Compositional and quality characteristics of paneer made from soya beans and buffalo milk under different heat treatments

Soya—buffalo milk (SBM) paneer was prepared from an admixture (1: 1 w/w, wet basis) of buffalo milk and tofu, the latter made by two methods (boiling and pressure cooking). Calcium sulphate (20 g litre^?1) and citric acid (100 g litre^?1) were used as coagulants for tofu and SBM-paneerpreparations, respectively. Significant differences (P0.05) were observed in the yield of okara and hulls of soya beans in the two methods. However, no significant differences were observed in the yield and composition of tofu. SBM-paneer( unfried and fried) showed no significant difference in composition between the methods, excepting the moisture and fat levels in the unfried SBM-paneer. Fried SBM-paneer prepared by pressure cooking showed a significant difference in the sensory score. Comparative appraisal of the composition of tofu, SBM-paneer ( fried and unfried) and whey obtained in the two methods are presented.     

Instrumental Textural Profile Analysis of Soy Fortified Pressed Chilled Acid Coagulated Curd (Paneer)

Abstract

Studies were conducted to observe the effect of varying fat content in milk (0–6%) and varying proportion of soy milk (7.5°B, 0–40%) in the blend on the textural properties of Soy Fortified Paneer (SFP). Instrumental Texture Analyzer of Stable Micro System was used to measure the texture of paneer containing varying level of fat and soy solids for texturel profile analysis (TPA). Texture profile data, thus obtained, were used to develop regression models between fat content in milk and proportion of soy milk in blend with that of the dependent variable hardness, cohesiveness, chewiness, springiness and adhesiveness. The high correlation coefficients of each developed model confirmed its suitability in representing experimental data. Based on to these models SFP samples prepared using a blend (15:85 v/v) of soy milk (7.5°B) and buffalo milk (3.12%) was found to be suitable for producing textural characteristics similar to that of control paneer sample.     

Characterisation and comparison of khoa prepared from camel milk with that from cow and buffalo milk

Khoa, a heat‐concentrated milk product, is used as a base material for the manufacture of many popular sweets. The comparison was made between various chemical compositions and characteristics of the khoa prepared from the camel milk with that prepared from the cow and the buffalo milk samples. The khoa prepared from the camel milk had the higher moisture, ash, acidity, soluble nitrogen, free fatty acids and peroxide value, but lower in fat, protein and lactose contents than that prepared from the cow and buffalo milk samples. There was no significant (P > 0.05) difference in 5‐hydroxymethyl furfural between khoa samples prepared from the three milks.     

Effects of polymerized goat milk whey protein on physicochemical properties and microstructure of recombined goat milk yogurt

Goat milk whey protein concentrates were manufactured by microfiltration (MF) and ultrafiltration (UF). When MF retentate blended with cream, which could be used as a starting material in yogurt making. The objective of this study was to prepare goat milk whey protein concentrates by membrane separation technology and to investigate the effects of polymerized goat milk whey protein (PGWP) on the physicochemical properties and microstructure of recombined goat milk yogurt. A 3-stage MF study was conducted to separate whey protein from casein in skim milk with 0.1-µm ceramic membrane. The MF permeate was ultrafiltered using a 10 kDa cut-off membrane to 10-fold, followed by 3 step diafiltration. The ultrafiltration-diafiltration-treated whey was electrodialyzed to remove 85% of salt, and to obtain goat milk whey protein concentrates with 80.99% protein content (wt/wt, dry basis). Recombined goat milk yogurt was prepared by mixing cream and MF retentate, and PGWP was used as main thickening agent. Compared with the recombined goat milk yogurt without PGWP, the yogurt with 0.50% PGWP had desirable viscosity and low level of syneresis. There was no significant difference in chemical composition and pH between the recombined goat milk yogurt with PGWP and control (without PGWP). Viscosity of all the yogurt samples decreased during the study. There was a slight but not significant decrease in pH during storage. Bifidobacterium and Lactobacillus acidophilus in yogurt samples remained above 10⁶ cfu/g during 8-wk storage. Scanning electron microscopy of the recombined goat milk yogurt with PGWP displayed a compact protein network. Results indicated that PGWP prepared directly from raw milk may be a novel protein-based thickening agent for authentic goat milk yogurt making.     

