Dados do Trabalho

Título

FOAM BLANKET DRYING: DETERMINATION OF THE MICROBIOLOGICAL AND FUNCTIONAL QUALITY OF POWDERED TROPICAL FRUITS

Introdução

Fruits are susceptible to rapid deterioration, linked to their complex matrix. Aiming to overcome this condition, the drying method presents itself as a promising alternative to enable the extension of its useful life, resulting in viable by-products for incorporation into new foods. The objective of this work was to dehydrate fruit pulps (watermelon and guava) through foam layer drying and evaluate its impact on the microbiological profile, composition of carotenoids, sugars, total phenolics and antioxidant capacity of the powders.

Material e Métodos

5 and 15g% (m/m) of additive (powdered albumin) were plotted for guava and watermelon, respectively, respecting the thermodynamic behavior of the system. The material was dried at 68°C until a porous film was obtained (±120”).

Resultados e Discussão

It was observed that the studied model presented ideal physicochemical parameters (moisture, pH, TSS, acidity, density, fluidity and cohesion and granulometry), also meeting the microbiological parameters established in Brazilian legislation, with regard to screening and quantification of Salmonella, Escherichia coli, aerobic mesophiles, Enterobacteriaceae, molds and yeasts. It is worth mentioning that the addition of the foaming agent during processing led to a decline in the a* chroma of the samples, with a significant increase in the L* chroma, which could compromise them sensorially. However, the phenolic content showed a significant increase (2.241 and 2.147 mg EAG/100g), with the same movement observed for the total carotenoid content evaluated by HPLC (9.717 and 5.247 µg/100g) with specific characterization of lycopene (6434 and 3194), β-carotene (775.5 and 334) and lutein (253.5) (µg/100g) and for sugars fructose (32.46 and 11.64) and glucose (17.03 and 3.70) (g/100g) for guava and watermelon, respectively, comparing their fresh pulp (control). There are positive effects on antioxidant capacity, by direct and indirect methods, after the drying process, in ABTS (260.1 and 78.27 µmolTE/g), ORAC (28.10 and 36.94 µmolTE/g) and FRAP (111.2 and 80.86 µmolFS/g) for guava and watermelon, respectively.

Conclusão

Remarkably, it is possible to observe that the production of fruit powders using the tested method is adequate from a technological point of view, considering variables such as reduced time and temperature, favoring the retention of nutrients and bioactive compounds and presenting high functional potential.