Technological aspects for restructuring concentrated pineapple pulp

This study investigated how different concentrations of alginate, low methoxy pectin and glycerol could be used to obtain restructured concentrated pineapple pulp, with the aid of response surface methodology. The results of a central composite design show that changes in pectin and alginate levels have statistically significant effects on the firmness of restructured pineapple fruit. Products with the highest values for firmness resulted from using 16 g/kg of both alginate and pectin independent of the concentration of glycerol used. Glycerol, used at the concentration of 100 g/kg, reduced the water activity of the restructured product to an intermediate moisture level (0.880), besides substituting part of the sucrose incorporated into the fruit pulp. A mixture of low methoxy pectin and alginate made it possible to obtain very firm structured fruits using acid pulps. The restructured fruit formulated with a high content of concentrated pineapple pulp (735 g/kg), low sugar content (210 g/kg) and a combination of alginate (20 g/kg), pectin (10 g/kg) and glycerol (100 g/kg), partially dehydrated to 20% moisture content (w.b.), was evaluated by a group of panelists and received a mean score of 5.45, between “liked slightly” and “liked moderately” on the seven-point hedonic scale.