Low Shear Rheology of Concentrated Tomato Products. Effect of Particle Size and Time

Bayod, Elena; Månsson, Pernilla; Innings, Fredrik; Bergenståhl, Björn; Tornberg, Eva

doi:10.1007/s11483-007-9039-2

Cited by 72 publications

(69 citation statements)

References 35 publications

(40 reference statements)

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“…Viscosity behavior of homemade tomato sauce is different from commercial sauce; which may be due to viscoelastic properties of tomato products, as they are primarily related to average volumetric diameter and insoluble solids content in tomato paste. The solids content is controlled by the tomato variety and processing conditions [10,17]. Furthermore, it has been shown that thermal pre-treatment of tomatoes caused the breaking of lycopene chains (natural polymer found in tomatoes) into smaller chains of isoprene [19].…”

Section: Resultsmentioning

confidence: 99%

“…However such characterizations are rare in the literature for tomato products [8][9][10][12][13][14][15][16]. The rheological properties of tomato products depend on several number of parameters, such as agronomic parameters (variety and maturity), compositional parameters (soluble solids, acidity and pectin content) and process parameters (finished product appearance and heat treatment) [13,17].…”

Section: Shear Rate Effect On the Viscosity Of Homemade And Commerciamentioning

confidence: 99%

“…Rheological characterization of tomato products is important not only for the design of unit operations, but also for optimization processes and quality assurance of food products [8,9]. Available information found in the literature is variable and is only concentrated on measurements of steady state shear [10]. Many studies only focus on the measurement of a condition or are empirical methods of evaluation.…”

Section: Introductionmentioning

confidence: 99%

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Shear Rate Effect on the Viscosity of Homemade and Commercial Tomato Sauce

Jorge-Octavio¹,

Claudia-Karina²,

Carmen³

et al. 2017

JFSE

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Rheological characterization of tomato products is important not only for design of unit operations, but also to optimize processes and guarantee high quality of food products. Time dependence is related with structural changes due to shear rate. Thus, rheological characterization as a function of time is extremely important to understand the changes that occurred in food products during commercial processes. However, these characterizations are rare in the literature for tomato products. Those rheological properties depend of several parameters, such as agronomic, structural and process parameters. In this study, the effect of shear rate on the viscosity at room temperature (22 °C) of two kinds of tomato sauce (homemade and commercial) is analyzed; using a Brookfield viscometer model 4535, Lab-Line Instruments. Homemade sauce was prepared with fresh saladette tomatoes from a local market. Rheological analysis was performed at shear rates from 0.05 to 10.47 s -1 ; using all the spindles available. Statistical analysis was made using LSD and Duncan tests with a confidence interval of 95% (p-value of 0.05). It was demonstrated that homemade and commercial tomato sauce behaved as a thixotropic fluid, due to the typical decrease on viscosity samples observed when testing time was increased. When tomato sauce is at rest, it has a gelled tridimensional structure; and, as soon as a shear stress is applied, the movement generates an alignment of tomato constituent chains in flow direction, breaking physic entanglements and thus causing a decrease in viscosity as a function of time. Furthermore, it was discovered that the viscosity of homemade sauce was higher than the viscosity of commercial sauce. The latter may be due to the pre-thermal treatment. During this unit operation, polymeric chains of lycopene most likely break into smaller chains of isoprene, causing the observed decrease in viscosity. Besides, commercial sauce contains additives, seasonings, preservatives and thickeners that are not in a homemade sauce.

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Section: Resultsmentioning

confidence: 99%

Section: Shear Rate Effect On the Viscosity Of Homemade And Commerciamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Shear Rate Effect on the Viscosity of Homemade and Commercial Tomato Sauce

Jorge-Octavio¹,

Claudia-Karina²,

Carmen³

et al. 2017

JFSE

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“…The viscoelastic behaviour of plant foods suspensions of tomato, carrot, broccoli, potato and apple have been studied by many researchers (Alvarez, Fernández & Canet 2004;Bayod et al 2007;Bayod & Tornberg 2011;Bengtsson & Tornberg 2011;Day et al 2010b;Den Ouden & Van Vliet 1997;Tanglertpaibul & Rao 1987). At high particle concentration all these plant food suspensions show solid-like behaviour where G´ > G˝, show shear thinning behaviour and have a yield stress.…”

Section: Rheological Behaviour Of Plant Based Suspensionsmentioning

confidence: 99%

“…However, the impact of processing techniques on the cell wall structure depends on the type of fruit or vegetable Redgwell, Curti & Gehin-Delval 2008). Research on tomato based products has shown that reducing the particle size using homogenisation increased the yield stress and viscosity of tomato paste (Bayod et al 2007;…”

Section: Complexity In Characterising Texture Modified Foods To Gain mentioning

confidence: 99%

Insights into rational design of plant based foods to improve management of dysphagia

Tobin¹

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Normal swallowing is a complex process which requires sufficient mastication and lubrication of the food to transport the bolus from the mouth to the pharynx. In people suffering from dysphagia this process is not well coordinated and they often have difficulty in transporting food and water from the mouth to the stomach, which can lead to choking or aspiration. Modification of food texture by mincing or pureeing normal food is used to prevent these complications; however inconsistencies in texture can affect the consumption of these foods. Hence, malnutrition, dehydration and aspiration pneumonia, are a common problem with dysphagia sufferers.Using green peas as a model food system, this project investigated the effect of three method of comminution -mincing, pureeing and freeze-fracturing (processing whilst frozen) -on the macro and microstructure of the peas and its impact on rheological behaviour and sensory perception.Comminution of peas resulted in a particulated soft solid with hierarchical structures with broad range of particle sizes and shapes i.e. from large clusters of cells (5 mm) to starch granules (10 µm) which were released from broken cells. These pea particles were suspended in serum released during cellular structure breakdown. The high concentration, broad particle size distributions, variations in morphology and deformability of particles made this system complex and challenging to measure. Vane geometry was used to evaluate the rheological behaviour of comminuted peas, as it enabled accurate measurement of dispersions containing large particles without altering the product structure and it also eliminated any wall slip effects. The effect of pea variety, particle size distribution and amount of serum or added water on rheological behaviour was studied.Results demonstrated that comminuted peas were characteristically solid-like with higher elastic than viscous modulus (G´ > G˝). They also exhibited a yield stress which is an important parameter in these systems as it is a good indicator of the amount of effort required to initiate flow during oral processing. Minced peas with over 50% of the particle >1 mm in size had broader size distribution, which packed better than narrower distributions of pureed peas, resulting in higher G´ and yield stress. Changing the particle size distributions by systemically increasing the percentage of minced peas in a mince/puree blend also increased G´ and yield stress. This indicated that particle size distribution can be used to modify flow behaviour, while keeping the solids content the same.Diluting minced and pureed peas with incremental amounts of water showed that in such concentrated systems, small changes in solid to liquid ratio had a considerable impact on G´ and yield stress, as small increments in the liquid phase decreased G´ and yield stress dramatically. The variety of pea did not impact on the particle size distribution, but it affected the amount of serum released and particle firmness. These findings showed that particle concentratio...

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Design of Foods Using Naturally Structured Materials

Foster

2013

Formulation Engineering of Foods

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Low Shear Rheology of Concentrated Tomato Products. Effect of Particle Size and Time

Cited by 72 publications

References 35 publications

Shear Rate Effect on the Viscosity of Homemade and Commercial Tomato Sauce

Shear Rate Effect on the Viscosity of Homemade and Commercial Tomato Sauce

Insights into rational design of plant based foods to improve management of dysphagia

Design of Foods Using Naturally Structured Materials

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