Total, soluble and insoluble oxalates were extracted and analyzed by high performance liquid chromatography (HPLC) following the preparation of kimchi using silver beet (Beta vulgaris var. cicla) stems and leaves. As silver beet contains high oxalate concentrations and consumption of high levels can cause the development of kidney stones in some people, the reduction of oxalate during preparation and fermentation of kimchi was investigated. The silver beet stems and leaves were soaked in a 10% brine solution for 11 h and then washed in cold tap water. The total, soluble and insoluble oxalate contents of the silver beet leaves were reduced by soaking in brine, from 4275.81 ± 165.48 mg/100 g to 3709.49 ± 216.51 mg/100 g fresh weight (FW). Fermenting the kimchi for 5 days at 19.3 ± 0.8 °C in 5 L ceramic jars with a water airtight seal resulted in a mean 38.50% reduction in total oxalate content and a mean 22.86% reduction in soluble oxalates. The total calcium content was essentially the same before and after the fermentation of the kimchi (mean 296.1 mg/100 g FW). The study showed that fermentation of kimchi significantly (p < 0.05) reduced the total oxalate concentration in the initial mix from 609.32 ± 15.69 to 374.71 ± 7.94 mg/100 g FW in the final mix which led to a 72.3% reduction in the amount of calcium bound to insoluble oxalate.

This study assessed the microbial risk of fresh produce collected from a compost farm, a crop-livestock rotation farm and a traditional farm in Canterbury, New Zealand. A total of 79 vegetable samples were collected from 3 different farming systems. No Escherichia coli O157:H7 was detected, but 95, 92 and 44% of the samples from the organic farm had unsatisfactory aerobic plate count (APC), E. coli, and Staphylococcus aureus levels respectively compared to the traditional farm, with corresponding values of 66, 88 and 27% based on guidelines for ready-to-eat foods. Resistance profiling showed that S. aureus and Salmonella spp. from all farms showed a higher resistance to vancomycin, erythromycin, ampicillin and penicillin antibiotics. The fresh produce collected from the organic farms was more contaminated with a wider range of pathogens than those from the traditional farm. Since the consumer perception of organic produce is because of its ‘chemical free’ status with little regard to the microbial status, it is prudent to conduct further studies to determine the type(s) of microbial hazards and how they behave under different climatic conditions and also address bacterial resistance to antibiotics in farming environments.

Cold atmospheric-pressure plasma has been suggested to induce antitumor immune responses as a local anticancer treatment. In this study, we investigated whether streamer discharge plasma, a type of cold atmospheric-pressure plasma, enhances the antitumor effects of anti-programmed cell death protein 1 (PD-1) antibody therapy in a murine colon tumor model. Colon26 tumor-bearing mice were randomly assigned to four groups: Control, anti-PD-1 antibody alone, plasma treatment alone and combination treatment with anti-PD-1 antibody and plasma groups. Three independent tumor growth experiments were performed. Under conditions in which anti-PD-1 antibody and plasma treatments alone showed limited effects on tumor growth, the combination treatment delayed tumor growth. Analysis of longitudinal tumor growth curves using a linear mixed model revealed a significant interaction among time, anti-PD-1 antibody treatment and plasma treatment in the integrated dataset, supporting a combined effect on tumor growth. Exploratory flow cytometric analysis showed a numerically lower percentage of F4/80+ macrophage-enriched cells and numerically higher percentages of CD8+ T cell-related populations in the combination group. However, no statistically significant interaction between plasma treatment and anti-PD-1 antibody treatment was detected for any of the flow cytometric parameters. Overall, the pooled analysis supported a combined antitumor effect of local streamer discharge plasma and anti-PD-1 antibody treatment, although the magnitude of the combined effect varied among the three experiments.