Role of indigenous enzymes in proteolysis of casein in caprine milk

Terpenoids as Human Neutrophil Elastase (HNE) Inhibitors: A Comprehensive Review of Natural Anti-inflammatory Isoprenoids

Human neutrophil elastase (HNE) is an enzyme that plays a key role in the body's inflammatory response. It has been linked to several diseases such as chronic obstructive pulmonary disease (COPD), emphysema, and cystic fibrosis. As potential treatments for these diseases, HNE inhibitors are of great interest. Metabolites derived from plants, particularly terpenoids such as β-caryophyllene found in black pepper and other plants, and geraniol present in several essential oils, are recognized as significant sources of inhibitors for HNE. Because of their ability to inhibit HNE, terpenoids are considered promising candidates for developing novel therapies to treat inflammatory conditions such as COPD and emphysema. Furthermore, nature can serve as an excellent designer, and it may offer a safer drug candidate for inhibiting HNE production and activity in the future. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses were searched to get relevant and up-to-date literature on terpenoids as human neutrophil elastase inhibitors. This review focuses on the isolation, chemical diversity, and inhibition of human neutrophil elastase (HNE) of various terpenoids reported from natural sources up to 2022. A total of 251 compounds from various terpenoids classes have been reported. Further, it also provides a summary of HNE inhibitors and includes a thorough discussion on the structure-activity relationship.

The Effect of Alpha s1 Genotype on Some Physiological and Chemical Milk Characteristics in Garganica Goat

In the present study individual milk samples were collected from 80 Garganica goats and the population was genotyped for CSN1S1. Seven different alleles were observed with the A allele found as predominant, followed by the F and B allele, and 14 different genotypes were observed. A proteomic approach was used to classify the individual milk on the basis of protein abundance: four levels of αs1-casein (CN) expression were identified as high (HAS-1), intermediate (IAS-1), low (LAS-1), and null (NAS-1). The present paper aimed to investigate the influence of the level of expression of αs1-casein fraction in milk on proteolytic activities, chemical composition, and renneting properties of individual Garganica goat milk. Results from the present study evidenced that the level of expression of αs1-casein fraction in Garganica goat milk affected chemical composition, curd firmness, and indigenous proteolytic enzymes. In particular, fat, protein, and casein content were higher in HAS-1 and IAS-1 compared to LAS-1 and NAS-1. The SCC decreased passing from the HAS-1 to the NAS-1 and the curd firmness displayed the highest value in HAS-1. The activity of plasmin (PL) was higher in HAS-1 and IAS-1 groups compared to the LAS-1 and NAS-1; whereas, PL plasminogen-derived (PG) activity was the highest in NAS-1 group. On the contrary, the activity of elastase was the highest in LAS-1, intermediate in the IAS-1 group, and the lowest in HAS-1 and NAS-1 groups. Present data demonstrated that the level of synthesis of αs1-CN reflects the efficiency of the mammary gland in the activation of the cellular mechanisms and influences the proteolytic activity in milk, especially the PL-PG system.

Antioxidant properties of Milk and dairy products: a comprehensive review of the current knowledge

Milk and dairy products are integral part of human nutrition and they are considered as the carriers of higher biological value proteins, calcium, essential fatty acids, amino acids, fat, water soluble vitamins and several bioactive compounds that are highly significant for several biochemical and physiological functions. In recent years, foods containing natural antioxidants are becoming popular all over the world as antioxidants can neutralize and scavenge the free radicals and their harmful effects, which are continuously produced in the biological body. Uncontrolled free radicals activity can lead to oxidative stresses, which have been implicated in breakdown of vital biochemical compounds such as lipids, protein, DNA which may lead to diabetes, accelerated ageing, carcinogenesis and cardiovascular diseases. Antioxidant capacity of milk and milk products is mainly due to sulfur containing amino acids, such as cysteine, phosphate, vitamins A, E, carotenoids, zinc, selenium, enzyme systems, superoxide dismutase, catalase, glutathione peroxidase, milk oligosaccharides and peptides that are produced during fermentation and cheese ripening. Antioxidant activity of milk and dairy products can be enhanced by phytochemicals supplementation while fermented dairy products have been reported contained higher antioxidant capacity as compared to the non-fermented dairy products. Literature review has shown that milk and dairy products have antioxidant capacity, however, information regarding the antioxidant capacity of milk and dairy products has not been previously compiled. This review briefly describes the nutritional and antioxidant capacity of milk and dairy products.

