Differences in whey protein content between cow's milk collected in late pasture and early indoor feeding season from conventional and organic farms in Poland

Characterization and estimation of the bioaccessibility of essential elements in organic milk by INFOGEST protocol

The study estimated the bioaccessibility of calcium, phosphorus and magnesium in organic milk (ORG), compared to conventional (CNV) by the INFOGEST in vitro protocol. Total proteins, lipids and lactose were evaluated, the determination of essential minerals was performed by FAAS and phosphorus by colorimetric method. All ORG samples showed protein content equivalent to CNV and lower lactose and lipid content. Within different brands and batches, two batches of ORG presented higher levels of Na and lower levels of K and P, while all batches showed higher values for Ca and no differences for Mg. The bioaccessibility of magnesium was greater than 60%. ORG showed the highest values of bioaccessible calcium (12-65%) against CNV (11-27%). Phosphorus showed bioaccessibility higher than 74% in CNV. The variability of the results was related to different factors inherent to the matrices, such as casein and fatty-acids content and electrolytes standardized in the protocol.

Grass-Fed and Non-Grass-Fed Whey Protein Consumption Do Not Attenuate Exercise-Induced Muscle Damage and Soreness in Resistance-Trained Individuals: A Randomized, Placebo-Controlled Trial

Eccentric muscle contractions can cause structural damage to muscle cells resulting in temporarily decreased muscle force production and soreness. Prior work indicates pasture-raised dairy products from grass-fed cows have greater anti-inflammatory and antioxidant properties compared to grain-fed counterparts. However, limited research has evaluated the utility of whey protein from pasture-raised, grass-fed cows to enhance recovery compared to whey protein from non-grass-fed cows. Therefore, using a randomized, placebo-controlled design, we compared the effect of whey protein from pasture-raised, grass-fed cows (PRWP) to conventional whey protein (CWP) supplementation on indirect markers of muscle damage in response to eccentric exercise-induced muscle damage (EIMD) in resistance-trained individuals. Thirty-nine subjects (PRWP, n = 14; CWP, n = 12) completed an eccentric squat protocol to induce EIMD with measurements performed at 24, 48, and 72 h of recovery. Dependent variables included: delayed onset muscle soreness (DOMS), urinary titin, maximal isometric voluntary contraction (MIVC), potentiated quadriceps twitch force, countermovement jump (CMJ), and barbell back squat velocity (BBSV). Between-condition comparisons did not reveal any significant differences (p ≤ 0.05) in markers of EIMD via DOMS, urinary titin, MIVC, potentiated quadriceps twitch force, CMJ, or BBSV. In conclusion, neither PRWP nor CWP attenuate indirect markers of muscle damage and soreness following eccentric exercise in resistance-trained individuals.

The Influence of Selected Factors on the Nutritional Value of the Milk of Cold-Blooded Mares: The Example of the Sokólski Breed

This study assessed the effect of access to pasture, lactation number, and foals’ sex on the nutritional value of milk (79 samples) from nine mares. The following were analysed: content of dry matter, protein, fat, lactose, and ash; percentages of α-lactalbumin (α-La), β-lactoglobulin (β-Lg), serum albumin (SA), immunoglobulins (Ig), lactoferrin (Lf), and lysozyme (Lz) in the total protein; and the fatty acid profile. Mares without access to pastures were shown to produce milk with a higher dry matter content, including fat, lactose, and ash; higher percentages of β-Lg, α-La, Ig, and Lf; and a better fatty acid profile. The milk from mares with access to pasture contained more protein, including higher percentages of SA and Lz. Milk from mares in lactations 4–6 had the highest fat and protein concentrations and the lowest lactose concentration. The α-La level was highest in lactation 1, Lf in lactations 2–3, and Lz in lactations 4–6. Milk from mares in lactations 4–6 had the best fatty acid profile (the lowest concentration of saturated fatty acids (SFAs) and the highest concentration of monounsaturated fatty acids(MUFA) and polyunsaturated fatty acids (PUFA)). Milk from mothers of female offspring had higher dry matter, fat, and protein concentrations, a higher share of lysozyme, and a better fatty acid profile.