Effects of gelation temperature on Mozzarella-type curd made from buffalo and cows’ milk. 1: Rheology and microstructure

The rheology and microstructure of Mozzarella-type curds made from buffalo and cows’ milk were measured at gelation temperatures of 28, 34 and 39 °C after chymosin addition. The maximum curd strength (G′) was obtained at a gelation temperature of 34 °C in both types of bovine milk. The viscoelasticity (tan δ) of both curds was increased with increasing gelation temperature. The rennet coagulation time was reduced with increase of gelation temperature in both types of milk. Frequency sweep data (0.1–10Hz was recorded 90 min after chymosin addition, and both milk samples showed characteristics of weak viscoelastic gel systems. When both milk samples were subjected to shear stress to break the curd system at constant shear rate, 95 min after chymosin addition, the maximum yield stress was obtained at the gelation temperatures of 34 °C and 28 °C in buffalo and cows’ curd respectively. The cryo-SEM and CLSM techniques were used to observe the microstructure of Mozzarella-type curd. The porosity was measured using image J software. The cryo-SEM and CLSM micrographs showed that minimum porosity was observed at the gelation temperature of 34 °C in both types of milk. Buffalo curd showed minimum porosity at similar gelation temperature when compared to cows’ curd. This may be due to higher protein concentration in buffalo milk.     

Understanding the effect of milk composition and milking season on quality characteristics of chhana

The quality characteristics of chhana varied due to the milk composition (cow‐, buffalo‐, and mixed‐ milk) which in turn was affected by the milking season (summer and winter). Upon heating and acidification of milk samples water holding phenomena and denatured protein association within and with other components lead to variation in both macroscale properties (color, texture, and rheology) and molecular bonding patterns (FTIR character). Yield, lightness (L* value), textural firmness, and elastic modulus of chhana increased with increasing proportion of buffalo milk in mixed milk due to higher total solids and less moisture content in both the seasons. Total protein, fat, water, and interaction between them and extent of hydrogen bonding significantly affected the rheological and textural properties of chhana samples.     

广西水牛奶和荷斯坦牛奶中蛋白质和氨基酸的含量及组成分析

目的研究广西区内生水牛奶和荷斯坦生牛奶中蛋白质、氨基酸含量及其组成特性,分析水牛奶和荷斯坦牛奶的差异。方法采用盐酸水解法处理牛奶样品,通过氨基酸自动分析仪测定氨基酸含量,分析水牛奶和荷斯坦牛奶氨基酸的含量和组成;通过凯氏定氮法测定牛奶中蛋白质含量。结果 18份牛奶样品中蛋白质、氨基酸的测定结果表明,生水牛奶的蛋白质和氨基酸含量均高于荷斯坦生牛奶,而水牛奶和荷斯坦牛奶中各氨基酸含量占氨基酸总量的比值相近。结论该方法为广西生水牛奶和荷斯坦生牛奶的鉴别提供参考。     

Genome-wide association studies to identify quantitative trait loci affecting milk production traits in water buffalo

