Antioxidant capacity of bovine milk as assayed by spectrophotometric and amperometric methods

Evaluation of close up antimicrobial therapies for treatment and prevention of subclinical mastitis in the herds with high prevalence of Staphylococcus aureus

This field trial was conducted to evaluate two antibiotics at a close-up period in curing the existing IMI and to prevent new clinical and subclinical Intramammary infection (IMI). Two hundred and twelve Holstein cows were assigned to one of three treatment groups: TYLO, MARB and CONT. Cows in TYLO group received 10 mg/kg Tylosin for three days at the close-up period (21 days before calving), cows in MARB group received single SC injection of 8 mg/kg SC marbofloxacin at the close-up period and cows in CONT group remained untreated. Milk samples were collected for somatic cell count, microbial culture and Total oxidant/antioxidant capacity before drying-off, and 3 and 7days post calving. Antimicrobial susceptibility test and RAPT-PCR were performed on S.aureus isolates. No significant differences were detected in total cure rate within the groups, but S. aureus cure rates in TYLO and MARB were significantly higher than in CONT (74 and 73.5 % Vs 58.1 %). No significant differences in total new IMI were observed. Furthermore, the rate of new S. aureus IMI was higher in both treatment groups than in CONT group. Clinical mastitis rate in TYLO (3.8 %) and MARB (5.8 %) was significantly lower than CONT (11.3 %). Paired S. aureus isolates from dry-off and post-calving have been clustered into 9 different RAPD types (A-I). 8 paired strains collected at dry-off were identical to those at post-calving,and 35 strains had more than 60 % dissimilarity. Administration of Tylosin or Marbofloxacin is not useful in all cases;however, they have the potential to reduce the incidence of post-calving clinical mastitis and improve S.aureus cure rate if used selectively.

Formation of di-Tyrosine in pasteurized milk during shelf storage

Formation of the protein crosslink di-Tyrosine was studied in PET-bottled pasteurized milk exposed to fluorescent light in a commercial display cabinet. An HPLC method with fluorescence detection was developed and intra-laboratory validated using pure di-Tyrosine synthesized on purpose. Di-Tyrosine was detected after 1-day lightening and increased up to 7 days, reaching around 250 and 320 µg/g protein in whole and partly skimmed milk, respectively. Afterward, a progressive decrease occurred. By transmission electron microscopy with specific immune gold labelling, presence of di-Tyrosine was observed for the first time on the surface of casein micelles of lightened milk. The crosslink formation, however, did not bring to protein aggregation phenomena detectable by laser light scattering measurements. Exposure to light also induced degradation of riboflavin and decrease of yellowness index. Di-Tyrosine proved to be a suitable indicator to evaluate the progress of protein oxidation in pasteurized milk during storage on the market.

Promising role of Lawsonia inermis L. leaves extract and its nano-formulation as double treatment against aflatoxin toxicity in ulcerated-rats: Application in milk beverage

Aflatoxins are an unavoidable contaminant of foods. The current work aimed to study the ameliorating effect of Lawsonia inermis L. extract and its nano-formulation versus aflatoxin ingestion in ulcerative rats. Lawsonia inermis L. bioactivity was evaluated by both antioxidant & antimicrobial assays. The nanoparticles characterization measurements were evaluated. Different parameters in the fortified milk beverage were assessed. Seventy two Sprague-Dawley male rats were randomized into 12 groups (6 rats/group) where peptic ulcer was induced with a single aspirin dose (500 mg/kg BW) orally. The nutritional and biochemical parameters were evaluated. The results showed that antioxidant activity and total phenolic content increased with increasing nano-formulation ratio. A remarkable improvements in all the treated groups, either for ulcer alone or for aflatoxin exposed ulcerative groups in normal and nano-formulation. Conclusively, Lawsonia inermis L. & its nano-formulation could act as dual therapy for ulcer treatment and the hazardous effects of aflatoxin exposure.

Compositional Differences of Greek Cheeses of Limited Production

Greece has a long tradition in cheesemaking, with 22 cheeses registered as protected designation of origin (PDO), 1 as protected geographical indication (PGI), and 1 applied for PGI. Several other cheeses are produced locally without any registration, which significantly contribute to the local economy. The present study investigated the composition (moisture, fat, salt, ash, and protein content), color parameters, and oxidative stability of cheeses that do not have a PDO/PGI certification, purchased from a Greek market. Milk and cheese types were correctly assigned for 62.8 and 82.1 % of samples, respectively, through discriminant analysis. The most important factors for milk type discrimination were L, a and b color attributes, salt, ash, fat-in-dry-matter, moisture-in-non-fat-substance, salt-in-moisture, and malondialdehyde contents, whereas a and b, and moisture, ash, fat, moisture-in-non-fat substance contents, and pH were the most influential characteristics for sample discrimination according to cheese type. A plausible explanation may be the differences in milk chemical composition between three animal species, namely cows, sheep, and goats and for the manufacture procedure and ripening. This is the very first report on the proximate analysis of these, largely ignored, chesses aiming to simulate interest for further study and production valorization.

The Importance of Dietary Antioxidants on Oxidative Stress, Meat and Milk Production, and Their Preservative Aspects in Farm Animals: Antioxidant Action, Animal Health, and Product Quality-Invited Review

The biological effects of oxidative stress and associated free radicals on farm animal performance, productivity, and product quality may be managed via dietary interventions-specifically, the provision of feeds, supplements, and forages rich in antioxidants. To optimize this approach, it is important first to understand the development of free radicals and their contributions to oxidative stress in tissue systems of farm animals or the human body. The interactions between prooxidants and antioxidants will impact redox homeostasis and, therefore, the well-being of farm animals. The impact of free radical formation on the oxidation of lipids, proteins, DNA, and biologically important macromolecules will likewise impact animal performance, meat and milk quality, nutritional value, and longevity. Dietary antioxidants, endogenous antioxidants, and metal-binding proteins contribute to the 'antioxidant defenses' that control free radical formation within the biological systems. Different bioactive compounds of varying antioxidant potential and bio-accessibility may be sourced from tailored feeding systems. Informed and successful provision of dietary antioxidants can help alleviate oxidative stress. However, knowledge pertaining to farm animals, their unique biological systems, and the applications of novel feeds, specialized forages, bioactive compounds, etc., must be established. This review summarized current research to direct future studies towards more effective controls for free radical formation/oxidative stress in farm animals so that productivity and quality of meat and milk can be optimized.

