Effect of combined high pressure-temperature treatments on color and nutritional quality attributes of pineapple (Ananas comosus L.) puree

High pressure processing (HPP) had a significant effect (p < 0.05) on the color and bioactive components in pineapple puree at 200-600 MPa/50-70 degrees C/10-20 min. The pH, soluble solids and titrable acidity were not significantly affected by HPP. At 50 and 60 degrees C, total color change (Delta E*) was in well visible range (3 < Delta E* < 6) at all pressures; whereas it was highly distinguishable (6 < Delta E* < 12) at 70 degrees C. The trend was true for browning indices also. The maximum loss in ascorbic acid was 20 and 25% at 60 and 70 degrees C, respectively. Total phenolic content increased during HPP up to 50 degrees C and then decreased at elevated temperatures (60 and 70 degrees C). Flavonoids were stable up to 50 degrees C at pressure levels. Response surface models developed for all the quality attributes indicated that temperature had a more detrimental effect than pressure within the domain. Industrial relevance: Consumer demand for high quality pineapple puree with minimal processing explores the possibility of applying high pressure processing (HPP) as an alternative nonthermal processing to this product. On the other hand, association of moderate temperature (30-70 degrees C) with high pressure is necessary to inhibit the enzymatic spoilage in the product. Though HPP at moderate temperature ensures the product safety and longer shelf life, the impact on process parameters on the nutritional and other organoleptic properties of the product cannot be neglected. Detailed study on the effect of high pressure process parameters viz, pressure, temperature and treatment time on the nutritional quality attributes is needed prior to the optimization of HPP conditions. Developed RSM models to each quality attribute will quantify the changes happening during FIPP combined with moderate temperatures. (C) 2015 Elsevier Ltd. All rights reserved.