Impact of pH adjustment on the characteristics of processed cheese from sheep milk and cow milk

The effects of milk from different species (sheep/cow) and pH adjustment in the production of Requeijão cremoso, a kind of processed cheese, were investigated. The results showed that the sheep's Requeijão cremoso had higher pH (∼3%), lower yellowness index (∼11%), and lower brightness (∼12%) after 5 days of storage, and at least 40% lower hardness compared to the Requeijão made from cow milk. The pH adjustment did not change the visual appearance of the samples but affected their hardness in different ways, with an increase of up to 16% for the cheese from cow milk and a reduction of up to 39% for the cheese produced from sheep milk. The results suggested that the protein-protein interactions were favoured in the Requeijão cremoso from sheep milk, while a protein network with higher water holding capacity and increased hardness was observed for the samples from cow milk