An Evaluation of the Clotting Properties of Three Plant Rennets in the Milks of Different Animal Species

Effects of animal rennet, fermentation-produced chymosin, and microbial coagulants on bovine milk coagulation properties

Coagulants play a crucial role in cheese production by catalyzing milk curdling, with traditional animal rennet long serving as the primary choice. However, due to cost, availability, and ethical concerns, various substitutes such as microbial coagulants and fermentation-produced chymosin (FPC) have emerged. This study aimed to evaluate the effects of 8 commercial coagulants, including 1 bovine rennet, 2 bovine FPC, 1 camel FPC, 3 microbial (i.e., Rhizomucor miehei) coagulants, and 1 bovine FPC variant, on the coagulation properties of bovine milk. The coagulants were tested at 3 different doses (35, 50, and 65 international milk clotting units per liter) across 8 batches of unhomogenized, pasteurized, full-fat, bovine milk purchased from different commercial brands, in 2 replicates, for a total of 384 coagulation analyses (8 milk batches × 8 coagulants × 3 doses × 2 replicates). Specifically, traditional milk coagulation properties and curd firmness at given times were assessed using a lactodynamograph. Key findings indicated significant variations in coagulation patterns across the coagulants. Bovine rennet demonstrated an intermediate coagulation profile among all FPC and microbial coagulants. The bovine and camel FPC exhibited faster coagulation than the bovine animal rennet, with the camel FPC showing the quickest coagulation and curd-firming rates. The microbial coagulants, although exhibiting slower coagulation rates for a given dose, produced curd-firming dynamics different from those of all FPC. The bovine FPC variant exhibited high performance comparable to that of the camel FPC in the coagulation process. Overall, this study highlights the distinct coagulation characteristics of various coagulants, offering insights into their suitability for different cheese-making applications. The coagulant dose significantly affected the coagulation pattern, with a clear linear increase in dose influencing gelation and varying effects on other coagulation traits. These findings can guide producers in selecting the optimal coagulant and dose based on specific cheese production needs.

Goat Cheese Produced with Sunflower (Helianthus annuus L.) Seed Extract and a Native Culture of Limosilactobacillus mucosae: Characterization and Probiotic Survival

The microbiological and biochemical properties of a goat cheese produced using Helianthus annuus (sunflower) seed extract as a coagulant and the potentially probiotic autochthonous culture Limosilactobacillus mucosae CNPC007 were examined in comparison to a control cheese devoid of the autochthonous culture. Throughout a 60-day storage period at 6 ± 1 °C, lactobacilli maintained a count of above 8 log CFU/g. Additionally, its viability in cheeses subjected to the in vitro gastrointestinal conditions demonstrated improvement over this period. Specifically, the recovery of lactobacilli above 6 log CFU/g was observed in 16.66% of the samples in the first day, increasing to 66.66% at both 30 and 60 days. While total coliforms were detected in both cheese trials, this sanitary parameter exhibited a decline in L. mucosae cheeses during storage, falling below the method threshold (<3 MPN/g) at 60 days. This observation suggests a potential biopreservative effect exerted by this microorganism, likely attributed to the higher acidity of L. mucosae cheeses at that point (1.80 g/100 g), which was twice that of the control trial (0.97 g/100 g). Furthermore, distinct relative proportions of >30 kDa, 30-20 kDa, and <20 kDa proteins during storage was verified for L. mucosae and control cheeses. Consequently, either the H. annuus seed extract or the L. mucosae CNPC007 autochthonous culture influenced the biochemical properties of the cheese, particularly in terms of proteolysis. Moreover, L. mucosae CNPC007 acidification property resulted in a biopreservative effect throughout the storage period, indicating the potential as a promising source of probiotics for this product.

Plant and Arthropod IgE-Binding Papain-like Cysteine Proteases: Multiple Contributions to Allergenicity

Papain-like cysteine proteases are widespread and can be detected in all domains of life. They share structural and enzymatic properties with the group's namesake member, papain. They show a broad range of protein substrates and are involved in several biological processes. These proteases are widely exploited for food, pharmaceutical, chemical and cosmetic biotechnological applications. However, some of them are known to cause allergic reactions. In this context, the objective of this review is to report an overview of some general properties of papain-like cysteine proteases and to highlight their contributions to allergy reactions observed in humans. For instance, the literature shows that their proteolytic activity can cause an increase in tissue permeability, which favours the crossing of allergens through the skin, intestinal and respiratory barriers. The observation that allergy to PLCPs is mostly detected for inhaled proteins is in line with the reports describing mite homologs, such as Der p 1 and Der f 1, as major allergens showing a frequent correlation between sensitisation and clinical allergic reactions. In contrast, the plant food homologs are often digested in the gastrointestinal tract. Therefore, they only rarely can cause allergic reactions in humans. Accordingly, they are reported mainly as a cause of occupational diseases.

