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Rampanti,  G., Belleggia, L., Cardinali, F., Milanović, V., Osimani, A., Garofalo, C., Ferrocino, I., and Aquilanti, L. 2023. Microbial Dynamics of a Specialty Italian Raw Ewe’s Milk Cheese Curdled with Extracts from Spontaneous and Cultivated Onopordum tauricum Willd. 2023. Microorganisms, 11(1), 219. https://doi.org/10.3390/microorganisms11010219 

Abstract: Milk coagulants prepared by maceration of flowers harvested from both spontaneous and cultivated Onopordum tauricum Willd. and a commercially available coagulant obtained from Cynara cardunculus L. (control) were assayed for small-scale manufacturing of Caciofiore, an Italian specialty raw ewe’s milk cheese produced in a family run dairy farm located in the Marche region (Central Italy). The microbiota of the three thistle-based milk coagulants and their effect on the microbial dynamics of raw milk cheeses during fermentation and maturation (from day 0 up until day 60) were investigated through a combined approach based on viable counting and Illumina DNA sequencing. In both the control and experimental cheeses, despite the slight differences emerged depending on the coagulant used, Lactococcus lactis and Debaryomyces hansenii were the prevalent species among bacteria and fungi, respectively. Moreover, raw ewe’s milk was the main factor affecting the evolution of both the bacterial and fungal microbiota in all cheeses. The overall similarities between control and experimental cheeses herein analyzed supports the exploitation of Onopordum tauricum Willd. as an alternative milk coagulating agent for production of Caciofiore and, more in  general, raw ewe’s milk cheeses.

Keywords: Caciofiore cheese; vegetable rennet; thistle rennet; Onopordum tauricum Willd.; microbial

dynamics; Illumina DNA sequencing

Rampanti, G., Ferrocino, I., Harasym, J., Foligni, R., Cardinali, F., Orkusz, A., Milanović, V., Franciosa, I., Garofalo, C., Mannozzi, C., Mozzon, M., Osimani, A., Aquilanti, L. 2023. Queijo Serra da Estrela PDO Cheese: Investigation into Its Morpho-Textural Traits, Microbiota, and Volatilome. Foods, 12(1), 169. https://doi.org/10.3390/foods12010169 

Abstract: Queijo Serra da Estrela is a PDO Portuguese cheese produced through coagulation of raw ewe’s milk using cardoon (Cynara cardunculus L.) flowers. The present research was aimed at depicting an up-to-date and comprehensive overview of the microbiota of Queijo Serra da Estrela cheese. To this end, viable counting and metataxonomic analysis were carried out on cheeses sampled from four Portuguese artisan producers. Physico-chemical and morpho-textural analyses were also performed, together with the analysis of volatile organic compounds (VOCs). Finally, non-starter lactic acid bacteria (NSLAB) isolated from the cheeses were characterized for their enzymatic activities using a semi-quantitative method. According to the metataxonomic analysis, Lactococcus lactis and Lactococcus piscium were the species occurring at the highest relative abundance. The isolates collected from the cheeses were assigned to Enterococcus durans, Enterococcus faecalis, Enterococcus faecium, Enterococcus lactis, Levilactobacillus brevis, Latilactobacillus graminis, Leuconostoc mesenteroides, and the Lacticaseibacillus casei group. The enzymatic characterization of these cultures highlighted esterase, aminopeptidase, acid phosphatase, beta-galactosidase, alpha-glucosidase, and beta-glucosidase among the major enzymatic activities. Fungal populations were dominated by Debaryomyces hansenii and Kurtzmaniella zeylanoides; however, species rarely found in cheese (e.g., Candida boidinii, Vishniacozyma victoriae, and Starmerella) were also detected. The volatile compounds characterizing the analyzed cheeses were carboxylic acids and esters, followed by carbonyl compounds and alcohols.

Keywords: lactic acid bacteria; metataxonomic analysis; enzymatic activity; Lactococcus lactis;

Portuguese cheese

Foligni, R., Mannozzi, C., Gasparrini, M., Raffaelli, N., Zamporlini, F., Tejada, L., Bande-De León, C., Orsini, R., Manzi, P., Di Costanzo, M.G., Ritota, M., Aquilanti, L., Mozzon, M. 2022. Potentialities of aqueous extract from cultivated Onopordum tauricum (Willd.) as milk clotting agent for cheesemaking. Food Research International, 158, 111592. https://doi.org/10.1016/j.foodres.2022.111592

Abstract: In Western and Central Mediterranean countries proteases from wild herbaceous perennial plants commonly known as “thistles” have been used as milk coagulants in cheese-making for centuries. For the first time, the technological and biochemical traits of proteases from cultivated Onopordum tauricum Willd. (Taurian thistle, bull cottonthistle) were assessed. The optimal conditions for minimizing the clotting time and the non-specific proteolytic activity were estimated at the highest (T = 43–45 ◦C; [Ca2+] = 11–13 mM) and the lowest (T = 35–39 ◦C; [Ca2+] = 5 mM) temperature and calcium ion levels in the explored range respectively, thus highlighting the difficulty to set the best operative compromise in the first step of cheesemaking. In the conditions adopted in common cheesemaking practice (T = 37 ◦C; pH = 6.5) 1 mL of reconstituted extract from cultivated thistles coagulated 10 mL of ewe’s and goat’s milk in 114–146 and 129–167 s, respectively, and 1 mL of reconstituted extract from spontaneous thistles coagulated 10 mL of ewe’s and goat’s milk in 232–294 and 428–621 s, respectively, while no significant differences in the non-specific proteolytic activity between cultivated and spontaneous O. tauricum extracts were observed. The purified enzyme (tauricosin) was identified as an aspartic protease made up of two sub-units with molecular weights of 32 and 9.6 kDa, respectively. Experimental data encouraged the exploitation of O. tauricum as a new and sustainable non-food crop in marginal and rainfed lands of Mediterranean countries, thus reducing the potential biodiversity losses due to wild collection.
Keywords: Vegetable coagulant; Milk clotting; Aqueous extract; Clotting activity; Protease; Onopordum tauricum; Taurian thistle