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The value of milk hinges on its physicochemical functionality under processing conditions. We examined composition-functionality relationships with individual milks from 24 New Zealand dairy cows, sampled at 3 times over the season. Milks were classified into type A or B, according to the shape of 3-point heat coagulation time versus pH profiles. Milk type changed over the season for half of the cows in the study. Best subsets regression suggested that different factors controlled heat stability in the 2 milk types. Urea concentration was key for both types, but for type A milks, osmotic pressure and milk solids were the most important predictors of heat stability, whereas casein micelle size and ionic calcium predicted heat stability for type B milks. This study revealed that milk type is prone to change over the season, and the findings suggest that optimizing heat stability could be achieved by different means for type A versus type B milks.

Milk fat globule size plays a significant role in stability, microstructure and nutritional functionalities of dairy-based products. Understanding of thermal stability of differentiated-size fat globules in dairy creams can provide intervention opportunities for improving functionalities and shelf-life of dairy-based products. This study focused on apparent thermal and UHT stability of native, homogenized (from native cream) and recombined creams (sodium caseinate-stabilized anhydrous milk fat) as a function of their fat globule sizes at 18 and 36% fat contents. Native creams were fractionated by the two-stage centrifugal method into five sizes (~1.45, ~2.45–3.65, ~3.85 and ~4.5 μm) whereas homogenized and recombined creams (~1.45, ~2.45, ~3.85 and ~4.5 μm) were obtained by microfluidisation. All cream samples were tested for thermal stability at 140 °C following a test similar to Heat Coagulation Time. Some selected creams were also studied for UHT stability at 140 °C for 4 s. Native creams exhibited diverse thermal stability depending upon fat content and size; however, native creams (~2.45–3.65 and ~4.5 μm) were UHT stable. Native creams of all sizes were also significantly more thermal stable than homogenized creams. Homogenized creams of all sizes at both fat contents showed poor apparent thermal and UHT stability. It appeared that small fat globules of native creams were more heat stable than larger fat globules at 18% fat content. Recombined creams made with sodium caseinate as emulsifier (without the presence of other milk components) were the most stable among all. However, dilution of recombined cream with skim milk or lactose significantly reduced their apparent thermal stability, but they were UHT stable.

peer-reviewed The effect of pH, adjusted using either hydrochloric acid (HCl), citric acid or sodium hydroxide, on calcium ion (Ca2+) activity, and consequent changes in viscosity and heat coagulation time (HCT) of milk protein concentrate (MPC) was investigated. Reducing the pH of MPC dispersions resulted in a reduction in their viscosity, which subsequently increased during heat treatment. The maximum heat stability of MPC was observed at pH 6.7. Reducing the pH of MPC from 6.7 to 6.2 resulted in a significant (P < 0.05) increase in Ca2+ activity, and reduction in HCT. Such changes were more extensive using HCl compared with citric acid. Increasing the pH greater than 6.7 also led to a reduction in HCT but a decrease in Ca2+ activity. These results demonstrate the importance of pH adjustment, and choice of acidulant, on Ca2+ activity, viscosity, and heat coagulation properties of MPC concentrates during processing.

peer-reviewed The effects of key manufacturing steps (heat treatment, evaporation and spray drying) during the manufacture of low- and high-heat skim milk powders (SMP) on the physico-chemical and processing characteristics of milk, and concentrates of varying total solids (TS) levels prepared by reconstituting the milk powders, were evaluated. Milk heat treatment had the most pronounced effect, with an increase in severity of heat treatment from 72 °C × 15 s to 120 °C × 120 s, prior to evaporation resulting in higher heat coagulation time (HCT) at pH 6.3–6.6 and ethanol stability (ES) at pH 6.2–6.6, and a marked deterioration of rennet-induced coagulability. Increasing TS of the milk on reconstitution from 9.4 to 25% reduced HCT at pH >6.3 and ES at pH 6.6–7.0, increased ES at pH 6.2–6.4, and led to partial recovery of rennet-coagulability. The results highlight how heat treatment may be used to customise the functionality of SMP to different applications.