Essential and Toxic Mineral Content and Fatty Acid Profile of Colostrum in Dairy Sheep

Simple Summary

Colostrum is of interest to the scientific community because of its nutritional and therapeutic capabilities. The aims of this study were to characterize the macro and micro composition of colostrum from Sarda dairy sheep and to compare it with the composition of the mature milk of the same breed. The results of this survey showed a large variation in the immunoglobulin concentration in colostrum, which could affect the acquisition of passive immunity by lambs. The strong correlation between immunoglobulin G and the total protein content suggests that this can be used to estimate the immunoglobulin content in sheep colostrum. The concentration of essential minerals is higher in colostrum than in milk as a result of mineral salt block supplementation at the end of gestation. Colostrum has a significantly different fatty acid profile than milk, and this is due to the specific needs of newborn lambs.

Abstract

Colostrum is a major source of immunity in ruminants. It allows the transfer of antibodies from the mother to the fetus, and it is the exclusive source of nutrients for the newborn. The objectives of this study were (i) to characterize the macro and the micro composition of colostrum; (ii) to analyze the antioxidant capacity, fatty acid profile, and essential and toxic mineral content of colostrum; and (iii) to compare FA profiles and the amount of trace elements between colostrum and mature milk. For these purposes, samples of colostrum and milk were collected from a representative sample of animals from eight sheep dairy farms in the north of Sardinia (Italy). Fat, proteins, and seven essential and toxic minerals were measured in all samples of colostrum and milk. Furthermore, the FA profile was also measured in both matrices, while total antioxidant capacity was measured only in colostrum samples. The average amounts of fat and protein (TP) concentration in colostrum were 7.8% and 16%, respectively. Additionally, an average amount of 40 ± 20 g dm⁻³ was found for immunoglobulin G (IgG). As regards the antioxidant capacity of colostrum, a large variation was observed between samples from different farms for test 2, 2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), which was 30 ± 10% (mean ± standard deviation). High levels of selenium (Se), zinc (Zn), and copper (Cu) were found in colostrum (200 µg kg⁻¹, 25,000 µg kg⁻¹, and 1200 µg kg⁻¹, respectively). A strong positive correlation between TP and IgG was observed (r = 91%). In colostrum, the amount of IgG is positively correlated with Se and Zn, as they are essential minerals to the immune system. The FA profile demonstrated higher levels of medium and long chain fatty acids in colostrum than in mature milk, and this is mainly true for arachidonic acid (ARA), ecosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA). This study provided new information on the quality of colostrum in Sarda dairy sheep and showed the different composition of fatty acids between colostrum and mature milk.

Milk tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), interferon (IFN-γ) and oxidative stress markers as new indicators for fascioliasis in dairy water buffaloes

Sixty Bubaline milk samples with corresponding blood samples were obtained from flocks at random in Cairo and Giza Governorates. The aerobic bacteria & somatic cells were counted and evaluated the physicochemical parameters of milk. Both milk and serum of buffaloes' were evaluated for tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interferon (IFN-ɤ) by quantitative real-time PCR protocol, and oxidative stress markers were measured spectrophotometrically. There was a significant difference (p < 0.05) between the mean values of whole milk physicochemical aspects except the moisture % & pH values were recorded for infested and non-infested animals. For F. gigantica infested animals, the milk TNF-α, IL-1β, interferon IFN-γ, malondialdehyde (MDA), and total antioxidant capacity (TAC) values were 17.5 ± 0.67, 18.5 ± 0.71, 19.25 ± 0.74, 7.75 ± 0.29, and 1.1 ± 0.04, respectively (lesser than serum values) with a significant difference (p < 0.05) between positive and negative samples for both examined serum and milk samples. There was also a significant (p < 0.05) negative relationship between MSCC & fat% and protein%, while a significant (p < 0.05) positive relationship between MSCC and the investigated milk cytokines in F. gigantica infested animals. This study is considered one of the fewest investigations of milk cytokines and oxidative stress markers in buffaloes fascioliasis diagnosis. Meanwhile, monitoring these genes modification that is active in the milk-producing gland is significant to typify the act technicality of the inherited immunity that helps the progress of schemes to retain the udder health.

The Effect of Sustainable Feeding Systems, Combining Total Mixed Rations and Pasture, on Milk Fatty Acid Composition and Antioxidant Capacity in Jersey Dairy Cows

This study was carried out to assess the effect of using pasture combined with total mixed ration (TMR) on milk production and composition, fatty acid (FA) profiles, fat-soluble antioxidant content, and total milk antioxidant capacity (TAC). In addition, the effect of milk pasteurization and storage at 2 °C for 4 days, lipophilic antioxidants and TAC were assessed. Two homogeneous groups of Jersey cows (n = 8) were constituted, which were randomly assigned to one of the two treatments: TMR (without access to pasture), or partial mixed diet (pTMR: grazing 8 h/day + TMR indoors). To establish FA profiles and lipophilic antioxidants’ changes in milk during the grazing period, in case of the pTMR group the experimental period was spilt in three grazing periods: P1 (May), P2 (June), and P3 (June/July). Milk yielded from cows having limited access on pasture (pTMR diet) showed an improved FA profile, with higher concentrations of FAs considered benefic for human health (vaccenic acid (VA), conjugated linoleic acid (CLA), omega-3 FA (n-3 FA)) (p < 0.01) and a lower concentration of FAs with hypercholesterolemiant potential (C12:0, C14:0, and C16:0) (p < 0.05), compared to that of the TMR diet. This change in FA profile was correlated with improved sanogenous lipid indices of milk fat (n-6/n-3 FA atherogenic index and thrombogenic index). Milk yielded during the P1 grazing period had higher concentrations of VA, CLA, and n-3 FA (p < 0.05) and lower concentrations of C14:0 and C16:0 (p < 0.01); it exhibited the best values for the main sanogenous fat lipid indices of fat. Moreover, pTMR milk showed a higher α-tocopherol, retinol, and β-carotene content (p < 0.05), positively correlated with TAC values in milk (P1 ˃ P2 ˃ P3). By comparison, cows fed using the TMR diet yielded a higher quantity of milk (p < 0.05), but a lower fat and protein content (p < 0.01), and also a higher saturated FAs and n-6 FA content (p < 0.05) together with a lower concentration of lipophilic antioxidants in milk. Thermal treatment showed no effect on α-tocopherol and retinol content in milk, but their concentrations decreased during the storage, at the same time a TAC decrease. The results of this study prove the positive effect of using pasture combined with TMR on FA profiles, milk antioxidant content, and antioxidant capacity, with beneficial effects on nutrition and health in humans.

