The new research, published in the LWT - Food Science and Technology, taps into growing interest in the development of water-in-oil-in-water (W/O/W) emulsions. Current application of the technique is limited due to difficulties with the stability of the internal water droplets. This is linked to thermodynamic stability issues, and their strong tendency for droplet coalescence.
Previously, water-in-oil-in-water emulsions have been investigated for their potential to reduce the fat content in products like mayo, salad dressings, sauces and dips.
"In this work, it was established that reduced-fat cheese-like products manufactured from skim milk and water in-oil-in-water emulsions stabilized with hydrocolloids closely emulated some of the textural characteristics of its full milk-fat counterpart, despite their completely different structural arrangements," wrote the authors from
"Additionally, reduced-fat cheese-like products had similar preference scores than that corresponding to its full milk-fat counterpart."
The new research prepared reduced-fat 'cheese' from skim milk and different W/O/W emulsions and compared physical and chemical composition, and sensory characteristics to full-fat cheese prepared from high fat milk (27 g of fat per litre).
Five reduced-fat cheese-like products were prepared by the team by adding multiple emulsions containing canola oil and stabilised/emulsified by carboxymethylcellulose (CMC), gum Arabic (GA), and amidated low-methoxyl pectin (LMP), and blends of GA-LMP or GA-CMC.
The Mexican researchers report that, as could be expected, the chemical composition, structure, yield and texture of the reduced-fat cheeses were dependent on the emulsifying/stabilising agents.
Specifically, use of gum arabic contributed to a higher yield and fat content the reduce-fat cheese, compared to CMC. On the other hand, CMC produced an cheese-like product with a texture reminiscent of the full-fat cheese, stated the researchers.
"Differences in the textural behaviour among the [reduced-fat] cheeses with time can be attributed to the effect of the biopolymers on the size and distribution of the emulsion droplets in the protein matrix and the interactions taking place among the biopolymers molecules and cheese components (i.e. milk proteins and water)," they explained.
A panel of 80 consumers (48 women) was recruited to assess the products. After three days after manufacture, no differences in preference was reported for any of the reduced-fat cheeses or the WFC cheese.
After 15 days similar results are reported, with the exception of a lower preference for the CMC-containing cheese - described by the consumers as producing a "teeth grinding" sensation.
"The development of cheese-like products containing emulsified vegetable oils in substitution of saturated milk-fat can contribute to improve consumers' health," wrote the researchers.
"Consumers are demanding low- and reduced-fat products, with a healthy saturated-unsaturated fat balance, in order to reduce the risk factor for heart disease, which is now the world's leading cause of death."
The researchers were affiliated with the Universidad Autonoma Chapingo, Universidad Autonoma Metropolitana-Iztapalapa, and the Universidad Autonoma del estado de Mexico.
Source: LWT - Food Science and Technology (Elsevier)
Published online ahead of print, doi: 10.1016/j.lwt.2008.01.006
"Structural and textural characteristics of reduced-fat cheese-like products made from W1/O/W2 emulsions and skim milk"
Authors: C. Lobato-Calleros, A. Sosa-Perez, J. Rodriguez-Tafoya, O. Sandoval-Castilla, C. Perez-Alonso, E.J. Vernon-Carter