Production and properties of yoghurt and ymer made from ultrafiltrated milk

• Published in: Desalination 1980-01, Vol.35, p.213-222
• Main Author: Mogensen, G.
• Format: Article
• Language: English
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/S0011-9164(00)88612-9

Yoghurt and Ymer are examples of fermented products which are concentrated in solids non fat (SNF). Ymer is a Danish dairy product which is heavily concentrated. According to Danish legislation it must contain at least 6% milk protein and at least 11% SNF. Originally this concentration was achieved by draining off 50% whey after fermentation. The development of ultrafiltration to an industrial scale opened new possibilities to facilitate standardization of SNF, increase product yield and rationalize the production. The chemical composition of ymer made from ultrafiltrated milk differs, however that prepared in the traditional way. Presumably due to the increased content of calcium and phosphorous, UF-ymer is liable to develop a brittle consistency just as the flavour is changed unfavourably. Research has shown that the retention of calcium and phosphorous is affected by the heat treatment of the milk prior to UF and the temperature at which the milk is ultrafiltrated. The influence on product consistency is, however, rather negligible and the small decrease in calcium retention at lower filtration temperature could not compensate for the decrease in filtration capacity. Due to the changed chemical composition of the UF-ymer, the manufacturing technology has to be changed.