Iron-Deficiency in Atopic Diseases: Innate Immune Priming by Allergens and Siderophores

Although iron is one of the most abundant elements on earth, about a third of the world's population are affected by iron deficiency. Main drivers of iron deficiency are beside the chronic lack of dietary iron, a hampered uptake machinery as a result of immune activation. Macrophages are the principal cells distributing iron in the human body with their iron restriction skewing these cells to a more pro-inflammatory state. Consequently, iron deficiency has a pronounced impact on immune cells, favoring Th2-cell survival, immunoglobulin class switching and primes mast cells for degranulation. Iron deficiency during pregnancy increases the risk of atopic diseases in children, while both children and adults with allergy are more likely to have anemia. In contrast, an improved iron status seems to protect against allergy development. Here, the most important interconnections between iron metabolism and allergies, the effect of iron deprivation on distinct immune cell types, as well as the pathophysiology in atopic diseases are summarized. Although the main focus will be humans, we also compare them with innate defense and iron sequestration strategies of microbes, given, particularly, attention to catechol-siderophores. Similarly, the defense and nutritional strategies in plants with their inducible systemic acquired resistance by salicylic acid, which further leads to synthesis of flavonoids as well as pathogenesis-related proteins, will be elaborated as both are very important for understanding the etiology of allergic diseases. Many allergens, such as lipocalins and the pathogenesis-related proteins, are able to bind iron and either deprive or supply iron to immune cells. Thus, a locally induced iron deficiency will result in immune activation and allergic sensitization. However, the same proteins such as the whey protein beta-lactoglobulin can also transport this precious micronutrient to the host immune cells (holoBLG) and hinder their activation, promoting tolerance and protecting against allergy. Since 2019, several clinical trials have also been conducted in allergic subjects using holoBLG as a food for special medical purposes, leading to a reduction in the allergic symptom burden. Supplementation with nutrient-carrying lipocalin proteins can circumvent the mucosal block and nourish selectively immune cells, therefore representing a new dietary and causative approach to compensate for functional iron deficiency in allergy sufferers.

Neither Incretin or Amino Acid Responses, nor Casein Content, Account for the Equal Insulin Response Following Iso-Lactose Loads of Natural Human and Cow Milk in Healthy Young Adults

Human milk contains <50% less protein (casein) than cow milk, but is equally effective in insulin secretion despite lower postingestion hyperaminoacidemia. Such potency of human milk might be modulated either by incretins (glucagon-like polypeptide-1,GLP-1); glucose-inhibitory-polypeptide, GIP), and/or by milk casein content. Healthy volunteers of both sexes were fed iso-lactose loads of two low-protein milks, i.e., human [Hum] (n = 8) and casein-deprived cow milk (Cow [↓Cas]) (n = 10), as well as loads of two high-protein milks, i.e., cow (n = 7), and casein-added human-milk (Hum [↑Cas]) (n = 7). Plasma glucose, insulin, C-peptide, incretins and amino acid concentrations were measured for 240′. All milks induced the same transient hyperglycemia. The early [20′−30′] insulin and C-peptide responses were comparable among all milk types apart from the low-protein (Cow [↓Cas]) milk, where they were reduced by <50% (p < 0.05 vs. others). When comparing the two high-protein milks, GLP-1 and GIP [5’−20’] responses with the (Hum [↑Cas]) milk were lower (by ≈2−3 fold, p < 0.007 and p < 0.03 respectively) than those with cow milk, whereas incretin secretion was substantially similar. Plasma amino acid increments largely reflected the milk protein content. Thus, neither casein milk content, nor incretin or amino acid concentrations, can account for the specific potency of human milk on insulin secretion, which remains as yet unresolved.

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.

Effect of Reversal of Whey-Protein to Casein Ratio of Cow Milk, on Insulin, Incretin, and Amino Acid Responses in Humans

Scope

Milk‐proteins, besides lactose, stimulate insulin and incretin secretion. Although whey‐proteins (WP) are more efficient than casein (Cas) in hormone secretion, the effects of reversal of the (WP/Cas) ratio in whole‐milk are poorly known.

