Enzimas produzidas durante os diferentes estágios de fermentação das sementes de cupuaçu (theobroma grandiflorum (willdenow ex sprengel) schumann)

Abstract

The cupuassu plant (Theobroma grandiflorum (Willdenow ex Sprengel) Schumann) is widespread in the wild or cultivated form throughout the north of Brazil. The fruit contains an average of 32 seeds per fruit, corresponding 20% to 30% of the fruit, but they are usually discarded, although they can be used to produce a kind of chocolate called "cupulate", using the same process of cocoa (Theobroma cacao L.), except the step to remove the pulp until obtain the fermented and dried seeds, because they belong to the same genus. Fermentation of cocoa and cupuaçu beans involves microbial processes and the action of enzymes that act on the physical, chemical and biochemical reactions responsible for developing the precursors of the flavor and taste of chocolate. Among these changes can be noted the hydrolysis of proteins to form peptides and amino acids and the hydrolysis of sucrose on glucose and fructose. The products of these reactions during roasting, by means of the Maillard reaction, contribute to the formation of the flavor of chocolate. Due to lack of information about the action of enzymes in fermented cupuassu seeds, the objective of this study was to determine the enzymes present during the different stages of fermentation of cupusassu seeds (Theobroma grandiflorum (Willdenow ex Sprengel) Schumann) and also analyze variations in temperature, pH and acidity during the process and establish the relationship with the production of these enzymes during fermentation. The fermentation of cupuassu beans was carried in wooden boxes with a capacity of 25 kg for a period of 7 days, according to the recommendations proposed by Venturieri (1988). The seeds, every 24 hours, were removed from the surface, middle and bottom of the boxes for the determination of pH and acidity and to make acetone powder which was used as a source of enzymes. It was detected the presence of amylase, cellulase, invertase, pectinesterases, polygalacturonase, peroxidase, polyphenol oxidases, proteases and lipases. The maximum temperature of cupuassu seeds was 46.7 º C after 72 h of fermentation. The mean pH and acidity were inversely proportional with the pH ranged from 3.92, on zero time, to 6.32 after 168 h of fermentation and the average acidity ranged from 17.29 to 4.89 meq NaOH / 100 g of dry seed. All the enzymes, except protease, showed maximum enzyme activity in the first 72 hours of fermentation, coinciding with the anaerobic phase of fermentation, where temperatures ranged from 35 to 47 °C and pH varied from 4.2 to 4.6. There was a correlation between the enzymatic activity of alpha-amylase, beta-amylase, peroxidase and polygalacturonase with the fermentation time and also with the pH and acidity measured during the 7 days of fermentation cupuassu beans. The temperature did not exert any influence on the activity of these enzymes. The Invertase and pectniesterase were influenced only by the fermentation temperature. The other parameters had no effect on enzyme activity of these enzymes. The incubation time, pH, temperature and acidity measured during the 168 hours of cupuassu seeds fermentation had no significative influence on the enzymatic activity of cellulase, lipase, protease and polyphenoloxidase.