Reconstituting Powdered Milk
Nonfat Dry Milk (NFDM) reconstitution is a key application as milk powder and protein powders are added back into water for the production of: fresh cheese, cheese dips, processed cheese food, cheese spreads, cottage cheese and cream cheese.
How To Reconstitute Powdered Milk
Most common devices used to incorporate and disperse NFDM tend to incorporate a significant amount of air and cause agglomerates to form due to lack of the proper amount of shearing action of the gums and caseinates. Excess air entrainment causes foaming and foaming requires time to let the milk de-aerate and can encapsulate undispersed/ undissolved powder ingredients leaving a scum in the milk silo resulting in more cleaning and a waste of product. After reconstituting powdered milk, the milk must be passed through a plate and frame heat exchanger (pasteurizer – often referred to as a HTST (High temperature, short time). Air in the milk passing through the heat exchanger leads to poor heat transfer and possible hot spots and burn-on.
Agglomerates lead to poor yields from ingredients, especially when using expensive proteins and gums. Non hydrated/poorly dispersed material can foul the heat exchanger surface resulting in burn on and difficult cleaning. Also, possible damage/interference can occur to downstream homogenizers (although the milk is typically filtered ahead of this step).
Solutions to Milk Powder Reconstitution
The Quadro Ytron in-line Powder Disperser is capable of dispersing skimmed milk powder, gums and caseinates into water quickly and completely lump-free, in a single-pass. One cheese making company reported single pass concentrations at 26% by weight with the ability to empty an 800 kg super sac in 10 minutes (176 lbs/min). The inline unit has been shown to yield consistent viscosities approximately 30% higher than traditional methods. Gum hydration tanks, pre-dispersion fluids and post-filtering are not required with the use of a Ytron Powder Disperser. The technology is capable of producing single-pass, lump-free Xanthan gum solutions at flow rates from 15 to 120 USGPM (60-450 LPM).
Processed Cheese Smoothing Processed cheese is a product made by blending various natural cheeses & cheese powders, emulsifying salts, common salt, preservatives, dry milk powder, whey and fat together, followed by cooking to liquefy the mixture to provide a homogeneous mass ready for forming & cooling. For process cheese slices, the molten cheese is cast on a roller drum, followed by cutting into ribbons, slicing and packaging. An international cheese manufacturer approached Quadro to find a solution to problems encountered when adding reclaimed fresh cheese to their process. The addition of reclaimed cheese results in large savings of raw material costs.
However, the existing horizontal ribbon blender did not provide sufficient mixing and shearing action resulting in hard agglomerates of cheese and shortening passing to the downstream cooking and forming steps leading to off-spec, wasted product.
Processed Cheese Blending Solutions
Quadro Ytron Z Emulsifier is recommended for installation following the ribbon blender for de agglomeration and to smooth the pre-mix prior to cooking. Optimal speeds and rotor/stator tooling geometries were finalized following trials on five (5) different cheese blends. The result was a smooth, consistent product with no hard agglomerates.
Processed Cheese Sauce and Cheese Dips
A large processor of cheese dips and sauces was struggling with the manufacturing of their product. The product, a high concentration of powders (maltol (30% concentration by weight)) and modified starch (9% concentration by weight) into water (50% concentration by weight) was coming out lumpy and at a low production rate. The existing equipment, a Tri-blender style eductor, was not imparting enough shear to properly wet out the powders.
Quadro Liquids Equipment Solutions
A Quadro Ytron® Powder Disperser was employed to overcome these problems. After proper tooling selection, the resulting product came out at high production rates, single pass with no lumps at 300 cps.
Blended Cottage Cheese
A processor was blending cottage cheese (40% by wt) and skim milk, blended together with an in-tank high shear blender. The discharge had to be pumped through a plate and frame heat exchanger. Any cottage cheese lumps would stick to the plates and burn-on/clog the unit.
Cottage Cheese Process Solutions
A Quadro Ytron® Z Emulsifier was tested successfully to size reduce 1⁄4 to 1⁄3 inch lumps. The product produced was a creamy smooth sauce. Samples left for 72 hrs experienced no degradation.
Another processor purchased a Quadro Ytron® Z Emulsifier to complete the dispersion and hydration of gums/starches used in a cottage cheese pre-mix. Powders were initially added to a Tetra All Mix but did not disperse/hydrate sufficiently. The Z was installed after the unit to complete the hydration.