Bioactive Peptides in Animal Food Products

Proteins of animal origin represent physiologically active components in the human diet; they exert a direct action or constitute a substrate for enzymatic hydrolysis upon food processing and consumption. Bioactive peptides may descend from the hydrolysis by digestive enzymes, enzymes endogenous to raw food materials, and enzymes from microorganisms added during food processing. Milk proteins have different polymorphisms for each dairy species that influence the amount and the biochemical characteristics (e.g., amino acid chain, phosphorylation, and glycosylation) of the protein. Milk from other species alternative to cow has been exploited for their role in children with cow milk allergy and in some infant pathologies, such as epilepsy, by monitoring the immune status. Different mechanisms concur for bioactive peptides generation from meat and meat products, and their functionality and application as functional ingredients have proven effects on consumer health. Animal food proteins are currently the main source of a range of biologically-active peptides which have gained special interest because they may also influence numerous physiological responses in the organism. The addition of probiotics to animal food products represent a strategy for the increase of molecules with health and functional properties.

Activities of indigenous proteolytic enzymes in caprine milk of different somatic cell counts

Individual caprine milk with different somatic cell counts (SCC) were studied with the aim of investigating the percentage distribution of leukocyte cell types and the activities of indigenous proteolytic enzymes; proteolysis of casein was also studied in relation to cell type following recovery from milk. The experiment was conducted on 5 intensively managed dairy flocks of Garganica goats; on the basis of SCC, the experimental groups were denoted low (L-SCC; <700,000 cells/mL), medium (M-SCC; from 701,000 to 1,500,000 cells/mL), and high (H-SCC; >1,501,000 cells/mL) SCC. Leukocyte distribution differed between groups; polymorphonuclear neutrophilic leukocytes were higher in M-SCC and H-SCC milk samples, the percentage macrophages was the highest in H-SCC, and levels of nonviable cells significantly decreased with increasing SCC. Activities of all the main proteolytic enzymes were affected by SCC; plasmin activity was the highest in H-SCC milk and the lowest in L-SCC, and elastase and cathepsin D activities were the highest in M-SCC. Somatic cell count influenced casein hydrolysis patterns, with less intact α- and β-casein in H-SCC milk. Higher levels of low electrophoretic mobility peptides were detected in sodium caseinate incubated with leukocytes isolated from L-SCC milk, independent of cell type, whereas among cells recovered from M-SCC milk, macrophages yielded the highest levels of low electrophoretic mobility peptides from sodium caseinate. The level of high electrophoretic mobility peptides was higher in sodium caseinate incubated with polymorphonuclear neutrophilic leukocytes and macrophages isolated from M-SCC, whereas the same fraction of peptides was always the highest, independent of leukocyte type, for cells recovered from H-SCC milk. In caprine milk, a level of 700,000 cells/mL represented the threshold for changes in leukocyte distribution, which is presumably related to the immune status of the mammary gland. Differences in the profile of indigenous lysosomal proteolytic enzymes in caprine milk may influence the integrity of casein based on proteolysis patterns of sodium caseinate incubated with isolated and lysed leukocyte types.

Role of somatic cells on dairy processes and products: a review

Somatic cells are an important component naturally present in milk, and somatic cell count is used as an indicator of udder health and milk quality. The role of somatic cells in dairy processes and products is ill-defined in most studies because the role of these cells combines also the concomitance of physicochemical modifications of milk, bacterial count, and the udder inflammation in the presence of high somatic cell count. The aim of this review is to focus on the role of somatic cells themselves and of endogenous enzymes from somatic cells in milk, in dairy transformation processes, and in characteristics of final products overcoming biases due to other factors. The immune function of somatic cells in the udder defense and their protective role in milk will be primarily considered. Different characteristics of milk induced by various somatic cell counts, types, and their endogenous enzymes influencing directly the technological properties of milk and the final quality of dairy products will be discussed as well. By comparing methods used in other studies and eliminating biases due to other factors not considered in these studies, a new approach has been suggested to evaluate the effective role of somatic cells on dairy processes and products. In addition, this new approach allows the characterization of somatic cells and their endogenous enzymes and, in future research, will allow the clarification of mechanisms involved in the release of these components from somatic cells during dairy processes, particularly in cheese technologies.

