Antioxidant Activity Of Milk Research Articles

Determination of antioxidant activity in milk extracts with phosphomolibdate method

Antioxidants are mainly non-nutrient compounds in both human and animal feed, but have the antioxidant capacity in vitro to provide an artificial power index in preventing the destruction of cells and tissue potential by inhibiting nutrient oxidation. Milk contains lipophilic and hydrophilic antioxidants, which play a key role in maintaining. The efficiency of extraction for determining the antioxidant activity of milk corresponds to the method used for plant extraction. For this purpose, the phosphor molybdenum method based on the reduction of Mo (VI) in Mo (B) in samples of milk. Extracts obtained with methanol and ethanol, Soxlet method. Green complexes formed at acidic pH value, measurements of spectrophotometer (UV), λ = 695 nm. The values of milk samples are compared with respect to the calibration curve of gallic acid range (0.00 to 14.00 μg / ml, y = 0.0344 + 0.0519, R2 = 0.9709). The results of milk extract was concentration/ c = 3, 80; 2.35; 3.78; 4.85 / (μg / ml). The highest value of antioxidant activity in packs milk, which has 3.2% fat, also affects the fat and the presence of vitamin E, which found in fat droplets and has a synergistic effect with vitamin C. It concluded that the highest value of the total antioxidant activity in milk obtained from the first sample due to the use of several types of feed – alfalfa, two types of concentrated and straw, which proves the dependence of antioxidant activity on the impact of nutrients, that is, of their type and quantities.

By-Products Valorization: Peptide Fractions from Milk Permeate Exert Antioxidant Activity in Cellular and In Vivo Models.

The discarding of agri-food by-products is a stringent problem due to their high environmental impact. Recovery strategies can lead to a reduction of waste and result in new applications. Agri-food waste represents a source of bioactive molecules, which could promote health benefits. The primary goal of this research has been the assessment of the antioxidant activity of milk permeate, a dairy farm by-product, and the isolation and identification of peptide fractions endowed with antioxidant activity. The chromatographic extraction of the peptide fractions was carried out, and the peptides were identified by mass spectrometry. The fractions showed radical scavenging activity in vitro. Moreover, the results in the Caco-2 cell model demonstrated that the peptide fractions were able to protect from oxidative stress by stimulating the Keap1/Nrf2 antioxidant signaling pathway, increasing the transcription of antioxidant enzymes. In addition, the bioactive peptides can affect cellular metabolism, increasing mitochondrial respiration. The action of the peptide fractions was also assessed in vivo on a zebrafish model and resulted in the protection of the whole organism from the adverse effects of acute cold stress, highlighting their strong capability to protect from an oxidative insult. Altogether, the results unveil novel recovery strategies for food by-products as sources of antioxidant bioactive peptides that might be utilized for the development of functional foods.

Stage of lactation, parity, breed, milk composition and minerals affect the non-enzymatic antioxidant activity of sheep milk

The aims of this study were to i) characterize sheep milk for non-enzymatic antioxidant activity via 2 different assays, namely the ferric reducing antioxidant power (FRAP) and the 2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), and ii) investigate the effect of milk composition and animal-related parameters on these 2 assays by using Generalized Additive Mixed Model (GAMM) approach. A total of 740 ewes belonging to Massese and Comisana breeds were sampled once during the morning milking across 11 sampling sessions. All milk samples were analyzed for fat, protein, casein, and lactose, somatic cell score (SCS) and minerals (Ca, Mg, Na and Cl). The FRAP and DPPH assays were tested to measure the non-enzymatic antioxidant activity of milk, expressed as μM eq. ascorbic acid/mL of milk and % of inhibition, respectively. The GAMM model included the effect of parity and breed as parametric terms, and the effect of days in milk (DIM), milk yield and the interactions protein × fat, casein × SCS, Ca × Mg and Na × Cl as smooth terms. The sampling day was included in the model as random effect. Results revealed that the non-enzymatic antioxidant capacity of sheep milk, expressed as FRAP, was affected by DIM, potentially because of changes in milk composition over time. Conversely, parity and breed of ewes affected DPPH, suggesting that age- and breed-specific factors are related to specific components in milk acting as hydrogen donors. Milk fat and high casein percentages were found to significantly affect FRAP, while protein content was crucial for high DPPH levels. Additionally, Ca and Mg emerged as important non-enzymatic antioxidants for both FRAP and DPPH, highlighting their important role in antioxidant activity of sheep milk. On the other side, combinations of Na and Cl were particularly influential for FRAP, revealing the complex relationship between these minerals and non-enzymatic antioxidant activity of milk. These findings offer valuable insights into the factors affecting the antioxidative properties of sheep milk, highlighting the need for further exploration of other non-enzymatic antioxidants and their contribution to the total antioxidant activity.

