Influence of the extrusion operating conditions on the antioxidant, hardness and color properties of extruded mango

- Process variables and formulation were related with quality parameters of mango bars.
- The RSM and PCA allowed to find the optimum operating conditions for producing mango bars.
- Bars with adequate texture/color and rich in antioxidants were found in two working regions.

The effects of extrusion temperature (50-100 °C) and formulation (glycerin 0-3%, dried fruit moisture 8-14%, glucose 5-15% and xanthan gum 0-3%) on technological (hardness and color) and nutritional (antioxidant activity-AA and total polyphenol content-PC) quality parameters for extruded mango bars were analyzed using response surface methodology (RSM) and principal component analysis (PCA).The PC increased, first, when the extrusion temperature was at lower values and the dried ingredient content was higher, and second, with higher temperatures and xanthan gum content. The AA showed similar behavior but decreased when the liquid ingredients were at their lowest values.Extrudate hardness remained fairly constant, except for an increase at low barrel temperature and high non-fruit ingredients content. The bars measured color parameters were affected the most by fruit moisture.Two principal components explained 73.00% of the total variability by PCA. The results for the relationships of PC and AA with barrel temperature and xanthan gum content were similar to those obtained by RSM.Based on previous findings, some responses were set as optimization objectives that suggested two sets of conditions for optimum extrusion.