Methods and Results

Healthy volunteers received two different cow‐milk drinks, at identical lactose (0.36 g × kg⁻¹ BW) and total‐protein (0.18 g × kg¹ BW) loads, but at reversed WP/Cas ratio. One is cow‐whole milk with a ≈20/80 [WP/Cas] ratio, the other an experimental cow‐milk with a ≈70/30 [WP/Cas] ratio ([↑WP↓Cas]‐milk). Both milk‐types induced the same mild hyperglycemic response. Following [↑WP↓Cas]‐milk, the [20′–90′] insulin incremental area (iAUC) (+ ≈44%, p < 0.035), and the [20′–120′] C‐peptide iAUC (+ ≈47%, p < 0.015) are greater than those with cow‐milk. Similarly, following [↑WP↓Cas]‐milk, the GLP‐1 [20′–90′] iAUC (+96%, p < 0.025), and the GIP [30′–60′] iAUC (+140%, p < 0.006), were greater than those with cow‐milk. Plasma total and branched‐chain amino acids are also greater following the [↑WP↓Cas] than cow‐milk.

Conclusions

Reversal of the (WP/Cas) ratio in cow‐milk enhanced the insulin response, an effect possibly mediated by incretins and/or amino acids(s). These data may be useful in designing specific milk formulas with different effects on insulin and incretin response(s).

Organic versus Conventional Raw Cow Milk as Material for Processing

Milk, as one of the basic raw materials of animal origin, must be of adequate hygienic and physicochemical quality for processing. The aim of the article was to compare the quality of raw milk from three production systems, intensive, traditional (together referred to as conventional), and organic, as material for processing, as well as the quality of products made from it. Particular attention was focused on hygienic quality (somatic cell count and total bacterial count), physical characteristics (acidity), basic nutritional value (content of dry matter, total protein, casein, fat, and lactose), content of health-promoting substances (whey proteins, fatty acids, vitamins, and minerals), and technological parameters (rennet clotting time, heat stability, and protein-to-fat ratio). Research assessing the quality of organic milk and dairy products is significantly less extensive (if available at all) than for milk from conventional production (intensive and traditional). The available reports indicate that raw milk from organic farms is more valuable, especially in terms of the content of health-promoting compounds, including vitamins, fatty acids, whey proteins, and minerals. This applies to organic dairy products as well, mainly cheese and yoghurt. This is explained by the fact that organic farming requires that animals are kept in the pasture. However, the hygienic quality of the raw milk, and often the products as well, raises some concerns; for this reason, organic milk producers should be supported in this regard, e.g., through consultancy and training in Good Hygienic Practices. Importantly, milk production in the traditional and organic systems is in line with the concept of the European Green Deal.

Potential Protective Protein Components of Cow's Milk against Certain Tumor Entities

Milk and dairy products, especially from cow's milk, play a major role in the daily human diet. It is therefore hardly surprising that the subject of milk is being extensively researched and that many effects of individual milk components have been characterized as a result. With the wealth of results available today, the influence of milk on the development of various types of cancer and, in particular, its often protective effects have been shown both in vitro and in vivo and in the evaluation of large-scale cohort and case-control studies. Various caseins, diverse whey proteins such as α-lactalbumin (α-LA), bovine α-lactalbumin made lethal to tumor cells (BAMLET), β-lactoglobulin (β-LG), or bovine serum albumin (BSA), and numerous milk fat components, such as conjugated linoleic acid (CLA), milk fat globule membrane (MFGM), or butyrate, as well as calcium and other protein components such as lactoferrin (Lf), lactoferricin (Lfcin), and casomorphines, show antitumor or cytotoxic effects on cells from different tumor entities. With regard to a balanced and health-promoting diet, milk consumption plays a major role in a global context. This work provides an overview of what is known about the antitumoral properties of proteins derived from cow's milk and their modes of action.

