Product Stability in
Dairy System
Food products consist of many kinds of ingredients which often time have conflicting characteristics and functions. These conflicting ingredients react to each other resulting product instability and sub-optimal product performance.
The presence of milk fat, lactose, calcium, vitamins, mineral and salts, protein, and enzyme in milk creates an overly complex structure in dairy products. The additional of other ingredients in many dairy products sometimes resulting in an unstable product.
Without a proper product development and stabilizing system, dairy products may have many stability defects that occurs during production and distribution. Solid sedimentation, fat and protein separation, settling and syneresis are some of the many stability defects that can be observed visually.
Dairy system with poor product stability also affects its texture and mouthfeel. Sweet Condensed Milk may crystallize through extreme temperature change. Minerals may react with other ingredients, producing grittiness in liquid milk products. Proteins may aggregate and form unwanted gel and marbling effect. Excessive ice crystals can form i in ice cream from water migration.
Product Stability also determines length of shelf life. So often, because of poor stabilizing system, a product appearance deteriorates before the products itself is unsafe to eat. Since the correct stabilizing system can help to preserve food ingredient structure, it is very critical to stabilize the ingredients of a dairy system to prevent waste by discarding product from a premature expiration because of the undesirable mouthfeel, texture, and overall appearance.
The correct combinations of hydrocolloids, a terms that often used to describe individual stabilizer, will create a stabilizing network by binding liquids to create weak gel, trapping and binding solids, fat and oil, calcium, and protein.
The suspension of solids inside the matrix network prevents any sedimentation, separation, syneresis, in milk and ice crystal formation in ice cream. The correct stabilizing system will keep the dairy system stabilized and prevent undesirable visual defects that include color separation, cocoa and solid sedimentation, and marbling.
Common stabilizers used in dairy products are either polysaccharides, such as natural gums, fibers and modified starches; or proteins, such as whey and gelatin.Their paramount benefits are due to their ability to provide high degree of water affinity and water holding capacity in the dairy system. The presence of extensive hydroxyl groups in these ingredients allow the desired hydrophilic properties beneficial to stabilize dairy system. Due to such characteristic, such ingredients can produce uniform dispersion that combines the nature of both true solution and suspension. Hence, the nomenclature of hydrocolloids are often used within food industry; where the prefix “Hydro” means water, and “colloid” means uniform gelatinous substance, inferring to their high capabilities to bind water. It is critical to combine several hydrocolloids to achieve unique synergetic rheological properties in order to achieve desired stability and texture in dairy products
Hydrocolloids vary in characters, functionality and performance. Many thickens when dispersed in water, while others form gels. Some gels maybe spreadable and some are brittle. Some hydrocolloids will contribute opacity and other remain clear. A few gives a unique thixothropic behavior while many gives irreversible thickening and gelling properties.
Each hydrocolloid possesses some strength and weakness. Understanding the characters of the dairy system to be stabilized along with extensive knowledge of the strength and weakness of each available hydrocolloid is very important to create an optimal blend of stabilizing system.