Chemical and Microbiological Characteristics of Ewes' Milk Cheese Manufactured with Extracts from Flowers of Cynara cardunculus and Cynara humilis as Coagulants

Abstract

The chemical and microbial characteristics as well as the flavor and aroma of Los Pedroches cheese made using aqueous extracts of Cynara cardunculus L. flowers were compared with those of cheeses manufactured with extracts of Cynara humilis L. throughout ripening. The two thistle species assayed were found to have no appreciable effect on the moisture, fat, protein, and NaCl contents of the cheese or on its water activity, flavor, and aroma; however, the use of C. humilis resulted in reduced lactic acid content (p < 0.001) and higher pH values (p < 0.05) relative to those of cheese specimens produced with C. cardunculus. The protein breakdown of the cheeses was assessed in terms of soluble nitrogen (SN), nonprotein nitrogen (NPN), and amino acid nitrogen (AAN). Proteolysis was more marked and rapid in cheese containing C. cardunculus as coagulant, the SN and NPN contents of which were significantly higher (p < 0. 01) than those of the cheese obtained with the species C. humilis; AAN contents were similar in both species of Cynara throughout ripening. Although total viable, coliform, and lactobacilli counts were similar in cheeses produced with both types of plant coagulant throughout ripening, enterobacteria and yeasts counts (p < 0.01) and molds counts (p < 0.05) were higher in cheese produced with C. humilis than in cheese obtained with C. cardunculus.

Comparative evaluation of Bacillus licheniformis 5A5 and Aloe variegata milk-clotting enzymes

“…However, the increasing consumption of cheese and the decreasing number of slaughtered calves have led to an increased price of calf rennet and a search for alternative milk coagulants. Those facts have been accompanied by the recent Bovine Spongiform Encephalomyelitis (BSE) disease in dairy cattle (Vioque et al, 2000). This situation encourages the search for other sources of rennet substitutes from microbial or plant sources to meet the needs of the expanding cheese industry.…”

Advances in the role of a plant coagulant (Cynara cardunculus) in vitro and during ripening of cheeses from several milk species

“…In contrast, Fernández-Salguero and Sanjuán [24] showed that residual α s -and β-caseins were more concentrated in cheese produced with animal rennet than in cheese produced using plant coagulant (C. cardunculus), but no statistically significant differences were found between these two types of coagulant. Vioque et al [66] showed that WSN was higher in cheeses manufactured with extracts of C. cardunculus than with C. humilis, but WSN in cheeses with C. humilis was much higher than in Los Pedroches cheese manufactured with chymosin [24]. The electrophoretic patterns of the WISF of both cheeses were claimed to unfold a higher susceptibility of α s -than β-casein to proteolysis [24,36,53].…”

“…Cheeses manufactured with ovine milk using extracts from C. cardunculus as coagulant were compared with cheeses manufactured with commercial animal rennet [24,53], or with extracts of Cynara humilis [66]. Comparing averages and 95% confidence intervals, it has been stated [53] that the type of coagulant has no significant effect upon cheese bulk chemical composition throughout ripening, and that no significant microbiological differences were detected between cheeses manufactured with C. cardunculus or animal rennet.…”

“…Comparing averages and 95% confidence intervals, it has been stated [53] that the type of coagulant has no significant effect upon cheese bulk chemical composition throughout ripening, and that no significant microbiological differences were detected between cheeses manufactured with C. cardunculus or animal rennet. Vioque et al [66] reported that extracts of C. cardunculus or C. humilis have no appreciable effect on bulk composition, but extracts of the latter resulted in higher lactic acid content and higher pH values than in those cheeses produced with C. cardunculus. Those authors reported that microbiological viable counts (total, coliforms and lactobacilli) were similar in cheeses produced with both types of plant coagulant, although enterobacteria, yeasts and moulds were found at higher viable numbers in cheese produced with C. humilis than with C. cardunculus.…”

“…Unstandardised utilisation of this coagulant is claimed to cause poor organoleptic quality and contribute to day-to-day variation of cheeses; however, dried flowers of C. cardunculus have been successfully employed for many centuries in the Iberian Peninsula for the manufacture of traditional semi-hard cheeses, i.e. such traditional cheese varieties as Serra da Estrela [1,30,44,65], La Serena (from ewe's milk) [23,36,42], Guía (from a mixture of ewe's and cow's milk) [25] and Los Pedroches (from ewe's milk) [7,24,66]. A few experiments have also been carried out pertaining to the manufacture of such French cheeses as Camembert and Gruyère [2], and such Italian cheeses as Bel Paese, Grana and Provolone [3].…”