In this study, the optimal parameters for the photodynamic inactivation (PDI) of Staphylococcus aureus in bacterial suspensions and in cheese were assessed using a water-soluble curcumin salt as the photosensitizer (PS).

Acerola is a tropical fruit that stands out for its high content of ascorbic acid and phenolic compounds. However, there is currently a lack of information on the effects of the preparation and domestic storage of fruit juices, especially that of acerola. The objective of this work was to evaluate the effect of different liquefying times (10, 30 and 50 s) and cold storage at 4 °C for 0, 24, 48 and 72 h in domestic acerola juice. In relation to such, physicochemical determinations were performed, including pH, total titratable acidity, antioxidant potential, contents of phenolic compounds and total flavonoids in juices produced from the whole fruit, the pulp and acerola seed extracts. Whole fruit juice, liquefied for 10 s, had the highest pH and lowest acidity averages (P≤0.05). The contents of phenolic and flavonoid compounds ranged from 26.06±1.18 to 168.34±24.63 mg of gallic acid equivalents (GAE)/100 mL and 11.17±0.96 to 49.45±1.43 mg of catechin equivalents (CE)/100 mL, respectively. Total phenolics were higher in whole acerola juices and total flavonoids in seed extracts, both when liquefied for 50 s. The antioxidant potential ranged from 0.12±0.01 to 4.26±0.78 mmol of Trolox equivalents (TE)/100 mL, and was also higher in whole acerola juice, liquefied for 50 s (P≤0.05). The results showed that acerola pulp has higher phenolic content and antioxidant potential, while seeds have more flavonoids. The liquefying time of the whole fruit for 50 s and consumption during the first 24 h, were the best conditions tested in this study, for obtaining a juice with a high content of phenolic and antioxidant activity.

Efeito da suplementação oral de selênio e tocoferol sobre a membrana plasmática espermática em touros da raça Brangus* Effect of oral supplementation of selenium and tocopherol on the spermatic plasma membrane in Brangus bulls

ResumoObjetivou-se avaliar o efeito da estação do ano sobre a qualidade do sêmen fresco e criopreservado de reprodutores Pantaneiros (Bos taurus) criados em condições tropicais. Foram utilizados 7 touros Pantaneiros e 3 Nelores (controle), dos quais foi aferido circunferência escrotal, consistência testicular e após a coleta e congelamento do sêmen realizada análise de motilidade, vigor, defeitos menores, maiores e totais, concentração, integridade de membrana plasmática e acrossomal para sêmen fresco e além destas, estresse oxidativo para sêmen criopreservado. O experimento foi conduzido em delineamento inteiramente casualizado, e arranjo fatorial 2x2 (2 raças e 2 estações do ano). A raça, estação do ano ou a interação entre eles, não alteraram significativamente as médias de circunferência escrotal, consistência testicular, motilidade, vigor, concentração, integridade de membrana acrossomal e porcentagem de defeitos menores. A integridade da membrana plasmática no sêmen fresco sofreu efeito da estação do ano e foi menor no inverno em ambas raças (95,76 ± 1,77% vs. 87,07 ± 4,78% P=0,03). A estação do inverno aumentou a porcentagem de defeitos maiores (29,15% vs. 16,44%, P<0,01) e totais (17,49% vs. 30,45%, P<0,01). Os parâmetros do sêmen congelado não foram influenciados pela raça, estação do ano ou interação entre elas. Portanto, nas condições edafoclimáticas estudadas, os reprodutores Pantaneiros apresentaram redução na sua qualidade seminal na estação do inverno.Palavras-chave: estresse oxidativo, temperatura ambiente, raças localmente adaptadas. AbstractThe aim of the present study was to evaluate the effect of seasonality on the quality of fresh and cryopreserved semen of Pantaneiro breed (Bos taurus) bulls raised under tropical conditions. Scrotal circumference and testicular consistency were performed in seven Pantaneiro and three Nellore (control) bulls. Sperm motility, vigor, minor, major and total defects, concentration, plasma and acrosomal membrane integrity were assessed in fresh and post-thawed semen. Additionally, oxidative stress was determined in post-thawed semen samples. The experiment was done in a complete randomized design, with a 2x2 factorial arrangement (2 breeds and 2 seasons). Breed, season of the year or the interaction of both did not alter scrotal circumference, testicular consistency, motility, vigor, concentration, acrosomal membrane integrity and percentage of minor defects (P<0.05). Plasma membrane integrity of fresh semen was affected by the season and was smaller in winter in both breeds (95.76 ± 1.77% vs 87.07 ± 4.78%, P=0.03). Nevertheless, also in the winter there was an increase in the percentage of major (29.15% vs 16.44%, P<0.01) and total defects (17.49% vs. 30.45%, P<0.01) in fresh semen samples. Breed, season or interaction of both did not influence the sperm parameters of cryopreserved semen. Thus, in the studied climatic conditions, the Pantaneiro breed bulls present decrease in semen quality mainly in the winter season.Keywords: oxidative stress, environment tempe...