Effect of Farming System (Organic vs. Conventional) and Season on Composition and Fatty Acid Profile of Bovine, Caprine and Ovine Milk and Retail Halloumi Cheese Produced in Cyprus

The present work aimed to evaluate the effect of farming practices and season on the fat and protein content and fatty acid (FA) profile of milk and Halloumi cheese produced in Cyprus. Over a year, raw bulk-tank milk samples from cow, goat, and sheep farms were collected seasonally from all organic (11) and representative conventional (44) dairy farms, whereas Fresh Halloumi cheese samples were collected monthly from retail outlets (48 organic and 48 conventional samples in total). The different farming practices did not affect the milk fat content of ruminants, while protein levels were decreased in organic bovine and caprine milk. Under organic farming practices, milk and cheese contained increased values of total mono-unsaturated FA (MUFA) and poly-unsaturated FA (PUFA), and specific FA, such as oleic, conjugated linoleic, linoleic, and α-linolenic acids. Total saturated FA (SFA) levels were particularly decreased in organic samples and, consequently, the atherogenic indices of milk and cheese were decreased. Season influenced milk and Halloumi cheese FA profile; spring samples had lower SFA and higher PUFA and MUFA concentrations. Overall, the organic farm practices improved the lipid profile of milk and Halloumi cheese, which is more likely attributed to the different feeding strategies applied in organic dairy farms.

Bovine Holo-Beta-Lactoglobulin Cross-Protects Against Pollen Allergies in an Innate Manner in BALB/c Mice: Potential Model for the Farm Effect

The lipocalin beta-lactoglobulin (BLG) is a major protein compound in cow's milk, and we detected it in cattle stable dust. BLG may be a novel player in the farm protective effect against atopic sensitization and hayfever. In previous studies, we demonstrated that only the ligand-filled holo-form of BLG prevented sensitization to itself. Here, we investigated whether holo-BLG could, in an innate manner, also protect against allergic sensitization to unrelated birch pollen allergens using a murine model. BALB/c mice were nasally pretreated four times in biweekly intervals with holo-BLG containing quercetin-iron complexes as ligands, with empty apo-BLG, or were sham-treated. Subsequently, mice were intraperitoneally sensitized two times with apo-BLG or with the unrelated birch pollen allergen apo-Bet v 1, adjuvanted with aluminum hydroxide. After subsequent systemic challenge with BLG or Bet v 1, body temperature drop was monitored by anaphylaxis imaging. Specific antibodies in serum and cytokines of BLG- and Bet v 1-stimulated splenocytes were analyzed by ELISA. Additionally, human peripheral blood mononuclear cells of pollen allergic subjects were stimulated with apo- versus holo-BLG before assessment by FACS. Prophylactic treatment with the holo-BLG resulted in protection against allergic sensitization and clinical reactivity also to Bet v 1 in an unspecific manner. Pretreatment with holo-BLG resulted in significantly lower BLG-as well as Bet v 1-specific antibodies and impaired antigen-presentation with significantly lower numbers of CD11c+MHCII+ cells expressing CD86. Pretreatment with holo-BLG also reduced the release of Th2-associated cytokines from Splenocytes in BLG-sensitized mice. Similarly, in vitro stimulation of PBMCs from birch pollen allergic subjects with holo-BLG resulted in a relative decrease of CD3+CD4+ and CD4+CRTh2 cells, but not of CD4+CD25+CD127- Treg cells, compared to apo-BLG stimulation. In conclusion, prophylactic treatment with holo-BLG protected against allergy in an antigen-specific and -unspecific manner by decreasing antigen presentation, specific antibody production and abrogating a Th2-response. Holo-BLG therefore promotes immune resilience against pollen allergens in an innate manner and may thereby contribute to the farm protective effect against atopic sensitization.