Enrichment of milk antioxidant activity by dietary supplementation of red clover isoflavone in cows and its improvement on mice intestinal health

Red clover (Trifolium pratense) isoflavone was supplemented to dairy cows, and antioxidant capacity of milk was assessed. Treated cows increased the activities of antioxidant enzymes, reduced production of oxidation products, and enhanced the concentrations of vitamin E and vitamin C. Moreover, milk fatty acid profile was positive influenced by 8 g/kg red clover isoflavone, with changes in the lower saturated and higher unsaturated fatty acids. We further demonstrated the efficacy of antioxidant capacity of milk in mice, found that milk from cows feeding red clover isoflavone increased the expressions of antioxidant enzymes, and alleviated lipopolysaccharide (LPS)-stimulated tissue damage of duodenum and jejunum, which was related to upregulated metabolism pathways of carbohydrate, lipid, and amino acid, as well as downregulated inflammatory related pathways. Together, dietary supplementation of red clover isoflavone is an effective way to improve milk antioxidant capacity, providing a natural strategy for developing functional foods.

In Vitro Inhibition of α-Amylase, α-Glucosidase and Antioxidant Activity of Milk Containing Fenugreek Seed Alcoholic Extract.

The aim of this study was to evaluate the effect of fenugreek seed alcoholic extract (FSAE) at the levels of 0.15% and 0.30% (V/V) on the selected properties of enriched milk during the 10-day storage period at 4°C. The results demonstrated that with the addition of FSAE, the pH, brightness intensity and white color coefficient decreased and the values of acidity, viscosity, a* and b* indexes, total phenol content (TPC), total flavonoid content (TFC), antioxidant activity (AA) and enzyme inhibitory activity of enriched milk samples increased significantly compared to the control (p < 0.05). During the storage period, a decrease in TPC, TFC, AA and inhibitory activity was observed in all samples (p < 0.05). The FSAE was able to significantly reduce total microbial count (TMC) in milk samples (p < 0.05). In terms of sensory characteristics, the best sensory scores during the storage period were related to the sample containing 0.15% (V/V) FSAE. Overall, a positive and direct relationship was found between the beneficial effects of FSAE and its concentration. Finally, according to the results of the overall acceptance score in sensory tests, the sample containing 0.15% (V/V) FSAE was introduced as the best sample.

Supplementation with antioxidants and phenolic compounds in ruminant feeding and its effect on dairy products: a systematic review.