The heat stability of low (LH) and high heat (HH) nonfat dry milk (NDM) that received a radio frequency dielectric heat (RFDH) treatment at 75, 80 or 85 °C for different periods of time (between 43 and 125 min) was assessed. NDM was reconstituted at 3.5% (w/w) protein. Heat stability was assessed at 140 °C by recording the heat coagulation time. Samples were evaluated at native pH, and adjusted pH from 6.4 to 7.2. LH samples heated to 75 °C or 80 °C showed greater heat stability than non-treated LH at pH 6.4 to 6.8. Data suggest that RFDH treatment of LH induced associations between whey proteins and casein micelles, which increased the heat stability in this pH region. The same effect was not observed in the HH samples, suggesting different reactions may be induced. Dry heating NDM may affect protein associations differently from liquid systems, depending upon the conditions.

Background We experienced a patient with multiple myeloma whose urine contained a considerable amount of Bence Jones protein (BJP), which demonstrated poor thermal reactivity in heat coagulation test. The mechanism for this phenomenon was assessed. Methods Immunoelectrophoretic analyses reveal that a band corresponding to BJP in the urine had 2,600 Dalton by reduction after glycosidase treatment, but not after sialidase treatment. In addition, the glycosidase-treated urine tested positive in heat coagulation test. Conclusions Glycosylation of the immunoglobulin light chain, which has rarely been seen, is the cause of the unexpected behavior of this patent's BJP in heat coagulation tests.

Oil-in-water emulsion systems formulated with plant proteins are of increasing interest to food researchers and industry due to benefits associated with cost-effectiveness, sustainability and animal well-being. The aim of this study was to understand how the stability of complex model emulsions formulated using lentil proteins are influenced by calcium fortification (0 to 10 mM CaCl2) and thermal processing (95 or 140 &deg, C). A valve homogeniser, operating at first and second stage pressures of 15 and 3 MPa, was used to prepare emulsions. On heating at 140 &deg, C, the heat coagulation time (pH 6.8) for the emulsions was successively reduced from 4.80 to 0.40 min with increasing CaCl2 concentration from 0 to 10 mM, respectively. Correspondingly, the sample with the highest CaCl2 addition level developed the highest viscosity during heating (95 &deg, C &times, 30 s), reaching a final value of 163 mPa&middot, s. This was attributed to calcium-mediated interactions of lentil proteins, as confirmed by the increase in the mean particle diameter (D[4,3]) to 36.5 &micro, m for the sample with 6 mM CaCl2, compared to the unheated and heated control with D[4,3] values of 0.75 and 0.68 &micro, m, respectively. This study demonstrated that the combination of calcium and heat promoted the aggregation of lentil proteins in concentrated emulsions.

Reconstituted milk protein concentrate (RMPC) showed higher thermal stability than reconstituted skimmed milk powder (RSMP) at equal protein level (7.5%); heat coagulation time (HCT) 6.80 and 1.80 min, respectively. RMPC contained lower concentration of milk minerals as compared to RSMP. The total mineral content of RMPC was matched with RSMP using mineral salts, which decreased its HCT to 1.55 min. Individual Ca, Mg, Na and K content of RMPC were also matched. Addition of CaCl2·2H2O and MgCl2·6H2O to RMPC reduced it HCT and made it unsuitable to UHT processing. NaCl added RMPC was UHT stable (UHT run-time>120 min). KCl added samples showed diminished UHT stability (run-time 15 min) and lower overall heat-transfer coefficient. Addition of mineral salts increased protein aggregation. The reduced amount of minerals in RMPC as compared to RSMP, notably potassium content per protein unit, appeared to be responsible for its high heat stability.

To improve the nutritional and physiological functionality of cheese analogs, fermented cheese analogs treated with Flavourzyme® were developed and the effects of roasting soy flour and fermentation time (1, 2, and 3 days) with rice straw on their quality characteristics, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), isoflavone content, and antioxidant activity were examined. Heat coagulation was the highest for the unroasted and roasted soy flour groups fermented for 1 day, with the unroasted group having higher values than the roasted group, regardless of fermentation time. The daidzein and genistein contents were the highest in the soy flour and roasted soy flour groups fermented for 2 days and 1 day, respectively. The antioxidant activity and heat extension were the highest for the soy flour group and roasted soy flour group fermented for 1 day, respectively. In the SDS-PAGE patterns, protein subunits of P26 in roasted soy flour groups were consistently decomposed by increasing the fermentation time. The yield and pH in both groups decreased as fermentation time increased. The adhesiveness of the soy flour group was highly increased by fermentation, and the cohesiveness, springiness, and appearance of the roasted soy flour group were improved by fermentation. The optimum fermentation time for the fermented cheese analogs was 1 day, as higher yields, heat coagulation, heat extension, lightness, dE, cohesiveness, and springiness were obtained. Between the two groups fermented for 1 day, the soy flour group showed better heat coagulation, genistein content, antioxidant activity, cohesiveness, springiness, and adhesiveness; however, the roasted soy flour group showed better yield and heat extension.

