SPRAY DRIED MILK POWDER

SPRAY DRIED MILK POWDER -

Spray drying is a major process of water removal and particle formation in milk powder production.

Principle-

Spray drying is remove the water from the milk concentrate as fast and as low temperature as possible so as the minimize heat damage to the milk solids. This is achieve by spraying the milk concentrate as very fine droplets by nozzle or rotary atomizer into hot dry stream at 180-220°C.

Atomising the pre-heated and concentrate milk to form a Spray of very large, suitably designed drying chamber where they come in contact with current of hot air. Due to high temperature and large surface area the milk particles evaporated their moisture almost instantaneously and transform into a fine powder. Then remove continuously.

There is sufficient transport of water to the droplets surfaces keep saturated condition the evaporation of water from surfaces proceed at a constant rate and liquid droplets shrinks as water is evaporated.

Foam Spray Drying

Milk→Pump→Forcing inert gas into liquid → Atomizer. →Drying chamber →Dried Products

Other than drying whole milk and skim milk this process is mainly applied to dry milk products and by products such as butter milk, Cream (sweet and sour) , whey and emulsifieemulsified cheese slurry. This is done by forcing gas into liquid products after pump but before the atomizer.

Material-

Anhydrous milk fat ( AMF) and two industrial spray dried milk ( SMP and WMP) were obtained from a local. dairy company. The milk powders were commercial products that had freshly manufacturer and packed consumer use. The capacity of the driers which the powders were at least 4t powders/ h.

Composition -

The hexane (>95%) used in this study was purchase from Asia Pacific Specialty Chemical Ltd.(Auckland, New Zealand)

Effect of feed solids content-

In order to investigate the effect of feed solids content on surface composition of spray-dried SMP, a series of SMPs was produced using different feed solids content (10%, 20% and 30% ( w/w) and the surface composition. of powders were analysed using ESCA.

Manufacture of Spray Dried Milk Powders

The predominant method of drying milk and milk. products is spray drying. The condensed milk from the evaporator is pumped to a balance tank and from there passed through a filter and introduced into drying chamber with or without preheating. The solubility of skim milk powder is not affected up to a preheating temperature of 80°C. Feeding cold concentrated milk to the drier may result in sticking to the chamber causing more burnt or scorched particles in the final powder. Either a pressure nozzle or spinning-disc is used for atomising the concentrate into fine droplets and exposing to a current of hot air as they fall into the spray chamber. As water is evaporated from the droplets they become powder particles. While the inlet temperature reaches up to 215°C the temperature in the chamber drops down Almost instantly to the temperature of outlet air (about 95° C in one stage drying). Residual moisture is one of the most important properties of milk powder both from a quality and economic point of view. The outlet temperature is usually used as the parameters by which final moisture of the product is controlled. Dry products is taken away immediately after drying. The powder coming out of the drier is preferably cooled to 30 °C secondary air stream before packaging and storage. Cooling is done to prevent clumping, sticking and heat damage to the products.

Reference-

Sciencedirect- Esther H

Name- Shikha Brisenia

Class- M.Sc ( Food Technology) 2 semester

Roll no- 23