Milk and dairy products have great importance in human nutrition related to the presence of different nutrients, including protein, fatty acid profile and bioactive compounds. Dietary supplementation with foods containing these types of compounds may influence the chemical composition of milk and dairy products and hence, potentially, the consumer. Our objective was to summarize the evidence of the effect of supplementation with antioxidants and phenolic compounds in the diets of dairy animals and their effects on milk and dairy products. We conducted a systematic search in the MEDLINE/PubMed database for studies published up until July 2022 that reported on supplementation with antioxidants and phenolic compounds in diets that included plants, herbs, seeds, grains and isolated bioactive compounds of dairy animals such as cows, sheep and goats and their effects on milk and dairy products. Of the 94 studies identified in the search, only 15 met the inclusion criteria and were analyzed. The review revealed that supplementation with false flax cake, sweet grass, Acacia farnesiana, mushroom myceliated grains and sweet grass promoted an effect on the milk lipid profile, whereas supplementation with dried grape pomace and tannin extract promoted an effect on the milk and cheese lipid profiles. In six studies, the addition of Acacia farnesiana, hesperidin or naringin, durum wheat bran, mushroom myceliated grains, dried grape pomace and olive leaves increased the antioxidant activity of milk. In conclusion, supplementation with bioactive compounds had a positive impact which ranged from an increase in antioxidant capacity to a decrease in oxidative biomarkers such as malondialdehyde.

Evaluating the effects of direct-fed microbial supplementation on the performance, milk quality and fatty acid of mid-lactating dairy cows.

The objective of the experiment was to investigate the effect of a mixture of direct-fed microbial (DFM) on feed intake, nutrient digestibility, milk yield and composition, milk fatty acid and blood parameter in crossbred mid-lactating cows. Twenty-four crossbred Holstein cows (body weight = 650±15kg; days in milk = 100±20; daily milk yield = 25±3kg) were used in a completely randomized design with three treatments: (1) CON, without DFM; (2) LS, inoculation with Lactobacillus fermentum (4.5 × 108 CFU/day) plus Saccharomyces cerevisiae (1.4×1010 CFU/day); and (3) LSM, inoculation with LS plus Megasphaera elsdenii (4.5 × 108 CFU/day). All animals received the same ration with 45.7% forage and 54.3% concentrate. Results showed that the highest feed intake was observed in treatments LS and LSM (p = 0.02). Compared with the CON, milk production, 4% fat-corrected milk, energy-corrected milk, fat (kg/day), protein (kg/day) and lactose (kg/day), FE and percent of fat were increased (p<0.05) by LSM, but unaffected by LS. Also, compared with the CON, both LS and LSM increased antioxidant activity (p<0.05). The concentration of C18:2c n-6 increased significantly in treatment LSM compared with the CON (p = 0.003). The concentration of C20:0 increased significantly in treatment LS compared with the CON (p = 0.004). The highest concentrations of insulin, glucose, triglyceride and cholesterol were observed by LSM (p<0.05). Compared with the CON, both LS and LSM increased blood monocyte, neutrophil, eosinophil and basophil (p<0.05), and blood lymphocyte was increased (p = 0.02) only by LSM. The results of the research showed that the use of DFMs had no effect on the digestibility, microbial load and the major part of fatty acids in milk. However, it improved feed intake, milk yield and antioxidant activity of milk and also increased the milk concentration of C18:2 n-6.

Assessment of bioactive components of essential oils for antimicrobial activity in the dairy food matrix

Essential oils as a whole have been widely investigated for their antimicrobial properties against spoilage microorganisms and pathogens. However limited information is available about the inhibitory activities of components of EO in foods and more specifically in dairy food matrices. The widespread components of common EOs were evaluated for their antibacterial activity in media and skim milk. Amongst the EO components, trans-cinnamaldehyde and eugenol were the most effective on the basis of disk assay and minimum bactericidal concentrations in milk. The MBC of these EOs was unaffected by the conditions of the incubation temperature of milk. However the MBC was decreased in paneer slurry against L.monocytogenes and E. coli O157:H7 when incubated at 7 °C than37 °C. In the dairy spread, trans-cinnamaldehyde and eugenol were effective in inhibiting TBC, coliform, and yeast &amp; mold count at 0.26 mg/g without affecting sensory properties. The microbial load in paneer made from EO added to milk (10 mg/ml) significantly inhibited microbial growth during storage. In addition eugenol has shown antioxidant activity in milk through ABTS radical scavenging assay.

