Aspartic Proteinases (Cyprosins) from Cynara Cardunculus Spp. Flavescens Cv. Cardoon; Purification, Characterisation, and Tissue-Specific Expression

Abstract

Flowers of C cardunculus (cardoon) have been used in Portugal since many centuries to make cheese with raw ewe or/and goat milk. Several types of cheeses are well known and highly appreciated for their taste and quality. Examples are Serra, Serpa and Azeitão. The skills of making these artisanal cheeses have been inherited over generations within the same families and are still used today. Farmers collect the mature flowers or upper part of styles during June and July and store them in dry places to be used for clotting of milk during the next seasons, autumn and winter. Traditionally the cheeses are made mainly with fresh ewe’s milk. The proteinases are extracted from flowers with lukewarm water. This extract is filtered through a cloth which contains a spoon of salt. The milk (2–4 1 per cheese) is also passed through the cloth and then left for coagulation during 30–45 minutes. The whey is removed by collecting the curd in another piece of cloth, and afterwards it is brought into shape with a mold. The ripening period is around 6 weeks at 12°C (room temperature in some regions during winter) in a humid and aerated environment.