Protein recovery from residual bovine whey: Influence of acid thermo-coagulation

Thermal treatment of acidified bovine whey is one of the most efficient traditional methods for the recovery and use of residual proteins in this byproduct and an alternative way of sustainable use of this type of resource. The yield of protein recovery from residual whey obtained as a byproduct was evaluated using the acid thermo-coagulation method. Bovine whey samples were collected in dry and rainy seasons and were subjected to acid thermo-coagulation, and the protein sample preparation was achieved using the TCA/Acetone and TCA/Acetone/Phenol methods. The determination of peptides was accomplished by electrophoresis SDS-PAGE. The TCA/Acetone/Phenol method reported better performance with a higher yield (22.2 μg/ml) than the classic TCA/Acetone method (8.8 μg/ml). The proteins found in higher proportion in whey samples of the dry season, representing 82.6 % of the total protein content, while in whey samples of rainy season equivalent up to 65.4 % of total proteins. The acid thermo-coagulation technique showed high-efficiency performance in whey peptide recovery.

Effects of Some Food Components on Non-Alcoholic Fatty Liver Disease Severity: Results from a Cross-Sectional Study

Background: The high prevalence of non-alcoholic fatty liver disease (NAFLD) observed in Western countries is due to the concurrent epidemics of overweight/obesity and associated metabolic complications, both recognized risk factors. A Western dietary pattern has been associated with weight gain and obesity, and more recently with NAFLD. Methods: This is a baseline cross-sectional analysis of 136 subjects (79 males) enrolled consecutively in the NUTRIATT (NUTRItion and Ac-TiviTy) study. Study subjects had moderate or severe NAFLD diagnosed by using Fibroscan-CAP. Food Frequency Questionnaire was used to obtain information about food intake. Statistical analysis included descriptive statistics and a multivariable logistic regression model. Results: The mean age was 49.58 (±10.18) with a mean BMI of 33.41 (±4.74). A significant inverse relationship was revealed between winter ice-cream intake and NAFLD severity (O.R. 0.65, 95% C.I. 0.95–0.99); chickpeas intake and NAFLD severity (O.R. 0.57, 95% C.I. 0.34–0.97), and not industrial aged-cheeses type (O.R. 0.85, 95% C.I. 0.74–0.98). A statistically significant positive association also emerged between rabbit meat (O.R. 1.23, 95% C.I. 1.01–1.49), industrial type aged cheeses (O.R. 1.17, 95% C.I. 1.01–1.35), milk-based desserts (no winter ice cream) (O.R. 1.11, 95% C.I. 1.01–1.21), fats (O.R. 1.12, 95% C.I. 1.01–1.25), and NAFLD severity. Conclusion: The fresh foods from non-intensive farming and high legume intake that characterize the Mediterranean diet would seem to be beneficial for patients with NAFLD.

Concentration of Bioactive Components in the Milk of Simmental Cows Depending on the Feeding System

The aim of the study was to determine the yield and chemical composition of milk from TMR-(group I) and pasture-fed Simmental cows (group II). The study was conducted with second and third lactation Simmental cows between 30 and 200 days of lactation. The present research showed that compared to TMR feeding, the use of summer pasture feeding and proper supplementation with high-energy feeds allow for higher milk yield and higher nutritive value of the milk. Compared to TMR-fed cows (group I), milk from pastured cows (group II) was characterized by a more beneficial composition of protein fractions, and a higher content of α-lactalbumin, β-lactoglobulin and lactoferrin. It also contained more vitamins A and E, calcium, magnesium and iodine, and had a significantly (P≤0.05) lower cholesterol content. The milk of cows from group II contained over twice as much CLA (1.59% of all acids) and 35% more n-3 PUFA, which resulted in a more beneficial n-6/n-3 fatty acids ratio of 2.88. In addition, this milk contained significantly (P≤0.05) less saturated fatty acids (SFA) and significantly more (P≤0.05) mono-(MUFA) and polyunsaturated fatty acids (PUFA). Consequently, the MUFA:SFA and PUFA:SFA ratios in this group were more favourable at 0.448 and 0.066, respectively. Also the content of desirable fatty acids (DFA) with hypocholesterolemic effects was higher in group II, which resulted in a more beneficial DFA:OFA ratio of 0.8 in this group. In conclusion, the use of summer pasture feeding and a proper supplemented feeding ration in Simmental cows with high-energy feeds allow for high milk yield and high nutritive value of the milk.