Heat-induced modifications were investigated upon heating recombined concentrated milk emulsions in the absence and presence of zwitterionic lysophospholipids or zwitterionic and anionic dialkylphospholipids of varying alkyl chain length. Among the lysophospholipids, 1-stearoyl-2-hydroxy-sn-3-phosphocholine demonstrated the greatest heat-stabilising effect, whereas 1-myristoyl-2-hydroxy-sn-glycero-3-phosphocholine resulted in increased viscosity and particle size as compared with its longer analogue. The protein recovery results showed that additional protein deposition at the oil-water interface was partly prevented upon lysophospholipids addition, especially by the ones characterised by a longer alkyl chain. The dialkylphospholipids exhibited a remarkable heat-stabilising effect upon addition at relatively low concentrations. As in the case of lysophospholipids, the longest alkyl chain phospholipids provided evidence of increased heat stability compared with 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol and 1,2-dimyristoyl-sn-glycero-3-phosphocholine. Moreover, anionic PG was characterised by an optimum concentration above which the heat-stabilising effect was weakened, whereas in the case of zwitterionic PC, the beneficial effect increased continuously with added concentration.

Paneer represents a South Asian variety of soft cheese prepared by acid and heat coagulation of milk. It is popular throughout South Asia and used in the preparation of a number of several culinary preparations and snacks. It is a rich source of high quality animal protein, fat, minerals and vitamins. Due to availability of different types of milk and variation in milk composition, various techniques have been developed for the production of paneer as per the requirements of the consumers with appreciable improvement in the yield and other quality characteristics. Some of the modifications recommended in the preparation of paneer are discussed in this review. Examples of some ‘value-added’ paneer have been dealt.

The impact of using natural fermentation with lactic acid bacteria (LAB), chemical acidification with liquid lactic acid, and encapsulated citric, gluconic or lactic acid were evaluated in raw and cooked salami-type products. Liquid lactic acid resulted in an immediate pH drop and significant increase in L*(lightness) and a*(redness) values, as well as clumping of the ground meat particles that exhibited moisture release due to excessive protein denaturation. Overnight LAB fermentation also resulted in increased L*and a*values, but unlike direct acid addition, did not cause moisture loss or clumping. Spectra data, collected after both treatments reached pH 4.6, revealed pretty similar curve shape, with higher values for the fermented product at 420–550 nm and 610–670 nm. The encapsulated acids, designed to release acid at about 62C, did not affect the color of the raw meat batters. Cooking of all treatments resulted in higher L*and a*values, both by about 50%. L*and a*values were pretty similar for all the acidified and non-acidified control. The only exception was a no-nitrite control, which showed a significantly (P

The thermal stability and physico-chemical properties of individual buffaloes’ colostrum (5 animals) were followed during three days after postpartum. The heat stability of the first postpartum milk can be visually defined in terms of the time required to induce coagulation at boiling temperature. Gradually marked variations of heat coagulation time were detected up to 60 h postpartum milking when heated at boiling temperature. The thermal stability of individual buffalo’s colostrum gradually increased with progressive postpartum milking, namely, at 1 h (0.55 min.), 6 h (3.53 min.), 12 h (7.10 min), 24 h (12.30 min), 36 h (18.10 min), 48 h (21.05 min) and 60 h (24.13 min). But at 72 h postpartum, no visual change (coagulation) was observed during heating at boiling temperature for one hour. It can be seen that first postpartum milk was very unstable to heat treatment with coagulation at boiling temperature. Hydrometer is a simple, rapid and of low cost method to evaluate the quality of colostrum. Colostral immunoglobulins concentrations measured from one partial to third consecutive complete milking at 12 h intervals postpartum decreased at different rates over time or number of milking. The colostrum is thicker, stickier and slightly yellowish compared to normal milk, the specific gravity was higher than that of normal milk and the pH is lower. The total solids, total protein, fat and ash contents were highest after parturition and then decreased rapidly to reach values of normal milk almost after three days of parturition, where the protein content was the most variable constituent. While the changes in the lactose content followed an opposite trend.

