The Aggregated and Micellar Forms of ß-Casein Purified from Donkey and Bovine Milk Present Potential as Carriers for Bioactive Nutritional Compounds.

In recent years, there has been a growing interest in the pure casein fraction of milk protein, particularly ß-casein due to its physicochemical properties as well as its bio- and techno-functional properties. The utilization of self-assembled ß-caseins from bovine origin as nanocarriers for the delivery of nutraceutical compounds or drugs has increased dramatically. Concerning ß-caseins from other milk sources, the use of hypoallergenic donkey ß-caseins as a potential delivery vehicle for nutraceutical hydrophobic compounds is beginning to generate interest. The present review deals with casein micelles models, bovine and donkey ß-casein molecular structures, as well as their physical-chemical properties that account for their exploitation in nutraceutics and pharmaceutics. This review work suggests the possibility of developing delivery systems for hydrophobic bioactive compounds using ß-casein purified from hypoallergenic donkey milk, highlighting the potential of this protein as an innovative and promising vehicle for enhancing the enrichment and bioavailability of various bioactive substances in food products.

Effects of different steam injection conditions on cappuccino's nutritional profile.

The quality parameters of cappuccinos prepared with pasteurized milk or ultra-high-temperature milk steam-injected at different temperatures by a professional coffee machine have been assessed. In particular, the protein profile, the content of vitamins and lactose, the lipid peroxidation process, and the involvement of milk proteins in the foam formation were evaluated. The nutritional quality of milk seems not affected by the steam injection treatment carried out at a temperature of 60-65 °C, but at higher temperatures a decrement of lactoperoxidase, vitamin B6 and folic acid was observed. The milk used in cappuccino preparation is very important: pasteurized milk can form a more consistent and lasting foam with respect to ultra-high-temperature milk because of the presence of ß-lactoglobulin and lactoferrin, both playing an important role in the foam formation and stability. This work would provide additional information to the coffee industry for the preparation of high nutritional and organoleptic quality cappuccinos.

The Research Field of Meat Preservation: A Scientometric and Visualization Analysis Based on the Web of Science.

Meat plays a significant role in human diets, providing a rich source of high-quality protein. With advancements in technology, research in the field of meat preservation has been undergoing dynamic evolution. To gain insights into the development of this discipline, the study conducted an analysis and knowledge structure mapping of 1672 papers related to meat preservation research within the Web of Science Core Collection (WOSCC) spanning from 2001 to 2023. And using software tools such as VOSviewer 1.6.18 and CiteSpace 5.8.R3c allowed for the convenient analysis of the literature by strictly following the software operation manuals. Moreover, the knowledge structure of research in the field of meat preservation was synthesized within the framework of "basic research-technological application-integration of technology with fundamental research," aligning with the research content. Co-cited literature analysis indicated that meat preservation research could be further categorized into seven collections, as well as highlighting the prominent role of the antibacterial and antioxidant properties of plant essential oils in ongoing research. Subsequently, the future research direction and focus of the meat preservation field were predicted and prospected. The findings of this study could offer valuable assistance to researchers in swiftly comprehending the discipline's development and identifying prominent research areas, thus providing valuable guidance for shaping research topics.

Changes in the Physical-Chemical Properties and Volatile Flavor Components of Dry-Cured Donkey Leg during Processing.

In order to explore the quality variation and flavor formation of dry-cured donkey leg, the changes in physical−chemical composition, lipolytic, free amino acids content and volatile flavor compounds were investigated in this study. Six fresh, trimmed hind legs with average weight of 8.12 ± 0.8 kg were taken from male Dezhou donkeys slaughtered at the age of 24 months with the average live weight of 240 kg. The entire processing time was eight months long including six stages, specifically: cooling, salting, air-drying, fermenting and aging. Samples were collected at 0 d, 10 d, 20 d, 30 d, 65 d, 105 d and 165 d of processing. The results showed that the pH value remained stable in the range of 6.2~6.6. The moisture and water activity significantly decreased (p < 0.05) during processing. The chloride content, ash, total volatile basic nitrogen (TVB-N) and peroxide value (POV) significantly increased (p < 0.05), from 0.45% to 12.39%, from 3% to 17%, from 1.43 mg/kg to 8.98 mg/kg and from 1.39 g/100 g to 5.26 g/100 g, respectively. The thiobarbituric acid (TBARS) value reached its highest value of 0.39 mg MDA/kg at the end of the salting stage and then decreased to 0.34 mg MDA/kg. Eighteen free amino acids and fifteen free fatty acids were detected, and their contents were significantly increased during processing (p < 0.05). Volatile compounds were analyzed using solid-phase microextraction (SPME) and gas chromatography−mass spectrometry (GC−MS). Among 114 volatile compounds detected in dry-cured donkey leg, aldehydes, esters, alkane and alcohols were more abundant in the final products, with relative concentrations of 41.88%, 5.72%, 5.35% and 5.25%, respectively. Processing significantly affected the physical−chemical properties, which could contribute to the formation of flavor substances of dry-cured donkey leg.

