Optimised production and spray drying of ACE-inhibitory enzyme-modified cheese.

The proteolytic stage of the digestion process of white cheese curd was optimised to maximise the angiotensin I-converting enzyme (ACE)-inhibitory activity of the final enzyme-modified cheese (EMC) paste. It was found that bioactive peptides generation in EMC paste was of multi-variable dependent nature and could be optimised by targeted selection of specific component variables. Maximum ACE-inhibitory was obtained by proteolysis at 48 °C for 25 h with 1 g Flavourzyme/kg cheese curd. This bioactive EMC paste was subsequently spray-dried. The drying conditions were optimised to obtain a highly soluble powder to warrant quick and complete hydration, with the lowest water activity to maximise long term storage. The higher the inlet drying air temperature, the greater was the solubility of resultant EMC powder. Differential scanning calorimetry analysis revealed that the highest drying air temperature (200 °C) resulted in a lower glass transition temperature for the potentially bioactive EMC powder.