DEVELOPMENT OF A PROTEIN FORTIFIED FRUIT BEVERAGE AND ITS QUALITY WHEN PROCESSED WITH PULSED ELECTRIC FIELD TREATMENT

Pulsed electric field treatment (PEF), was explored to process a beverage at 30C. A protein fortified fruit based beverage was developed using proteins, orange juice, guar gum, sucrose, calcium lactate, citric acid, natural flavor and color. It was processed at low pH (3.75) using both a heat pasteurization and a PEF treatment. PEF treated beverage had less protein denaturation and lower loss of vitamin C compared with that of the heat treated beverage. The heat treated beverage had a slightly higher apparent viscosity than the PEF treated beverage and developed sedimentation in the container during storage. The PEF processed beverage maintained its natural orange juice like color better than the heat treated beverage, which developed a slightly whitish color. However, the PEF treated product was less microbiologically stable (5 months) at refrigeration temperature compared with the heat treated product which was stable for more than 12 months. It was concluded that more technological improvements are needed to process food safely by PEF technology.