Syrah Grape Skin Residues Has Potential as Source of Antioxidant and Anti-Microbial Bioactive Compounds.

In this study, we evaluated the effects of ultrasound-assisted extraction (UAE) under different time-temperature conditions on the content of bioactive compounds, antioxidant and antimicrobial activities of Syrah grape skin residue. The application of UAE showed a positive effect on the extraction of total flavonoids, and a negative effect on total polyphenols. The temperature of 40 °C and 60 °C without the UAE caused an increase of 260% and 287% of the total polyphenols, respectively. Nineteen individually bioactive compounds were quantified. The anthocyanin concentration (malvidin-3,5-di-O-glucoside 118.8-324.5 mg/100 g) showed high variation, to a lesser extent for phenolic acids, flavonoids, flavonols, procyanidins and stilbenes due to the UAE process. The Syrah grape skin residue has a high concentration of total phenolic compounds of 196-733.7 mg·GAE/100 g and a total flavonoid content of 9.8-40.0 mg·QE/100 g. The results of free radical scavenging activity (16.0-48.7 mg/100 mL, as EC50) and its inhibition of microbial growth (0.16 mg/mL, as EC50 for S. aureus, and 0.04 mg/mL, as EC50 for E. coli) by grape skin extract (UAE 40:20) indicate high antioxidant and antibacterial activity. It was concluded that the use of ultrasound needs further analysis for its application in this context, as it has shown deleterious effects on some compounds of interest. Syrah grape skin residue has potential as a source of bioactive antioxidants, antimicrobial activity and for use as a functional food ingredient.

Elaboração de bolo de chocolate sem glúten, para portadores de doença celíaca / Production of chocolate cake without gluten for celiac disease patients

A doença celíaca (DC) é uma enteropatia auto-imune desencadeada pela ingestão de glúten presente em alguns cereais. O objetivo deste trabalho foi elaborar um bolo de chocolate a partir de formulações isentas de glúten com farinha de milho, fécula de batata e amido de arroz, e avaliar a aceitação destas preparações. De acordo com os resultados, não houve diferença estatística significativa entre as amostras à base de amido de arroz, fécula de batata e a de farinha de trigo, sugerindo que estas formulações poderiam ser também bem aceitas por pacientes celíacos. Todavia, a formulação à base de farinha de milho não foi aceita por este mesmo grupo. Nas condições deste experimento, foram verificadas outras opções para que os portadores de DC possam usufruir de um bolo de chocolate, sendo este alimento geralmente eliminado da dieta por ser elaborado com farinha de trigo.