A comparison of the sensory and rheological properties of molecular and particulate forms of xanthan gum

Dysphagia management in Parkinson's disease: Comparison of the effect of thickening agents on taste, aroma, and texture

Dysphagia is a frequent symptom in Parkinson's disease (PD). Thickening liquids facilitates safe swallowing, however, low treatment compliance is a major issue, due to patients' dislike of thickened liquids. Some studies suggest a negative impact of gum-based thickeners, currently most used in clinical practice, on sensory properties compared to starch-based thickeners. This has not yet been investigated in PD. This study's aim was to compare taste, texture, and aroma of gum-based and starch-based thickened soups in participants with PD. Gum-based resource thicken up clear (RTUC) and starch-based kitchen products potato starch (PS) and quinoa flour (QF) were evaluated in broccoli soup. Texture, aroma, and taste were characterized by rheology, volatile, and sensory profiling. Thickened soups were evaluated in participants with PD and controls through a paired comparison test. Reduced release of 61.4%, 46.2%, and 38.5% of volatiles was observed after thickening with RTUC, PS, and QF, respectively. Overall taste intensity was reduced in RTUC- and PS-thickened soup, respectively. Taste and aroma of PS-thickened soup were considered more intense by 70.3% and 63.8% of all participants, respectively (n = 36 PD, n = 41 controls), 56.3% preferred the PS-thickened soup's texture . Taste and aroma of QF-thickened soup were considered more intense by 68.1% and 65.6% of all participants, respectively (n = 47 PD, n = 31 controls), 58.0% preferred the QF-thickened soup's texture. Starch-based thickeners demonstrated higher taste and aroma intensity. However, volatile and sensory profiling demonstrated reduced taste and aroma in all thickeners. Combining kitchen products with flavor enhancers may increase palatability of thickened beverages.

A comparison of the sensory and rheological properties of different cellulosic fibres for food

The impact of different cellulosic microstructures formed by highly entangled fibre networks was studied for food applications as dietary fibre. This paper reports the impact of the microstructure on the rheological and sensory behaviour of the aqueous suspensions of particulate and fibrillated forms of softwood cellulosic fibres, and was compared with citrus fibres. An aqueous suspension of cellulosic fibres shows stable viscoelastic gel-like behaviour as a function of frequency. The particulate form of cellulosic fibres showed the lowest shear viscosity as compared with the entangled network system at comparable concentrations. To provide further insight into the relationship between the structure of cellulosic fibre and taste (salt) perception, an aqueous suspension with matched shear viscosities were studied. A hypothesis to explain why softwood cellulosic fibre (CTE) with an entangled network structure prolongs the taste perception is presented.

Shear rheology and filament stretching behaviour of xanthan gum and carboxymethyl cellulose solution in presence of saliva

The objective of the work reported in this paper is to determine if saliva addition has an effect on the rheology of xanthan gum solutions. The reasons for the interest was that it has been previously reported that flavour release from high viscosity xanthan thickened foods is not reduced in the same way as foods thickened by other hydrocolloids at comparable viscosities. It was previously postulated that this could be due to an interaction between saliva and xanthan that could change the microstructure and rheology of xanthan solutions. In this work the effect of saliva on the rheology of CMC and xanthan solutions was compared. Solutions of molecularly dissolved xanthan gum and CMC mixed with water or human whole saliva at a ratio of 5:1 showed little impact of the presence of saliva on steady shear or dynamic viscosity for the two hydrocolloids. In filament thinning experiments saliva addition significantly increased filament break-up time for xanthan gum while it had little effect on the break-up time of the CMC filament. Also, filament thinning appeared a lot less even and was not as reproducible in the case of xanthan gum. Addition of CMC and hydroxypropyl methylcellulose (HPMC) to xanthan gum solutions showed a similar increase in break-up time to saliva, but to see this effect the viscosity of the added CMC or HPMC solution had to be very much higher than the viscosity of saliva. The results are discussed in the context of the structure of xanthan gum and the reported extensional rheology of saliva.

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Shear rheology of xanthan gum and CMC not affected by saliva.

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Filament break-up time shorter for xanthan than CMC at comparable viscosity.

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Saliva increases filament break-up time for xanthan but not for CMC.

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Rigid rod conformation of xanthan promotes interaction with saliva mucin fraction.