Milk Salts Research Articles

Distribution of Salts in Milk and Cheese: Critical Methodological Aspects

The salt fractions of milk consist of cations (e.g., Ca, Mg, and Na) and anions (e.g., phosphate, citrate, and chloride). These salts are present as free ions or in complexes with other ions or proteins, primarily the caseins. Furthermore, significant levels of Ca and phosphate are also found in insoluble form, inside the casein micelles. The distribution of salts between this micellar phase and the soluble phase is important for the stability and properties of milk and dairy products. Various processes, such as (ultra-)centrifugation, (ultra-)filtration, dialysis, and selective precipitation have been used to separate the micellar and soluble phases in milk and dairy products to allow for studying the salts’ distribution between these phases. These different methods can lead to different levels of soluble salts because the salts in the supernatant from centrifugation, the permeate from ultrafiltration, and the diffusate from dialysis can differ notably. Hence, understanding which components are fractionated with these techniques and how this affects the levels of the soluble salts determined is critical for milk and dairy products. Applying the aforementioned methods to cheese products is further challenging because these methods are primarily developed for fractionating the soluble and micellar phases of milk. Instead, methods that analyze salts in water-soluble extracts, or soluble phases expressed from cheese by pressing or centrifugation are typically used. This review focuses on the significance of salt distribution and variations in salt fractions obtained using different methodologies for both milk and cheese.

Assessment of protein and phospholipid bioaccessibility in ultrafiltered buttermilk cheese using TIM-1 in vitro gastrointestinal methods

To meet the high consumer demand, butter production has increased over the last few years. As a result, the buttermilk (BM) co-produced volumes require new ways of adding value, such as in cheese manufacturing. However, BM use in cheese milk negatively influences the cheesemaking process (e.g., altered coagulation properties) and the product’s final quality (e.g., high moisture content). The concentration of BM by ultrafiltration (UF) could potentially facilitate its use in cheese manufacturing through an increased protein content while maintaining the milk salt balance. Simultaneously, little is known about the digestion of UF BM cheese. Therefore, this study aimed to characterize the impact of UF BM on cheese manufacture, its structure, and its behavior during in vitro digestion. A 2-fold UF concentrated BM was used for cheese manufacture (skim milk [SM] – control). Compositional, textural, and microstructural analyses of cheeses were first conducted. In a second step, the cheeses were fed into an in vitro TNO gastrointestinal digestion model (TIM-1) of the stomach and small intestine and protein and phospholipid (PL) bioaccessibility was studied. The results showed that UF BM cheese significantly differed from SM cheese regarding its composition, hardness (p < 0.05) and microstructure. However, in TIM-1, UF BM and SM cheeses showed similar digestion behavior as a percentage of protein and PL intake. Despite relatively more non-digested and non-absorbed PL in the ileum efflux of UF BM cheese, the initially higher PL concentration contributes to an enhanced nutritional value compared to SM cheese. To our knowledge, this study is the first to compare the bioaccessibility of proteins and PL from UF BM and SM cheeses.

Studying the concentration of xenobiotics in milk and developing the biosensor method for their rapid determination

In this article the content of toxic xenobiotics (heavy metals and pesticides) in cow milk collected from 5 districts of Eastern Kazakhstan was examined and their cumulative properties were determined. The content of organochlorine pesticides (HCCH, DDT) was not detected in the analyzed milk. The content of mercury and arsenic in milk samples does not exceed the maximum allowable concentration (0.005 and 0.05 mg/kg, respectively). The content of cadmium above the maximum allowable concentration (0.03 mg/kg) was found in milk sampled from Shemonaikha and Katon-Karagai districts. The content of lead and zinc above the maximum allowable concentration (0.1 and 5.0 mg/kg, respectively) was found in milk samples taken from all 5 studied districts. The content of copper above the maximum allowable concentration (1.0 mg/kg) was found in milk samples collected from 4 districts under study (Borodulikha, Beskaragai, Shemonaikha and Katon-Karagai). Based on the analysis of information data the need to develop an accelerated method of determining toxic xenobiotics in milk was substantiated. The basic directions of modernization of the biosensor for determination of cadmium and lead salts in milk and dairy products were selected. A new approach to the process of immobilization of the enzyme on the surface of a substrate for cadmium and lead salts determination in milk has been developed. The efficiency of using a polymeric plate with a graphite conducting layer as a basis for the enzyme biosensor was established.