Comparative analysis of the degree of hydrolysis and antioxidant activity of milk and whey hydrolysates

The degree of hydrolysis and antioxidant activity of protein hydrolysates from fresh cow’s milk and whey obtained by the action of the proteolytic enzymes papain, bromelain and chymosin were compared. The lowest degree of hydrolysis in fresh milk hydrolysates was reported for sample MP1 (10 min reaction time, treatment with 0.1 mg/ml papain), and the highest percentage was obtained at hydrolysate MB12 (at 60 min reaction time, treatment with 1.0 mg/ml bromelain). For the whey samples in sample WC1 (10 min reaction time, treatment with 1.0 μl/ml chymosin), the percentage of hydrolysis was the lowest. The highest percentage was achieved at WP12 hydrolysate using papain at a concentration of 1 mg/ml and a 60-min reaction time. The obtained values for the antioxidant capacity of the hydrolysed products show a higher activity compared to the starting substrates. The highest activity in the milk hydrolysates of 11.32 mg TE/100 ml was found in variant MB3, and in the whey hydrolysates of 7.83 mg TE/100 ml - in variant WP7. Hydrolysates treated with chymosin had lower TE values compared to the hydrolysate’s variants, treated with papain and bromelain.

Breed and Feeding System Impact the Bioactive Anti-Inflammatory Properties of Bovine Milk.

In the present study, we aimed at assessing the influence of breed and feeding system on the bovine milk profile of betaines and carnitines and milk capacity in counteracting the inflammatory endothelial cell (EC) damage induced by interleukin (IL)-6. In the first experimental design, two breeds were chosen (Holstein vs. Modicana) to investigate the biomolecule content and antioxidant capacity in milk and dairy products. In the second experimental design, two feeding systems (pasture vs. total mixed ratio) were tested only in Holstein to evaluate the possible effect on the functional profile of milk and dairy products. Finally, the bulk milk from the two experimental designs was used to evaluate the efficacy of preventing IL-6-induced endothelial inflammatory damage. Results showed that Modicana milk and whey had higher biomolecule content and antioxidant activity compared to Holstein milk (p < 0.01). Milk from Holstein fed TMR showed higher concentration of γ-butyrobetaine, δ-valerobetaine (p < 0.01), and l-carnitine (p < 0.05). Similarly, whey from Holstein fed TMR also showed higher content of δ-valerobetaine, glycine betaine, l-carnitine, and acetyl-l-carnitine (p < 0.01) compared to the Holstein fed pasture. Conversely, the antioxidant activity of milk and dairy products was not affected by the feeding system. In ECs, all milk samples reduced the IL-6-induced cytokine release, as well as the accumulation of reactive oxygen species (ROS) and the induction of cell death, with the most robust effect elicited by Modicana milk (p < 0.01). Overall, Modicana milk showed a higher content of biomolecules and antioxidant activity compared to Holstein, suggesting that the breed, more than the feeding system, can positively affect the health-promoting profile of dairy cattle milk.

Content and bioaccessibility of bioactive compounds with potential benefits for macular health in tiger nut products

Clinical studies have associated the consumption of tiger nuts (Cyperus esculentus L.), and its derivates, with improved macular health, due to the presence of certain liposoluble compounds with antioxidant activity, especially to lutein and zeaxanthin. However, the benefits derived from ingestion of tiger nut products may vary depending on the release of these compounds from the food matrix to the digestive fluids and their eventual bioabsorption. Therefore, this study aims at evaluating the influence of the food matrix on the liberation and final bioaccessibility of bioactive compounds with positive impact on macular health in different tiger nut products (flour, oil, and milk with and without added sucrose). The in vitro digestibility of macronutrients and the release of vitamin E, lutein, zeaxanthin, β-carotene, and total polyphenols of tiger nut products was studied. In addition, the antioxidant activity of the bioaccessible fraction was determined by ABTS, DPPH and FRAP assays. Results showed that tiger nut milk resulted in the greatest proteolysis and total polyphenols bioaccessibility. Moreover, flour can contribute to hypoglycaemia and, alongside oil, were the best sources of carotenoids and vitamin E. Gastrointestinal digestion increased the antioxidant activity of milk, but the addition of sucrose decreased this effect. The food matrix was a highly relevant factor protecting or hindering the digestion and release of bioactive compounds in the digestive environment. Thus, tiger nut products are presented as ingredients with great potential to develop functional foods oriented to macular health.