Comparative protein composition analysis of goat milk produced by the Alpine and Saanen breeds in northeastern Brazil and related antibacterial activities

The protein composition of goat milk differs between goat breeds and could present regional trends. The aim of this study was to comparatively analyze the protein composition of goat milk produced by the Alpine and Saanen breeds in northeastern Brazil and to evaluate the antibacterial activity of its protein fractions. SDS-PAGE, 2-DE electrophoresis and RP-HPLC analyses revealed the absence of αs1-casein in the milk of both breeds and no differences between the αs2-casein, β-casein, β-lactoglobulin and α-lactalbumin profiles. The amounts of soluble proteins and β-casein hydrolysis residues were higher in Saanen milk. Only the protein fraction containing the largest amounts of casein (F_60–90%) inhibited bacterial growth, with MIC values between 50 and 100 mg/mL. This study describe for the first time three important points about the goat milk protein of two Brazilian goat breeders: absence of α-s1 casein in the protein profile, differences between the milk protein composition produced by goats of Alpine and Saanen breeders and antibacterial activity of unbroken proteins (casein-rich fraction) present in these milk.

Comparison of the principal proteins in bovine, caprine, buffalo, equine and camel milk

Proteomic analysis of bovine, caprine, buffalo, equine and camel milk highlighted significant interspecies differences. Camel milk was found to be devoid of β-lactoglobulin, whereas β-lactoglobulin was the major whey protein in bovine, buffalo, caprine, and equine milk. Five different isoforms of κ-casein were found in camel milk, analogous to the micro-heterogeneity observed for bovine κ-casein. Several spots observed in 2D-electrophoretograms of milk of all species could tentatively be identified as polypeptides arising from the enzymatic hydrolysis of caseins. The understanding gained from the proteomic comparison of these milks may be of relevance both in terms of identifying sources of hypoallergenic alternatives to bovine milk and detection of adulteration of milk samples and products.

The Garfagnina goat: a zootechnical overview of a local dairy population

Domestic livestock with a limited distribution are increasingly recognized in the action plans of the European Union as a reason for protecting rural land. The preservation and enhancement of the native germplasm and traits selected through the ages in different areas of farming is the first step in increasing typical products at a time when high quality products are increasingly in demand. This is the first time that a zootechnical overview has been performed on the Italian native goat population named "Garfagnina," which is registered on the Tuscan regional repertory of genetic resources at risk of extinction. The aim of the study was to give added value to this population by focusing on particular traits that could be used for promoting typical products. Data on the size of the local goats, zoometric measures, breeding system, milk quality, and genetic polymorphisms were collected to get insight into the current state of the population of this type of goat. The native goat population is reared in Tuscany in central Italy, mostly for its milk. The local goat farms considered in our study are located in the hills and mountains of the northwestern Tuscan Apennine area. For every farm we measured at least 10% of the reproductive females (273), randomly chosen, and all reproductive males (47) for a total of 320 subjects. Regarding the management of the animals and the feeding system, semi-extensive farming is practiced in all the flocks. From a morphological point of view the animals are relatively homogeneous, especially in terms of zoometric data, whereas they show a wider variability regarding coat. Milk gross and fatty acid composition were similar to that reported in the literature for bulk goat milk. Moreover, the average of somatic cell count and standard plate count found in Garfagnina goat milk indicated good hygienic farm management and correct milking practices, although milking is mainly manual. The average number of globules per milliliter found in Garfagnina goat milk was almost double compared with the literature, whereas the average diameter was lower. Milk coagulation properties were scarce, thus indicating poor cheesemaking aptitude of Garfagnina milk. Selecting haplotypes carrying alleles associated with a higher expression of the specific casein could help improve milk cheesemaking aptitude. Moreover, the rather high frequency of the faint CSN1S1*F allele and the occurrence of CSN2*0 might suggest that Garfagnina goat milk could be used, after an appropriate selection, for direct consumption of milk at low casein content for intolerant human subjects.