Supplementation of Dimethylglycine Sodium Salt in Sow Milk Reverses Skeletal Muscle Redox Status Imbalance and Mitochondrial Dysfunction of Intrauterine Growth Restriction Newborns.

The current study sought to understand the mechanism underlying skeletal muscle dysfunction brought on by intrauterine growth restriction (IUGR) and to explore the treatment benefits of applying dimethylglycine sodium salt (DMG-Na) in sow milk to newborns during the suckling period. Each of the 10 sows delivered one newborn with a normal birth weight (NBW) and one with an IUGR. Additionally, two NBW and two IUGR newborns were collected per litter of another 10 sows. The 20 NBW newborns were divided between the N (sow milk) and ND (sow milk + 0.1% DMG-Na) groups, while 20 IUGR newborns were divided between the I (sow milk) and ID (sow milk + 0.1% DMG-Na) groups. The skeletal muscle histomorphology, redox status, and levels of gene and protein expression were worse (p < 0.05) in the I group than in the N group. In addition, supplementation with DMG-Na (ND and ID groups) improved (p < 0.05) those parameters compared to the unsupplemented groups (N and I groups). Inhibited nuclear factor erythroid 2-related factor 2 (Nrf2)/sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptorγcoactivator-1α (PGC-1α) activity resulted in decreased redox status, skeletal muscle structural damage, skeletal muscle mitochondrial function impairment, and decreased performance in IUGR newborns. Supplementation of DMG-Na in sow milk activated the Nrf2/SIRT1/PGC-1α in IUGR newborns, thereby improving their skeletal muscle performance.

Effect of seasonal variation in Temperature Humidity Index on milk production and its composition in Murrah buffaloes

The present study was aimed to evaluate the effect of seasonal variation in Temperature Humidity Index (THI) on milk production and composition in Murrah buffaloes. Eight adult lactating Murrah buffaloes of 3-5 years of age and insecond to fourth lactation were selected in summer and winter season. Meteorological variables such as ambient temperature and relative humidity were recorded and THI was calculated during the period of study. Milk samples were collected from Murrah buffaloes and evaluated for the concentration of milk fat, protein, SNF, lactose and salt. The data was analyzed using SPSS v.20. The results indicated that average milk production, milk fat, protein and SNF decreased significantly (p&lt;0.05) in summer in comparison to winter, while lactose and salt did not differ significantly (p&gt;0.05) in between seasons. From the present study it was concluded that high THI imposes significant heat stress and negatively affects milk production and composition in Murrah buffaloes. Hence, additional feed, shelter and management practices might be adopted to overcome the negative effects of thermal stress and also to optimize milk production of the animals.

Quantitative multivalent binding model of the structure, size distribution and composition of the casein micelles of cow milk

Compatible theories describing the size distribution of milk casein micelles, the partition of milk salts and the formation of calcium phosphate nanocluster complexes are combined to provide the first quantitative model of the cow casein micelle. Complexes of caseins with calcium phosphate nanoclusters associate with each other and the remaining (free) caseins to form a stable, polydisperse distribution of micelle sizes. The micelles in the distribution have a highly hydrated coat-core structure in which the calcium phosphate nanoclusters, and caseins bound directly to them, occur only in the core whereas the free caseins are found in both the coat and core. The theory is used to describe the structure, substructure, surface potential, size distribution, and the salt and protein composition of casein micelles in a standard cow milk. Multivalent casein–casein interactions through short, linear, amino acid sequence motifs determine many aspects of casein micelle formation and stability.

