Characterization of Cynara cardunculus L. flower from Alentejo as a coagulant agent for cheesemaking

Clotting and Proteolytic Activity of Freeze-Dried Crude Extracts Obtained from Wild Thistles Cynara humilis L. and Onopordum platylepis Murb

The rising interest in finding alternatives to animal rennet in cheese production has led to studying the technological feasibility of using and exploiting new species of herbaceous plants. In this research work, and for the first time, freeze-dried extracts from Cynara humilis L. (CH) and Onopordum platylepis Murb. (OP) were studied for mineral and protein content, and their clotting and proteolytic activity were compared to those of Cynara cardunculus L. (CC). The effect of extract concentration (5-40 mg extract/mL), temperature (20-85 °C), pH (5-8), and CaCl₂ concentration (5-70 mM) on the milk clotting activity (MCA) of CC, CH and OP extracts was evaluated. The MCA values were significantly higher in CC at the same extract concentration. The extract that showed the most significant increase in clotting activity due to increased temperature was OP, with maximum activity at 70 °C. The pH value for maximum milk clotting was 5.0 for both CC and CH, whereas, in the case of OP, the pH value was 5.5. CaCl₂ enhanced the clotting capacity of the extracts, particularly for OP and CH. Furthermore, proteolytic activity (PA) and the hydrolysis rate increased with increasing time and enzyme concentration, with CC being the extract that achieved the highest caseinolytic activity.

The wide spectrum of industrial applications for cultivated cardoon (Cynara cardunculus L. var. Altilis DC.): A review

Cynara cardunculus L. var. altilis DC. belongs to the Asteraceae family and is widely used. This species is integrated into the Mediterranean diet and has broad applicability due to its rich chemical composition. Its flowers, used as a vegetable coagulant for gourmet cheese production, are rich in aspartic proteases. Leaves are rich in sesquiterpene lactones, the most abundant being cynaropicrin, while stems present a higher abundance of hydroxycinnamic acids. Both classes of compounds exhibit a wide range of bioactive properties. Its chemical composition makes it applicable in other industrial sectors, such as energy (e.g., manufacturing of biodiesel and biofuel) or paper pulp production, among other biotechnological applications. In the last decade, cardoon has been identified as a competitive energy crop, constituting an opportunity for the economic recovery and development of the rural areas of the Mediterranean basin. This article reviews the chemical composition, bioactive properties, and multifaceted industrial applications of cardoon.

Bioactive Compounds from Cardoon as Health Promoters in Metabolic Disorders

Cardoon (Cynara cardunculus L.) is a Mediterranean plant and member of the Asteraceae family that includes three botanical taxa, the wild perennial cardoon (C. cardunculus L. var. sylvestris (Lamk) Fiori), globe artichoke (C. cardunculus L. var. scolymus L. Fiori), and domesticated cardoon (C. cardunculus L. var. altilis DC.). Cardoon has been widely used in the Mediterranean diet and folk medicine since ancient times. Today, cardoon is recognized as a plant with great industrial potential and is considered as a functional food, with important nutritional value, being an interesting source of bioactive compounds, such as phenolics, minerals, inulin, fiber, and sesquiterpene lactones. These bioactive compounds have been vastly described in the literature, exhibiting a wide range of beneficial effects, such as antimicrobial, anti-inflammatory, anticancer, antioxidant, lipid-lowering, cytotoxic, antidiabetic, antihemorrhoidal, cardiotonic, and choleretic activity. In this review, an overview of the cardoon nutritional and phytochemical composition, as well as its biological potential, is provided, highlighting the main therapeutic effects of the different parts of the cardoon plant on metabolic disorders, specifically associated with hepatoprotective, hypolipidemic, and antidiabetic activity.