The influence of added lyophilized butter serum on the heat stability of milk was investigated. The addition of lyophilized serum from salted butter to unconcentrated skimmed milk (SM) reduced the heat coagulation time (HCT) at, and increased the pH of, the maximum in the pH-HCT profile and caused disappearance of the minimum. NaCl had similar effects on the heat stability of SM as lyophilized salted butter serum, whereas lyophilized serum from unsalted butter had little effect. The addition of lyophilized salted butter serum to concentrated skimmed milk (CSM) also shifted the pH of maximum heat stability to a higher value and, at certain concentrations, increased the maximum HCT; similar effects were obtained on addition of NaCl, but lyophilized serum from unsalted butter had little effect. These results suggest that the effects of lyophilized serum from salted butter on the heat stability of SM or CSM are due primarily to the presence of a high level of NaCl in this serum.

Defatted meals and protein concentrates from six accessions of Sinapis alba and one accession of Brassica juncea mustard seeds were analysed for their polypeptide profile and functional properties. Two types of protein concentrates were prepared using acid-induced and calcium-induced protein precipitations. Meals from the S alba seeds had similar polypeptide composition, which was different from that of the B juncea meal. Non-reducing sodium dodecyl sulfate polyacrylamide gel electrophoresis showed that two of the major polypeptides (50 and 55 kDa) in S alba seeds were susceptible to acid-induced precipitation but resistant to calcium-induced precipitation. The B juncea meal proteins were significantly (p ≤ 0.05) more susceptible to heat coagulation than the S alba meal proteins. Emulsifying activity index was significantly higher (p ≤ 0.05) in the B juncea meal and protein concentrates when compared with similar products from S alba. It was concluded that the presence of a high-molecular-weight (135 kDa) disulfide-bonded polypeptide could have contributed to the lower emulsifying power of the S alba products when compared with the B juncea proteins that do not have this polypeptide. Copyright © 2005 Society of Chemical Industry

Summary A thin-caliber applicator system was developed for laser ablation of lung metastases. Feasibility of lung metastases ablation as well as the complication rate and clinical results were evaluated. We calibrated the miniaturized applicator system in non-perfused bovine liver for maximum energy supply and necessary flow of the cooling saline solution in reference to a commercially available system (Power laser applicator kit, Somatex, Teltow, Germany). The size of heat coagulation in bovine liver was 24 ± 2 ml with the miniaturized system in comparison to a size of 29 ± 7 ml for the existing applicator. 15 W were applied for 20 min and a saline flow of 40 ml/h with the miniaturized applicator and 30 W, 20 min, 60 ml/min with the standard applicator. 21 patients with 32 lung metastases were then treated and the results as well as minor and major complications were evaluated. Ablation was technically successful in all but 2 patients. 14 patients were considered to be effectively treated. Their metastases showed a marked reduction of volume. Volume reduction took several months to develop. Successful treatment had either a ground-glass appearance of the treated site or a cystic defect as a morphological correlate. We conclude that successful ablation of lung metastases is possible with a miniaturized applicator.

The 1H-magnetic resonance imaging technique was applied for monitoring the extent of the heat coagulation in the shell egg. It is demonstrated that spin-spin relaxation time (T2) is an effective marker to observe the extent of coagulation in egg white and yolk and that the T2 value image is quite useful to recognize non-destructively the extent and status of coagulation of the heated eggs. This technique can also be applied to the material science as well as food science for observation of the inner status of the objects.

