Polpa de cajá (Spondias mombin L.) processada por alta pressão hidrostática

Abstract

High pressure processing (HPP) can generally inactivate microorganisms and enzymes responsible for food deterioration. The food material is submitted to elevated pressures (from 100 MPa up to 1000 MPa). One of the key advantages of this technology is that it enables food processing at ambient temperature, maintaining the quality of fresh foods, with minimal effects on its flavour and nutritional value. The aim of this study was to evaluate the effects of HPP on yellow mombin pulp (Spondias mombin L.) preservation in order to assure its microbiological safety and its sensory and nutritional quality. The study was conducted at Embrapa Food Technology (Rio de Janeiro, RJ, Brazil). The yellow mombin pulp was processed by HPP using different levels of pressure and retention time, according to a central composite design. Microbiological analyses (Salmonella spp., Coliforms at 35 and 45°C, Moulds and Yeasts) were carried out, as well as physical-chemical analyses (pH, titrable acidity, soluble solids), peroxidase activity, carotenoids, antioxidant activity, total phenolics, volatile compounds profile and instrumental color. The shelf life of the nectar formulated from the pressurized pulp was also assessed. The sensory characteristics of the referred nectar and from the in natura pulp (control), as well as commercial yellow mombin pulps were evaluated using Quantitative Descriptive Analysis (QDA). The same samples were evaluated regarding consumer acceptance. Data were analyzed through Analysis of Variance, Principal Component Analysis (PCA), Internal Preference Mapping, Cluster Analysis, and External Preference Mapping, using Statistica and XLSTAT software. HPP effectively inactivated the initial contamination and preserved the refrigerated nectar for 28 days. There was no negative effect on the total phenolic content and antioxidant activity. Peroxidase was not fully inactivated on none of the treatments. HPP showed no significant effect on the colour, pH and titrable acidity. Regarding the aroma profile, there was no major change in the relative concentrations of the various compounds compared to the control sample. The ideal levels of pulp concentration and sweetness determined by the consumers was 33% and 10.4%, respectively. QDA revealed a sensory similarity between the nectar formulated from pressurized pulp and control pulp. The pressurized sample and the control one were preferred by participants on the Acceptance Test. Cluster Analysis revealed three distinct segments of consumers.