Peptide concentration and structure.
Improving our knowledge of the relationship between peptide
concentration and structure and foam performance can lead to a better
understanding, analysis and control of this complicated property. Many
juices and other beverages, including beers and wines, are typically
clear when they are produced but slowly develop haze during storage.
Frequently the haze results from chemical interactions among proteins,
polyphenols and polysaccharides. The particular protein fractions
involved in haze formation often have an amino acid composition, which
promotes interaction with phenolic compounds. The modeling of haze
formation as a function of initial product composition can help us
predict cost-effective treatments that provide the desired stability.
Stable clouds are desired in some juices and other beverages. Foam is an
important property of some beverages, particularly beer and champagne.
Protein is typically the most important component of foam, although
other substances may also be involved. The relatively stable foam of
beer, for example, results from an interaction between a protein
fraction rich in basic and aromatic amino acids and the hop bitter
compounds. Studies designed to learn more about producing and
stabilizing cloudy natural juice products are in progress. Various
proactive factors, including selective filtration, extraction
conditions, homogenation and enzymatic modification, are being explored.
Contact: Karl J. Siebert, Department of Food Science and Technology,
Cornell University, 129 Food Research Laboratory, Geneva, NY 1445.
Phone: 315-787-2299. Email: firstname.lastname@example.org.