Dishwashers are one of the sources of bacterial contamination in dishes despite the fact that they comprise extreme environments due to the high temperature, high pH, and the presence of detergents during their operation. In this study, viable bacteria were isolated from 6 door-type and 8 conveyor-type dishwashers that were being used in food service facilities. Each door- and conveyortype dishwasher was divided into 6 and 9 sections respectively. Thermophilic bacteria, which grow at 60˚C, were obtained from 5 sections of door-type dishwashers, but obtained from one section of conveyor-type dishwashers tested. The 16S rRNA sequences of the cultured isolates revealed that fewer Gram-negative bacterial strains were found in door-type dishwashers than in conveyor-type dishwashers. The most frequently identified bacterial species in the samples tested were spore-forming bacteria, such as Bacillus and Anoxybacillus species. This study highlights the vulnerabilities presented by dishwashers used in food service facilities.

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Histamine, known as bioactive amine, is synthesized through histidine decarboxylase (HDC). HDC is the sole enzyme that catalyzes histamine production in the human body and thus HDC inhibitor is expected to control histamine-mediating biological activity by controlling histamine production. In the present study, active compound that inhibits HDC activity was sought from strawberry cultivar 'Tokun' that was the most effective cultivar among 11 different cultivar of strawberries. From active fraction of ethyl acetate soluble part, tiliroside, a flavonoid glucoside, was isolated as an HDC inhibitor with IC50 = 40.3 μM. Casuarictin, an ellagitannin, was detected from some active fractions and showed potent inhibition with IC50 = 3.3 μM. Judging from potency of inhibition and content of 'Tokun' extract, casuarictin rather than tiliroside contributed to HDC inhibition of 'Tokun' extract more effectively. Tiliroside, on the other hand, was thought to be a possible marker to predict effective strawberry cultivar for HDC inhibition.

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In this work, plant extract–metal ions hybrid nanoflowers (HNFs) were synthesized and their catalytic and antimicrobial properties were examined. While the sweet and sour lemon peel extract (acquired in boil water) and its primary elements were engaged as organic elements in the creation of NFs, copper (II) ions (Cu2+) were the inorganic element. Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray (EDX) spectroscopy, and Fourier Transform Infrared Spectrometry (FT-IR) were examined to characterize the structures of the NFs. The structural examination showed that the existence of Cu–O and Cu–N bonds in NFs can be a sign of the creation of NFs. Antimicrobial activities of the NFs were systematically studied against Candida albicans (ATCC 90028), Staphylococcus aureus (ATCC 25923), and Escherichia coli (ATCC 25922) with broth microdilution and short time-kill assay. The peroxidasemimicking activity based on the NFs' Fenton-like response mechanism was assessed against guaiacol in the presence of H2O2. The findings have shown that plant extract-based hybrid NFs technology is promising and can find prospective applications in numerous technical areas.

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