Antioxidant Activity of Milk and Dairy Products.

Simple SummaryConsumption of food products that are rich in natural antioxidants improves the antioxidant status of an organism through protection against oxidative stress and damage. Milk and dairy products (yogurt and cheese) accounting for approximately 25–30% of the average human diet are undoubtedly a rich source of compounds exhibiting antioxidant properties. The aim of the study was to present a review of literature data on the antioxidant potential of raw milk and dairy products (milk, fermented products, and cheese) and the possibility to modify its level at the milk production and processing stage. The antioxidant capacity of milk and dairy products is mainly related to the presence of sulfur amino acids, whey proteins (especially β-lactoglobulin), vitamins A, E, and C, or β-carotene. The processes of fermentation or cheese maturation are associated with the release of bioactive peptides, which are responsible for the level of the antioxidant status of the product. The use of probiotic strains significantly enhances the antioxidant status. The antioxidant status of milk and dairy products can be modified with the use of natural additives in animal nutrition or at the stage of milk processing. Herbal mixtures, seeds, fruits, and waste from the fruit and vegetable industry are used most commonly. It is worth emphasizing that regular consumption of natural dairy antioxidants minimizes the risk of development of civilization diseases (e.g., cardiovascular disease, cancer, or diabetes). It also slows down the aging process in the organism.The aim of the study was to present a review of literature data on the antioxidant potential of raw milk and dairy products (milk, fermented products, and cheese) and the possibility to modify its level at the milk production and processing stage. Based on the available reports, it can be concluded that the consumption of products that are a rich source of bioactive components improves the antioxidant status of the organism and reduces the risk of development of many civilization diseases. Milk and dairy products are undoubtedly rich sources of antioxidant compounds. Various methods, in particular, ABTS, FRAP, and DPPH assays, are used for the measurement of the overall antioxidant activity of milk and dairy products. Research indicates differences in the total antioxidant capacity of milk between animal species, which result from the differences in the chemical compositions of their milk. The content of antioxidant components in milk and the antioxidant potential can be modified through animal nutrition (e.g., supplementation of animal diets with various natural additives (herbal mixtures, waste from fruit and vegetable processing)). The antioxidant potential of dairy products is associated with the quality of the raw material as well as the bacterial cultures and natural plant additives used. Antioxidant peptides released during milk fermentation increase the antioxidant capacity of dairy products, and the use of probiotic strains contributes its enhancement. Investigations have shown that the antioxidant activity of dairy products can be enhanced by the addition of plant raw materials or their extracts in the production process. Natural plant additives should therefore be widely used in animal nutrition or as functional additives to dairy products.

Impact of ultrasound treatment on viability of Staphylococcus aureus and the human milk antioxidant activity

This study aimed to evaluate the application of thermosonication for the viability of Staphylococcus aureus and the antioxidant activity of HM. The US effect on the S. aureus was measured by counting viable cells in discarded HM immediately before and after different treatments varying time (1, 5 and 10 minutes) and temperature (20, 30, 40, 50 and 60 °C) through surface plating on standard agar. The antioxidant activity evaluation was carried out by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. With Regarding microbiological quality, it can be concluded that treatment with US at 60 °C for 10 minutes was the most effective in terms of reducing the viability of S. aureus, in addition to presenting a significant increase in the content of antioxidants when compared to raw and pasteurized milk samples.

Evaluating the Suitability of Hazelnut Skin as a Feed Ingredient in the Diet of Dairy Cows.