Effect of different feeding regimes on productive performances of HF × Kankrej crossbred cows

Present experiment was conducted to study the effect of different feeding regimes on productive performances of HF × Kankrej crossbred cows. The study was conducted on 18 crossbred cows which were distributed into three treatment groups comprising of 6 animals each. Animals of T1 (Farmers’ feeding) group were maintained as per the feeding regime followed by small and marginal farmers in India. Animals of T2 (Modified feeding) group comprised of feeding with scientific interventions. Animals of T3 (Farm feeding) group were fed as per feeding practices followed at Livestock Research Station, Anand Agricultural University. Milk yield and 4% Fat Corrected Milk (FCM) yield was significantly higher in T2 and T3 as compared to T1 group. Lactation yield was highest in T3 followed by T2 and T1 groups. Average total solid of milk was significantly more in T3 as compared to T1 and T2 groups. Milk fat was maximum in T3 followed by T2 and T1 groups which did not differ significantly among each other. SNF, protein and lactose content of milk was found significantly higher in T3 as compared to T1 and T2 groups. Milk salt was highest in T3 followed by T2 and T1 group which differed significantly among each other. It may be concluded from the present study that feeding regime significantly influenced productive performances of crossbred cows as modified feeding group performed better over farmers feeding group and at par with farm feeding group.

Controlling the hardness of ice cream, gelato and similar frozen desserts

Controlling the hardness of ice cream, gelato and similar frozen desserts

The influence of cows stresses resistance on cheese yield and quality

The influence of cows stresses resistance on cheese yield and quality

An exploration of food industry led reformulation on fortified food staples in Ireland.

Food industry led reformulation efforts have attempted to address the prevalence of obesity by modifying nutrient compositions in food products. This study explored progress in nutrient composition alterations in products in Irish supermarkets by comparing the nutrient labels of products sold in 2014 and 2017. We conducted two supermarket audits in 2014 and 2017 to examine the changes in the nutrient profile of cereals, breads, spreads, unflavoured milks, yogurts and juices. Information on the nutrients of interest to the study (energy, protein, fat, carbohydrate, saturated fat, salt, sugar and some micronutrients) were extracted and stored in Microsoft Excel. The nutrient profile of each product was compared across the two timepoints. Our study shows that the mean level of sugars in cereals remains high and that the mean level of salt remains high in cereals, breads, and spreads. In total, 143 products were directly compared (86 cereals, 26 breads, 17 spreads and 14 milks). Our study shows that the composition of salt and sugar in cereal, bread, spreads and milk has declined by 12 and 7%, respectively. Saturated fat has declined in cereals (7%), but has increased in breads (12%), spreads (1%), and milks (5%). Manufacturers increased the serving sizes in nine cereals and one milk. From a population health perspective, the results are encouraging but care should be exercised by the food industry not to allow total fat and saturated fat levels to creep upwards. Further research and engagement of public health specialists and the food industry are needed.

Aqueous Leaf Extract of Senduduk (Melastoma malabathricum L.) Could Improve the Physicochemical Properties of Beef Sausage Dough

Improving comminuted meat products characteristics using a natural agent, such as phytochemicals, in order to replace the use of nitrite, have become a need due to the health reason. The quality of the sausage is also affected by the initial characteristics of the dough. Therefore, this research was conducted to investigate the effect of aqueous leaf extract of senduduk (Melastoma malabathricum L.) on the physicochemical properties of beef sausage dough. Different four formulas as treatment were employed to form the dough: formula A was as a control consisted of beef meat, vegetable oil, skim milk powder, tapioca, salt, phosphate, and seasoning; formula B was control added with extract 0.55%; formula C was control added with sodium nitrite 0.0011%, and formula D was control added with extract 0.55% and sodium nitrite 0.0011%. All ingredients were blended to be the dough. The result of the study denoted that the extract (B and D) significantly decreased (P<0.05) pH, and aw value with no difference in water content among the dough. The total phenolic content of the dough containing extract (B and D) was markedly higher (P<0.05) than were others. It increased significantly on antioxidant capacity, scavenging activity, and reduced the thiobarbituric acid reactive substances (TBARS) value of the dough. There was also no nitrite residual detected in all dough. In conclusion, the extract could improve the physicochemical properties of beef sausage dough and replace the use of nitrite in the dough.