Water buffalo is the second largest resource of milk supply around the world, and it is well known for its distinctive milk quality in terms of fat, protein, lactose, vitamin, and mineral contents. Understanding the genetic architecture of milk production traits is important for future improvement by the buffalo breeding industry. The advance of genome-wide association studies (GWAS) provides an opportunity to identify potential genetic variants affecting important economical traits. In the present study, GWAS was performed for 489 buffaloes with 1,424 lactation records using the 90K Affymetrix Buffalo SNP Array (Affymetrix/Thermo Fisher Scientific, Santa Clara, CA). Collectively, 4 candidate single nucleotide polymorphisms (SNP) in 2 genomic regions were found to associate with buffalo milk production traits. One region affecting milk fat and protein percentage was located on the equivalent of Bos taurus autosome (BTA)3, spanning 43.3 to 43.8 Mb, which harbored the most likely candidate genes MFSD14A, SLC35A3, and PALMD. The other region on the equivalent of BTA14 at 66.5 to 67.0 Mb contained candidate genes RGS22 and VPS13B and influenced buffalo total milk yield, fat yield, and protein yield. Interestingly, both of the regions were reported to have quantitative trait loci affecting milk performance in dairy cattle. Furthermore, we suggest that buffaloes with the C allele at AX-85148558 and AX-85073877 loci and the G allele at AX-85106096 locus can be selected to improve milk fat yield in this buffalo-breeding program. Meanwhile, the G allele at AX-85063131 locus can be used as the favorable allele for improving milk protein percentage. Genomic prediction showed that the reliability of genomic estimated breeding values (GEBV) of 6 milk production traits ranged from 0.06 to 0.22, and the correlation between estimated breeding values and GEBV ranged from 0.23 to 0.35. These findings provide useful information to understand the genetic basis of buffalo milk properties and may play a role in accelerating buffalo breeding programs using genomic approaches.     

Rennet coagulation of buffalo milk as affected by some factors

Thrombelastograph was used to measure the rennet coagulation properties of buffalo milk. The combined effect of pH with temperature fat and protein contents, addition of whey protein concentrat (WPC) and sodium chloride on rennet coagulation (r) and clot forming (K₂₀) times were evaluated. The fat content had little effect on r or K₂₀ compared to pH. Increasing temperature from 30 to 40 °C or the protein content of UF milk retentate from 3 to 12% decreased K₂₀ and K₂₀ of buffalo milk. The K₂₀ was greatly affected by the replacement of casein with 10, 20, 30 and 40% WPC while r was less affected. Addition of sodium chloride (2–10%) increased and K₂₀ and the effect was more pronounced at low pH. The relations between the studied factors and r and K₂₀ of buffalo milk were calculated and discussed.     

Short communication: Factors affecting coagulation properties of Mediterranean buffalo milk

The aim of this study was to investigate sources of variation of milk coagulation properties (MCP) of buffalo cows. Individual milk samples were collected from 200 animals in 5 herds located in northern Italy from January to March 2010. Rennet coagulation time (RCT, min) and curd firmness after 30 min from rennet addition (a₃₀, mm) were measured using the Formagraph instrument (Foss Electric, Hillerød, Denmark). In addition to MCP, information on milk yield, fat, protein, and casein contents, pH, and somatic cell count (SCC) was available. Sources of variation of RCT and a₃₀ were investigated using a linear model that included fixed effects of herd, days in milk (DIM), parity, fat content, casein content (only for a₃₀), and pH. The coefficient of determination was 51% for RCT and 48% for a₃₀. The most important sources of variation of MCP were the herd and pH effects, followed by DIM and fat content for RCT, and casein content for a₃₀. The relevance of acidity in explaining the variation of both RCT and a₃₀, and of casein content in explaining that of a₃₀, confirmed previous studies on dairy cows. Although future research is needed to investigate the effect of these sources of variation on cheese yield, findings from the present study suggest that casein content and acidity may be used as indicator traits to improve technological properties of buffalo milk.     

Production and quality improvement of Indian cottage cheese (Paneer) using high pressure processing

Paneer, a product of India similar to cottage cheese, was prepared from cow's milk heat-treated (90 °C/5 min) (HTMP) or high-pressure (HP) treated (500 MPa/15 min) (HPPMP) for achieving pasteurization. HTMP and HPPMP paneer samples were HP treated (500 MPa for 15 min) again after vacuum packaging to get HTMP/HPP and HPPMP/HPP samples, respectively. The third set of samples were obtained by dipping HTMP and HPPMP paneer samples in 2% lactic acid solution and then subjecting them to the same HP treatment and stamped as HTMP/LA/HPP and HPPMP/LA/HPP, respectively. All six types of vacuum-packed paneer were studied for changes in moisture, acidity, pH, color, texture, and microbiological quality during storage at 5 ± 1 °C and 25 ± 1 °C. High-pressure treatment of milk increased the yield of paneer significantly (P < 0.05) from 13.9 ± 0.59% (HTMP) to 18.2 ± 0.32% (HPPMP). Paneer treated with lactic acid and high-pressure treatment (HTMP/LA/HPP and HPPMP/LA/HPP) had higher textural stability than HTMP, HTMP/HPP, HPPMP, and HPPMP/HPP for up to 28 days, but had a reduced moisture content, higher acidity, and lower whiteness index. High-pressure treatment of vacuum-packed paneer (HTMP/HPP and HPPMP/HPP) led to the formation of a more compact paneer matrix (higher hardness), higher moisture expulsion, and yellowness (b*). Thus, high-pressure processing of paneer could pave paths for extending paneer shelf-life without any additives and thermal treatment.     

