Qualidade do fruto de Ziziphus joazeiro (Mart.), obtenção da farinha e cinética de secagem sob temperaturas e formas de processamento.

Abstract

A typical tree of the Brazilian semiarid region bears a fruit called Juazeiro fruit, which has functional potential because of its high concentration of bioactive compounds and its antioxidant capacity. However, it is very susceptible to deterioration, due to its high respiratory profile, low acidity and high moisture. Hence, it is necessary to use processing techniques to prolong its useful life. Thus, the purpose of this thesis was to evaluate the quality of the Ziziphus Joazeiro fruit (Mart.), in order to obtain flours and conduct the study of the drying kinetics under temperatures and forms of processing. The processing of the pulp/peel and foam at temperatures of 122, 131, 140, 149 and 158 °F, in a hothouse with air circulation. The physicochemical composition, bioactive compounds and antioxidant capacity were carried out in the pulp/peel of the fresh fruit and in the flours. The pulp/peel and foam drying kinetics of the fruit at temperatures of 122, 131, 140, 149 and 158 °F, with the application of Lewis‟s, Page‟s, Henderson‟s and Pabis‟s mathematical models, while Cavalcanti Mata‟s model was fitted to the description of the kinetics. The pulp/peel had excellent foaming activity and functional potential, due to the high concentration of phenolic compounds. Kiln drying with air circulation was a viable technique to produce juazeiro fruit flours, as it resulted in the concentration of soluble solids, soluble sugars, reducers and non-reducers, phenolic compounds, flavonoids and anthocyanins, in addition to increasing the antioxidant capacity. Pulp/peel drying at 149°F is recommended to produce fruit flour with a significant concentration of phenolic compounds, ascorbic acid and greater antioxidant capacity. Drying the foam at 158°F was efficient in the production of flour using less process time, greater yield, light color and higher concentration of sugars. Among the mathematical models tested, Page‟s and Cavalcanti Mata‟s came closer to the experimental points when compared to other models. Page's model was recommended due to easy application and proper adjustment to the drying curve. The use of these flours in food products, such as bakery and confectionery, as well as the development of formulations with nutritional and functional appeal, should be explored.