Effect of Pregnancy and Dry Period on Raw Milk Quality of Water Buffalo in Chitwan, Nepal

One hundred and fifty four water buffaloes of Chitwan district were used to determine the variations in the composition of raw milk and milk yield due to pregnancy and dry period. Primary data for the study was collected using a well-designed questionnaire. Effect of dry period length and pregnancy were taken under consideration that determines the lactational efficiency. Effect of pregnancy on various milk components was also studied. The components analyzed in milk were fat, protein, SNF, density, lactose, total solid and salt. For better understanding the effect of pregnancy, the data obtained were categorized into two classes: pregnant and non-pregnant. The data thus obtained was analyzed using SPSS version 24. Fresh milk samples were collected and analyzed using milk analyzer in the laboratory. Results of present study unveiled that the salt, protein, lactose and SNF content in milk of non-pregnant buffalo is significantly lower (p<0.01) than that of pregnant one. But fat, density and total solid content of milk of pregnant buffalo had no significant difference (p>0.05) than that of non-pregnant one. Results also revealed that the length of dry period has significant effect on milk components and total yield. Among all other milk components, salt content in milk shows higher level of significance (p<0.05). The significant effect (p<0.05) of pregnancy on milk yield is generally observed after the 5th month of gestation.

Effect of Pregnancy and Dry Period on Raw Milk Quality of Water Buffalo in Chitwan, Nepal

One hundred and fifty four water buffaloes of Chitwan district were used to determine the variations in the composition of raw milk and milk yield due to pregnancy and dry period. Primary data for the study was collected using a well-designed questionnaire. Effect of dry period length and pregnancy were taken under consideration that determines the lactational efficiency. Effect of pregnancy on various milk components was also studied. The components analyzed in milk were fat, protein, SNF, density, lactose, total solid and salt. For better understanding the effect of pregnancy, the data obtained were categorized into two classes: pregnant and non-pregnant. The data thus obtained was analyzed using SPSS version 24. Fresh milk samples were collected and analyzed using milk analyzer in the laboratory. Results of present study unveiled that the salt, protein, lactose and SNF content in milk of non-pregnant buffalo is significantly lower (p<0.01) than that of pregnant one. But fat, density and total solid content of milk of pregnant buffalo had no significant difference (p>0.05) than that of non-pregnant one. Results also revealed that the length of dry period has significant effect on milk components and total yield. Among all other milk components, salt content in milk shows higher level of significance (p<0.05). The significant effect (p<0.05) of pregnancy on milk yield is generally observed after the 5th month of gestation.

Effects of the inclusion of detoxified argan press cake in the diet of dairy goats on milk production and milk quality

This study was carried out to assess the effect of the incorporation of detoxified argan press cake on milk yield, physicochemical composition, and microbial quality of raw Alpine goat milk produced in the Meskala-Essaouira region of southwestern Morocco. The detoxification method, adopted for the removal of saponin present in the argan press cake, succeeded in reducing these antinutrients from 4.56 to 0.4 mg/g, allowing it to be used as livestock feed. The average of milk production increased by 24% for the detoxified argan press cake (DAPC) group compared to the argan press cake and local diet groups. The diets and lactation stages had a significant effect (P < 0.05) on fat, protein, total solids, and salt in milk. Lactation stage and diet also had a significant effect (P < 0.001) on saponin concentrations in goat milk. Microbiological analysis showed that microbial flora of raw goat milk samples decreased with lactation stage. In terms of performance, DAPC could replace a conventional diet for goats without substantial detrimental effects.

A quantitative model of the bovine casein micelle: ion equilibria and calcium phosphate sequestration by individual caseins in bovine milk.