A statistical strategy for optimizing the production of α-galactosidase by a newly isolated Aspergillus niger NRC114 and assessing its efficacy in improving soymilk properties

Background

α-Galactosidase is widely distributed in plants, microorganisms, and animals, and it is produced by different fungal sources. Many studies have confirmed the valuable applications of α-galactosidase enzymes for various biotechnological purposes, like the processing of soymilk.

Results

Aspergillus niger NRC114 was exploited to produce the extracellular α-galactosidase. One factor per time (OFT) and central composite design (CCD) approaches were applied to determine the optimum parameters and enhance the enzyme production. The CCD model choices of pH 4.73, 1.25% mannose, 0.959% meat extract, and 6-day incubation period have succeeded in obtaining 25.22 U/mL of enzyme compared to the 6.4 U/mL produced using OFT studies. Treatment of soymilk by α-galactosidase caused an increase in total phenols and flavonoids by 27.3% and 19.9%, respectively. Antioxidant measurements revealed a significant increase in the enzyme-treated soymilk. Through HPLC analysis, the appearance of sucrose, fructose, and glucose in the enzyme-treated soymilk was detected due to the degradation of stachyose and raffinose. The main volatile compounds in raw soymilk were acids (45.04%) and aldehydes (34.25%), which showed a remarkable decrease of 7.82% and 20.03% after treatment by α-galactosidase.

Conclusions

To increase α-galactosidase production, the OFT and CCD approaches were used, and CCD was found to be four times more effective than OFT. The produced enzyme proved potent enough to improve the properties of soymilk, avoiding flatulence and undesirable tastes and odors.

Graphical Abstract

Antioxidant Activity of Milk and Dairy Products

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.

Detection of anti-Neospora caninum antibodies in sheep's full-cream milk by a time-resolved fluorescence immunoassay

Ovine neosporosis, caused by the Apicomplexan parasite Neospora caninum, leads to reproductive failure worldwide. Nowadays, there is a trend to develop diagnostic techniques using non-invasive samples, such as milk, in order to reduce animal stress, sample collection effort, and costs. The objective of this study was to develop and validate a highly sensitive and specific serological technique, based on a time resolved-fluorescence immunoassay using a N. caninum GRA7 antigen (GRA7-TRFIA), for the detection of anti-N. caninum immunoglobulins G on sheep' full-cream milk samples. An analytical validation was performed, including intra- and inter-assay precision, analytical sensitivity and accuracy. The diagnostic performance of the assay was evaluated by studying the positive-negative discrimination by Mann Whitney U tests. In additon optimal cut-offs, diagnostic sensitivity and specificity, and areas under the curve were calculated by three Receiver Operating Curve (ROC) analyses, using GRA7-TRFIA and a N. caninum tachyzoite soluble extract-based ELISA (NcSALUVET-ELISA) in blood sera, and the coinciding results of both techniques, as reference techniques. Moreover, Spearman's correlation of GRA7-TRFIA in milk with the techniques in sera and agreement (kappa values) were also estimated. GRA7-TRFIA for milk samples showed an adequate precision, with high analytical sensitivity and accuracy. Regarding ROC analyses, at the optimal cut-offs, the diagnostic sensitivity and specificity were more than 90 % in all cases. In addition, GRA7-TRFIA values in milk were more positively correlated to GRA7-TRFIA values in blood sera than in the case of values obtained with NcSALUVET-ELISA. GRA7-TRFIA in milk showed an almost perfect agreement with GRA7-TRFIA in blood sera (kappa = 0.98) and with the coinciding results of GRA7-TRFIA and NcSALUVET in blood sera (kappa = 1.00), while it has a substantial agreement with NcSALUVET-ELISA (kappa = 0.69). In the light of these results, GRA7-TRFIA in full-cream milk samples is a highly sensitive technique that could be used for screening anti-N. caninum antibodies in sheep flocks.

Effect of Storage and Heat Treatment of Milk Destined for Cheese Production on Its Oxidative Characteristics

The oxidative stability of milk and dairy products is a very interesting topic for the dairy industry due to the growing demand for foods containing bioactive compounds with positive health effects. The aim was to evaluate the oxidative stability of milk intended for cheese production. The effect of storage time, heat pre-treatment, and milk pasteurization temperature on the characteristics of milk and cheese was investigated. The cheese samples were produced with pasteurized milk at both 72 and 77 °C for a time of 15 s using three types of milk: raw fresh milk processed within 48 h of milking, raw stored milk processed within 96 h, and thermized milk that was heat-treated upon arrival at the dairy and processed within 96 h of milking. In total, three repetitions were carried out for each type of milk and pasteurization. Samples of milk before and after pasteurization and cheese at 14 days of storage were analyzed. Antioxidant activity decreased from starting milk to milk after pasteurization to final cheese. The longer storage time of the milk had significant effects on the antioxidant stability of the cheese (64.95 vs. 59.05% of antioxidant activity). Thermization of the milk further reduced the stability of the cheese (54.05% of antioxidant activity). The greater antioxidant stability of fresh milk and cheeses produced with fresh milk is the first result that encourages the production of cheese from a milk that best preserves its original characteristics.

