3.2.2.4. Colour
Extruded products with added PP did not present any colour differences among them, but, in general, they showed a darker colour (p ⩽ 0.05) than treatments without pomace. This reduction in lightness may have been caused by the presence of PP in the final product and also due to browning reactions, such as Maillard and caramelization, promoted by the presence of sugar in the added material. Similarly, Dehgahn-Shoar et al. (2010) observed reduction in lightness of extruded products when working with tomato skin.
Three of the four treatments where PP was added and the blend moisture content adjusted to 15%, presented higher a* values (p ⩽ 0.05) when compared with the control (Table 5). The increase in redness may have been caused by browning reactions due to processing temperatures and presence of sugars in the pomace. Specifically for the treatments with 15% of moisture, this effect could have been enhanced, because Maillard reaction is favored by low moisture. Similar results were observed by Yağcı and Göğüş (2009), who verified that an increase in moisture content generally decreased the redness of the final products.
The use of pineapple pomace did not affect (p ⩾ 0.05) the yellowness (b* value) of the extrudates (Table 5), when results were compared to the control.
3.2.2.5. Moisture content
There was no significant difference (p ⩾ 0.05) among the moisture content of the treatments with PP addition and the control, indicating that the drying step after extrusion (100 °C/10 min) probably homogenised the moisture content of the extruded products (Table 5). These results are important for the purpose of treatments comparison in the texture analysis.
3.2.2.4. ColourExtruded products with added PP did not present any colour differences among them, but, in general, they showed a darker colour (p ⩽ 0.05) than treatments without pomace. This reduction in lightness may have been caused by the presence of PP in the final product and also due to browning reactions, such as Maillard and caramelization, promoted by the presence of sugar in the added material. Similarly, Dehgahn-Shoar et al. (2010) observed reduction in lightness of extruded products when working with tomato skin.Three of the four treatments where PP was added and the blend moisture content adjusted to 15%, presented higher a* values (p ⩽ 0.05) when compared with the control (Table 5). The increase in redness may have been caused by browning reactions due to processing temperatures and presence of sugars in the pomace. Specifically for the treatments with 15% of moisture, this effect could have been enhanced, because Maillard reaction is favored by low moisture. Similar results were observed by Yağcı and Göğüş (2009), who verified that an increase in moisture content generally decreased the redness of the final products.The use of pineapple pomace did not affect (p ⩾ 0.05) the yellowness (b* value) of the extrudates (Table 5), when results were compared to the control.3.2.2.5. Moisture contentThere was no significant difference (p ⩾ 0.05) among the moisture content of the treatments with PP addition and the control, indicating that the drying step after extrusion (100 °C/10 min) probably homogenised the moisture content of the extruded products (Table 5). These results are important for the purpose of treatments comparison in the texture analysis.
การแปล กรุณารอสักครู่..