The white appearance of skim milk is due to strong light scattering by colloidal particles called casein micelles. Bovine casein micelles comprise expressed proteins from four casein genes together with significant fractions of the total calcium, inorganic phosphate, magnesium and citrate ions in the milk. Thus, the milk salts are partitioned between the casein micelles, where they are mostly in the form of nanoclusters of an amorphous calcium phosphate sequestered by caseins through their phosphorylated residues, with the remainder in the continuous phase. Previously, a salt partition calculation was made assuming that the nanoclusters are sequestered only by short, highly phosphorylated casein sequences, sometimes called phosphate centres. Three of the four caseins have a proportion of their phosphorylated residues in either one or two phosphate centres and these were proposed to react with the nanoclusters equally and independently. An improved model of the partition of caseins and salts in milk is described in which all the phosphorylated residues in competent caseins act together to bind to and sequester the nanoclusters. The new model has been applied to results from a recent study of variation in salt and casein composition in the milk of individual cows. Compared to the previous model, it provides better agreement with experiment of the partition of caseins between free and bound states and equally good results for the partition of milk salts. In addition, new calculations are presented for the charge on individual caseins in their bound and free states.

Effect of ascorbic acid rich, micro-nutrient fortified supplement on the iron bioavailability of ferric pyrophosphate from a milk based beverage in Indian school children.

Nutritional anemia is a significant public health issue with 50-80% prevalence in Indian children. Fortification of food, specifically milk, with iron is a potential approach to increase dietary iron intake. Ferric pyrophosphate [Fe4(P2O7)3] is organoleptically neutral and is less soluble in acid medium and, further, has low bioavailability in milk. However, since ascorbic acid is a potent enhancer of iron absorption, the coadministration of ascorbic acid with Fe4(P2O7)3 might enhance the absorption of iron. We evaluated the effect of ascorbic acid on iron absorption from a Fe4(P2O7)3 and an ascorbic acid fortified milk beverage with respect to milk fortified with Fe4(P2O7)3 alone. A double-blind, two-way crossover, randomized study was conducted in 25 mildly anemic children. The test group received milk fortified with beverage powder containing 7 mg isotopically labeled iron (57Fe/58Fe) as Fe4(P2O7)3, equimolar proportions of ascorbic acid and 200 mg of calcium whereas control group received milk fortified with energy, calcium and iron equivalent beverage powder. Fractional iron absorption was measured by erythrocyte incorporation of stable isotopes of iron (57Fe/58Fe) in both the groups. The fractional iron absorption from the control drink was 0.80% (95% CI: 0.57, 1.12). Fortifying the milk with an equimolar amount of ascorbic acid increased the fractional iron absorption almost 2-fold to 1.58% (95% CI: 1.13, 2.22). The presence of ascorbic acid in an equimolar ratio with that of iron from Fe4(P2O7)3 salt in milk as a fortificant enhanced iron absorption when compared to milk fortified with only Fe4(P2O7)3.

STUDY OF INFLUENCE OF CALCIUM CONTENT IN MILK ON QUALITY INDICATORS OF COTTAGE CHEESE

The analysis was realized, and the dependence between the calcium content and organoleptic and functional-technological properties of milk as a raw material for producing sour milk cheese was determined. It was demonstrated, that alongside with other factors, the important role in milk clotting belongs to calcium, which role is in binding of free OH-groups of phosphoric acid of casein micelles. As a result of the aforesaid, their negative charge and colloid stability decrease with further hydrophilicity decrease with further aggregation of casein molecules. It was established, that the excessive content of calcium in milk is negative that is manifested in formation of the dry and brittle consistence of sour milk cheese. There was offered the way of calcium content regulation in milk by its decalcification using the natural sorbent of sodium alginate. Regulation of the milk salt system, especially, the calcium content as an initial raw material for producing sour milk cheese by the change of the content and condition of calcium allowed to correct parameters of the process of sour milk cheese making and its functional-technological properties, especially, moisture-keeping ability, form stability and other. It was established, that the decrease of the calcium content in milk provides getting sour milk cheese with the soft, easily smearing consistence, without whey separation. The obtained data on the characteristic of organoleptic indicators fully correlate with studies of the microstructure and dispersity of sour milk cheese. It was determined, that milk decalcification results in raising dispersity of sour milk cheese at the synchronous increase of the percent content of protein particles with minimal size characteristics in the system. It was elucidated, that the microstructure of studied samples consists of protein grains of the same form, evenly distributed by the whole volume. Based on the obtained experimental data, there were corrected parameters of the technological process of sour milk cheese production. There were elaborated ways of formation of the culinary products assortment on the base of sour milk cheese, produced of decalcified milk.