Correlations between the content of selected whey proteins in cow milk

The aim of the study was to determine the correlations between the concentrations of major whey proteins in cow milk. A total of 2,278 milk samples from Polish Holstein-Friesian (Black-and-White and Red-and-White varieties), Simmental and Jersey cows were analysed. In each sample the content of major whey proteins, i.e. α-lactalbumin, β-lactoglobulin, bovine serum albumin, lactoferrin and lysozyme were determined by the RP-HPLC method. Matrix scatter plots were prepared to determine the correlations between the concentrations of individual whey proteins. In the vast majority of cases a significant relationship was found between the content of individual whey proteins. Taking into account the production season and breed of cow, highly significant (p=0.001) negative correlation coefficients were obtained for the content of α-lactalbumin and bovine serum albumin, for α-lactalbumin and lysozyme, for β-lactoglobulin and bovine serum albumin, and for β-lactoglobulin and lysozyme. Positive correlations were observed for the concentrations of α-lactalbumin with β-lactoglobulin, lactoferrin and lysozyme, as well as for bovine serum albumin with lysozyme.

Pasture feeding conventional cows removes differences between organic and conventionally produced milk

Perceptions of production methods for organic and conventional milk are changing, with consumers prepared to pay premium prices for milk from either certified organic or conventional grass-fed cows. Our study investigated whether chemical composition differed between milk produced by these two farming systems. Sampling was conducted on two farms sets, each comprised of one organic and one conventional farm. All farms applied year-round pasture grazing. Milk samples were collected throughout the milking season and analysed for free oligosaccharides, fatty acids, major casein and whey proteins, and milk fat volatiles. Fatty acids were influenced by breed and fertilizer application. Oligosaccharides differed between farming systems, with causes presently unknown, while farm set was the dominant influence factor on protein composition. Factors identified in this study influencing milk composition are not exclusive to either farming system, and pasture feeding conventional cows will remove differences previously reported for organic and conventionally produced milk.

Degrees of Antioxidant Protection: A 2-Year Study of the Bioactive Properties of Organic Milk in Poland

The aim of this study was to determine the nutritional value of organic milk in Poland, investigate the influence of diet on antioxidant capacity and degree of antioxidant protection (DAP), and to examine the effect of season on the bioactive properties of milk from organic farms. From 2014 to 2015, 820 milk samples were collected from 6 organic farms during indoor feeding season (IDS) and pasture feeding season (PS). Pasture feeding season + corn grain (PSCG) cows' daily ration during pasture feeding season was enriched with 4 kg a day of corn to improve dietary energy balance. Milk obtained during PS was found to have a higher fat content, slight but significantly lower protein content compared with milk from IDS. The study showed that the content of monounsaturated fatty acids (MUFA) in milk fat was strongly linked to the concentration of polyunsaturated fatty acids (PUFA) and, to a lesser extent, on the supply of MUFA. The IDS data (concentration of vitamin E, A, and β-carotene) showed the lowest values compared with the PS and PSCG groups. Total antioxidant status (TAS) and DAP showed an increasing trend in organic milk. PSCG was associated with highest level of DAP (9% higher than PS and 79% higher than IDS) and TAS (37% higher than PS and 79% higher than IDS). The results obtained show that supplementation of the basic ration with corn grain improved both TAS and DAP. The higher DAP and TAS value is responsible for product stability, considering the risk factor related to levels of cholesterol-oxide intake in humans.

Effect of supplementation of cows diet with linseed and fish oil and different variants of β-lactoglobulin on fatty acid composition and antioxidant capacity of milk

BACKGROUND

The aim of this study was to determine the influence of polymorphic variants of β-lactoglobulin in cows supplemented with linseed and fish oil on the fatty acid composition and antioxidant capacity of milk. From the herd of 320 Polish Holstein Friesian cows three groups of cows were selected according to the variants of β-LG (β-LGAA, β-LGBB, β-LGAB). During the first 7 days (the initial period) all the cows were fed the same total mixed ration (TMR) diet. From day 8 to 28,150 g fish oil and 250 g linseed (FOL) was added to the TMR diet of each cow.