Milk metabolites, proteins and oxidative stress markers in dairy cows suffering from Staphylococcus aureus subclinical mastitis with or without spontaneous cure

Our objective was to evaluate relationships between milk components (acute phase proteins, enzymes, metabolic parameters and oxidative indices) and the spontaneous cure outcome of Staphylococcus aureus subclinical mastitis in dairy cows. The values of haptoglobin, serum amyloid A (SAA), malondialdehyde (MDA), total antioxidant capacity, milk urea nitrogen (MUN), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), electrolytes (Cl and K), total protein, albumin, α-lactalbumin, β-lactoglobulin, and immunoglobulin were measured in milk samples of S. aureus subclinical mastitis cows with spontaneous cure (n = 23), S. aureus subclinical mastitis cows without spontaneous cure (n = 29) and healthy cows (n = 23). The comparison of measured parameters revealed that subclinical mastitis cows with spontaneous cure had lower ALP and haptoglobin concentrations both at diagnosis and after cure (P < 0.05). In contrast, total antioxidant capacity and MDA concentration in subclinical mastitis cows without spontaneous cure significantly increased with time (P < 0.05). We can suggest that elevated haptoglobin concentration and higher ALP activity indicative of enhanced oxidative stress could potentially serve as early diagnostic indicators of chronic disease and the persistence of S. aureus subclinical mastitis in dairy cows.

Measurement of Antioxidant Capacity of Meat and Meat Products: Methods and Applications

At present, a wide variety of analytical methods is available to measure antioxidant capacity. However, this great diversity is not reflected in the analysis of meat and meat products, as there are a limited number of studies on determining this parameter in this complex food matrix. Despite this, and due to the interest in antioxidants that prevent oxidation reactions, the identification of antioxidants in meat and meat products is of special importance to the meat industry. For this reason, this review compiled the main antioxidant capacity assays employed in meat and meat products, to date, describing their foundations, and showing both their advantages and limitations. This review also looked at the different applications of antioxidant properties in meat and meat products. In this sense, the suitability of using these methodologies has been demonstrated in different investigations related to these foods.

The impact of the oxidative status on the reproduction of cows and the calves’ health – a review

The profitability of cattle farming is largely determined by ensuring high-quality breeding animals for replacement and longevity in production. The provision of breeding animals requires adequate fertility of the cowherd and then intensive weight gain in the calf rearing period. For ensuring these demands, many management aspects must be considered. Continuous monitoring of the herd’s health status, including redox status, is essential. This review aims to provide a summary of relevant scientific data published in the last few decades regarding the role of oxidative stress (OS) in infertility of dairy cows and developmental diseases in calves, the major predisposing factors, and possible prevention.

Chemical Characteristics and Oxidative Stability of Buffalo Mozzarella Cheese Produced with Fresh and Frozen Curd

Milk and dairy products can have variable contents of antioxidant compounds that contribute to counteract the oxidation of lipids and proteins during processing and storage. The content of active antioxidant compounds is closely linked to their protection by oxidation. Freezing is one of the factors that can reduce antioxidant activity. Freezing of milk or curd is frequently used in case of the seasonality of milk production and/or seasonal increased demand for some products. In this paper, the effect of using frozen curd on the oxidative stability of buffalo Mozzarella cheese was evaluated. Samples of buffalo Mozzarella with different frozen curd content (0%, 5%, 20%, and 50%) were produced and analyzed at one and nine days. Mozzarella cheese with higher frozen curd content had a significant increase in redox potential parallel to the decrease in antioxidant activity, showing less protection from oxidation. Lipid and protein oxidation, expressed respectively by malondialdehyde and carbonyl content, increased significantly with increasing frozen curd. At nine days, carbonyls significantly increased while malondialdehyde content did not vary, showing that during storage, fat was more protected from oxidation than protein. The average carbonyl levels were comparable to those of some cooked cheeses, and the malondialdehyde levels were even lower. The results of this study stimulate the investigation of new strategies to decrease the oxidative damage in cheeses produced in the presence of factors decreasing oxidative stability.

Genetic and Non-Genetic Variation of Milk Total Antioxidant Activity Predicted from Mid-Infrared Spectra in Holstein Cows

Simple Summary

The total antioxidant activity (TAA) of food is important for human health and results from the contribution of different nutraceutical compounds. Direct determination of TAA in food is time-consuming and expensive. Infrared technologies allow the prediction of difficult-to-measure traits with certain accuracy in several organic matrices, including TAA of bovine milk. In order to understand the background of TAA and identify potential strategies to improve this feature in bovine milk, we explored its non-genetic sources of variation and estimated heritability and correlations with traits of economic interest in a large database of Holstein cows.

Abstract

Food antioxidants enhance products shelf life and stability during technological treatments through the maintenance of their physical and chemical properties. Moreover, they are endowed with several positive effects on human health, including cell membranes preservation, enzyme functionality, and DNA integrity. Milk has been described in relation to a wide array of fat soluble and water-soluble antioxidant compounds, in particular vitamin A, C, and E, lactoferrin and peptides derived from casein and whey proteins. The total antioxidant activity (TAA) of milk is a novel and scarcely explored trait, defined as the sum of antioxidant contributions of the aforementioned compounds. On this background, the aims of the present study were to investigate the variability of milk TAA on a large scale exploiting predictions obtained through mid-infrared (MIR) spectroscopy and to estimate genetic parameters of this trait in Holstein cows. Individual milk samples were collected between January 2011 and December 2018 during the routine milk recording procedure. Samples were analysed for gross composition through MIR spectroscopy and MIR spectra were stored. Milk TAA was then predicted (pTAA) from the stored milk MIR spectra (111,653 test-day records of 9519 cows in 344 herds) using the previously developed prediction model; considering the prediction accuracy, pTAA might be considered a proxy of the TAA determined through the reference method. Overall, pTAA averaged 7.16 mmoL/L of Trolox equivalents, showed a nadir around 40 days after calving and increased thereafter, following a linear trend up to the end of lactation. The lowest pTAA was observed in milk sampled from June to September. Milk pTAA was heritable (0.401 ± 0.015) and genetically associated to fat yield (0.366 ± 0.049), crude protein (CP) yield (0.238 ± 0.052), fat percentage (0.616 ± 0.022) and CP percentage (0.754 ± 0.015). The official selection index of Italian Holstein put the 49% of the emphasis on fat and protein yield and percentage; therefore, it derives that an indirect favourable selection for milk pTAA should be already in progress in Italian Holstein population.