Simple SummaryAgriculture is estimated to generate about 700 million tons of waste annually in the Eurpoean Union (EU). Most of the by-products derived from the agricultural industry become organic waste, thus resulting in the loss of valuable nutrients and bioactive compounds and causing environmental and economic issues. Increasing the efficiency of waste management is a major global challenge that must be met in order to minimize the abovementioned negative impacts. Some agro-industrial by-products can be valorized by their inclusion in feed formulations. Hazelnut skin is a by-product of the hazelnut industry. It is a good source of phenolic compounds, polysaccharides, unsaturated fatty acids, and vitamin E. In this study, we evaluated the productive performance of dairy cows in response to the inclusion of hazelnut skin in the diet. We observed no effects of hazelnut skin on either the milk production level or fat and protein contents. The oleic acid concentration in milk was strongly increased by including hazelnut skin in the cows’ diet. Improvements in the antioxidant activity and sustainability of milk production in terms of food–feed competition were also observed. These results are of practical application for feed manufacturers and farmers, as they support the inclusion of sustainable and low-cost feed ingredients in ruminant diets, with the aim of supporting the expected increase in livestock production in the upcoming years.Hazelnut skin (HS) was evaluated as a source of nutrients for dairy cows. In total, 26 Aosta Red Pied cows were divided into two balanced groups. All cows were fed hay ad libitum. The control group was also given 6 kg of concentrate, while the hazelnut skin group (HAZ) was given 1 kg of the same concentrate that was substituted by 1 kg of HS. The dry matter intake of the cows was reduced by the dietary inclusion of HS (p ≤ 0.001). The milk yield and main constituents were unaffected by treatment. Milk from HAZ cows showed decreased concentrations of de novo saturated fatty acids (FAs), odd- and branched-chain FA, α-linolenic acid, and long-chain n-3 FAs, as well as increased concentrations of stearic acid, oleic acid, linoleic acid, total monounsaturated FAs, trans biohydrogenation intermediates, and α–tocopherol. Replacing the concentrate with HS increased the human-inedible feed quota in the diet and improved the sustainability of milk production in terms of the food-feed competition. Our results suggest that it is possible to add economic value to organic waste from the hazelnut industry using HS as a feed ingredient for dairy cows, enhancing the feed efficiency and milk antioxidant activity and having expected impacts on the nutraceutical quality of milk fat.

Can Agro-Industrial By-Products Rich in Polyphenols be Advantageously Used in the Feeding and Nutrition of Dairy Small Ruminants?

Simple SummaryIn the Mediterranean area, where dairy sheep and goats are widespread, the use of by-products in the diet of small ruminants is an ancient practice. Today the great availability of industrial by-products produced at the local level (e.g., grape, olive, tomato and myrtle residues), appears to be a promising strategy for reducing competition with human edible foods and the cost of off-farm produced feeds since they are imported worldwide. Moreover, these co-feeds can contribute to reducing the ecological and water footprint associated with crop cultivation. The presence of bioactive compounds, such as polyphenols, confers added value to these materials. Several positive aspects are apparent when such by-products are included in the diets of small dairy ruminants, in particular on ruminal metabolism, animal health, and the quality of derived products.Recently, the interest in industrial by-products produced at the local level in Mediterranean areas, resulting from fruit and vegetable processes, has increased because of their considerable amounts of bioactive compounds, including polyphenols. In this review, we analyze the most recent scientific results concerning the use of agro-industrial by-products, naturally rich in polyphenols (BPRP), in the diets of small dairy ruminants. Effects on milk production, milk and rumen liquor fatty acid profile, metabolic parameters, and methane production are reviewed. The feed intake and digestibility coefficients were generally depressed by BPRP, even though they were not always reflected in the milk yield. The main observed positive effects of BPRP were on quality of the milk’s FA profile, antioxidant activity in milk and blood, a reduction of rumen ammonia, and, consequently, a reduction of milk and blood urea. The expected beneficial effects of dietary polyphenols in small ruminants were not always observed because of their complex and variable matrices. However, owing to the large quantities of these products available at low prices, the use of BPRB in small ruminant nutrition offers a convenient solution to the valorization of residues arising from agricultural activities, reducing feed costs for farmers and conferring added value to dairy products at the local level, in a sustainable way.

