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Rheological data on a food together with data on its composition and structure or microstructure should lead to understanding the interrelationships between them. A number of foods are dispersions of solids in liquids, liquids in liquids, or gas in liquids. The dispersed particles may be colloidal in nature with dimensions < 10 µm, or larger noncolloidal particles (> 10 µm). For both colloidal and noncolloidal dispersions (either in dilute or concentrated regimes), several theoretical equations exist that provide insights into the role of key rheological parameters, such as particle volume fraction and size, interparticle forces, and fractal dimension on their viscosity, yield stress, and modulus. When theoretical models cannot be easily applied to foods with complex structures, structural analysis and structure-based models provide insight into the role of solids loading and interparticle bonding on rheological behavior. In this review, recent studies on colloidal and noncolloidal food dispersions in which theoretical models as well as structural analysis were employed are discussed.

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ABSTRA ABSTRA ABSTRA ABSTRA ABSTRACT CT CT CT CT: I : I : I : I : Intr ntr ntr ntr ntrinsic stability and r insic stability and r insic stability and r insic stability and r insic stability and rheological pr heological pr heological pr heological pr heological proper oper oper oper operties of apple juice foams for foam mat dr ties of apple juice foams for foam mat dr ties of apple juice foams for foam mat dr ties of apple juice foams for foam mat dr ties of apple juice foams for foam mat drying w ying w ying w ying w ying wer er er er ere studied. e studied. e studied. e studied. e studied. Foams were prepared from clarified apple juice by adding various concentrations of 2 foaming agents of different Foams were prepared from clarified apple juice by adding various concentrations of 2 foaming agents of different Foams were prepared from clarified apple juice by adding various concentrations of 2 foaming agents of different Foams were prepared from clarified apple juice by adding various concentrations of 2 foaming agents of different Foams were prepared from clarified apple juice by adding various concentrations of 2 foaming agents of different nature: a protein (egg white at 0.5%, 1%, 2%, and 3% w/w) and a polysaccharide (methylcellulose at 0.1%, 0.2%, nature: a protein (egg white at 0.5%, 1%, 2%, and 3% w/w) and a polysaccharide (methylcellulose at 0.1%, 0.2%, nature: a protein (egg white at 0.5%, 1%, 2%, and 3% w/w) and a polysaccharide (methylcellulose at 0.1%, 0.2%, nature: a protein (egg white at 0.5%, 1%, 2%, and 3% w/w) and a polysaccharide (methylcellulose at 0.1%, 0.2%, nature: a protein (egg white at 0.5%, 1%, 2%, and 3% w/w) and a polysaccharide (methylcellulose at 0.1%, 0.2%, 0.5%, 1%, and 2% w/w), and whipping at different times (3, 5, and 7 min). In general, egg white foams were less 0.5%, 1%, and 2% w/w), and whipping at different times (3, 5, and 7 min). In general, egg white foams were less 0.5%, 1%, and 2% w/w), and whipping at different times (3, 5, and 7 min). In general, egg white foams were less 0.5%, 1%, and 2% w/w), and whipping at different times (3, 5, and 7 min). In general, egg white foams were less 0.5%, 1%, and 2% w/w), and whipping at different times (3, 5, and 7 min). In general, egg white foams were less stable but sho stable but sho stable but sho stable but sho stable but show w w w wed a higher degr ed a higher degr ed a higher degr ed a higher degr ed a higher degree of solidity (str ee of solidity (str ee of solidity (str ee of solidity (str ee of solidity (stronger str onger str onger str onger str onger structur uctur uctur uctur uctures), higher foaming capacity es), higher foaming capacity es), higher foaming capacity es), higher foaming capacity es), higher foaming capacity, and smaller bubble , and smaller bubble , and smaller bubble , and smaller bubble , and smaller bubble average diameter than methylcellulose foams. Foam stability increased with increasing concentrations of either average diameter than methylcellulose foams. Foam stability increased with increasin...

Steam heating of crushed apples in the range 65–70°C for 15 to 20 sec controlled enzymatic browning and effectively stabilized cloudiness. Particles in fresh pressed cloudy apple juice were 3 mm but after 15 min of centrifugation at 4200 × g almost all particles had a diameter of 1 mm, and cloud could be considered stable. Median and modal diameters were virtually coincident, suggesting a symmetrical distribution. The specific surface area of the cloudy juice particles was 50 mm2/g and no agglomeration occurred.