Volatile Profile in Yogurt Obtained from Saanen Goats Fed with Olive Leaves

The aim of this study was to evaluate the development of volatile compounds in yogurt samples obtained from goats fed a dietary supplementation with olive leaves (OL). For this purpose, thirty Saanen goats were divided into two homogeneous groups of 15 goats each: a control group that received a standard diet (CG) and an experimental group whose diet was supplemented with olive leaves (OLG). The trial lasted 28 days, at the end of which the milk of each group was collected and used for yogurt production. Immediately after production, and after 7 days of storage at 4 °C in the absence of light, the yogurt samples were characterized in terms of fatty acid profile, oxidative stability and volatile compounds by the solid-phase microextraction (SPME)-GC/MS technique. Dietary OL supplementation positively affected the fatty acid composition, inducing a significant increase in the relative proportion of unsaturated fatty acids, mainly oleic acid (C18:1 cis9) and linolenic acid (C18:3). With regard to the volatile profile, both in fresh and yogurt samples stored for 7 days, the OL supplementation induced an increase in free fatty acids, probably due to an increase in lipolysis carried out by microbial and endogenous milk enzymes. Specifically, the largest variations were found for C6, C7, C8 and C10 free fatty acids. In the same samples, a significant decrease in aldehydes, mainly heptanal and nonanal, was also detected, supporting-at least in part-an improvement in the oxidative stability. Moreover, alcohols, esters and ketones appeared lower in OLG samples, while no significant variations were observed for lactones. These findings suggest the positive role of dietary OL supplementation in the production of goats' milk yogurt, with characteristics potentially indicative of an improvement in nutritional properties and flavor.

Impact of post fermentation cooling patterns on fatty acid profile, lipid oxidation and antioxidant features of cow and buffalo milk set yoghurt

Background

In the manufacturing of set yoghurt, after reaching 4.6 pH, post fermentation cooling is applied to stop the bacterial activity. Depending upon the required textural and flavor attributes, one phase and two phase cooling patterns are accordingly selected. In one phase cooling, temperature of the yoghurt is rapidly decreased below 10 °C using blast freezing and then it is gradually dropped to 4-5 °C. In two phase cooling, temperature of yogurt is rapidly decreased to less than 20 °C and then it is gradually decreased to 4-5 °C. These cooling phases have a significant impact on textural and flavor perspectives of yoghurt. It is necessary to study the impact of industrially adopted cooling patterns on fatty acid profile, antioxidant characteristics, lipid oxidation and sensory characteristics of cow and buffalo milk set yoghurt.

Methods

This experiment was organized in a completely randomized design and every treatment was replicated five times to minimize the variation. Whole cow and buffalo milk without any standardization were converted to set yoghurt (400 g cups) using Strepotococcus thermophillus and Lactobacillus bulgaricus as starter bacteria. After reaching 4.6 pH, cow and buffalo yoghurt samples were exposed to three different cooling patterns. In first trial, samples of cow and buffalo yoghurt were cooled from 43 °C to 25 °C in 1 h and finally cooled to 4-5 °C in another hr. (T₁). In second trial, samples were cooled from 43 °C to 18 °C in 1 hr. and finally cooled down to 4-5 °C in another 1 h. (T₂). In third trial, samples were cooled from 43 °C to 4-5 °C in 2 h (T₁). Alteration in fatty acid profile, total antioxidant capacity, reducing power, free fatty acids, peroxide value, conjugated dienes, vitamin A, E, color and flavor of cow and buffalo yoghurt samples were assessed for 20 days at the frequency of 10 days.

Results

All the three cooling patterns had a non-significant effect on compositional attributes of yoghurt. Buffalo milk yogurt had higher percentage of fat, protein and total solids than yoghurt prepared from cow milk (p < 0.05). At zero day, DPPH free radical scavenging activity of T₂ and T₃ was significantly higher than T₁. This may be due to the longer exposure of T₁ at relatively higher temperature than T₂ and T₃. Effect of storage period up to 10 days was non-significant in T₂ and T_3. Reducing power of cow and buffalo milk yoghurt was also significantly affected by the cooling patterns applied. Reducing power of T₂ and T₃ was considerably higher than T₁ (p < 0.05). At zero-day, total antioxidant capacity of cow and buffalo milk yoghurt in T₃ was 42.6 and 61.4%, respectively. At zero day, total antioxidant capacity of T₂ and T₃ was significantly higher than T₁. Effect of storage on total antioxidant capacity of T₂ and T₃ remained non-significant till 10 days of storage. At zero day, the impact of cooling patterns on fatty acid profile of T₁, T₂ and T₃ was non-significant, whereas, storage period had a marked impact on fatty acid profile. After 10 days, T₁ was considerably different in fatty acids from T₂ and T₃. After 10 days of storage of cow milk yoghurt in T₁, concentration of C_4:0, C_6:0, C_8:0, C_10:0, C_12:0, C_14:0, C_16:0, C_18:0, C_18:1 and C_18:2 decreased by 0.1, 0.11, 0.09, 0.07, 0.21, 0.38, 0.28, 0.27, 0.44 and 0.06%, respectively. Cow milk yoghurt in T₁ after 10 days of storage, concentration of C_4:0, C_6:0, C_8:0, C_10:0, C_12:0, C_14:0, C_16:0, C_18:0, C_18:1 and C_18:2 decreased by 0.07, 0.15, 0.04, 0.17, 0.20, 0.34, 0.27, 0.36 and 0.04%, respectively. After 10 days of storage in T₂ and T₃, loss of fatty acids was 1.2 and 3.61% from C_4:0 to C_10:0, respectively. Milk type had no effect on peroxide value of yoghurt. Cooling of cow and buffalo yoghurt from 43 °C to 25 °C had a pronounced effect on peroxide value. At zero day, peroxide values of cow and buffalo yoghurt in T₁ were 0.32 and 0.33 (MeqO₂/kg). At zero day, peroxide value of cow and buffalo yoghurt in T₂ were 0.24 and 0.26 (MeqO₂/kg). At zero day, peroxide value cow and buffalo yoghurt in T₃ were 0.23 and 0.25 (MeqO₂/kg). Cooling patterns i.e. from 43 °C to 25, 18 and 5 °C (T₁, T₂ and T₃) had a significant effect on the amount of vitamin A and E. Concentration of vitamin A and E in T₁ were significantly less than T₂ and T₃. Cooling patterns had a significant effect on texture, T₁ had a thick texture with higher viscosity as compared to T₂ and T₃. Thickness of yoghurt was in the order of T₁ > T₂ > T₃ with no difference in color and flavor score till 10 days of storage.