Effect of heat treatments on antioxidant properties and insulin content of camel milk

The aim of this study was to evaluate the changes in antioxidant activity and insulin content of camel milk after thermal treatment. Camel milk samples were collected from dairy farm (ICAR-National Research Centre on Camel, Bikaner, India). The samples were processed with two heat treatment methods: High Temperature Short Time (HTST) and Low Temperature and Long Time (LTLT) and fresh camel milk (untreated) was used as control. The antioxidant activity of the milk was measured by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and 2, 2’-azino-bis (3-ethylbenzthiazoline-6-sulfonate) (ABTS) radical scavenging activity. Insulin concentration was determined using ELISA kits in the different milk samples. DPPH radical scavenging activity was significantly lower (p 0.05) difference in the insulin content in heat treated groups when compared with control group. Thus, data suggested that the milk processing by HTST pasteurisation preserves the antioxidant activity as well as insulin content in camel milk.

Antioxidant Activity and Consumer Acceptance Level in Milk Enriched With Phlorotanin of Sargassum sp.

Brown seaweed Sargassum sp. contains florotanin which can be used as an antioxidant. The objective of this study was to determine the effect of the addition of Sargassum sp. on the antioxidant activity and consumer preferences of milk. Sargassum sp. was extracted using 50% ethanol followed by ethyl acetate. The florotanin extract was added to the pasteurized milk at a concentration of 0; 0.25; 0.50% (w/w). The milk was then tested for antioxidant activity, pH, and chemical composition, also the levels of consumer acceptance. The results showed that the antioxidant activity of milk added with florotanin extract at 0; 0.25%; 0.50% and commercial milk were 57.64±1.4%; 67.5±6.1%; 71.9±8.74%; and 32.5±5.77%, respectively. The addition of florotanin extract had no significant effect (p&gt; 0.05) on pH and chemical composition but had a significant effect on antioxidant activity and consumer acceptance (p &lt;0.05), especially at the level of preference for aroma and taste which tended to decrease.

Impact of Bovine Lipocalin-2 Gene on the Antioxidant Activity of Milk from Polish Holstein-Friesian Cows

Simple SummaryRecently, an increased interest in high health-value food products rich in natural antioxidants has been observed. Milk and milk products are one of the richest sources of biologically active compounds with antioxidant properties in products of animal origin. Lipocalin-2 (LCN2) is a small secreted protein, which is involved in inflammatory processes. Due to the fact that LCN-2 can be produced by various types of cells in response to oxidative stress and LCN2 gene polymorphism has been associated with the somatic cells count in cow’s milk, the aim of this study was to validate the association of LCN2 polymorphism with antioxidant activity of milk from Holstein-Friesian cows. Four single nucleotide polymorphisms (SNPs) was identified, one of which g.98793763G>C was associated with higher antioxidant capacity in milk. The antioxidant capacity of milk also varied according to the age of cows, their daily milk yield, and somatic cell count (SCC) in milk.In the recent years, antioxidant properties of food products have become an important aspect for consumers. Milk is a very good source of easily absorbable proteins and minerals, as well as a valuable source of antioxidants. Lipocalin-2 (LCN2), given that, inter alia, it is produced in large quantities by various types of cells in response to oxidative stress caused by physical or chemical factors, it can be considered a protein that determines the total antioxidant capacity of milk. The main objective of this study was to analyze polymorphisms within the lipocalin-2 gene and to determine their impact on antioxidant activity of milk from Holstein-Friesian cows. The genotyping was carried out by sequencing of PCR products. To determine the antioxidant activity of milk, the Trolox equivalent antioxidant capacity (TEAC) method was used. A total of four polymorphic sites were identified in the examined segment of the bovine lipocalin-2 gene. It was shown that cows of the CC genotype at the locus g.98793763G>C produced milk of significantly higher antioxidant capacity. The antioxidant capacity of milk also varied according to the age of cows, their daily milk yield, and SCC in milk.