Therapeutic potential of popular fermented dairy products and its benefits on human health

In the current arena of time, the transformation of society has improved the standard of living in terms of lifestyle and their nutritional demands and requirements. The microorganisms under controlled conditions and the enzymatic transformation of dietary components are the processes that resulted in fermented foods and beverages. Fermented dairy products with high nutritional value are "the pearls of the dairy industry." During fermentation, fermented dairy products produce bioactive compounds and metabolites derived from bacteria. Research indicates the beneficial effects of probiotics found in dairy products on human health is making lightning-fast headway these days. The utilization of lactic acid bacteria as probiotics for the prevention or treatment of disease has been a driving force behind the discovery of novel potential probiotics found in naturally fermented milk. Probiotics such as lactic acid bacteria and bifidobacteria found in fermented dairy products have a variety of health benefits, including innate immune enhancement, diarrhea treatment, inflammatory bowel disease, diabetes, Tuberculosis, and obesity, relieving irritable bowel disease symptoms, preventing cancer, improving lactose tolerance, lowering cholesterol, enhancing antioxidant activity, and antimicrobial activity against pathogens. This review aims to evaluate the therapeutic efficacy and nutritional and microbiological properties of popular fermented dairy products and their health benefits.

Future Perspective and Technological Innovation in Cheese Making Using Artichoke (Cynara scolymus) as Vegetable Rennet: A Review

Milk coagulation is a process used for the formulation of different dairy products such as cheese. In this process, milk undergoes changes in its chemical stability thanks to acidification or enzymatic reactions. Traditionally, milk coagulation has been carried out with rennet of animal origin, but recently, the research of new types of rennet such as microbial rennet and vegetable rennet has increased. This study aims to present an organized review of the most relevant information on lactic coagulation, its relationship with vegetable rennets, and the importance of the botanical genus Cynara in the extraction of vegetable rennets, focusing on the coagulant potential of artichoke (Cynara scolymus). We conducted this literature review and found that lactic coagulation and vegetable rennets are linked through the enzymatic activity of the latter. The results of the main studies demonstrated a strong relationship between vegetable rennets and protease enzymes as well as the presence of these enzymes in extracts of cardoon (Cynara scolymus) and artichoke (Cynara scolymus). In addition, studies highlight the presence of thistle extracts in artisanal cheese preparations in the Iberian Peninsula. Based on the results of the studies, a comparison between cheeses made with vegetable rennet and those made with traditional rennet was also carried out. Although the results show that the use of vegetable rennet in the manufacture of cheese can confer undesirable characteristics, the use of extracts from Cynara plants demonstrates that vegetable rennets have an industrial potential, especially the one obtained from artichoke (Cynara scolymus) due to its high availability. Nevertheless, specific studies are required for a better understanding and application of this rennet.

Milk clotting enzymes from marine resources and their role in cheese-making: A mini review

With the continual increase in global cheese consumption, rennet, the traditional milk coagulant, is unable to meet the growing demand in cheese production. Although several proteases from other sources have been used for cheese-making, they suffer various shortcomings. The ocean is home to a huge and diverse range of life forms, which represent a vast potential source of proteases. Marine proteases have been isolated from a number of marine species, including sponge, jellyfish, seaweed and marine animals, and some have been shown to be suitable as milk-clotting enzymes for cheese making. This review summarizes the latest studies on rennet substitutes from marine resources and their role in cheese-making. The emphasis of the review is on the isolation and purification of the marine proteases, the biochemical characteristics of these enzymes, especially their caseinolytic and milk-clotting properties, as well as their cleavage sites on casein. Some of the marine proteases have been applied as milk-clotting agent in cheese-making, with the resultant production of cheese with comparable characteristics, including sensory characteristics, to calf rennet cheese. The review concludes by highlighting the challenges and opportunities for future research in the field.

Application of Plant Proteases in Meat Tenderization: Recent Trends and Future Prospects

Papain, bromelain, and ficin are commonly used plant proteases used for meat tenderization. Other plant proteases explored for meat tenderization are actinidin, zingibain, and cucumin. The application of plant crude extracts or powders containing higher levels of compounds exerting tenderizing effects is also gaining popularity due to lower cost, improved sensory attributes of meat, and the presence of bioactive compounds exerting additional benefits in addition to tenderization, such as antioxidants and antimicrobial effects. The uncontrolled plant protease action could cause excessive tenderization (mushy texture) and poor quality due to an indiscriminate breakdown of proteins. The higher cost of separation and the purification of enzymes, unstable structure, and poor stability of these enzymes due to autolysis are some major challenges faced by the food industry. The meat industry is targeting the recycling of enzymes and improving their stability and shelf-life by immobilization, encapsulation, protein engineering, medium engineering, and stabilization during tenderization. The present review critically analyzed recent trends and the prospects of the application of plant proteases in meat tenderization.

