Influence of Cardoon Flower (Cynara cardunculus L.) and Flock Lactation Stage in PDO Serra da Estrela Cheese.

Serra da Estrela (SE) cheese is one of the most appreciated Portuguese cheeses, being produced only from raw ewe's milk, cardoon flower and salt. Cardoon takes part in two important processes in cheese production-coagulation and proteolysis-contributing to its unique features. Furthermore, milk chemical characteristics change during the milking season, being another factor that account for the high variability of cheese attributes. Therefore, the purpose of this work is to study the influence of cardoon flower (commercial, 6 M and 3 M) and flock lactation stage (November 2018, February and April 2019) in the final characteristics of SE cheese. The parameters analysed were moisture, protein, fat and salt contents, texture and colour. Results showed that flock lactation stage has the highest influence in all the studied characteristics, corresponding the early stages of lactation to the most protein-rich and low-fat cheeses. Cardoon flower affects mainly fat and rind colour. This study allows us to conclude that seasonal changes in ewe's milk have a considerable impact in cheese attributes, and that although cardoon type had a more restrained effect, when used with expertise it may help adjust cheese sensory characteristics in order to obtain a final product that matches consumer acceptability requirements.

Chemical composition and in vitro biological activities of cardoon (Cynara cardunculus L. var. altilis DC.) seeds as influenced by viability.

Cardoon is a multi-purpose crop for several industries. In this study, cardoon seeds were separated according to the viability and characterized for their chemical composition and bioactivities. Viable seeds contained higher levels of α-tocopherol (6.7 mg/100 g), lipids (23.11 g/100 g, manly oleic and linoleic acids), and free sugars (5.4 g/100 g) than the unviable ones. The hydroethanolic extract of viable seeds presented a higher concentration of phenolic compounds, namely 5-O-caffeoylquinic (8.0 mg/g) and 3,5-O-dicaffeoylquinic (43.9 mg/g) acids, and greater in vitro antioxidant activity. Both extracts showed antibacterial properties, but the best results were achieved with unviable seeds. The extracts had similar antifungal activity but did not reveal anti-inflammatory capacity or cytotoxicity to the tested cell lines. Therefore, while viable seeds contained antioxidant phytochemicals and an energy and carbon source for germination, unavailable seeds stood out for their potential to be used in the development of bio-based antibacterial ingredients.

Cardoon as a Sustainable Crop for Biomass and Bioactive Compounds Production.

Cardoon is a multi-purpose and versatile Mediterranean crop, adapted to climate change, with a wide spectrum of potential applications due its added value as a rich source of fibers, oils and bioactive compounds. The Cynara species are a component of the Mediterranean diet and have been used as food and medicine since ancient times. The important role of cardoon in human nutrition, as a functional food, is due to its high content of nutraceutical and bioactive compounds such as oligofructose inulin, caffeoylquinic acids, flavonoids, anthocyanins, sesquiterpenes lactones, triterpenes, fatty acids and aspartic proteases. The present review highlights the characteristics and functions of cardoon biomass which permits the development of innovative products in food and nutrition, pharmaceutics and cosmetics, plant protection and biocides, oils and energy, lignocellulose materials, and healthcare industries following the actual trends of a circular economy.

Phenolic profile and bioactivity of cardoon (Cynara cardunculus L.) inflorescence parts: Selecting the best genotype for food applications.

This study was designed to characterize the phenolic profile and bioactivity of hydroalcoholic extracts from different cardoon (Cynara cardunculus L.) genotypes. The analytical work focussed on the inflorescence stigmas, owing to their application in cheese production. Nevertheless, other parts were concomitantly analysed aiming to define their possible use in related applications. Phenolic profiles obtained by LC-DAD-ESI/MSn showed significant differences among different cardoon genotypes, but apigenin and caffeoylquinic acid derivatives were generally the major molecules in all samples. Genotype influence has also been observed in relation to the antioxidant and antibacterial activities. Besides their strong antioxidant activity, the cardoon inflorescences showed satisfactory antibacterial activity, namely against Gram-positive strains, with particularly low MIC in Listeria monocytogenes. Overall, it was possible to identify the cardoon genotype (within the selected ones) providing the best standardized ingredient (stigma) with considerable added-value to be included in the process of cheese making.

Selected Cardoon (Cynara cardunculus L.) Genotypes Suitable for PDO Cheeses in Mediterranean Regions.

Cardoon flower extract is a traditional and exclusive rennet used for some PDO cheeses in several Mediterranean regions, due to its extremely high concentration in cardosins. In this preliminary study, six individual cardoon genotypes (1M - 6M) were selected because they revealed a wide and consistent diversity of total and specific cardosin concentrations in flowers. During three growing seasons, the stability of 12 biochemical characteristics of flower extracts and 26 plant morphological descriptors was confirmed. Surprisingly, the cardosin profiles of each genotype, based on four main groups A0, A1, A and B, were stable during the annual flower harvesting period and over all three years using ion-exchange chromatography and native-PAGE electrophoresis. This knowledge will allow an improvement in the quality and standardization of cardosin profiles from cardoon flowers used for cheese production and other innovative applications. The results obtained are promising for the development of a plant breeding program based on biochemical and morphological characteristics in order to obtain the most adapted plant architecture for combined purposes related to specific cardosins composition, flower and plant biomass production, and ease of harvesting.