Tau protein is the main component of neurofibrillary tangles of Alzheimer's disease (AD). Immunohistochemistry of tau protein is useful in the diagnosis of AD but produces diffuse staining of neocortical neurons in fire fatalities. To learn the cause of this phenomenon, we examined the temporal neocortex of 13 fire fatalities and 9 fatalities unrelated to fire. The diffuse tau immunoreactive neurons were observed in 10 fire fatalities with heat coagulation of the cerebrum. Diffuse staining was not found in the three fire fatalities without heat coagulation of the cerebrum or in fatalities unrelated to fire. The immunoreactivity progressively increased as a function of the degree of cerebral heat coagulation. These results demonstrate that diffuse tau immunoreactivity of neocortical neurons is a post-mortem phenomenon caused by prolonged exposure of the head to intense heat. Forensic pathologists should consider this phenomenon when they diagnose AD in fire fatalities.

The effects of ovalbumin (OA) on heat coagulation of ovotransferrin (OT) were studied by heating at 65 °C for 10 min in 10 mM phosphate buffer, pH 7.0. The heat interactions between OA and OT were investigated by turbidity development and polyacrylamide gel electrophoresis. From the change in turbidities of various mixtures of 0.05% OT and OA induced by heating, it was found that OA had the inhibiting capacity against OT coagulation. The inhibiting capacity of OA was reduced by adding NaCl to OA-OT mixture on heating. The heat-denatured OA that was preheated above 70 °C exhibited markedly the inhibiting capacity against OT coagulation at 65 °C. A possible mechanism by which OA inhibited the OT coagulation was discussed. It was presumed that OA interacted mutually with OT by the electrostatic attractive force, unfolded together by heating, and then formed soluble aggregates with OT through intermolecular forces such as hydrophobic and disulfide bonds and, consequently, such a process might inhibit OT–OT interaction that led to coagulation.

Potato starch production encountered drastic changes during the last years, in particular in economics and substrate supply. Because of economically required reductions in subsidisation, production of potato starch will decrease. Changes in technology are characterised by savings in wash water and process water streams that are effected by increased efficiency introduced with new machinery and changed technological concepts. From an ecological point of view, an early and maximum fruit water separation (up to 95 %) based on dilution of gratings with process water and decanter separation allowed to reduce the fresh water supply to 0.4 to 0.5 m 3 /t of processed potatoes. For economical isolation of potato protein a correspondingly high protein recovery rate (up to 90%) is essential. Concerning starch extraction, a minimum of 95 % is reached in modern potato starch plants, but optimum engineering (rasping, decanting, sieving) gives recovery rates of 97 to 98 %. In starch refinement, three-phase nozzle separators equipped with wash water supply and constructed for efficient displacement washing allow to achieve a fine fibre removal of 98 % within three separation stages and a final concentration of purified starch milk of 22 to 23°Be. Potato protein isolates (protein content 83 to 85 %) are produced by isoelectric precipitation combined with heat coagulation while stringent solutions for treatment of de-proteinised fruit water are still lacking.

The characteristics of dialyzed and freeze-dried egg white that was dry-heated under various conditions (70−125 °C, 0 min−6 h) were studied. The dry-heated egg whites (DHEWs, 120 °C) showed the formation of insoluble aggregates (coagula) within 50 min, turbid soluble ones (50 min−2 h), and transparent soluble ones (2−6 h) according to the dry-heating times when solubilized at 10% concentration (pH 7.4) and reheated at 60 °C for 3.5 min. A transparent DHEW solution without any coagula when reheated was obtained by using a shorter dry-heating time and elevating the dry-heating temperature. It was also found that NaCl suppressed the turbidity development of DHEW solution promoted by CaCl2. When 10% DHEW solutions (120 °C, >2 h) were mixed with fresh egg white at the ratio of 1:1 in volume and heated at 60 °C for 3.5 min, coagulum formations in their mixtures were inhibited. The patterns of native− and SDS−PAGEs and gel filtration suggest that soluble aggregates of ovalbumin formed in the dry-heating process ...