Effects of Ageing on Donkey Meat Chemical Composition, Fatty Acid Profile and Volatile Compounds.

Donkey meat samples obtained from muscle Longissimus Thoracis Lumborum (LTL) taken from 14 entire donkey males slaughtered at 20 months and aged for 1, 8 and 15 days were analysed with the aim of determining the chemical composition, physical attributes, fatty acid profile and volatile compounds. Ageing did not significantly affect the chemical composition and colour parameters, while cooking loss was significantly (p < 0.05) higher at 8 and 15 days of ageing. Thiobarbituric acid reactive substances (TBARS) content significantly (p < 0.01) increased during ageing, while shear force values significantly (p < 0.01) decreased. Ageing significantly (p < 0.05) increased polyunsaturated fatty acids (PUFAs) determined both at 8 and 15 days after slaughter. Volatile compounds were analysed using solid-phase microextraction (SPME) and gas chromatography−mass spectrometry (GC−MS). Among 109 volatile compounds determined in donkey meat, hydrocarbons were the most common molecules detected. Ageing affected 21 of the detected volatile compounds; both total aldehydes and total ketones contents were significantly (p < 0.05) higher 15 days after slaughter. Total furans and total alcohols were significantly (p < 0.01) higher 15 days after slaughter, as well. Significant modifications of donkey meat volatile compounds can be attributed to ageing periods longer than 7 days.

Effects of Donkeys Rearing System on Performance Indices, Carcass, and Meat Quality.

This study compared growth rates, carcass, and meat quality obtained from 24 male crossbred donkey foals reared for meat production under an intensive (I) or extensive (E) feeding system. Donkeys were slaughtered at 16 months of age; the average final body weight, hot and cold carcass weight, and hot and cold dressing percentage were significantly higher (p < 0.05) in the I group. Samples of Longissimus Thoracis et Lumborum (LTL) were taken from each foal for chemical and physical analysis. Group I showed significant (p < 0.05) higher intramuscular fat, while the E group showed significantly (p < 0.05) higher protein and unsaturated fatty acids (UFA) contents, including n-3 essential fatty acids. Saturated fatty acids (SFA) and glycogen were significantly higher (p < 0.05) in the intensive system, monounsaturated fatty acids (MUFA) were significantly higher in the extensive system. The ratio PUFA/SFA was significantly higher (p < 0.05) in group E. The Thrombogenic Index (TI) was significantly higher (p < 0.05) in the I group. Meat tenderness was significantly higher (p < 0.05) in group I. The feeding system had no effect on cholesterol content and meat color characteristics. Donkeys average daily gain, carcass weight, and some meat quality parameters were significantly affected by the rearing system.

Vitamins in Human and Donkey Milk: Functional and Nutritional Role.

BACKGROUND: Whole milk is a good source of all the nutrients, and it also contains a sufficient number of vitamins to permit regular the growth of the neonate. Dairy cow milk can create allergy in infants less than 12 months old because of the high caseins and ß-lactoglobulin content. In these circumstances, donkey milk can represent a good replacement for dairy cows' milk in children affected by Cow Milk Protein Allergy (CMPA) because of its close chemical composition with human milk, mainly due to its low protein and low mineral content. Milk vitamin content is highly variable among mammalian species and it is strictly correlated with the vitamin status and the diet administered to the mother. Fat-soluble vitamins content in donkey milk is, on average, lower compared to ruminants' milk, while vitamin C content determined in donkey milk is higher compared to dairy cows' milk, showing a great similarity with human milk. In donkey milk, the content of vitamins of the B-complex such as thiamine, riboflavin, niacin, pyridoxine, and folic acid is higher compared to human milk. The use of donkey milk as a new functional food must be further evaluated in interdisciplinary clinical trials in which pediatricians, dietitians, and food scientists must be involved to deepen the knowledge about the positive health impact of donkey milk in different sensitive people, especially children and the elderly.

Comparison of Carcass and Meat Quality Obtained from Mule and Donkey.

