Physicochemical and Microbiological Evaluation of Commercial Tomato Concentrates Consumed In Egypt

Abstract

This research was undertaken to determine quality characteristics of twenty four samples of commercial concentrated tomato puree was conducted. Fourteen brands of jar (A), five brands of sachet (B) and five brands of can (C) were evaluated for chemical, physical and microbiological properties. Analysis included each of the following determinations: Total soluble solids, pH values, titratable acidity, sodium chloride content, ash content, colour, consistency, Howard mould count, total plate count, mould and yeast. Total soluble solids ranged from 20 to 25%, 22 to 25% and 18% to 30% for A, B and C, respectively. The pH values for all types of concentrated tomato puree were below 4.3. Titratable acidity ranged from 1.18 to1.9% for samples (A), 1.18 to 1.88% for samples (B) and 1.09 to 2.05% for samples (C). The sodium chloride content varied from 1.73 to 3.40%, 1.94 to 3.70% and 0.84 to 2.81% and ash content ranged from 3.2-5.2%, 3.83-4.98% and 2.48-6.06%, respectively. Colour measured by Hunter Lab Colormeter ranged between1.43 to 2.31, 1.51 to 2.11 and 1.67 to 2.09 a*/b*, while consistency ranged from 5.9-11.9 cm/30s, 7.45 to 12.67cm/30s and 5.70 to 9.01cm/30s, for samples A, B and C, respectively. Microbial growth could not be detected in all samples with one sachet concentrated tomato puree being the exception. Howard mould content varied between 12-20, 16-24 and12-20%, for samples A, B and C, respectively.