Oilseed Extracts from Local Markets as Promising Coagulant Agents for Milk from Various Mammalian Species

The aim of this study was to identify novel milk coagulants to be used in cheesemaking. For this purpose, aqueous extracts from safflower (Carthamus tinctorius), sunflower (Helianthus annuus), flax (Linum usitatissimum) and sesame (Sesamum indicum) seeds were tested for their caseinolytic (CA) and milk coagulating properties (MCA) in skim milk at temperatures of 25, 37, 50, 65 and 80 °C. The seed oil samples with the highest temperature ranges in regard to coagulation efficiency were then tested in cow, buffalo, goat and sheep milks and the MCA and curd yield (CY) parameters were measured at different temperatures. Due to their high milk coagulation efficiency (CE) in all types of milk and at different temperatures, the sesame and sunflower seed extracts proved to be particularly interesting and their CY parameters were similar to those obtained with animal rennet. Moreover, our results confirm that oilseed coagulants are capable of coagulating milk and can also be considered as potential animal rennet substitutes. This study provides valuable insights into the development of potential vegetable coagulants that could be used for various production processes aimed at specific target consumers.

Composition and aptitude for cheese-making of milk from cows, buffaloes, goats, sheep, dromedary camels, and donkeys

Bovines account for about 83% of the milk and dairy products consumed by humans worldwide, the rest represented by bubaline, caprine, ovine, camelid, and equine species, which are particularly important in areas of extensive pastoralism. Although milk is increasingly used for cheese production, the cheese-making efficiency of milk from the different species is not well known. This study compares the cheese-making ability of milk sampled from lactating females of the 6 dairy species in terms of milk composition, coagulation properties (using lactodynamography), curd-firming modeling, nutrients recovered in the curd, and cheese yield (through laboratory model-cheese production). Equine (donkey) milk had the lowest fat and protein content and did not coagulate after rennet addition. Buffalo and ewe milk yielded more fresh cheese (25.5 and 22.9%, respectively) than cow, goat, and dromedary milk (15.4, 11.9, and 13.8%, respectively). This was due to the greater fat and protein contents of the former species with respect to the latter, but also to the greater recovery of fat in the curd of bubaline (88.2%) than in the curd of camelid milk (55.0%) and consequent differences in the recoveries of milk total solids and energy in the curd; protein recovery, however, was much more similar across species (from 74.7% in dromedaries to 83.7% in bovine milk). Compared with bovine milk, the milk from the other Artiodactyla species coagulated more rapidly, reached curd firmness more quickly (especially ovine milk), had a more pronounced syneresis (especially caprine milk), had a greater potential asymptotical curd firmness (except dromedary and goat milk), and reached earlier maximum curd firmness (especially caprine and ovine milk). The maximum measured curd firmness was greater for bubaline and ovine milk, intermediate for bovine and caprine milk, and lower for camelid milk. The milk of all ruminant species can be used to make cheese, but, to improve efficiency, cheese-making procedures need to be optimized to take into account the large differences in their coagulation, curd-firming, and syneresis properties.

Milk-clotting and hydrolytic activities of an aspartic protease from Salpichroa origanifolia fruits on individual caseins

In recent years, many attempts have been made to find new plant proteases to make artisan cheeses. The global increase in cheese consumption, together with a lower supply and increasing cost of calf rennet, religious factors (Islam and Judaism) and food choices (vegetarianism) have led to the search for suitable rennet substitutes for milk clotting. This study describes the milk-clotting and hydrolytic activities of an aspartic protease from Salpichroa origanifolia fruits (SoAP) on individual caseins to explore its potential use as an alternative to animal rennet. The milk-clotting index obtained for SoAP was 8.4 times lower than that obtained for chymosin. SoAP showed a higher degree of hydrolysis on α-casein than on the other fractions under the proposed conditions. RP-HPLC, mass spectrometry analyses and sequencing of the hydrolysates allowed identifying five peptides from α-casein, one peptide from β-casein, and three peptides from k-casein. In silico analysis showed that the peptides identified may display a wide variety of potential biological activities. These results demonstrate the possibility of using SoAP for the manufacture of new types or artisan cheeses, with the simultaneous added value of the potential health-promoting benefits of the bioactive peptides generated during the hydrolysis.

