Efeitos da ação combinada da alta pressão e temperaturas moderadas e adição de antioxidante sobre água de coco

• Autor(a) principal: Queiroz, Natália Maluf [UNESP]
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/154705; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/01-08-2017/000868975.pdf
• topic: Food technology; Tecnologia de alimentos; Coco - Produtos - Análise; Peroxidase; Antioxidantes; Alta pressão (Tecnologia)

Coconut water is considered a peculiar drink with distinctive taste and therapeutic properties, such as an electrolyte replacer by being rich in minerals, especially potassium, however, shows susceptibility to the enzymes polyphenol oxidase enzyme (PFO) and peroxidase (POD), associated with the development of pink color, which is one of the problems for its conservation. Enzymatic inactivation by high temperatures is the alternative commonly found, however affecting taste, which justifies the use of other technologies that do not require high temperatures, such as high pressure. This study aimed to evaluate the effects of different combinations of pressure (0.1 to 600 MPa), temperature (10 to 80°C) and addition of ascorbic acid (0 to 20 mg/100ml) on the enzyme activity of PFO and POD, retention of ascorbic acid and microbial contamination which occurs during the extraction and preparation of coconut water. An experimental design was proposed to determine pH, soluble solids, titratable acidity, ascorbic acid content, instrumental color, enzymatic activity of PFO and POD, and thermo tolerant coliforms, Salmonella sp. and molds and yeasts counts. The response surfaces with adjusted equations to the statistical model for the residual POD activity and residual ascorbic acid were obtained. The results showed that the addition of ascorbic acid at 10 and 20 mg/100 ml resulted in the inhibition of both enzymes studied, with a residual activity less than 10% in all experiments regardless of pressure and temperature. Inhibition of POD (4.61% residual activity) was obtained without the addition of ascorbic acid at atmospheric pressure and 80°C; under the same conditions it was found complete inhibition of PFO. In the pressure levels studied and without ascorbic acid, the maximum inhibition of PFO enzyme activity was 59.54% for the combination of maximum pressure (600 MPa) and maximum temperature (80°C), but with POD activity higher than the ...