Impact of environmental conditions on the ripening of Queijo de Évora PDO cheese

"Queijo de Évora" is a traditional Portuguese cheese from raw ewe's milk and granted with PDO label. It is ripened traditionally in rooms with empirical control of temperature and humidity. Nowadays, almost all cheese factories use rooms with temperature and humidity control, but still a significant heterogeneity among cheeses is acknowledged due to unequal distribution of environmental conditions. This paper discusses the influence of the environmental conditions on the ripening of Queijo de Évora, including the application of computational fluid dynamics in steady state conditions. Experimental data was obtained in cheeses ripened along the traditional ripening cycle, in different locations. A significant influence of environmental conditions was observed, especially air velocity and humidity, affecting physical-chemical, microbiological and sensory characteristics. Locations with higher air velocity, presented cheeses with lower moisture content, higher mesophilic bacteria count, darker appearance and higher number of holes. Locations with higher humidity presented cheeses with lower scores on some sensorial parameters like appearance, firmness and intensity of odor. The results of computational fluid dynamics made possible the identification of areas in and around the cheese stacks were the air distribution is less than adequate or uneven, which may influence the evolution of cheese during ripening.

Evaluation of gas holes in "Queijo de Nisa" PDO cheese using computer vision

"Queijo de Nisa" is a traditional Portuguese cheese, granted with PDO label, produced with raw ewe's milk in which the aqueous extract of cardoon flower Cynara cardunculus L. is the only coagulant allowed. As in similar cheeses with no use of starter cultures or pasteurisation, the quality and food safety are depending on prevention, high hygienic standards and a proper manufacturing process. This study investigated the use of computer vision as novel method for the evaluation of gas holes in Queijo de Nisa in three different ripening dates (0, 15 and 35 days). A total of 48 samples were produced using cardoon flower from three different origins (C1, C2 and C3) and a commercial vegetable coagulant (C4). The results presented a high correlation between image-dependent attributes and physical-chemical properties during ripening time, especially within the first 15 days of ripening time, where major structural changes were observed inside the Queijo de Nisa cheese. Principal component analysis presented a strong correlation (p < 0.05) between image parameters and the physical-chemical evolution until 15 days. From 15 to 35 days, the evolution of cheeses was mainly depending on structural parameters, like G'_1 Hz and hardness. No influence was observed due to the geographical origin of cardoon flower.

A New Insight on Cardoon: Exploring New Uses besides Cheese Making with a View to Zero Waste

Cardoon, Cynara cardunculus L., is a perennial plant whose flowers are used as vegetal rennet in cheese making. Cardoon is native from the Mediterranean area and is commonly used in the preparation of salads and soup dishes. Nowadays, cardoon is also being exploited for the production of energy, generating large amount of wastes, mainly leaves. These wastes are rich in bioactive compounds with important health benefits. The aim of this review is to highlight the main properties of cardoon leaves according to the current research and to explore its potential uses in different sectors, namely the food industry. Cardoon leaves are recognized to have potential health benefits. In fact, some studies indicated that cardoon leaves could have diuretic, hepato-protective, choleretic, hypocholesterolemic, anti-carcinogenic, and antibacterial properties. Most of these properties are due to excellent polyphenol profiles, with interesting antioxidant and antimicrobial activities. These findings indicate that cardoon leaves can have new potential uses in different sectors, such as cosmetics and the food industry; in particular, they can be used for the preparation of extracts to incorporate into active food packaging. In the future, these new uses of cardoon leaves will allow for zero waste of this crop.

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.

Plant Aspartic Proteases for Industrial Applications: Thistle Get Better

Plant proteases have a number of applications in industrial processes including cheese manufacturing. The flower of the cardoon plant (Cynara cardunculus L.) is traditionally used as a milk-clotting agent in protected designation of origin cheeses made from goat and sheep milk. Plant-derived rennets are of particular importance to consumers who wish to eat cheeses that are produced without harming any animals. In this review, we have highlighted the importance of plant proteases, particularly aspartic proteases, in industrial processes, as well as exploring more fundamental aspects of their synthesis. We have also reviewed and discussed the production of these enzymes using sustainable and cost-effective alternative platforms.