Reduced-fat white fresh cheese-like products obtained from W1/O/W2 multiple emulsions:: Viscoelastic and high-resolution image analyses

This paper focuses on the study of the rheological and structural changes of reduced fat cheeses (EC) obtained by substituting milk-fat by multiple emulsions (W-1/O/W-2) stabilized with different hydrocolloids in comparison to a full-fat white fresh cheese (WFC). Amidated low-methoxyl pectin, carboxymethylcellulose (CMC), gum Arabic (GA), and blends of these hydrocolloids were used as emulsion stabilizing agents. Cheeses storage (G') and loss (G") moduli as a function of strain % were determined and the ratio of tan 6 in the nonlineal viscoelastic region (tan delta(B)) to that in the lineal viscoelastic region (tan delta(A)) was obtained. The EC cheeses made from W-1/O/W-2 emulsions with GA (ECGA) and CMC (ECCMC) exhibited non-significantly different tan delta(B)/tan delta(A) ratio values from that of WFC cheese. Scanning electron micrographs (SEM) showed that all the cheeses exhibited different surface microstructure. Detrended fluctuation analysis (DFA) of SEM micrographs indicated that all cheeses structure displayed a hierarchical configuration, from well-ordered particles in the small scale range to randomly dispersed particles in the high scale range. The ECGA and ECCMC cheeses also showed similar particle distribution over the particle size range of 20-60 mu m to that of the WFC cheese. (c) 2006 Elsevier Ltd. All rights reserved.