ABSTRACT In this study, chemical changes during the development of acerola, cultivar Okinawa, were evaluated. The biochemical alterations during the development of the acerola cultivar Okinawa were evaluated, to determine the peroxidase activity (POD) and its thermal stability. Peroxidase (POD) has been considered the main enzyme responsible for the quality deterioration of fruits. Additionally, characteristics evaluated in this study can be important postharvest quality criteria for fruit processing, screening and breeding. Changes in physiological development were evaluated by the determination of moisture content, ascorbic acid, ashes, total and reducing sugars, pectin, chlorophyll a and b, amounts of anthocyanins, flavonols and total carotenoids. These biochemical determinations may serve as a basis for further improvement of techniques for predicting and modeling the optimal harvesting time. The values of chlorophylls, anthocyanins, flavonols, and carotenoids were higher in the peel rather than in the pulp (p < 0.05). Acerola presents high levels of ascorbic acid. The development of acerola (from opening of flowers to maturation of fruits) was of 25 days. The increase of the values for total and reducing sugars, anthocyanins, carotenoids, the solubilization of pectic acid and degradation of chlorophyll suggested that physiological maturation and harvest day occurred on days 19 and 23 after anthesis, respectively. The specific activity of POD was higher in the green stage. Maximum POD activity was observed at pH 6.5 and 45 ºC. Total inactivation was not achieved, suggesting the presence of isoenzymes with high thermal resistance. A loss of 50% of activity occurred after 4 minutes of treatment at 80 °C.

ABSTRACT The germplasm characterization and the analysis of genetic divergence are fundamental requirements to determine the genetic diversity available and peppers have considerable variability not most explored and quantified. Thus, the aim of this study was to characterize morphological and agronomically pepper accessions and their genetic divergence. The experiment was conducted in a greenhouse of the Department of Agronomy of the Universidade Federal Rural de Pernambuco, Recife, between the months of December 2014 to June 2015. Thirteen pepper accessions in pots were sown, the experimental design was a randomized block with six replications, and the experimental unit consisted of three pots. Seedling, leaves, plant and fruit characteristics were evaluated. For the analysis of genetic divergence, the Mahalanobis distance and the UPGMA method were used. It was observed the formation of three distinct groups, being fruit width the trait that most contributed to the genetic discrimination of the accessions. Group I presented larger fruits, Group II showed heavier and wider fruits and Group III had mostly smaller, lighter and thinner fruits. There were differences for most of the evaluated characteristics, showing great morphological and agronomic variability among the accessions. The peppers have a high potential to be exploited in breeding.

Abstract The spray drying process of a mixed juice of acerola and seriguela was optimized using a 2 4 full factorial design with 16 factorial points and 3 central points. The independent variables were different levels of inlet temperature (110°, 140° and 170 °C), feed flow (0.36, 0.60 and 0.84 L/h), amount of maltodextrin (14-26%) and maltodextrin dextrose equivalent (DE) (5, 10 and 15 DE). The responses were water activity (Aw), moisture content (MC), hygroscopicity (Hyg), powder recovery (PR) and retention of ascorbic acid (RAA). After optimization, an acceptance test and multiple comparison test were performed. Temperature exerted a great influence on Aw, MC and RAA. The optimal drying conditions to obtain acerola and seriguela juice mix powder were an inlet temperature of 140 °C, a flow rate of 0.60 L/h, 20% maltodextrin 10 DE. There was no significant difference in the acceptance of the quality attributes or in the multiple comparison test between the nectars made with the juice mix powder. Acceptance was approximately 70%. Therefore, this acerola and seriguela mix powder can be considered a good source of ascorbic acid and a potential ingredient for the food industry.