Role of antioxidant molecules in milk of sheep

Abstract Sheep milk contains a large number of antioxidant molecules, such as whey proteins, vitamins, fatty acids and others. In sheep milk the oxidation process is naturally balanced by the presence of constitutive antioxidant agents, however, the abundance of this antioxidant compounds depends also by the stressor conditions to which animal can be exposed. The stage of lactation together with particular environmental conditions, such as the high ambient temperatures, can cause an imbalance between oxidants and antioxidants, being responsible for the oxidative stress that can be measured both in plasma and in milk samples. Different methods to measure the antioxidant activity of milk have been proposed, according to each single antioxidant compounds and to the need for consumers’ health of decreasing the exposition to oxidized proteins capable for creation of a novel class of allergens. However, the golden standard for the measurement of antioxidant activity in milk has not still found. Therefore, the present review aims at describing the roles of various antioxidant molecules of milk, and provides an overview of the different methods available to measure the total antioxidant capacity of milk.

Short communication: Space allocation in intensive Mediterranean buffalo production influences the profile of functional biomolecules in milk and dairy products

The aim of the present study was to determine if space allocation influenced the concentration of biomolecules in buffalo milk and dairy products. Intensively housed buffaloes (n = 96) were randomly assigned to 2 groups according to days in milk, parity, and milk yield: group S10 had a space allocation of 10 m2 per buffalo and group S15 had a space allocation of 15 m2 per buffalo. Individual milk yield was recorded daily. Twice a month, a bulk milk sample was collected for each group, as well as whey, ricotta, and mozzarella cheese, to assess cheese yield and to conduct HPLC-electrospray ionization-tandem mass spectrometry, milk antioxidant activity, and cell viability analyses. We tested milk extracts from the 2 groups in vitro to evaluate their efficacy in counteracting endothelial oxidative damage induced by high glucose. We evaluated reproductive function in 28 buffaloes from each group using the Ovsynch-timed artificial insemination program. We observed no differences in milk quantity or quality in terms of fat, protein, or lactose, and reproductive function did not differ between the 2 groups. Compared with group S10, group S15 had higher concentrations of carnitine (56.7 ± 1.1 vs. 39.8 ± 0.7 mg/L in milk and 40.9 ± 0.8 vs. 31.7 ± 0.7 mg/L in whey), acetyl-l-carnitine (51.9 ± 0.3 vs. 39.7 ± 0.7 mg/L in milk and 41.1 ± 1.7 vs. 28.7 ± 2.6 mg/L in whey), propionyl-l-carnitine (34.8 ± 1.0 vs. 21.0 ± 0.9 mg/L in milk and 26.9 ± 0.8 vs. 17.6 ± 1.2 mg/L in whey), glycine betaine (23.1 ± 1.9 vs. 13.5 ± 1.6 mg/L in milk and 10.7 ± 0.4 vs. 7.9 ± 0.5 mg/L in whey), and δ-valerobetaine (24.2 ± 0.5 vs. 16.7 ± 0.5 mg/L in milk and 22.0 ± 0.9 vs. 15.5 ± 0.7 mg/L in whey). Group S15 also had higher total antioxidant activity than group S10 (56.7 ± 1.9 vs. 46.4 ± 1.13 mM Trolox equivalents). Co-incubation of high-glucose-treated endothelial cells with milk extracts from group S15 improved cell viability compared with cells treated with high glucose only; it also reduced intracellular lipid peroxidation (144.3 ± 0.4 vs. 177.5 ± 1.9%), reactive oxygen species (141.3 ± 0.9 vs. 189.3 ± 4.7 optical density units), and cytokine release (tumor necrosis factor-α, IL-1β, IL-6). Greater space allocation was associated with higher levels of biomolecules in buffalo milk. This could have been the result of improved welfare in buffaloes that were allocated more space.