Liquid organic fertilizer sprayed on shoots of Phaseolus vulgaris stimulates arbuscular mycorrhiza colonization and phosphate solubilizing microorganisms in soil

ABSTRACTProcessed organic agricultural byproducts such as liquid organic fertilizer (LOF) are promising alternatives that can improve crop productivity while reducing mineral fertilizer use and improving sustainability. The effects on beneficial soil organisms, such as arbuscular mycorrhizal (AM) fungi and phosphate solubilizing microorganisms (PSM), caused by LOF spraying on shoots is poorly understood. Therefore, we evaluated how AM colonization and soil PSM are affected by LOF spraying on common beans (Phaseolus vulgaris L.) grown in a greenhouse. The LOF was obtained by anaerobically fermenting a mixture of fresh water, cattle manure, bovine milk, sugarcane molasses and mineral salts. LOF was applied twice on the plant shoots. Fresh and dry mass of root and shoot, P content, P accumulation in the shoots and AMF spore counts in the soil were not LOF dose dependent. However, we found that a 5% LOF application stimulated AM colonization and led to dose-dependence for calcium and aluminium phosphate solubilizing bacteria and fungi. These results show that LOF sprayed on shoots causes responses on soil communities. We therefore endorse the use of LOF in low input agriculture.

Effect of whey protein concentrate, pH and salt on colloidal stability of acid dairy drink (Doogh)

Serum separation of Doogh, an Iranian yoghurt drink, is a major problem. In this study, the effects of whey protein concentrate (WPC) addition, pH of the product and dissolved salt (sodium chloride) in milk on the colloidal stability of Doogh were investigated. By increasing the amount of WPC (from 0.5 to 3%) and salt in milk (from 0 to 1.6%), the serum separation decreased. Increasing pH values of sample (from 3.5 to 4.5), WPC (from 0.5 to 4%) and salt concentration in milk (from 0 to 2%) also increased the samples’ viscosity. All samples showed Newtonian behaviour except samples at pH 4.5, containing 4% WPC and 2% dissolved salt in milk.

Isolation and identification of halophilic bacteria producing halotolerant protease

Halotolerant proteases are known as one of the important groups of enzymes that have been used widely in various industries. However, high production cost of proteases in term of energy used for sterilization and high risk of microbial contamination during fermentation become the obstacles during upstream processing. Moreover, proteases that capable to withstand with harsh conditions of salinity, temperature and pH are required in industry. Therefore, this study presents newly isolated halophilic bacteria producing halotolerant proteases. Halophilic bacteria were isolated from fermented fish sauce. Screening of the bacteria producing halotolerant protease enzymes was carried out by using skim milk salt agar containing 10% NaCl at pH 7 and incubated under aerobic condition at 37oC for 2 days. The selected isolates were identified based on their morphology followed by 16S rDNA gene sequence analysis. 40 colonies of halophiles bacteria were isolated, however, only 20 of them showing proteolytic activity. All of 20 isolates are motile and gram positive bacteria. From 20 isolates, only 6 were chosen for further analysis. B7 showed the highest proteolytic activity compared with others. Results of 16S rDNA gene sequence analysis showed 98% homology to Bacillus amyloliquefaciens subsp. plantarum strain FZB42. Therefore, B7 is identified as Bacillus amyloliquefaciens strain B7.