The aim of this study was to compare the carcass characteristics and the chemical and physical parameters of the meat produced by 10 male crossbred donkeys and 10 male mules slaughtered at 16 ± 1 years of age. The carcass weight and dressing percentage were significantly (p < 0.05) higher in mules. Samples of the muscle Longissimus thoracis (LT) were analyzed. Donkey meat showed a higher fat content, while the glycogen content was higher in the mule LT. The total collagen content was higher in the mule LT; in this muscle, the shear force values were higher compared to the donkey LT. The lightness parameter (L*) was lower in the mule LT, while the redness index (a*) was higher in the mule LT; this muscle showed a higher content of iron, while zinc was higher in the donkey muscle LT. The donkey LT muscle showed a higher content of essential amino acids (52.2%) compared to the mule LT (50.1%). The results obtained demonstrated that the chemical and physical traits of mule and donkey meat were similar to those of other kinds of equid meat.

Proteomic characterization of kefir milk by two-dimensional electrophoresis followed by mass spectrometry.

Kefir is a type of fermented milk obtained thanks to the introduction of "kefir grains" in mammalian milk. Kefir grains consist of lactic and acetic acid bacteria and yeasts in alternative proportions that are held together by a matrix of complex sugars known as "kefiran." Thanks to the fermentative process, the kefir milk is rich in nutraceutical substances such as amino acids, vitamins, and mineral salts. The most valuable compounds of kefir fermentation are mainly lactic acid, exopolysaccharides, and bioactive peptides, the resulting products of proteolytic release from milk proteins (caseins and whey proteins). Among the nutraceutical properties of kefir are antimicrobial and antitumor activity, immunomodulating effect, and cholesterol-lowering effect. Therefore, in light of these intriguing properties of kefir milk, in this work, a proteomic analysis, by two-dimensional electrophoresis followed by mass spectrometry, has been performed. As a result, milk-derived polypeptides were identified in commercial kefir milk from organic farming. In particular, polypeptides deriving from κ-, αs1 -, and αs2 -caseins that may have potentially beneficial effects on human health have been detected.

Dietary Intake of Vitamin D from Dairy Products Reduces the Risk of Osteoporosis.

BACKGROUND: Vitamin D and calcium are important dietary compounds that affect bone mass, even if other minerals (potassium, zinc, etc.) and vitamins (A, C and K) are also involved. Vitamin D and certain minerals, in fact, play an important role in calcium homeostasis and calcium absorption. Hip fracture incidence is higher in Europe and the United States, where calcium is frequently included in the human diet; while the occurrence of these fractures is lower in developing countries, where diets are often poor in calcium. This condition is named the "calcium paradox", and may be partially explained by phosphate toxicity, which can negatively affect mineral metabolism. It is important to maintain correct dietary calcium-phosphate balance in order to have a healthy life, reducing the risk of osteoporotic fractures in older people. Vitamin D can also act as a hormone; vitamin D2 (ergocalciferol) is derived from the UV-B radiation of ergosterol, the natural vitamin D precursor detected in plants, fungi, and invertebrates. Vitamin D3 (cholecalciferol) is synthesized by sunlight exposure from 7-dehydrocholesterol, a precursor of cholesterol that can also act as provitamin D3. Dietary intake of vitamin D3 is essential when the skin is exposed for short periods to ultraviolet B light (UV-B), a category of invisible light rays such as UV-A and UV-C. This can be considered the usual situation in northern latitudes during the winter season, or the typical lifestyle for older people and/or for people with very white delicate skin. The actual recommended daily intake of dietary vitamin D is strictly correlated with age, ranging from 5 µg for infants, children, teenagers, and adults-including pregnant and lactating women-to 15 µg for people over 65 years.

A comparison among ß-caseins purified from milk of different species: Self-assembling behaviour and immunogenicity potential.

