No abstract

Este é um artigo publicado em acesso aberto (Open Access) sob a licença Creative Commons Attribution, que permite uso, distribuição e reprodução em qualquer meio, sem restrições desde que o trabalho original seja corretamente citado. Cinética de secagem de acerola em leito de espuma e ajuste de modelos matemáticos Foam-mat drying kinetics for acerola and adjustment of the mathematical models ResumoA acerola (Malpighia emarginata DC) é uma fruta rica em nutrientes, principalmente vitamina C. No entanto, a perecibilidade do fruto in natura é alta. Desta forma, o processamento do fruto torna-se indispensável. Diante disto, o presente trabalho teve o objetivo de estudar a etapa de secagem da polpa de acerola em leito de espuma, além de avaliar o efeito da temperatura sobre a cinética de secagem da polpa de acerola e ajustar modelos matemáticos para descrever o processo. O experimento foi conduzido em três repetições. A espuma foi elaborada com 250 mL da polpa de acerola adicionada de 4% do agente espumante, sendo, então, espalhada uniformemente em bandejas de inox. AbstractAcerola (Malpighia emarginata DC) is a fruit rich in nutrients, especially vitamin C, but the in natura fruit is highly perishable and hence processing of the acerola pulp becomes indispensable. The aim of this paper was to study the foam mat drying process of acerola pulp to evaluate the effect of temperature on the drying kinetics of the pulp and fit mathematical models in order to describe the operation. The experiment was carried out with three repetitions. The foam was prepared with 250 mL of the pulp plus 4% of foaming agent and spread evenly in stainless steel trays. The selected drying air temperatures were 50 °C, 55 °C, 60 °C, 65 °C and 70 °C. The moisture ratios were then calculated and the Page, Henderson and Pabis and Lewis mathematical models fitted for each temperature. The Page model showed the highest determination coefficient (> 0.99) and lowest standard error for the regression at all temperatures (<0.03). The proposed generalized model presented a determination coefficient of 0.9933. The Page model and the generalized model were adequate to describe the drying process of the acerola pulp. The moisture contents of the dehydrated products were in accordance with the values established by Brazilian law. Keywords

IIDesenvolvimento de um suco misto de manga, goiaba e acerola utilizando delineamento de misturasDevelopment of a mixed juice of mango, guava and acerola using mixture design

This study investigated the degradation kinetics of the sensory attributes of commercial whole mango (cv. Ubá) juice and evaluated its sensory acceptability during storage. Samples of the product were stored in a BOD incubator at 25, 35, and 45 ºC under 24 hours light (650 lux) for 120 days. Sensory analyses (Quantitative Descriptive Analysis - QDA) were conducted with trained panel and consumers. The correlations between sensory and physicochemical characteristics (instrumental color and vitamin C content) were also assessed. Flavor, aroma, and color vary with temperature and time of storage. Aroma and flavor were most affected by temperature with values of Q10 and Ea equal to 4.16 and 25.31 kcal.mol-1; and 3.61 and 22.80 kcal.mol-1, respectively. The sensory changes observed by the trained panel are related to the degradation of vitamin C and changes in the color coordinates (L* and ΔE*) of mango juice. However, consumers were unable to detect changes in the overall quality of the juices. It was observed that the QDA can be a useful tool to assess shelf-life.

No abstract