Characterization of Dysphagia Thickeners Using Texture Analysis-What Information Can Be Useful?

Besides shear viscosity, other texture parameters (adhesiveness or cohesiveness) might be relevant for safe swallowing in people suffering from oropharyngeal dysphagia. Shear viscosity is assessed through protocols developed using a viscometer or a rheometer. In contrast, protocols and instruments (capillary break-up rheometer) to assess adhesiveness and cohesiveness are less common and much less developed. Other equipment such as texture analyzers can provide useful information on food properties. Here, we aimed to explore different texture analyzer settings (type of test, probe, and protocol) to characterize four commercial dysphagia thickeners at the shear viscosity levels recommended by manufacturers. Among the tests used (extrusion or penetration) with the different probes (disc, cone and shape holder, sphere, or cylinder), cone extrusion provided information about adhesivity, disc extrusion about sample cohesiveness, and sphere about penetration and sample elasticity. The test speeds used influenced the results, but only one speed is needed as the different speeds provided the same fluid information; for easiness, it is proposed to use 1 mm/s. Comparing the texture analyzer results with viscosity values obtained at different shears, the texture analyzer parameters reflected information that differ from shear viscosity. This information could be relevant for the therapeutic effect of thickening products and food characterization.

Type of starter culture influences on structural and sensorial properties of low protein fermented gels.

Organoleptic properties of skimmed milk fermented gels are progressively demanding to produce optimal quality yogurts. Chr-Hansen trademark registered cultures were used to produce low-protein (3.4%) gels to assess the ability to redesign the sensorial and textural properties with the choice of starter culture. Resulting gels were assessed for sensorial, textural, rheological, and microstructural properties and compared with a commercial control (4.5% protein). Mouth thickness, syneresis, firmness, elasticity, and consistency values were lower for polysaccharides-producing cultures. Such cultures contributed to the higher creaminess and tended to give higher ropiness. Observed differences among microstructures of the gel were minute. Microstructural and rheological data corresponded and reflected the instrumental and sensory interpretations. Strong correlations were observed between sensory and instrumental data. Nonprobiotics cultures resulted in promising overall gel properties compared with probiotic cultures according to the principal component analysis. Yet probiotic cultures resulted in lower syneresis than nonprobiotic cultures. Thus, the choice of bacterial culture modifies the sensorial and textural properties of fermented gel with strong correlations, as a result of altered gel network formation with the production of polysaccharides. Inferior textural and sensorial quality aspects, particularly at low protein levels, have negative impact on consumer demand of low protein yogurts. Thus, we attempted to gain required gel textural and sensorial properties with a choice of starter culture with a low protein level. Resulting gel properties at lowered protein content with different starter cultures are not fully known. The present study compares the effect of probiotic and nonprobiotic starter cultures on gel properties, as gel texture and sensory properties are of great interest and thus not willing to be compromised. In addition, we examined the overall texture profile of studied cultures and correlate with sensory properties. Therefore, reducing protein level in milk and achieving required gel properties with the choice of appropriate starter culture is of great commercial interest as a cost-cutting strategy to produce low-cost optimum quality yogurt.

Relationships between acceptance of sour taste and fruit intakes in 18-month-old infants.

The present study examined whether infants show an acceptance for extreme sour tastes and whether acceptance of sour taste is related to infants' fruit intake. Fruit intake of fifty-three infants at 6, 12 and 18 months was assessed using 3 d food records. Sour acceptance of these infants was studied at 18.1 (SD 1.5) months. Acceptance for four solutions differing in citric acid concentrations (0.00 M, 0.013 M, 0.029 M and 0.065 M) was measured by allowing infants ad libitum ingestion of each solution over brief time periods. The base solution to which citric acid was added was blackcurrant squash diluted in water. Infants' relative intake of each solution was used as a measure of sour acceptance. At 18 months, twelve infants readily accepted the two highest citric acid concentrations, whereas the remaining infants rejected these. Infants who accepted the most sour solutions had a significantly higher fruit intake (P = 0.025) and a higher fruit variety (P = 0.015) at 18 months than the infants who rejected the highly sour taste. Furthermore, infants who accepted the most sour solutions consumed fruits more frequently at 18 months (chi2 5.1; P = 0.024). Infants who accepted the sourest solutions also had a higher fruit intake at 6 months, and a significantly higher increase in their fruit intake from 12 to 18 months. This is the first scientific study that demonstrates the acceptance of sour tastes in some infants at the age of 18 months. Furthermore, the present results suggest a relationship between acceptance of sour tastes and infants' fruit intakes.