On-Line Prediction of Bostwick Consistency From Pressure Differential in Pipe Flow for Ketchup and Related Tomato Products

Abstract

An on-line sensor was developed by correlating pressure diflerential to Bostwick value for ketchup, crushed tomato and pizza sauce with Bostwick valuesfrom 4 -12. Flow rate was variedfrom 6.3 x I@' to 37 x I@' m3 /s (I to 6 gpm) and temperature from 93 to 46C. The consistency coeficient is reported. The correlation was compared to samples measured in a factoty, with mean deviations of 0.72 (2nd 0.52 cm for ketchup and pizza sauce, respectively.

Mechanical and Thermal Pretreatments of Crushed Tomatoes: Effects on Consistency and In Vitro Accessibility of Lycopene

“…Bostwick consistency Bostwick consistency measurements depend on the viscosity, density, and yield stress of the sample (Vercruysse and Steffe 1989; McCarthy and Seymour 1993; Barringer and others 1998). The densities of the heated crushed tomatoes were all in the same range, and their flow behavior could be compared using Bostwick consistency indices.…”

A Modified Methodology to Evaluate Viscosity of Non-Newtonian Liquid Foods with a Flow Channel Instrument

“…In the immediate time period, the flow is dominated by the inertial force rather than the viscous force. Additionally, the gate opened upward locally generates the flow which is opposite to the gravity, of which the magnitude differs easily depending on the operation of practitioners [8]. These phenomena render the gravity current analysis as approximate because the difference in the early period affects the following coincidence.…”

Correlation between in-line measurements of tomato ketchup shear viscosity and extensional viscosity

“…The viscosity of tomato ketchup is a major quality component for consumer acceptance. A rigorous selection of ingredients and a continuous control and adjustment of the variables for processing are necessary to achieve a constant and desirable quality in the final product (Barringer et al, 1998;Bottiglieri et al, 1991;Jin Choi et al, 2006). Since small variations of processing conditions and raw materials affects the tomato ketchup flow behaviour and its final viscosity, several methods have been developed to monitor its flow and consistency during processing.…”

“…This is a quick and inexpensive measurement that is regularly carried out for samples taken during processing and for the final product. The relationship between the viscosity measurement by shear rheology and the Bostwick measurement has been studied by several authors (Barringer et al, 1998;Bottiglieri et al, 1991;Haley and Smith, 2003;McCarthy et al, 2008), but while rotational viscometry is more expensive and difficult to use for continuous quality monitoring, the Bostwick measurement presents other significant limitations. Bostwick measurement data are influenced by the operator skills, levelling, dryness/cleanness of the instrument, temperature of the sample, shape of the leading edge of the flow, and serum separation at the edge of the flow.…”

“…In-line viscometry of tomato ketchup was developed to overcome these limitations, though at higher price. In-line ketchup viscosity measurements were performed by means of magnetic resonance (McCarthy and McCarthy, 2009), pressure differential (Barringer et al, 1998), in-line absorption photometry (Haley and Smith, 2003), and ultrasonic Doppler velocimetry (Jin Choi et al, 2006). Shear flow was characterized with these methods and it was assumed that this type of deformation was representative to the flow in the pipes during processing.…”