Conclusion

Results of current investigation indicated that milk type and post fermentation cooling patterns had a pronounced effect on antioxidant characteristics, fatty acid profile, lipid oxidation and textural characteristics of yoghurt. Buffalo milk based yoghurt had more fat, protein, higher antioxidant capacity and vitamin content. Antioxidant and sensory characteristics of T₁ were optimum till 10 days of storage.

Antioxidants and antioxidant methods: an updated overview

Antioxidants had a growing interest owing to their protective roles in food and pharmaceutical products against oxidative deterioration and in the body and against oxidative stress-mediated pathological processes. Screening of antioxidant properties of plants and plant-derived compounds requires appropriate methods, which address the mechanism of antioxidant activity and focus on the kinetics of the reactions including the antioxidants. Many studies evaluating the antioxidant activity of various samples of research interest using different methods in food and human health have been conducted. These methods are classified, described, and discussed in this review. Methods based on inhibited autoxidation are the most suited for termination-enhancing antioxidants and for chain-breaking antioxidants, while different specific studies are needed for preventive antioxidants. For this purpose, the most common methods used in vitro determination of antioxidant capacity of food constituents were examined. Also, a selection of chemical testing methods was critically reviewed and highlighted. In addition, their advantages, disadvantages, limitations and usefulness were discussed and investigated for pure molecules and raw extracts. The effect and influence of the reaction medium on the performance of antioxidants are also addressed. Hence, this overview provides a basis and rationale for developing standardized antioxidant methods for the food, nutraceuticals, and dietary supplement industries. In addition, the most important advantages and shortcomings of each method were detected and highlighted. The chemical principles of these methods are outlined and critically discussed. The chemical principles of methods of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical (ABTS^·+) scavenging, 1,1-diphenyl-2-picrylhydrazyl (DPPH·) radical scavenging, Fe³⁺-Fe²⁺ transformation assay, ferric reducing antioxidant power (FRAP) assay, cupric ions (Cu²⁺) reducing power assay (Cuprac), Folin-Ciocalteu reducing capacity (FCR assay), peroxyl radical (ROO·), superoxide radical anion (O₂^·-), hydrogen peroxide (H₂O₂) scavenging assay, hydroxyl radical (OH·) scavenging assay, singlet oxygen (¹O₂) quenching assay, nitric oxide radical (NO·) scavenging assay and chemiluminescence assay are outlined and critically discussed. Also, the general antioxidant aspects of main food components were discussed by a number of methods, which are currently used for the detection of antioxidant properties of food components. This review consists of two main sections. The first section is devoted to the main components in the food and pharmaceutical applications. The second general section comprises some definitions of the main antioxidant methods commonly used for the determination of the antioxidant activity of components. In addition, some chemical, mechanistic and kinetic basis, and technical details of the used methods are given.

Interactions between whey proteins and cranberry juice after thermal or non-thermal processing during in vitro gastrointestinal digestion

This study entails the possible interactions between whey protein and cranberry juice after processing, impacting either the protein digestibility or the bioaccessibility of cranberry antioxidants using an in vitro gastrointestinal digestion model.

Effects of industrial heat treatments on bovine milk oxylipins and conventional markers of lipid oxidation

The effects of industrial heat treatments of raw bovine milk subjected to Batch Pasteurization (BP), High Temperature Short Time (HTST) and Ultra High Temperature (UHT) on the formation of primary (hydroperoxide content and oxylipins) and secondary lipid oxidation products (thiobarbituric acid reactive species -TBARS) were evaluated. Total fatty acid content, percent of free fatty acids (FFA), and total antioxidant capacity (TAC) were also measured. Except for a 30% reduction in capric acid (C10:0) after UHT compared to BP, no significant differences in total fatty acid concentrations were detected amongst the heat treatments. Compared to raw bovine milk, no statistically significant effects of heat treatment were observed on percent FFA (0.29-0.31%), hydroperoxide concentration (0.0558-0.0624 mmol L^-1), and TBARS values (13.4-18.9 µg MDA kg^-1). HTST and UHT led to significant reductions (50-65%) in linoleic and alpha-linolenic acid oxidized metabolites compared with raw milk and batch pasteurized milk. Compared to raw milk (2943.7 μmol of TEAC L^-1), TAC was significantly reduced by all heat treatments (2245 - 2393 μmol of TEAC L^-1), although no statistically significant differences were observed amongst the treatments. The results demonstrate that heat processing reduces milk oxylipin content and antioxidant capacity and that oxylipin and TAC measurements provide a new sensitive approach to assess the impact of milk processing on lipid oxidation. The nutritional, shelf life and sensory implications of reduced oxylipins in HTST and UHT processed bovine milk merit further investigation.