Caseins are a family of proteins constituted by α-caseins (αs-1 and αs-2 caseins), ß-caseins and κ-caseins. ß-caseins, in particular, show a temperature and concentration-dependent self-assembling behaviour. Recently, ß-casein micelles have been proposed as natural nanocarriers for the delivery of hydrophobic compounds, promoting their bioavailability. Until now, all studies regarding both chemical-physical characterization and applications of ß-caseins have employed the protein of bovine origin. However, it could be interesting to exploit the use of ß-caseins from other milk sources for their potential encapsulation ability and immunogenicity but, at present, no information on the self-assembling behaviour is available for ß-caseins from the milk of species different from bovine. In this work, for the first time, ß-caseins from human milk and from donkey, goat, and sheep milk were purified and their self-assembling behaviour was compared to that of a commercial bovine ß-casein, the only one for which the concentration and temperature aggregation behaviour is known. Furthermore, a preliminary evaluation of the immunogenicity potential of ß-casein from other milk sources has been performed by cross-reaction experiments using anti-ß-casein antibodies from bovine origin. The results indicated a similar self-assembling profile among all ß-caseins examined compared to the bovine ß-casein, suggesting the possible use of ß-casein from other milk sources as nanocarriers. Since donkey and human ß-casein do not cross-react with bovine anti-ß-casein antibodies, they could be particularly interesting for the development of self-assembling systems with lower hypoallergenic potential.

Comparative proteomic analysis of two clam species: Chamelea gallina and Tapes philippinarum.

Clams have long been a fisheries and aquaculture sector of great importance in Italy, the main resource of fisheries is the Chamelea gallina of indigenous origin, whereas clams breeding is supported almost entirely by the Tapes philippinarum, a species of Indo-Pacific origin. Bivalve molluscs quality depends mainly on the water quality, and then by a series of factors such as water temperature and salinity, gametogenic cycle, food availability, and environmental conditions, that affect the Condition Index. In this work crude extracts obtained from the edible part of Chamelea gallina and Tapes philippinarum were analyzed by a proteomic approach based on a two-dimensional gel electrophoresis followed by liquid chromatography-tandem mass spectrometry, in order to detect biomarkers useful for identification of the two kinds of clams and to assess their nutritional characteristics. As a result, four differentially expressed spots were found and identified, namely enolase, cyclophilin-A, ribosomal protein L13 and actin-1.

A comparison of the carcass and meat quality of Martina Franca donkey foals aged 8 or 12 months.

The effects of slaughter age (8 vs 12 months) were investigated on meat and carcass quality obtained from Martina Franca donkey foals. Sixteen male foals were used, eight were slaughtered at 8 months of age with a mean (±s.e.) final body weight of 101±18kg and the remaining 8 foals slaughtered at 12 months of age with a mean final body weight of 122±13kg. Carcass weight and dressing percentage were higher (P<0.05) in older foals. Shear force value was lower (P<0.05) in donkeys slaughtered at 8 months of age (54.03N) compared to the same muscle Longissimus Thoracis et Lumborum (LTL) collected in older animals (62.66N). Muscle glycogen content was higher (P<0.05) in foals slaughtered at 12months of age. Donkey foal meat showed an interesting content of essential amino acids and a notable percentage of unsaturated fatty acids in both groups of animals, giving a high nutritional value to this alternative red meat.

Profile of nucleosides and nucleotides in donkey's milk.

Nucleotides play a crucial role to cellular functions; they can be obtained from the diet or through the nucleotide salvage pathway, however, in particular situations (occurring mainly in newborns) the metabolic demand of nucleotides exceeds the capacity of their synthesis. These molecules, are receiving attention from a nutraceutical point of view because of their potential direct role in regulating metabolism and infant body condition. Donkey's milk may be considered a good replacer for cow's milk in feeding children with severe Ig-E mediated cow's milk protein allergy, due to its high similarity with human milk. In this study, the presence of cytidine, uridine, CMP, UMP, guanosine, and adenosine, involved in numerous biochemical and physiological activities, were detected for the first time through a RP-HPLC method.

Hypoallergenic properties of donkey's milk: a preliminary study.

Cow's milk protein allergy (CMPA) is an abnormal immunological response to cow milk proteins, which results in IgE-mediated reactions. The therapeutic strategy to respond to CMPA envisages the total elimination of milk or the administration of cow's milk substitutes. For this reason the use of milk from other mammalian species was tested. Among them, donkey's milk proved to be the best alternative in feeding infants affected by CMPA, since its chemical composition is comparable to human milk. In this work an in vitrostudy was performed in order to analyze the IgE reactivity to milk protein allergens from cow, donkey and goat. In particular, immunoblotting experiments using sera from milk-allergic and non-allergic adult volunteers were conducted with the aim of verifying the hypoallergenic property of donkey's milk. This study provided a preliminary evidence of the hypoallergenicity of donkey's milk when compared to bovine and goat milk. Considering the obtained results, it would be possible to develop a sensitive diagnostic method for CMPA detection, based on chromatographic and immunoblotting analysis.

Carcass characteristics, meat quality and nutritional value of horsemeat: a review.

