Effect of Degree of Concentration and of Heat Treatment on Consistency of Tomato Pastes After Dilution

Abstract

Concentrated tomato products require dilution to 12% natural tomato soluble solids ( N T S S ) before consistency can be determined using the Bostwick consistometer. The data show that the measured value is dependent upon the amount of added water required to reach the specified solids content. The extent of desiccation of the water insoluble fraction of the solids and their inability to resorb maximally is proposed as the cause of the phenomenon. Heating is suggested as a n additional step in the determination of consistency of tomato products to reduce the error caused by inefficient resorption of water at ambient temperatures.Consistency is not considered a mandatory quality attribute of the concentrated product, tomato paste. However, lately it has assumed an economic importance as more of this product is used on a re-manufacturing

Viscometric Behavior of Reconstituted Tomato Concentrate

“…1 a Variation in apparent viscosity of reconstituted tomato concentrate with shear rate for 9.7% and 26.8% TSS at 20°C. b Rheograms of the reconstituted tomato concentrate (20.5% TSS) at indicated temperatures tency has been proposed (Marsh et al 1977;Barett et al 1998). Moreover, the consistency of tomato products is influenced by the presence of both intact cells and cell fragments, the pectic substances on their surfaces, and both soluble pectin and suspended particles in the serum (Barett et al 1998).…”

The Production and Quality of Tomato Concentrates

“…However, a limitation of the Bostwick Consistency is that its magnitude decreases exponentially with concentration, so that data cannot be obtained on viscous concentrates with more than about 15% total solids. 43 Therefore, it is necessary to dilute the sample to 12% NTSS 9 or 12.5 ± 0.1% NTSS 27 to obtain a reasonable reading. The Heinz Company specification, at 12.5 ± 0.1% NTSS, for the Bostwick consistency is that cold break tomato concentrates should travel 7 to 14 cm in 10 s and hot-break tomato concentrates should travel 7 to 10 cm in the same period.…”

Changes in viscosity and pectolytic enzymes of tomato and strawberry juices processed by high‐intensity pulsed electric fields

“…, 1995). In addition, modifications in pectin structure and composition may arise from the combined action of PME and PG, causing changes in the viscosity of juices (Marsh et al. , 1977; Sila et al.…”

“…It is generally claimed that varietal characteristics and the maturity of fruits at the moment of processing have a significant influence on the viscosity of fruit juices (Gould, 1992;Thakur et al, 1995). In addition, modifications in pectin structure and composition may arise from the combined action of PME and PG, causing changes in the viscosity of juices (Marsh et al, 1977;Sila et al, 2008). Thus, changes in viscosity could be greatly influenced by the degree of inactivation of the pectic enzymes after the HIPEF treatments.…”