Optimization of pasteurized milk with soymilk powder and mulberry leaf tea based on melatonin, bioactive compounds and antioxidant activity using response surface methodology

Melatonin is a natural hormone which regulates human circadian rhythms and is presented in milk at low concentrations. To improve melatonin concentration and amounts of bioactive compounds in pasteurized milk (PM), soymilk powder (SMP) and mulberry leaf tea (MLT) were added using mixture design response surface methodology (RSM) and levels of SMP, MLT and raw milk (RM) were optimized. PM containing 4.50% SMP, 4.50% MLT and 88.80% RM gave the highest chemical compositions, bioactive compounds and antioxidant activity. Mathematical models of chemical compositions, bioactive compounds and antioxidant activity showed significant differences, whereas sensory attributes were not significantly different in all modeled parameters. Optimum levels were 3.90% SMP, 4.50% MLT and 89.40% RM. Verification of optimum proportions showed that experimental values of chemical compositions, bioactive compounds and antioxidant activity agreed with model predictions. Optimum PM contained melatonin (1.49 ng/mL), free tryptophan (0.26 μg/mL), and total phenolic content (0.72 mg GAE/mL) with high antioxidant activity when assayed by DPPH, ABTS and FRAP. Results suggested that mixture design RSM has the potential to optimize SMP, MLT and RM levels to obtain PM with increased amounts of bioactive compounds and high melatonin content.

Fenpropathrin induces testicular damage, apoptosis, and genomic DNA damage in adult rats: Protective role of camel milk

Fenpropathrin (FNP) is a member of the synthetic pyrethroids. Herein, the present study was conducted to investigate, for the first time, the potentially harmful effects of FNP on the reproductive system of male rats. In addition, the prophylactic or concurrent influence of camel milk (CM) was assessed. Adult male rats were divided into five groups; control, vehicle control (oil), CM (2ml/rat/day), FNP (15mg/kg bwt/60 days), CM/FNP (prophylaxis) and FNP /CM (co-treated) groups. Sperm morphology, count, serum testosterone (TES), luteinizing hormone (LH) and follicle-stimulating hormone (FSH), thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC), superoxide dismutase (SOD), testicular enzymes, and comet assay analysis were estimated. In addition, histopathology, the ultrastructure of testicular tissue and apoptosis were evaluated. Reduced body weight and gonadosomatic index were observed in the FNP exposed group. TES, LH, FSH were markedly declined following FNP treatment. SOD and TAC concentrations were reduced while PC and TBARS were significantly elevated in FNP group indicating oxidative stress. Furthermore, FNP induced DNA damage and apoptosis in the testis which was evidenced histopathologically and by electron microscope examination. CM significantly counteracted FNP reprotoxic effects, particularly at the prophylactic routine (CM/FNP) than the co-exposure (FNP/CM) one. Conclusively, these findings verified that CM could be a potential candidate therapy against FNP reprotoxic impacts.

Chemical-nutritional parameters and volatile profile of eggs and cakes made with eggs from ISA Warren laying hens fed with a dietary supplementation of extruded linseed

Objective

The aim of this study was to evaluate the chemical-nutritional parameters, oxidative stability and volatile profile of eggs and cakes made with eggs from laying hens fed with a dietary supplementation of extruded linseed.

Methods

Two thousand ISA Warren laying hens were randomly divided into two groups: a control group was fed with a standard diet while the experimental group received the same diet supplemented with 7% of extruded linseed. The trial lasted 84 days, in which three samplings of laid eggs were performed. Samples of eggs and food systems arising from eggs were then analyzed in order to obtain information about β-carotene and total flavonoid content, antioxidant activity, fatty acid profile, lipid oxidation, and volatile profile.

Results

Linseed induced the increase of α-linolenic acid with consequent reduction of the ω-6/ω-3 ratio (4.3:1 in egg yolk); in addition to this, was evidenced the cholesterol reduction and the significant increase in total flavonoids and β-carotene, although no variations were detected in antioxidant capacity. Even in cooked products there was not only a direct effect of linseed in increasing α-linolenic acid, but also in inducing the reduction of cholesterol and its major oxidation product, 7-ketocholesterol. The dietary linseed integration was also shown to affect the volatile profile of baked products.

Conclusion

Data confirmed that dietary supplementation with extruded linseed resulted in food products with interesting implications for human health. With regard to the volatile profile of baked products it would be necessary undertake further sensorial analysis in order to evaluate any variations on flavor and consumer acceptability.

Chemical-nutritional quality and oxidative stability of milk and dairy products obtained from Friesian cows fed with a dietary supplementation of dried grape pomace

BACKGROUND

The aim of the study was to evaluate the nutritional properties of milk and cheese obtained from Friesian cows fed with a diet supplemented with dried grape pomace, a by-product of the oenological industry, which is very rich in polyphenols. This approach is inspired by the increasing interest in foods containing functional ingredients that may have beneficial effects on human health. During the testing period, analyses of the chemical and nutritional properties of milk and dairy products derived from it were performed; particular attention was given to the effect of cheese ripening on the oxidative stability and fermentation process, evaluating respectively the presence of malondialdehyde and γ-aminobutyric acid.

RESULTS

Dietary enrichment with grape pomace did not affect the milk composition but induced modifications in the fatty acid profiles in both milk and cheese with an increase in concentration of linoleic acid, trans-vaccenic acid, rumenic acid and total n-6 fatty acids. Moreover, after 30 days of cheese ripening, an increased oxidative stability and an increased concentration of γ-aminobutyric acid were found.

CONCLUSIONS

Our results indicated a general improvement in nutritional parameters of milk and related cheese obtained from Friesian cows that received the feeding enrichment with dried grape pomace. Further analysis should be performed to improve knowledge of the chemical and microbiological mechanisms at the source of these findings. © 2019 Society of Chemical Industry.