Development of polymer-based multifunctional composite particles of protease and peroxidase activities

A hybrid material (SL-PPN-HEP-HRP) of dual enzyme function was prepared by co-immobilization of papain (PPN) and horseradish peroxidase (HRP) on sulphate latex (SL) microspheres using heparin (HEP) polyelectrolyte as a building block in the sequential adsorption method. The doses of PPN, HEP and HRP were optimized in each step of the preparation process to achieve high functional and colloidal stability. The enzymes and the polyelectrolyte strongly adsorbed on the oppositely charged surfaces via electrostatic forces, and enzyme leakage was not observed from the hybrid material, as confirmed by colorimetric protein tests and microscopy measurements. It was found that the polyelectrolyte acted as a separator between PPN and HRP to prevent hydrolytic attack on the latter enzyme, which otherwise prevents the joint use of these important biocatalysts. Excellent colloidal stability was obtained for the SL-PPN-HEP-HRP composite and the embedded PPN and HRP showed remarkable protease and peroxidase activities, respectively, at least until five days after preparation. The present results offer a promising approach to develop biocatalytic systems of dual function, which are often required in manufacturing processes in the food industry, where the colloidal stability of such multifunctional materials is a key parameter to achieve remarkable efficiency.

Clotting Properties of Onopordum tauricum (Willd.) Aqueous Extract in Milk of Different Species

Plant proteases used in cheesemaking are easily available and could increase the acceptability of cheeses, otherwise hindered by ethical issues (e.g., religions, dietary habits, aversion to genetically engineered food and food ingredients). The milk clotting potential of Onopordum tauricum (Willd.) aqueous extract as an alternative to animal rennet was assessed for the first time in milk of different species (ewe, goat, cow). Among the aerial anatomical parts, i.e., receptacle, leaves, stems, and flowers, only the latter ones showed clotting properties. A response surface methodology (RSM) was used to explore the effects of three independent variables (temperature, pH, volume of coagulant) on the milk clotting activity (MCA) of the flower extract. A second-order polynomial model adequately described the experimental data and predicted a temperature value of 55 °C, a pH value of 4.9–5.7, and a volume of coagulant of 300–500 μL (added to 5 mL of milk) as optimal conditions to maximize the MCA. At a 35 °C temperature and natural milk pH of 6.7–6.8, the estimated MCA of the O. tauricum extract was 72–87, 69–86, and 75–151, in goat’s, ewe’s, and cow’s milk, respectively. In comparison, the MCA of calf rennet was 5.4–4.9, 3.3–14.7, and 4.9–16.7 times higher than that of the plant extract in goat’s, ewe’s, and cow’s milk, respectively.

Effects of animal versus vegetal rennet on milk coagulation traits in Mediterranean buffalo bulk milk

Given consumer interest in Mozzarella di latte di Bufala and other cheeses, and the growing interest of the cheese industry in offering products adequate for lactovegetarian consumers, this study aimed to compare clotting capacity of vegetal and animal rennet in buffalo milk. Milk coagulation properties of 1,261 buffalo bulk milk samples collected during milk quality testing were assessed by lactodynamography using commercial animal (75% chymosin and 25% bovine pepsin) and vegetal (Cynara cardunculus) rennets. Chemical composition of milk samples was predicted by MilkoScan (Foss Analytics, Hillerød, Denmark) calibrated with specific buffalo standards. Rennet effect (animal versus vegetal) was statistically analyzed with a paired t-test. Fat, protein, and lactose contents of milk samples were 7.94%, 4.52%, and 4.80%, respectively. A similar variability of milk coagulation properties was observed with both rennets, with the exception of greater variability of curd firmness at 30 min after the addition of vegetal rennet compared with animal rennet (73 and 26%, respectively). On average, when using plant rennet, milk started to coagulate and reached the 20-mm coagulum 12 ± 0.22 min and 1.9 ± 0.20 min, respectively, later than with animal rennet. Thirty minutes after rennet addition, curds were almost twice as firm in animal as in vegetal rennet (difference of 23.92 ± 0.66 mm). However, curd firmness at 60 min was only 1.21 ± 0.39 mm thicker with vegetal than with animal rennet. Moreover, when using animal rennet, 99.52% of samples started coagulating within the first 30 min of analysis, whereas only 70.42% did so when using vegetal rennet. We conclude that vegetal rennet has the capacity to coagulate buffalo milk, achieving a similar curd firmness to that of animal rennet at 60 min. Further studies are needed to evaluate the sensory characteristics and consumer acceptability of Mozzarella di latte di Bufala processed with vegetal rennet.