Jim Hourigan

Moisture sorption, compressibility and caking of lactose polymorphs

The aim of this study was to conduct storage studies on the moisture sorption and caking properties of lactose powder containing different polymorphs (i.e. alpha-monohydrate, alpha-anhydrous unstable, alpha-anhydrous stable, beta-anhydrous) and spray-dried lactose. The dry sample was compacted using a texture analyzer in paper cylinders and stored at relative humidity (RH) of 33%, 43%, 57% and 75% (25 degrees C, for 3 months). The samples were monitored for weight gain, moisture content, alpha/beta balance and hardness. A simple new method of powder compression for measuring the degree of hardness of caked lactose was developed using a texture analyzer. Clear distinctions were found in the storage behavior of the five different samples. Storage at various RHs caused severe caking to beta-lactose anhydrous and spray-dried lactose. The beta-lactose anhydrous was hygroscopic at 75% RH. The spray-dried lactose, which contained some amorphous lactose, was hygroscopic at all RHs studied. Its moisture sorption behavior differed from that of its major component, alpha-lactose monohydrate, by initially absorbing moisture then desorbing. alpha-Lactose monohydrate was less hygroscopic at 75% RH and it formed friable cakes. The alpha-lactose anhydrous stable was hygroscopic at 75% RH and initially formed hard cakes which became friable during storage. The unstable form of anhydrous alpha-lactose was hygroscopic at all levels of RH studied but did not cake.

Separation of bovine immunoglobulin G and glycomacropeptide from dairy whey

Abstract The concentration of immunoglobulins (Ig) in whey by selectively removing major whey proteins such as α-lactalbumin (αLA), β-lactoglobulin (BLG) and bovine serum albumin (BSA) has been studied using a polystyrene anion exchanger IRA93 and Amicon YM100 membrane. A process with IRA93 and 100 kD membrane treatment has been used to prepare Igs-enriched products from HCl–casein and colostral whey. The content of IgG in the product was 43.3% for HCl–casein whey and 93% for colostral whey, respectively. IRA93 selectively adsorbs glycomacropeptide from cheddar cheese whey at pH 4.7. The effects of pH, NaCl and diafiltration on fractionation of whey proteins by ultrafiltration were also studied.

Waste management and co-product recovery in dairy processing.

Publisher Summary Dairy processing in major dairy producing countries has undergone rationalization in recent years, with a trend toward larger yet fewer plants operated with less staff. Large processing plants have enabled the use of automated and more efficient equipment – including the use of specialized processes such as membrane filtration, ion exchange, and modern drying processes, thus increasing the opportunity for the recovery of milk solids that were formerly discharged. In addition, sophisticated process control systems have allowed improved processing efficiencies and cost savings. However, large-scale manufacturing increases the environmental burden on to smaller areas, loading the impact of liquid waste disposal, noise and gas emissions in the vicinity of the plant. There are several aspects of waste disposal that continue to be troublesome in the dairy industry, including acid whey, nanofilter permeates, mother liquor from lactose crystallization, clean-inplace waste, and spent ion exchange regeneration brines. Although limited utilization of many of these by-product streams is due to low returns and economies of scale, continued research and process optimization is required to overcome the remaining technological barriers for maximizing the recovery of dairy by-product streams.