Meat has exerted a crucial role in human evolution and is an important component of a healthy and well balanced diet due to its nutritional richness. The aim of the present review was to shed light on the nutritional composition of horsemeat and their benefits for human health. One of the reasons for such interest was the occurrence, in Europe several years ago, of dioxin, Bovine Encephalopathy and foot-and-mouth disease problems in farm animals. Therefore, consumers began to look for alternative red meats from other non-traditional species. There is no carcass classification system on horses designated to meat consumption. It would be advisable to standardize the equine meat market to reduce variations that may reflect differences in meat quality. The nutritional composition of horsemeat by comparison with pork, beef or poultry is characterized by low levels of fat and cholesterol (about 20% less), relatively high concentrations of n-3 fatty acids and heme iron indicating that its consumption may be beneficial for health. Therefore, horsemeat may supplement the meat market with good quality products, although as in other dietary components moderation is advisable.

Human cytidine deaminase: a biochemical characterization of its naturally occurring variants.

Human cytidine deaminase is an enzyme of the pyrimidine salvage pathways that metabolizes several cytosine nucleoside analogs used as prodrugs in chemotherapy. We carried out a characterization of the cytidine deaminase 79A>C and 208G>A Single Nucleotide Polymorphisms, in order to highlight their functional role and provide data that could help fine-tune the chemotherapic use of cytosine nucleosides in patients carrying the above mentioned SNPs. The 79A>C SNP results in a K27Q change in a protein region not involved in the catalytic event. The 208G>A SNP produces an alanine to threonine substitution (A70T) within the conserved catalytic domain. Q27 variant is endowed with a greater catalytic efficiency toward the natural substrates and the antileukemic agent cytarabine (Ara-C), when compared to K27 variant. Molecular modeling, protein stability experiments and site-directed mutagenesis suggest that K27 variant may have an increased stability with respect to Q27 due to an ionic interaction between a lysine residue at position 27 and a glutamate residue at position 24. The T70 variant has a lower catalytic efficiency toward the analyzed substrates when compared to the A70 variant, suggesting that patients carrying the 208G>A SNP may have a greater exposure to cytosine based pro drugs, with possible toxicity consequences.

Effects of thermal treatments on donkey milk nutritional characteristics.

Human breast milk is the best nutritional support to ensure right development and influence immune status of the newborn infant. However, when it is not possible to breast feed it may be necessary to use commercial infant formulas that mimic, where possible, the levels and types of nutrients present in human milk. Despite this, some formula-fed infants develop allergy and/or atopic disease compared to breast-fed infants. Most infants with cow's milk protein allergy (CMPA) develop symptoms before 1 month of age, often within 1 week after introduction of cow's milk-based formula. Donkey milk may be considered a good substitute for cow's milk in feeding children with CMPA since its composition is very similar to human milk. An in-depth analysis of the donkey milk protein profile has been performed in this study. The interest was focused on the milk proteins considered safe for the prevention and treatment of various disorders in human. Since donkey milk supply is related to its seasonal availability during the year, in this study were evaluated the effects of different thermal treatments on the protein fractions of donkey milk. The results obtained in fresh, frozen, powdered and lyophilized donkey milk showed different values in total proteins, caseins, whey proteins and lysozyme content. This study demonstrated the possibility of using lyophilization in order to maintain the nutritional characteristics of donkey milk. The article presents some promising patents on the effects of thermal treatments on donkey milk nutritional characteristics.

Site directed mutagenesis as a tool to understand the catalytic mechanism of human cytidine deaminase.

Cytidine deaminase (CDA), is one of the enzymes involved in the pyrimidine salvage pathways, which catalyzes the formation of uridine and deoxyuridine by the hydrolytic deamination of cytidine and deoxycytidine, respectively. Human CDA is a tetrameric enzyme of identical 15 kDa subunits, each containing an essential zinc atom in the active site. The substrate binds to each active site independently and the cooperativity between subunits has not been reported. CDA is able to recognize as substrates some antitumor and antiviral cytidine analogs rendering them pharmacologically inactive. In light of the role played by this enzyme, a deep knowledge of CDA active site and mechanism of catalysis is required. Site-directed mutagenesis, associated with molecular modeling studies, may be an important tool to discover the active site structure of an enzyme and consequently its mechanism of action. In this review are summarized the site-directed mutagenesis experiments performed on human CDA: through these studies it was possible to understand the role exerted by specific amino acid residues in CDA active site and in the contacts between subunits. The obtained results may open a way for designing new cytidine based drugs or more potent CDA inhibitors.