Tradition versus modernism in cheesemaking technology: a Portuguese case study encompassing plant coagulant, non-bovine milks and adventitious microflora

There is a long tradition of artisanal cheesemaking in Portugal. A number of cheese varieties are indeed manufactured locally from raw ewes' or goats' milk (or a mixture of both) at the farmhouse level, which are traded chiefly within their production area. Despite the current dominance of industrial cheeses on the world market obtained from pasteurised cows' milk, farmhouse ewes' and goats' milk cheeses still have an important market niche in that country, and are in increasingly higher demand owing to their organoleptic uniqueness. The most outstanding Appellation d'Origine Protegee (ADP) cheeses are Azeitao, Castel Branco, Evora, Nisa, Serpa and Serra da Estrela, for which the milk is clotted with a plant coagulant without deliberate addition of any starter or non-starter culture. The aforementioned coagulant is a crude aqueous extract from the flowers of Cynara cardunculus (cardoon) - a kind of thistle related to the globe artichoke, which can be found in dry, stony areas in Southern Portugal. Its (aspartic) proteinases possess an unusually wide specificity towards cleavage of peptide bonds; their activity spectra account for an extensive primary proteolysis of caseins to medium- and small-sized peptides. On the other hand, the adventitious microflora entail several lactic acid bacteria, e.g. Leuconostoc lactis and L. mesenteroides ssp. dextranicum, Lactobacillus paracasei ssp. paracasei, Lactococcus lactis ssp. lactis and Enterococcus faecium; their contribution to flavour development throughout ripening is crucial, especially owing to secondary proteolysis followed by amino acid catabolism toward small volatile molecules with a very low odour threshold.