Advanced search
Start date
Betweenand

Thermal inativation kinectic of peroxidase and poliphenoloxidase enzymes in açaí pulp (Euterpe oleracea Mart.) aiming quality and food security

Grant number: 08/03742-0
Support type:Regular Research Grants
Duration: March 01, 2009 - February 28, 2011
Field of knowledge:Agronomical Sciences - Food Science and Technology
Principal Investigator:Flávio Luís Schmidt
Grantee:Flávio Luís Schmidt
Home Institution: Faculdade de Engenharia de Alimentos (FEA). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The açaí (Euterpe oleracea Mart.) consists of a small purple fruit of slightly bitter taste whose content of pulp is proportionately less than the lump. Native to the Amazon region, it has become one of the fruits of greater popularity in the world, attracting consumers in markets as the North American and Japanese ones. In Brazil, the consumption of pulp açaí is very common in the northern region, where it is part of the daily diet of the population as well as in other states in other regions where it is marketed as frozen and consumed more diluted. The fruit is very perishable and, in general, many failures can occur in hygienic steps of harvesting, transporting and processing of it. Some studies report the high microbiological contamination of the pulp and its consumption has been identified as the main vehicle of the oral transmission of Acute Chagas disease in the brazilian amazon region. Moreover, the açaí has attracted interest from scientists of food due to their functional properties conferred by the presence of natural antioxidants, fibre, vitamin E, vitamin B1 and minerals such as calcium and potassium. Thus, it is necessary to the use of a technology that ensures the microbiological safety of the product without, however, significantly altering their physical and chemical characteristics and functional properties. The pasteurization is a type of heat treatment, applied to food, seeks the destruction of vegetative microbial cells and also the inactivation of enzymes components of the plant tissue that can be directly related to the process of deterioration and loss of sensory food. This paper proposes to study the kinetics of thermal inactivation of the enzymes peroxidase and polyphenoloxidase, naturally occurring in plants and known by termoestability for determining a suitable heat processing for maintaining the attributes of quality of açaí. These enzymes can retain activity even under refrigeration and freezing temperatures of conventional, causing loss of color, flavor, texture and nutritional components of the product. These changes are identified as the main cause of the rejection of açaí pulp pasteurized. To check the quality of pulp, it will be conducted several chemical , microbiological and quantitative determination analysis of antioxidants before and after the chosen thermal processing. (AU)