Chemistry Reference
In-Depth Information
Chapter 19
Xanthan Gum in Skim Milk: Designing
Structure into Acid Milk Gels
Pierre-Anton Aichinger,
1
Marie-Lise Dillmann,
1
Sabrina
Rami-Shojaei,
1
Alistair Paterson,
2
Martin Michel
1
and
David S. Horne
3
1
NESTLE
ยด
RESEARCH CENTER, VERS-CHEZ-LES-BLANC, CH-1000
LAUSANNE 26, SWITZERLAND
2
DEPARTMENT OF BIOSCIENCE, UNIVERSITY OF STRATHCLYDE,
204 GEORGE STREET, GLASGOW G1 1XW, SCOTLAND, UK
3
CHARIS FOOD RESEARCH, HANNAH RESEARCH PARK, AYR
KA6 5HL, SCOTLAND, UK
19.1 Introduction
Polysaccharides such as xanthan gum (XG) are widely used to enhance and
maintain textural and visual properties in food products. However, the under-
lying mechanisms are not sufficiently well understood. The interactions of
polysaccharides with other food ingredients are often ignored, although playing
an important role in structure formation during food processing. In dairy
products, various phenomena may occur due to the milk protein interacting
with the added polysaccharide.
1
It has been demonstrated
2,3
that the addition
of XG as 'thickener/stabilizer' to skim milk results in phase separation at the
natural pH of the mixtures. Furthermore, it has been shown
4
that XG incor-
poration has a great impact in drastically modifying the microstructure of acid-
induced gels made from pre-heated skim milk; this was also attributed
4
to phase
separation phenomena. These combined observations point to the importance
of the interactions of XG and milk protein in contributing to the microstructure
of materials made from their mixtures.
The microstructure of a food material determines its physical properties, and
is therefore crucial to product performance and acceptance by the consumer.
Hence, a profound understanding of structure formation is a prerequisite for
the improvement of existing food products and the development of novel food
materials with desirable properties. In the framework of the present study we
have investigated the impact of XG on acid-induced gel formation in skim milk,
289
Search WWH ::
Custom Search