Rheological Indices of Fruit Content in Jams: Influence of Formulation on Time‐dependent Flow of Sheared Strawberry and Peach Jams

Abstract

The influence of formulation factors [fruit content (25–55%), soluble solids content (60–70° Brix) and added pectin (0.3–0.7% in strawberry jams and 0.1–0.5% in peach jams)] on time dependent parameters has been analyzed in previously sheared jams. Twenty three samples of each fruit jam were prepared according to a second order composite rotatable design. Weltmann A values depended mainly on fruit content and on its interaction with the other two composition factors for both fruit jams. Weltmann B values, depended on the three variables and on fruit‐pectin interaction for strawberry jams, while for peach jams B values depended also on fruit‐soluble solids interaction. Predictive power of time dependent parameters for estimation of fruit content was low, but considering them in conjunction with soluble solids content and total pectin values explained 91.7% of the variability of fruit content in strawberry jams and 83.7% of same in peach jams.

Rheological characterisation of juices obtained from transgenic pectate lyase-silenced strawberry fruits

“…Some studies on the steady-shear rheological characterisation of strawberry processed into jam have been done (Carbonell, Costell, & Duran, 1991;Costell, Carbonell, & Duran, 1993;Grigelmo-Miguel & Martin-Belloso, 1999). However, the dynamic-shear characterisation of the strawberry juice has not so far been studied.…”

Effect of Concentration and Temperature on Flow Properties of Alyssum homolocarpum Seed Gum Solutions: Assessment of Time Dependency and Thixotropy

“…In contrast with our results, Razavi et al 34 and Razavi and Karazhian 17 reported that the B value for low-fat sesame paste/date syrup blends and Salep increased with shear rate, respectively. This model has also been considered appropriate to characterize the time dependence of the flow of other food products like salad dressings 35 , fruit jams 36 , or yogurt 37 . The A. homolocarpum seed gum concentration had a considerable effect on the degree of thixotropic behavior.…”

Flow behaviour of semi-solid dairy desserts. Effect of temperature

“…Stress decay in sample 1 fitted rather well to the Weltmann model when measured at 5 C (R 2 ¼ 0:920), but not so when measured at 25 C (R 2 ¼ 0:859). This model has also been considered appropriate to characterise the time dependence of the flow of other food products like salad dressings (Paredes, Rao, & Bourne, 1989), fruit jams (Carbonell, Costell, & Dur! an, 1991b) or yoghurts (O'Donnell & Butler, 2002).…”