The effect of varying casein/fat ratio on physicochemical and sensory qualities of Feta‐type cheese made using buffalo milk

The Feta‐type cheese was prepared with different casein/fat (C/F) ratios of buffalo milk using microbial rennet. The manufactured Feta cheeses were subjected to physicochemical and sensory quality at 15‐day interval up to 60 days of ripening. Sensory analysis discriminated the different level of C/F ratio of buffalo milk cheeses predominantly by age. There was no significant difference (P < 0.01) observed in cheese made from C/F ratio of 0.6–0.7 in terms of flavour. The titratable acidity (TA), soluble protein and free fatty acid appear to be age‐dependent and increased throughout the ripening in all experimental cheeses.     

Dielectric spectroscopy-based characterisation of different types of Paneer (Indian cottage cheese) in terms of texture,microstructure and functional groups

Different variants of Paneer were prepared with cow milk (CM), buffalo milk (BM), skimmed milk powder (SMP) and blends (40:60, 50:50, 60:40) of SMP with CM/BM. The Paneer composition, texture, microstructure and spread of functional groups were correlated with the dielectric capacitance values. Results depicted a strong correlation (R² > 0.95) between milk used for Paneer making and its proximate composition in terms of the capacitance value, and it was highest for CM followed by BM; 100% SMP Paneer recorded lowest values. Paneer made from blends of SMP and liquid milk had the lowest transmittance value, indicating higher total protein content.     

Mozzarella-Type Curd Made from Buffalo, Cows’ and Ultrafiltered Cows’ Milk. 1. Rheology and Microstructure

Rennet-induced curd was made from both natural buffalo and cows’ milk, and ultrafiltered cows’ milk (cows’ milk was concentrated such that it had a chemical composition approximately equivalent to that of the buffalo milk). These milk samples were compared on the basis of their rheology, physicochemical characteristics and curd microstructure. The ionic and soluble calcium contents were found to be similar in all milk samples studied. The total and casein bound calcium were higher in concentrated cows’ milk than in standard cows’ milk. Both cows’ milk types were found to have lower total and casein bound calcium than the buffalo milk. This is probably due to concentration of the colloidal part of milk (casein), during the ultrafiltration (UF) process. The rennet coagulation time was similar in UF cows’ and buffalo milk while both were shorter when compared with that of the cows’ milk. The dynamic moduli (G′, G″) values were higher in both the buffalo and UF cows’ milk than in the cows’ milk after 90 min coagulation. The loss tangent, however, was found to be similar in both the UF cows’ and buffalo milk curds and was lower than that observed for the cows’ milk (0.42, 0.42 and 0.48, respectively). The frequency profile of each type of curd was recorded 90 min after the enzyme addition (0.1–10 Hz); all samples were found to be “weak” viscoelastic, frequency dependent gels. The yield stress was also measured 95 min after the enzyme addition, and a higher value was observed in buffalo milk curd when compared with other curd samples made from both the natural cows’ milk and the UF cows’ milk. The cryo-scanning electron and confocal laser scanning micrographs showed that curd structure appeared to be more “dense” and less porous in buffalo milk than cows’ milk even after concentration to equivalent levels of protein/total solids to those found in the buffalo milk.     

