Impact of sulfite use and acidification on chemical quality components in thermally processed watermelon juices.

The present study compared pasteurized and reconstituted (from vacuum-concentrated) watermelon juices with sulfite use (∼40 mg/L) and acidification (pH = 4.2) to fresh watermelon juices. The products were evaluated for phenolics, free amino acids, carotenoids, sugars, organic acids, and alcohols by high-performance liquid chromatography-HPLC and the volatile profile by headspace-gas chromatography/mass spectrometry(HS-GC/MS). Pasteurization had no significant impact on most of the chemical components. Furthermore, it potentiated typical watermelon aromas (E,E)-2,6-nonadienal, (Z)-3-nonen-1-ol, 4-hexen-1-ol, (E,Z)-3,6-nonadien-1-ol, 6-amino-2-methyl-2-heptanol, (E)-6-nonenal, (E)-2-nonenal, pentanal, nonanal and 1-nonanol), without off-flavor compounds formation. On the other hand, the reconstituted juice showed reduced amino acids (serine, glutamine, and tryptophan), phenolics (epicatechin gallate, myricetin, and cis-resveratrol), carotenoids (lycopene, ß-carotene, and violaxanthin) and most volatile compounds. Our results showed that sulfite and acidification could maintain watermelon juice's nutritional and quality parameters after pasteurization. The vacuum concentration and reconstitution processes negatively impacted the evaluated compounds. Our findings contribute to improving thermal processes in watermelon juices for better preservation of nutrients, flavor, and bioactive compounds.

Sustained increase of paediatric invasive Streptococcus pyogenes infections dominated by M1UK and diverse emm12 isolates, Portugal, September 2022 to May 2023.

Since autumn 2022, observed numbers of paediatric invasive group A Streptococcus infections in Portugal (n = 89) were higher than in pre-COVID-19 seasons. Between September 2022 and May 2023, the dominant diagnoses were pneumonia (25/79), mostly with empyema (20/25), and sepsis (22/79). A number of cases required admission to intensive care (27/79) and surgery (35/79), and the case fatality rate was 5.1% (4/79). Genomic sequencing (n = 55) revealed multiple genetic lineages, dominated by the M1UK sublineage (26/55) and more diverse emm12 isolates (12/55).

Effect of commercial yeasts (Saccharomyces cerevisiae) on fermentation metabolites, phenolic compounds, and bioaccessibility of Brazilian fermented oranges.

Brazil is the largest producer of oranges worldwide, as well as one of the largest producers of orange juice. Alcoholic fermented beverages have been considered a marketable alternative for oranges. In this study, four S. cerevisiae commercial yeasts were evaluated for metabolites generated during orange juice (cv. 'Pêra D9') fermentation. Alcohols, sugars, and organic acids were evaluated by HPLC-DAD-RID during fermentation, and phenolic compounds were analyzed in fermented orange. Orange juice and fermented oranges were also subjected to digestion simulations. The yeasts presented an adequate fermentation activity, based on sugar consumption, and high ethanol (>10.5%) and glycerol (4.8-5.5 g/L) contents. The yeast strains T-58 and US-05 produced high levels of lactic acid. Phenolic compounds and antioxidant activity did not differ amongst yeasts, presenting hesperidin levels between 115 and 127 mg/L, respectively. The fermented orange showed a >70% bioaccessibility, compared to juice, especially for catechin, epigallocatechin-gallate, procyanidin-B2, rutin, and procyanidin-B1.