Chemical Lipophilization of Bovine α-Lactalbumin with Saturated Fatty Acyl Residues: Effect on Structure and Functional Properties

Bovine α-lactalbumin (α-LA) was chemically modified by the covalent attachment of fatty acid residues of different length (lauroyl, palmitoyl, and stearoyl) to modify its functional and antioxidant properties. Structural changes, functional properties, and antioxidant capacity in the pH interval between 3 and 10 were analyzed. Surface properties were improved. The esterification increased the hydrophobic interactions leading to a reduction in the solubility dependent on the incorporation ratio of the fatty acid residues. Improvement in emulsifying, foaming, and antioxidant properties were observed when the length of the fatty acid chains was short and mostly at a basic pH. With these results in mind, experiments could be conducted for the technological applications of these derivatives in the food, pharmaceutical, and cosmetic industries.

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.

A novel colorimetric paper sensor based on the layer-by-layer assembled multilayers of surfactants for the sensitive and selective determination of total antioxidant capacity

A new colorimetric paper sensor, (TBABr/SDS)₃/PAD, was successfully fabricated to detect TAC. Good selectivity and sensitivity toward TAC were achieved. The (TBABr/SDS)₃/PAD sensor has been applied for TAC detection in food samples.

Short communication: Compositional characteristics and aromatic profile of caciotta cheese obtained from Friesian cows fed with a dietary supplementation of dried grape pomace

The aim of the present work was to explore the chemical-sensorial characteristics and aromatic profile of caciotta cheese obtained from Friesian cows fed a diet enriched with grape pomace obtained from red grape (Vitis vinifera L.). Dietary enrichment with grape pomace influenced the production of caciotta cheeses in interesting ways from a compositional point of view, as cheese samples were rich in polyphenols, giving a high antioxidant potential. From a biochemical standpoint, we noted a slight decrease of proteolysis during ripening, whereas, according to the analysis of volatile compounds, lipolysis was the most relevant phenomenon in samples. The presence of bioactive compounds also modified the fatty acid profile of milk and cheese, leading to an increase in concentration of linoleic, vaccenic, and rumenic acids. No significant variations were found in the sensory profile. These results showed the potential of dietary grape pomace intake to influence the chemical-nutritional and nutraceutical properties of cow milk and cheeses, whose introduction to the market could be attractive to consumers, providing interesting implications for the dairy industry. Finally, our results identified of a valid use of an agro-industrial by-product, grape pomace, whose disposal generally presents economic and environmental problems.

Short communication: Phenotypic characterization of total antioxidant activity of buffalo, goat, and sheep milk

Free radicals are reactive and unstable waste molecules produced by cells, responsible of damages and alteration on DNA, proteins, and fat. The daily intake of antioxidant compounds, acting against free radicals and their detrimental effects, is essential for human health. Milk contains several compounds with antioxidant activity, and the sum of their reducing potential blocking free radicals development is defined as total antioxidant activity (TAA). This novel trait has been described in literature both in individual and bulk cow milk, but there are no reports from other dairy species. Therefore, the present study aimed to investigate phenotypic variation of TAA in individual samples of buffalo (n = 105), goat (n = 112), and sheep (n = 198) milk. Total antioxidant activity was measured through a reference spectrophotometric method, and expressed as millimoles per liter of Trolox equivalents (TE). The greatest TAA was observed in sheep milk, averaging 7.78 mmol/L of TE and showing also the broadest phenotypic variation expressed as coefficient of variation (13.98%). Significantly lower TAA values were observed for buffalo (7.35 mmol/L of TE) and goat (6.80 mmol/L of TE) milk, with coefficients of variation of 8.18 and 8.47%, respectively. Total antioxidant activity exhibited weak correlations with milk yield and chemical composition. Phenotypic values of TAA presented in this study will be used to assess the ability of mid-infrared spectroscopy to predict this new trait and thus to collect data at the population level.

Comparison of antioxidant capacity of cow and ewe milk kefirs

This research aimed to evaluate the effects of using either grain or commercial starter culture on the antioxidative capacity of cow and ewe milk kefirs. The antioxidant capacity of kefir samples during fermentation and 21 d of storage was assessed by using 3 assays: 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical cation decolorization; 2,2-diphenyl-1-picrylhydrazyl (DPPH^•) radical scavenging activity assay; and Fe⁺³-reducing power (ferric reducing antioxidant power assay, FRAP). Vitamin E and β-carotene contents were also quantified. All kefir samples exhibited varying values for DPPH, ABTS, and FRAP assays depending on the starter culture and milk type. Vitamin E and β-carotene contents were similar in all kefir samples during storage. The results of this study suggest that milk type (cow or ewe) and culture type (kefir grains or commercial starter) were the significant parameters for the antioxidative activity of kefir.

In vitro and in vivo antioxidant potential of milks, yoghurts, fermented milks and cheeses: a narrative review of evidence

The antioxidant potential (AP) is an important nutritional property of foods, as increased oxidative stress is involved in most diet-related chronic diseases. In dairy products, the protein fraction contains antioxidant activity, especially casein. Other antioxidants include: antioxidant enzymes; lactoferrin; conjugated linoleic acid; coenzyme Q10; vitamins C, E, A and D3; equol; uric acid; carotenoids; and mineral activators of antioxidant enzymes. The AP of dairy products has been extensively studied in vitro, with few studies in animals and human subjects. Available in vivo studies greatly differ in their design and objectives. Overall, on a 100 g fresh weight-basis, AP of dairy products is close to that of grain-based foods and vegetable or fruit juices. Among dairy products, cheeses present the highest AP due to their higher protein content. AP of milk increases during digestion by up to 2·5 times because of released antioxidant peptides. AP of casein is linked to specific amino acids, whereas β-lactoglobulin thiol groups play a major role in the AP of whey. Thermal treatments such as ultra-high temperature processing have no clear effect on the AP of milk. Raw fat-rich milks have higher AP than less fat-rich milk, because of lipophilic antioxidants. Probiotic yoghurts and fermented milks have higher AP than conventional yoghurt and milk because proteolysis by probiotics releases antioxidant peptides. Among the probiotics, Lactobacillus casei/acidophilus leads to the highest AP. The data are insufficient for cheese, but fermentation-based changes appear to make a positive impact on AP. In conclusion, AP might participate in the reported dairy product-protective effects against some chronic diseases.