This study assessed the fitting of mathematical models to the convective drying kinetics of osmotically pre-dehydrated papaya cubes. Papaya cubes were subjected to osmotic dehydration in sucrose solutions at 40 and 50 ºBrix, at temperatures of 50 and 60 ºC, followed by complementary convective drying in forced air circulation oven under three temperatures (50, 60 and 70 °C) and constant air velocity of 1.0 m s-1. Ten thin-layer drying mathematical models were fitted to the experimental data. The increase in air temperature and the decrease in osmotic solution concentration resulted in increased water removal rate. Based on the statistical indices, the Two Terms model was the one that best described the drying kinetics of the samples for all evaluated conditions. The effective diffusion coefficients increased with the elevation of air temperature, ranging from 1.766 x 10-10 to 3.910 x 10-6 m2 s-1, whereas the convective mass transfer coefficients ranged from 3.910 x 10-7 to 1.201 x 10-6 m s-1 with Biot number from 0.001 to 12.500.

Spirulina platensis is a cyanobacterium that can be consumed by humans, for its high contents of proteins and nutraceutical compounds. This study aimed to develop cookies mixed with S. platensis for nutritional enrichment purposes. The study conducted quality control analyses and elaborated formulations of cookies with different contents of S. platensis (0, 5, 10 and 15%), which were subjected to physical, chemical, microbiological and sensory analyses. In the cookies, the increase of S. platensis percentage led to increment in protein percentage, besides increments in minerals, compared with the cookie produced with only refined wheat flour. Cookies with 15% of S. platensis (F5) stood out regarding the percentages of protein and minerals, and were similar to the whole cookies with respect to the minerals; lipids and highest energetic value were observed in the standard cookies. Cookies mixed with 5% of S. platensis and standard cookies were preferred with the same score, indicating a possible acceptance in the market.

Myrtle is a fruit with great industrial potential, due to its nutritional characteristics and presence of phenolic compounds, especially anthocyanins. Nonetheless, the high perishability and short post-harvest life of this fruit limit its diffusion in the internal market and use in the food processing industry. Lyophilization of fruit pulps represents an alternative to increasing preservation time, resulting in a powder with higher stability and longer shelf life. In this context, this study was aimed to evaluate the stability of myrtle pulp powder during storage in laminated packages and under controlled conditions of temperature (between 30 and 40 ºC), and evaluate the kinetics of degradation of anthocyanins and flavonoids. As storage time increased at both temperatures, moisture content and water activity increased; and caused reductions of anthocyanins, flavonoids and lightness. In the evaluation of the kinetics of degradation of anthocyanins and flavonoids, the zero-order was the best model to represent the behavior and with higher stability at a temperature of 20 ºC.

Resumo A pomegranate is a species of wide use, especially due to the medicinal importance, where the fruits were appreciated around the world. The marketing of pomegranate has increased and aroused the interest of fruit producers in Brazil, however, knowledge of the quality and commercial viability of the fruit in natura is incipient. In this sense, this study aimed to determine the quality and postharvest life of pomegranates ‘Molar’ stored at 27ºC and 28% RH. Was used in a completely randomized design with four replications, each replicate consisting of five fruits and seven evaluation periods. At each assessment time 0, 3, 6, 9, 12, 15 and 18 days of storage after harvest is conducted through analysis of samples of fruits (n = 20), obtained at random from the container type plastic boxes, condition where the total of 140 fruit was stored in the experiment. In each evaluation period was assessed longitudinal and transverse length, fresh weight loss, weight of arils, juice volume, seed mass, shell mass, soluble solids (SS), titratable acidity (TA), pH, SS / TA, vitamin C and extern and interns appearance. Pomegranate ‘Molar’ produced in an organic system in semiarid from Paraíba is classified as sweet, with low acidity, less than 0,75% citric acid and soluble solid between 12 and 15%. The storage of fruits at 27 º C, 28% RH up to six days maintains appropriate biometric, physical-chemical and visual characteristics for the fresh fruit market. The storage of fruits at 27ºC, 28% RH for 18 days provocation dehydration of the skin, but not affect the quality or yield of juice extracted from the arils.

The drying of the mandacaru fruit consists in an alternative way to reduce loss during its harvest and therefore minimizes its waste. The objective of this study was to physicochemically characterize the mandacaru fruit both fresh and dehydrated in an air circulation oven using three drying temperatures (40, 50 and 60 ºC), related to the water content, water activity, pH, acidity and phenolic compounds. Three empirical mathematical models were used to describe the drying (Henderson and Pabis, Midilli and Page). The Midilli’s model had the best statistical indicators, fitting better to the experimental data. The fresh fruit showed water content of 82.75%, water activity of 0.986, titratable acidity of 0.18%, pH of 4.35 and phenolic compounds of 28.35 mg.100-1g. The parameters luminosity (L), intensity of red (+a), yellow intensity (+b), hue angle (hº) and chromaticity (C*) were respectively equal to 59.84±0.08; 5.72±0.06; 89.25±0.08; 5.72±0.06. The physicochemical compounds of the fruit were influenced by the drying, in which water content was 10.83, 8.31 and 7.56%, and the water activity was 3.99. 3.24 and 2.40 for the temperatures of 40, 50 and 60 ºC, respectively. The highest temperature caused a greater removal of water in the product along the drying. The dried mandacaru pulp showed titratable acidity of 0.41, 4.86 and 4.98%, pH of 4.76, 4.86 and 4.98 and phenolic compounds of 252.26, 156.53 and 196.10 mg.100-1g, and the parameters L (19.72, 23.41 and 26.15), a* (3.13, 1.31 and 1.30), b* (7.31, 6.53 and 9.14), H* (66.79, 78.69 and 81.92) and C* (7.95, 6.95 and 9.23) at the temperatures of 40, 50 and 60 ºC, respectively. The results of the characterization suggest the technological exploitation of the dried mandacaru fruit to add nutritional value to other foods or in the development of new products.