximation method for the prediction of the flow resistance coefficient in a design of valve.