Impact of washing and freezing on nutritional composition, bioactive compounds, antioxidant activity and microstructure of mango peels

Mango peels are widely produced and highly perishable. Disinfectant washing and freezing are among the most used methods to preserve foods. However, their impact on products' properties is conditioned by the foods' features. This study evaluated for the first time the phytochemical composition, antioxidant activity, and microstructure of mango peels washed with peracetic acid (27 mg/mL for 19 min) and frozen at -20 °C for 30 days. Washing decreased the content of vitamin C (-7%), penta-O-galloyl-β-d-glucose (-23 %), catechin (-30 %), and lutein (-24 %), but the antioxidant activity was preserved. Freezing changed mango peels' microstructure, increased free phenolic compounds, namely acid gallic (+36 %) and catechin (+51 %), but reduced bound phenolic compounds (-12 % to -87 %), bound phenolic compounds' antioxidant activity (-51 % to -72 %), and violaxanthin (-51 %). Both methods were considered adequate to conserve mango peels since fiber and the main bioactive compounds (free mangiferin, free gallic acid, and β-carotene) remained unchanged or increased.

Valorization of Mushroom By-Products as a Source of Value-Added Compounds and Potential Applications

Nowadays, the food sector is highly concerned with environmental issues and foreseen to develop strategies to reduce waste and losses resulting from activities developed in the food system. An approach is to increment added value to the agro-industrial wastes, which might provide economic growth and environmental protection, contributing to a circular economy. Mushroom by-products represent a disposal problem, but they are also promising sources of important compounds, which may be used due to their functional and nutritional properties. Research has been developed in different fields to obtain value added solutions for the by-products generated during mushroom production and processing. Bioactive compounds have been obtained and applied in the development of nutraceutical and pharmaceutical formulations. Additionally, other applications have been explored and include animal feed, fertilizer, bioremediation, energy production, bio-based materials, cosmetics and cosmeceuticals. The main purpose of this review is to highlight the relevant composition of mushroom by-products and discuss their potential as a source of functional compounds and other applications. Future research needs to explore pilot and industrial scale extraction methods to understand the technological feasibility and the economic sustainability of the bioactive compounds extraction and valorization towards different applications.

Tolerance to multiple metal stressors in emerging non-typhoidal MDR Salmonella serotypes: a relevant role for copper in anaerobic conditions

OBJECTIVES

Factors driving the expansion of particular MDR Salmonella serotypes/clones are not completely understood. We assessed if emergent MDR Salmonella serotypes/clones were more enriched in metal tolerance genes (e.g. to Cu/Ag) than other less frequent ones, as an additional feature to survive in environments contaminated with metals.

METHODS

Metal (Cu pco/Ag,Cu sil/Hg mer/As ars/Te ter) tolerance genes screening (PCR/sequencing), MICs of CuSO4/AgNO3 (aerobiosis/anaerobiosis), genetic element characterization (S1/I-CeuI PFGE) and conjugation assays were performed in a well-characterized Salmonella collection (n = 275 isolates; 2000-14; 49 serotypes/clones).

RESULTS

The sil ± pco genes were detected in 37% of isolates from diverse serotypes, mainly in emergent Rissen/ST469 and Typhimurium/ST34 European clone (100%), which are mostly associated with pig settings where Cu is highly used. These genes were frequently co-located with merA ± terF and/or antibiotic resistance genes in plasmids (100-270 kb; IncHI2/IncHI1/IncN/IncFIIA; mostly transferable by conjugation) or in the chromosome. Most sil ± pco(+) isolates (77%) were MDR contrasting with sil ± pco(-) ones (48%). The sil ± pco(+) isolates presented significantly higher MICCuSO4 under anaerobiosis (MIC50/MIC90 = 28/32 mM) and MICAgNO3 after previous Ag contact (MIC50/MIC90 > 3 mM) than sil(-) ones (MIC50/MIC90 = 2/8 mM to CuSO4; MIC50/MIC90 = 0.125/0.16 mM to AgNO3). Use of these modified methodological approaches allowed the establishment of CuSO4/AgNO3 tolerance cut-offs to differentiate sil(+) and sil(-) isolates, here firstly proposed.

CONCLUSIONS

This study demonstrates that acquisition of Cu/Ag tolerance genes (sil/pco genes) might contribute to the emergence of particular clinically relevant MDR Salmonella serotypes/clones by facilitating their survival in diverse metal-contaminated settings, particularly in pig production. Assessment of control measures for the use and/or accumulation of metals in diverse environments are needed to prevent a wider expansion of such strains or the emergence of new ones.

Compound odontoma--diagnosis and treatment: three case reports

Odontomas are the most common type of odontogenic tumors and generally they are asymptomatic. This paper describes three cases of compound odontomas diagnosed in children due to dislodgement or over-retention of primary anterior teeth and/or swelling of the cortical bone. In all cases, the surgical excision of the lesions was performed and, in one case, orthodontic treatment was adopted in order to move an impacted permanent tooth to its normal position. The results achieved indicate that the early diagnosis of odontomas allows the adoption of a less complex and expensive treatment and ensures better prognosis.