During the last decades, several researchers tried to clarify and fully explain the exact mechanism of the heat-induced coagulation which occurs during heating milk at elevated temperatures. Based on literature data, this phenomenon is mainly a consequence of heat denaturation and unfolding of the globular whey protein fraction of milk, which results in the exposure of the previously buried hydrophobic and free thiol groups. As the denaturation process proceeds, several interactions start to take place leading to the formation of a product with modified organoleptic and physicochemical characteristics. The most important interactions which are believed to take place during heating milk at high temperatures are the interactions between denatured whey proteins with themselves and/or the complex formation of denatured whey proteins (or whey protein aggregates) with casein micelles. The heat-induced network between milk proteins is essentially built due to the hydrophobic bonding between the denatured whey proteins, as well as the thiol-disulfide exchange between the denatured whey proteins with themselves and/or with the κ-caseins. In order to be able to apply high temperatures and at the same time to decrease the degree of protein complexation, the application of surface active molecules (surfactants) has been proposed. Previous studies described that the effect of surfactants on the heat stability of whey protein containing emulsions is based on the protein displacement or interaction with proteins bound on the oil interface, and/or interaction with free proteins in solution.

SUMMARYHeat coagulation time-pH curves at 140°C were obtained for 43 blended skim milk samples from Holstein cows to determine the effects of genetic variants of κ-casein and β-lactoglobulin on milk heat stability. The blended milk samples were similar in terms of protein content and milk salts, but were genotypically different for κ-casein (AA, AB) and β-lactoglobulin (AA, AB, BB). Type A curves were obtained for all milks. Maximum heat stability was affected by the κ-casein genotype (AB > AA, P < 0·01) but the influence of the β-lactoglobulin genotype was only significant when the κ-casein AA genotype was present (β-lactoglobulin AA > BB, P < 0·0001). Minimum heat stability was significantly higher (P < 0·0001) for milk genotyped κ-casein AB:β-lactoglobulin BB. The effects of milk genotyped κ-casein BB on maximum and minimum heat stability were determined by analysing individual milks: κ-casein BB:β-lactoglobulin AB (n=8) and reconstituted milks: κ-casein BB:β-lactoglobulin AA, AB and BB (n = 17). Type B curves were obtained on three occasions for individual κ-casein BB:β-lactoglobulin AB milk and on five occasions in the case of reconstituted milks with κ-casein BB:β-lactoglobulin AA, AB and BB. This suggests a relationship between the type B curve and the κ-casein B genetic variant. Comparison of the mean values of heat stability at the pH of maximum heat stability of each individual and reconstituted milk genotype suggested that the best genotype for κ-casein in terms of heat stability was BB.

Retinal tears were recognized as soon as ophthalmoscopy became available. They were initially considered to be secondary events, from choroidal exudation and pressure behind the detached retina. This led von Graefe and others to recommend cuts in the retina to drain subretinal fluid into the vitreous cavity. De Wecker (1875, 1879) and Leber (1882) first proposed that intrinsic tears within the retina are the cause of retinal detachment, but they faced extreme and long lasting opposition for this view. Surgical results at this time were uniformly disastrous, and therapeutic nihilism still prevailed when Dufour and Gonin became convinced around 1904-1906 that the retinal tear was indeed the origin of the detachment. It took ten years, however, before Gonin figured out how to close tears by exact placement of heat coagulation ("thermopuncture") and provide therapeutic evidence for his beliefs. When he first presented his results in 1921, colleagues jeered at him, especially Deutschmann and Sourdille who, like the other ophthalmic surgeons, denied the role of the tear (and still made "therapeutic" incisions through the detached retina). Recognition of Gonin's approach finally came at the International Congresses in Amsterdam 1928 and in Madrid in 1933. Sourdille modified his approach when his son Gabriel convinced him to change after 1930, but Deutschmann stuck to his horrific procedure until his death in 1935. Then a new generation of retinal surgeons took over, with subsequent discussion focused on finding the best methods to close the tears.

Changes in heat stability and rennet coagulation induced by adding phosvitin to milk were investigated. Phosvitin was added to skim milk and concentrated skim milk (22% total solids (TS)) as well as to whole milk, homogenized at different pressures (i.e. 0, 6·8, 20·4 and 34·01 MPa) and/or concentrated to 31% TS. Adding phosvitin to milk caused a decrease in pH, which resulted in destabilisation at the natural pH of the mixtures. The minimum in the heat coagulation time (HCT)-pH profile of unconcentrated milk was eliminated and the heat stability of concentrated milk improved. Increasing the homogenization pressure had a detrimental effect on heat stability, but unconcentrated milks containing phosvitin were more stable than controls. Phosvitin could not alleviate the detrimental effect of homogenization and concentration on heat stability, except when added after concentration in unhomogenized whole milk or milk homogenized at 6·8 MPa. Phosvitin delayed the enzymic coagulation of milk by inhibiting both steps of the renneting reaction. These changes were the result of sequestering of calcium from milk by phosvitin. An additional effect arising from complexation of phosvitin with the micellar caseins should not be ruled out.

