The Dairy Industry
- Introduction to the New Zealand Industry (PDF 307 kb)
This article gives an overview of the NZ dairy industry in the 1990's and describes the major components of cows' milk, the carbohydrates, the lipids (fats) and the proteins.
- Milkfat Products (PDF 71 kb)
This article describes the chemistry of milkfat and some of the processes to manufacture milkfat products commercially. The major processes are Fritz , developed from the traditional batch churning process of crystallised cream, and Ammix , in which fresh cream is mixed with cream and salt and shocked cooled to give rapid crystallisation.
- Milk Powder (PDF 44 kb)
This article describes how water is evaporated from milk by boiling at low pressure, and how this concentrate is turned into powder by spraying it as a fine mist into hot air. It also describes different products produced and lists the various consumer products of which it is a component.
- Manufacture and Use of Cheese Products (PDF 336 kb)
This article describes the major steps in all cheese making, milk acidification, milk coagulation to give curd, whey removal, packaging and storage. Glycolysis, lipolysis and proteolysis, the processes in the ripening of cheeses, and how manipulating the curd in different ways leads to different kinds of cheeses, are described.
- Casein Products (PDF 118 kb)
This article describes how casein, the principal protein in cows' milk, is extracted from it, the two major types of casein, acid and rennet, and the uses of different caseins in the manufacture of many foods and other non-food products.
- The Manufacture of Lactose (PDF 114 kb)
This article gives the structures of a- and ß- lactose, lactulose and lactic acid, and describes the extraction and purification of lactose from whey for the food and pharmaceutical industries.
- Whey Products (PDF 64 kb)
This article describes the major products made from whey in New Zealand : demineralised whey powder, whey protein concentrate, lactalbumin, whey protein hydrolysates, milk mineral products, demineralised permeate powders and alcohol.
- The Manufacture of Ethanol From Whey (PDF 131 kb)
This article describes why some wheys are unsuitable for lactose production, but how these are turned into ethanol by fermentation and distillation.
- Chemical Analysis in the New Zealand Dairy Industry (PDF 94 kb)
This article describes the large range of techniques, traditional to modern, simple to complex used in the industry. Gravimetric fat determination, Kjeldahl method for nitrogen determination, various methods in lactose determination, total solids determination and mineral determination are described.
- Environmental Issues in Dairy Processing (PDF 90 kb)
This article discusses the impact wastewater would have if released into the environment, methods to minimise the amount of both organic and inorganic material in the wastewater and methods of reducing the total volume of wastewater released.