Evaluation of survival of murine norovirus-1 during sauerkraut fermentation and storage under standard and low-sodium conditions

Effect of fermentation on the antioxidant properties and phenolic compounds of Bambangan (Mangifera pajang) fruit

The study aimed to determine the antioxidant activities and phenolic compounds of Bambangan (Mangifera pajang), a type of wild fruit belongs to the family of Anacardiaceae during fermentation at room (28 °C) and elevated temperature (35 °C). The antioxidant capacity was estimated based on 2,2-diphenyl-1-picyrlhydrazyl (DPPH) scavenging activity, ferric-ion-reducing power (FRAP), 2,2´-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation assay and oxygen-radical absorbing capacity (ORAC). A reversed phase high performance liquid chromatography (HPLC) was used to identify the phenolic compounds. Samples of bambangan fermented at 35 °C achieved the highest FRAP (141.42 mM Fe(II)/g extract) and ABTS values (5.00 mmol TE/g) within the first six days as compared to the samples fermented at room temperature (28 °C), which required 10 days to achieve the highest FRAP and ABTS values. No significant difference was found (p > 0.05) on the antioxidant activity of the samples that were kept at prolonged fermentation and storage. The total phenolic content (TPC) increased throughout the fermentation with the highest value of 44.69 ± 0.01 mg GAE/g. Gallic acid, chlorogenic acid, vanillin, ρ -coumaric acid and rutin are the major phenolic compounds identified in the fermented product. The results suggested that the antioxidant capacity of bambangan is affected by the fermentation temperature and the fermented product could be a source of antioxidants.

Physico-chemical and microbiological changes during the cabbage hybrid bravo heads fermentation: Salt, temperature and starter culture influence

The influence of temperatures (18, 22 and 26°C), salt (60, 70 and 80 g/kg) and starter culture (0, 0.025 and 0.050 g/kg) on physico-chemical and microbiological changes during fermentation in cabbage heads were investigated. The experiment was set up in industrial conditions, samples were taken after 0, 5, 12, 27 and 62 days in order to determine the changes in color, texture, biogenic amines content, microbiological parameters, pH, a_w, total sugar content, total acidity and salt content. Analysis of variance and Principal component analysis were applied to get a better overview of differences between samples and the similarities between different fermentation conditions. Significant color changes and softening of cabbage tissue did not occurred during the entire fermentation process. Cadaverine was not detected in samples containing starter culture, also the results were in range for maximum allowed putrescine and cadaverine doses for all cabbage samples. Total number of molds increased, contrary to number of yeasts on the last examined day in comparison with raw cabbage sample. Enterobacteriaceae were not detected after 5^th fermentation day, while sharp increase of lactic acid bacteria number occurred until 12^th day, and on the 12^th fermentation day was in range of 7.82 to 9.84 log cfu/g. The fermentation process led to decrease in pH, a_w and total sugar content, meanwhile total acidity 0.54%-0.89% and salt content 2.08%-3.19% in the cabbage heads increased, in comparison with raw sample where results for total acidity and salt content were 0.13% and 0.05%, respectively. Additionally, according Principal component analysis, temperature of fermentation had the greatest influence on the fermentation process, followed by the application of starter culture and then concentration of added salt.

Viruses in fermented foods: are they good or bad? Two sides of the same coin

The emergence of Coronavirus disease 2019 as a global pandemic has increased popular concerns about diseases caused by viruses. Fermented foods containing high loads of viable fungi and bacteria are potential sources for virus contamination. The most common include viruses that infect bacteria (bacteriophage) and yeasts reported in fermented milks, sausages, vegetables, wine, sourdough, and cocoa beans. Recent molecular studies have also associated fermented foods as vehicles for pathogenic human viruses. Human noroviruses, rotavirus, and hepatitis virus have been identified in different fermented foods through multiple routes. No severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) virus or close members were found in fermented foods to date. However, the occurrence/persistence of other pathogenic viruses reveals a potential vulnerability of fermented foods to SARS-CoV-2 contamination. On the other side of the coin, some bacteriophages are being suggested for improving the fermentation process and food safety, as well as owing potential probiotic properties in modern fermented foods. This review will address the diversity and characteristics of viruses associated with fermented foods and what has been changed after a short introduction to the most common next-generation sequencing platforms. Also, the risk of SARS-CoV-2 transmission via fermented foods and preventive measures will be discussed.