Changes induced by high hydrostatic pressure in acidified and non-acidified milk during Oaxaca cheese production

Oaxaca cheese, produced using the pasta filata method, is a very popular Mexican dairy products. In this work, the effect of high hydrostatic pressure (HHP) and the acidification process before and after HHP treatment of raw cow milk was studied at different pressure levels (150, 300 and 500 MPa) and holding times (10 and 30 min). Clotting time, proximal composition, microstructure, secondary protein structure and electrophoretic profile were evaluated. HHP did not influence clotting time in samples acidified before HHP, but it appears to have a positive effect at lower pressure treatments on non-acidified milk. Moisture, protein and fat were similar in cheeses treated at most HHP conditions regardless of the acidification. HHP did not influence the microstructure of cheese and the secondary structure of proteins. The use of HHP during the manufacture of Oaxaca cheese allowed preserving quality parameters evaluated without advantages in processing time and the product's proximal composition.     

Simultaneous detection of cow and buffalo species in milk from China, India, and Pakistan using multiplex real-time PCR

Asian countries are major producers of cow and buffalo milk. For quality and authenticity purposes, a multiplex real-time PCR assay was developed to specifically and simultaneously detect DNA from these 2 bovine species. Targeting the cytochrome b gene of mitochondrial DNA, common PCR primers amplified a 105-bp fragment, and 2 fluorescent probes specific to either cow or buffalo were designed for their identification. Specificity was successfully tested on 6 other species, including sheep and goat, and sensitivity reached 1% of cow DNA in buffalo DNA and vice versa. As an evaluation, the method was tested using 119 freeze-dried Asian milk samples from regional industrial milk facilities. Although these samples did not cover the entire Asian zone, the multiplex assay indicated that approximately 20% of the samples (mainly from India) showed high levels of cross-contamination of cow milk by buffalo milk, and vice versa. Fast, sensitive, and straightforward, this method is fit-for-purpose for the authenticity control of Asian milk.     

Short communication: Composition of milk protein and milk fatty acids is stable for cows differing in genetic merit for milk production

Changing the composition of milk protein and of milk fatty acids alters nutritional and physical properties of dairy products and their consumer appeal. Genetic selection for milk yield decreases concentrations of milk protein and of milk fat. Little is known, however, about how the decrease affects composition of milk protein and milk fatty acids. The objective of this study was to quantify changes in composition of milk protein and of milk fatty acids in cows differing in genetic merit for milk production. Three measures of genetic merit for milk production were used for each cow: genetic line, parent average predicted transmitting ability (PTA) for milk, and cow milk PTA. Composition of milk protein and milk fatty acids were compared in 448 milk samples from 178 cows representing 2 divergent lines of Holsteins that were bred for high or average PTA for milk and combined milk protein and fat yield. High-line cows (n = 97) produced more milk that contained less fat and had higher proportions of α_S1-casein in milk protein than did average-line cows (n = 81). We additionally obtained from 233 cows (178 cows representing the 2 genetic lines and 55 cows with ancestors from both genetic lines) the parent average milk PTA and cow milk PTA and compared composition of milk protein and of milk fatty acids in 592 milk samples. Cows whose parent average milk PTA was above or equal to the median of the 233 cows produced more milk that contained less protein and less fat and that tended to have greater proportions of α_S1-casein in milk protein than cows whose average milk PTA was below the median. Similarly, cows with above or equal median milk PTA of the 233 cows produced more milk that contained less protein and less fat and had greater proportions of α_S1- casein in milk protein than did cows with below-median milk PTA. Milk fatty acid composition was not consistently different between groups. Therefore, selection for milk yield decreased concentrations of milk protein and milk fat but had little effect on composition of milk protein and milk fatty acids.     

Aflatoxin M1 in buffalo and cow milk in Afyonkarahisar,Turkey

Potential hazardous human exposure to aflatoxin M₁ (AFM₁) via consumption of milk and milk products has been demonstrated by many researchers. The aim of this study was to investigate the presence of this mycotoxin in buffalo and cow milk samples in the city of Afyonkarahisar, Turkey. For this purpose, 126 buffalo and 124 cow milk samples were collected from dairy farms in Afyonkarahisar province. AFM₁ levels were determined by high-performance liquid chromatography with tandem mass spectrometric detection. Although AFM₁ was not detected in cow milk samples, AFM₁ was found above the limit of detection (<0.008–0.032 µg/L) in 27% (34 out of 126) of the buffalo milk samples. The results of this study indicated the importance of continuous surveillance of commonly consumed milk or milk product samples for AFM₁ contamination in Turkey.     