A CHANGE in pH when proteins are denatured has been reported by other workers1,2. When making observations of the change in pH of meat resulting from heat coagulation, we were struck both by the magnitude and by the variability of the change. Muscle is a highly buffered system3, and a change such as that observed, for example, from 5·6 to 5·9, indicates the production of a considerable amount of base.

To study the mechanism of the gel-strength increasing effect of sarcoplasmic proteins (Sp-P) on fish meat gel, the interaction between each component of Sp-P and actomyosin (AM) occurring during heating was examined. Heat coagulation temperature range was measured for each component by gradually heating the Sp-P extracts (I=0.05) from 9 fish species: 40-50 ℃ for 50K, 43K, and 23K; 50-60℃ for 94K, 60K, 40K, 30K, and 25K; 60-70℃ for 65K, 63K, 55K, and 35K; >70℃ for 20K components>. These components, however, remained in the mixed solution (I=0.7) of Sp-P and AM at a ratio of 1 to 2 even after heating at 80℃. This was attributable to the fact that the coagulable Sp-P components bound to AM molecules one after another at their coagulation temperatures were suspended in the solution.

Caseinoglycopeptides were isolated from sweet cheese whey by alcohol precipitation and ion exchange chromatography after heat coagulation of whey protein. The most successful method for obtaining the highest yield was by heating 10% (wt/vol) whey solution at pH 6.0 for 1h, followed by precipitation with cold ethyl alcohol (50% vol/vol). The caseinoglycopeptide was fractionated into sialo- and asialo-caseinoglycopeptides by peanut ( Arachis hypogoea ) lectin-affinity chromatography. Caseinoglycopeptides exhibited five peaks on reverse-phase HPLC, which were divided into the first peak of an asialo-caseinoglycopeptide and sialo-caseinoglycopeptide in the following four peaks. The ratio of asialo-caseinoglycopeptide in whole caseinoglycopeptide is approximately 10%. Asialo-caseinoglycopeptide also could be prepared from cheese whey acidified to pH 3.0 and heated for 1h at 98°C. Sialic acid in caseinoglycopeptide was completely released by this treatment. The yield of caseinoglycopeptide was approximately 1.1g from 100g of cheese whey powder.

Paneer is a South Asian variety of soft cheese prepared by addition of citric acid and heat coagulation of milk. It can be used in the preparation of a number of several culinary preparations and snacks. In India, around 7 per cent of the total milk produced is being converted to paneer. Value addition of paneer to make it more attractive in ready to eat form of nuggets in another way to delight consumers. Paneer nuggets are value added product prepared from paneer by steam cooking method. An economic viability is the most important factor to make place in the market for any food product along with its quality and sensory parameters. Considering the prevailing market, price of paneer nuggets is 300 per kg, cost of the developed paneer nuggets was 216.11 per kg a profit of 83.89 per kg could be obtained which is a good profit margin for the commercial viability and sustainability of the product. The break even output was calculated at 4.36 kg of product which is lower than the actual level of production indicating the viability of this enterprise.

Recent advances have been made in the understanding of factors that control the destabilization of milk proteins by alcohol and by heat. These advances are reviewed, and arguments are developed supporting a physical basis for the mechanism of alcohol-induced precipitation. These physical effects are contrasted with the mainly chemical reaction-based factors controlling heat coagulation. The benefits of these recent developments are illustrated by case studies on cream liqueurs and concentrated milk products.