RESULTS

The results showed that the diet supplemented with FOL was effective in reducing atherogenic and thrombogenic indices. Introducing supplementation improved the antioxidant capacity: higher concentration of C18:2cis-9 trans-11, C20:5 n-3, C22:6 n-3, bioactive whey proteins and vitamin soluble in fat has been recorded. The results showed that β-LGAA was associated with lower levels of atherogenic and thrombogenic indices and higher concentration of C22:5 n-6, phospholipids and β-carotene. β-LGBB favours a higher content of C18:1trans-11, C18:2cis-9 trans-11 and lactoferrin. β-LGAB was associated with higher concentrations of C20:5 n-3, Lysozyme, α-retinol, α-tocopherol and total antioxidant status.

CONCLUSION

Modification of the diet of cows with fish oil and linseed significantly influenced fatty acid composition and antioxidant properties of milk. The effect of β-LG phenotype on the fatty acid composition and antioxidant capacity of milk is variable, which could partly be the result of a β-LG phenotype × diet interaction.

Comparison of endotoxin levels in cow's milk samples derived from farms and shops

The observations on the protective effect of bacterial endotoxin in farm-derived cow's milk on childhood asthma and allergy are contradictory. The aim of this study was to determine the endotoxin levels in 'farm-derived whole raw' and 'processed shop' sources of cow's milk, and to test how the temperature and storing conditions might alter their endotoxin concentrations. Milk was collected from farms and shops. The level of endotoxin was measured by micro (gel-clot) Limulus amebocyte lysate test expressed as EU/ml. The concentration ranges of endotoxin were much higher and more widely scattered in the samples of whole raw farm milk than in the processed shop milk. Cold storage or heating increased the endotoxin concentrations in all samples of farm milk, but not in the processed shop milk. These results show that elevated levels of endotoxin in raw farm milk samples can occur from the cowshed or be formed during storage. In processed shop milk, storage does not cause any changes in the amount of endotoxin. Therefore, it is consistent that the handling and storage of raw milk alters the endotoxin concentrations, which may explain previous contradictory findings regarding the beneficial modulating effects on innate immunity toward allergy prevention in early childhood.

Invited review: organic and conventionally produced milk-an evaluation of factors influencing milk composition

Consumer perception of organic cow milk is associated with the assumption that organic milk differs from conventionally produced milk. The value associated with this difference justifies the premium retail price for organic milk. It includes the perceptions that organic dairy farming is kinder to the environment, animals, and people; that organic milk products are produced without the use of antibiotics, added hormones, synthetic chemicals, and genetic modification; and that they may have potential benefits for human health. Controlled studies investigating whether differences exist between organic and conventionally produced milk have so far been largely equivocal due principally to the complexity of the research question and the number of factors that can influence milk composition. A main complication is that farming practices and their effects differ depending on country, region, year, and season between and within organic and conventional systems. Factors influencing milk composition (e.g., diet, breed, and stage of lactation) have been studied individually, whereas interactions between multiple factors have been largely ignored. Studies that fail to consider that factors other than the farming system (organic vs. conventional) could have caused or contributed to the reported differences in milk composition make it impossible to determine whether a system-related difference exists between organic and conventional milk. Milk fatty acid composition has been a central research area when comparing organic and conventional milk largely because the milk fatty acid profile responds rapidly and is very sensitive to changes in diet. Consequently, the effect of farming practices (high input vs. low input) rather than farming system (organic vs. conventional) determines milk fatty acid profile, and similar results are seen between low-input organic and low-input conventional milks. This confounds our ability to develop an analytical method to distinguish organic from conventionally produced milk and provide product verification. Lack of research on interactions between several influential factors and differences in trial complexity and consistency between studies (e.g., sampling period, sample size, reporting of experimental conditions) complicate data interpretation and prevent us from making unequivocal conclusions. The first part of this review provides a detailed summary of individual factors known to influence milk composition. The second part presents an overview of studies that have compared organic and conventional milk and discusses their findings within the framework of the various factors presented in part one.