Factors affecting variations in the detailed fatty acid profile of Mediterranean buffalo milk determined by 2-dimensional gas chromatography

Buffalo milk is the world's second most widely produced milk, and increasing attention is being paid to its composition, particularly the fatty acid profile. The objectives of the present study were (1) to characterize the fatty acid composition of Mediterranean buffalo milk, and (2) to investigate potential sources of variation in the buffalo milk fatty acid profile. We determined the profile of 69 fatty acid traits in 272 individual samples of Mediterranean buffalo milk using gas chromatography. In total, 51 individual fatty acids were identified: 24 saturated fatty acids, 13 monounsaturated fatty acids, and 14 polyunsaturated fatty acids. The major individual fatty acids in buffalo milk were in the order 16:0, 18:1 cis-9, 14:0, and 18:0. Saturated fatty acids were the predominant fraction in buffalo milk fat (70.49%); monounsaturated and polyunsaturated fatty acids were at 25.95 and 3.54%, respectively. Adopting a classification based on carbon-chain length, we found that medium-chain fatty acids (11–16 carbons) represented the greater part (53.7%) of the fatty acid fraction of buffalo milk, whereas long-chain fatty acids (17–24 carbons) and short-chain fatty acids (4–10 carbons) accounted for 32.73 and 9.72%, respectively. The n-3 and n-6 fatty acids were 0.46 and 1.77%, respectively. The main conjugated linoleic acid, rumenic acid, represented 0.45% of total milk fatty acids. Herd/test date and stage of lactation were confirmed as important sources of variation in the fatty acid profile of buffalo milk. The percentages of short-chain and medium-chain fatty acids in buffalo milk increased in early lactation (+0.6 and +3.5%, respectively), whereas long-chain fatty acids decreased (?4.2%). The only exception to this pattern was butyric acid, which linearly decreased from the beginning of lactation, confirmation that its synthesis is independent of malonyl-CoA. These results seem to suggest that in early lactation the mobilization of energy reserves may have less influence on the fatty acid profile of buffalo milk than that of cow milk, probably due to a shorter and less severe period of negative energy balance. Parity affected the profiles of a few traits and had the most significant effects on branched-chain fatty acids. This work provided a detailed overview of the fatty acid profile in buffalo milk including also those fatty acids present in small concentrations, which may have beneficial effects for human health. Our results contributed also to increase the knowledge about the effects of some of the major factors affecting buffalo production traits and fatty acid concentrations in milk, and consequently its technological and nutritional properties.     

Effects of gelation temperature on Mozzarella-type curd made from buffalo and cows' milk: 2. Curd yield, overall quality and casein fractions

The overall quality of Mozzarella-type curds made from buffalo and cows' milks were measured at gelation temperatures of 28, 34 and 39°C, and cutting times of 45, 60, 75 and 90min after chymosin addition. The curd yield and moisture content decreased with increasing gelation temperature, while whey fat losses increased. The effect of higher gelation temperature (39°C) was more pronounced in cows' milk than buffalo milk. This results in more fat losses and lower yields in both milk samples at a gelation temperature of 39°C. The minimum losses of fat and protein in rennet whey occurred at a gelation temperature of 34°C in both milk samples. The curd yield was higher in buffalo milk as compared to cows' milk. This is due to difference in total solids (fat and protein contents) of the two types of bovine milk. The different cutting times had a small effect on the yield and overall quality of curds made from both milk types. Curd moisture and loss tangent have a strong relationship with respect to effects of gelation temperature. Two different curd drainage methods (centrifugation and Buchner funnel filtration) were used to compare the final overall quality of Mozzarella-type curds made from both milk types. The α(s1) and β casein fractions were found to be in different proportions in the two milk types. The total- and casein bound-calcium were higher in buffalo milk than cows' milk. The total protein, casein and fat were also found to be higher in buffalo milk than cows' milk.