Antivenoms are preparations of intact or fragmented (F(ab')2 or Fab) immunoglobulin G (IgG) used in human medicine to treat the severe envenomings resulting from the bites and stings of various animals, such as snakes, spiders, scorpions, or marine animals, or from the contact with poisonous plants. They are obtained by fractionating plasma collected from immunized horses or, less frequently, sheep. Manufacturing processes usually include pepsin digestion at acid pH, papain digestion, ammonium sulphate precipitation, caprylic acid precipitation, heat coagulation and/or chromatography. Most production processes do not have deliberately introduced viral inactivation or removal treatments, but antivenoms have never been found to transmit viruses to humans. Nevertheless, the recent examples of zoonotic diseases highlight the need to perform a careful assessment of the viral safety of antivenoms. This paper reviews the characteristics of equine viruses of antivenoms and discusses the potential of some manufacturing steps to avoid risks of viral contamination. Analysis of production parameters indicate that acid pH treatments and caprylic acid precipitations, which have been validated for the manufacture of some human IgG products, appear to provide the best potential for viral inactivation of antivenoms. As many manufacturers of antivenoms located in developing countries lack the resources to conduct formal viral validation studies, it is hoped that this review will help in the scientific understanding of the viral safety factors of antivenoms, in the controlled implementation of the manufacturing steps with expected impact on viral safety, and in the overall reinforcement of good manufacturing practices of these essential therapeutic products. UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP)

Sandesh represents the traditional Indian dairy product used as sweet dairy desserts, prepared by acid and heat coagulation of milk. It is popular throughout eastern part of India especially in West Bengal. It is a rich source of high quality animal protein, fat, minerals and vitamins. It is appreciated by people belonging to all age groups and social levels. Due to availability of different types of milk and variation in milk composition, various techniques have been developed for the production of sandesh as per the requirements of the consumers with attendant improvement in the yield and other quality characteristics. The aim of the present review paper is to update the production methods of sandesh, moisture sorption isotherms, textural properties and value addition to Sandesh.

Ovalbumin (OVA) was aggregated stepwise by dry heating at 120 degrees C with a gradual increase in its heating times (10 min-6 h). The inhibiting effects of DHOVAs (OVAs dry-heated for various times up to 6 h) on the heat coagulation of ovotransferrin (OT) were studied. DHOVAs and OT were solubilized at 5% (w/w) concentration with 10 mM sodium phosphate buffer, pH 7.4. Their solutions were mixed at the volume ratio of 1:1 and reheated at 60 degrees C for 3. 5 min. Some remarkable differences according to dry-heating time were observed: coagulum formations were greatly inhibited in the solutions mixed with DHOVAs treated for more than around 2.0 h, with decreasing turbidity as dry-heating time increased. In addition, the effects of reheating time and temperature, as well as those of pH and ionic strength, were also examined on coagulum formation and turbidity development in connection with dry-heating time. Thus, the inhibiting effects of dry-heated egg white on the heat coagulation of fresh egg white previously described were confirmed on the molecular level of OVA and OT.

Buttermilk prepared on a laboratory scale from raw cream, or on a commercial scale from flash-pasteurized cream (90 degrees C for 1 to 2 s), exhibited a type B heat coagulation time-pH profile (i.e., stability increased as a function of pH). The high heat stability of buttermilk in the pH range of the minimum of a type A milk (pH approximately 6.8 to 7.0) appears to be related to differences in the serum phase constituents (i.e., a low calcium and beta-Lg concentration and a high nonmicellar kappa-CN content).

A simple method for coagulating proteins in aqueous leaf extract, through microbial fermentation, has been reported. The Leaf Protein Concentrate (LPC) obtained through this fermentation has been compared with those obtained through conventional heat coagulation methods to show that the former improves the yield and nutritional quality of LPC.

Journal of Dairy Research, 59 (2), ISSN:0022-0299, ISSN:1469-7629

Publisher Summary About 80% of the protein in milk is casein. The casein is present as colloidal particles, the so-called “casein micelles.” Casein monomers have little secondary structure; therefore, they are not able to be denatured by heat. Nevertheless, an intensive heat treatment of milk results in coagulation, principally by aggregation of the casein micelles. The study on heat coagulation of milk products so far has focused almost exclusively on the effect of compositional and processing factors on the Heat Coagulation Time (HCT), which is the time needed at a certain high temperature (120-140°C) to cause visible coagulation in an agitated sample of milk. This chapter focuses on the application of fractal aggregation theory to the heat coagulation of milk products and presents some results of the application of fractal aggregation theory to the heat coagulation of milk products. It concludes that at the conditions where simple flocculation predominates, the heat coagulation strongly depends on the initial volume fraction of particles. Fractal aggregation theory describes this dependence rather well.