Valéria Santos de Oliveira

Caracterização físico-química e comportamento higroscópico de sapoti liofilizado

The sapodilla is a fruit considered exotic, as other fruits have high rates post-harvest losses. Dehydration by freeze drying demonstrates to be a good technique to take advantage of the excess of production offering to the consumer safety and stable products. The aim of this study is to evaluate the hygroscopic behavior, physicochemical and mineral composition of sapodilla powder obtained by freeze-drying using adsorption isotherms. The following analysis were performed: pH, total soluble solids, total titratable acidity, ascorbic acid, total, reducing and non-reducing sugar and moisture. The sapodilla powder, as a concentrated product, showed high levels of reducing sugars (9.67% - 36.09%), total soluble solids (15.67 to 65.50 o Brix) and ascorbic acid (8.45 to 9.84mg/100 g). The sapodilla powder showed to be a good source of minerals, mainly potassium and phosphorus. The adsorption isotherms were constructed adjusting experimental data to mathematical models of BET, GAB, Oswin and Henderson. The models of GAB and Oswin were more appropriate to fit the experimental data for the sapodilla powder with errors of 18.01% and 18.10% respectively, while BET model showed a higher error for this product.The sapodilla is a fruit considered exotic, as other fruits have high rates post-harvest losses. Dehydration by freeze drying demonstrates to be a good technique to take advantage of the excess of production offering to the consumer safety and stable products. The aim of this study is to evaluate the hygroscopic behavior, physicochemical and mineral composition of sapodilla powder obtained by freeze-drying using adsorption isotherms. The following analysis were performed: pH, total soluble solids, total titratable acidity, ascorbic acid, total, reducing and non-reducing sugar and moisture. The sapodilla powder, as a concentrated product, showed high levels of reducing sugars (9.67% 36.09%), total soluble solids (15.67 to 65.50 ° Brix) and ascorbic acid (8.45 to 9.84mg/100 g). The sapodilla powder showed to be a good source of minerals, mainly potassium and phosphorus. The adsorption isotherms were constructed adjusting experimental data to mathematical models of BET, GAB, Oswin and Henderson. The models of GAB and Oswin were more appropriate to fit the experimental data for the sapodilla powder with errors of 18.01% and 18.10% respectively, while BET model showed a higher error for this product.

Effect of high power low frequency ultrasound processing on the stability of lycopene.

The stability of lycopene was evaluated after application of high power low frequency ultrasound. The study was carried out on a solution containing pure lycopene to evaluate the direct effect of ultrasound on lycopene and on tomato purée to evaluate the direct and indirect effects of ultrasound application within a food matrix. Power densities ranging from 55 to 5000 W/L and temperatures ranging from 23°C (ambient) to 60°C were evaluated. The experiments on pure lycopene showed that the application of ultrasound did not have any direct effect over lycopene. However, the retention of lycopene in tomato puree has decreased indicating an indirect effect on lycopene stability caused by high concentration of hydrogen peroxide and the activation of peroxidase enzymes leading to the reduction of ascorbic acid and its regenerative action towards lycopene.

Physico chemical and hygroscopic behavior of sapodilla lyophilized

The sapodilla is a fruit considered exotic, as other fruits have high rates post-harvest losses. Dehydration by freeze drying demonstrates to be a good technique to take advantage of the excess of production offering to the consumer safety and stable products. The aim of this study is to evaluate the hygroscopic behavior, physicochemical and mineral composition of sapodilla powder obtained by freeze-drying using adsorption isotherms. The following analysis were performed: pH, total soluble solids, total titratable acidity, ascorbic acid, total, reducing and non-reducing sugar and moisture. The sapodilla powder, as a concentrated product, showed high levels of reducing sugars (9.67% - 36.09%), total soluble solids (15.67 to 65.50 o Brix) and ascorbic acid (8.45 to 9.84mg/100 g). The sapodilla powder showed to be a good source of minerals, mainly potassium and phosphorus. The adsorption isotherms were constructed adjusting experimental data to mathematical models of BET, GAB, Oswin and Henderson. The models of GAB and Oswin were more appropriate to fit the experimental data for the sapodilla powder with errors of 18.01% and 18.10% respectively, while BET model showed a higher error for this product.The sapodilla is a fruit considered exotic, as other fruits have high rates post-harvest losses. Dehydration by freeze drying demonstrates to be a good technique to take advantage of the excess of production offering to the consumer safety and stable products. The aim of this study is to evaluate the hygroscopic behavior, physicochemical and mineral composition of sapodilla powder obtained by freeze-drying using adsorption isotherms. The following analysis were performed: pH, total soluble solids, total titratable acidity, ascorbic acid, total, reducing and non-reducing sugar and moisture. The sapodilla powder, as a concentrated product, showed high levels of reducing sugars (9.67% 36.09%), total soluble solids (15.67 to 65.50 ° Brix) and ascorbic acid (8.45 to 9.84mg/100 g). The sapodilla powder showed to be a good source of minerals, mainly potassium and phosphorus. The adsorption isotherms were constructed adjusting experimental data to mathematical models of BET, GAB, Oswin and Henderson. The models of GAB and Oswin were more appropriate to fit the experimental data for the sapodilla powder with errors of 18.01% and 18.10% respectively, while BET model showed a higher error for this product.