Effects of dairy factory, milk casein content and titratable acidity on coagulation properties in Trentingrana dairy industry

2016 ◽  
Vol 83 (2) ◽  
pp. 242-248 ◽  
Author(s):  
Mauro Penasa ◽  
Valentina Toffanin ◽  
Nicola Cologna ◽  
Martino Cassandro ◽  
Massimo De Marchi

The objective of the present study was to investigate the effect of environmental factors, milk casein content and titratable acidity on milk coagulation properties (MCP) of samples routinely collected in the Trento province (northeast Italy) under field conditions. Rennet coagulation time (RCT, min), curd-firming time (k20, min) and curd firmness (a30, mm) were determined by Formagraph on 14 971 samples from 635 herds associated to 17 dairy factories. Besides MCP, fat, protein, and casein percentages, titratable acidity (TA), and somatic cell and bacterial counts were available. A standardised index of milk aptitude to coagulate (IAC) was derived using information of RCT and a30. An analysis of variance was conducted on MCP and IAC using a fixed effects linear model. Approximately 3% of milk samples did not form a curd within the testing time (30 min) and k20 was missing for 26% of milks. The percentage of samples without information on k20 largely differed among dairy factories (1·7–20·9%). Significant differences were estimated between the best and the worst dairy factory for RCT (−2 min), k20 (−1·2 min), a30 (+3·4 mm) and IAC (+2·6 points). Milk casein content and TA were important factors in explaining the variation of MCP and IAC, supporting the central role of these two traits on technological properties. The Trento province is heterogeneous in terms of dairy systems and this could explain the differences among dairy factories.

2018 ◽  
Vol 61 (2) ◽  
pp. 215-220 ◽  
Author(s):  
Carmen L. Manuelian ◽  
Mauro Penasa ◽  
Giulio Visentin ◽  
Martino Cassandro ◽  
Massimo De Marchi

Abstract. This study aimed to characterize milk coagulation properties (rennet coagulation time, curd-firming time and curd firmness 30 min after rennet addition to milk) and major mineral contents (Ca, Mg, P, K and Na) in Pinzgauer dual-purpose cattle breed. The edited dataset consisted of 7763 milk observations from 851 cows reared in 60 herds in the Alpine area of Bolzano province (Italy). Data were analysed through a linear mixed model which included stage of lactation, parity and their interaction as fixed effects, and cow and herd test date as random effects. Rennet coagulation time, curd-firming time and curd firmness 30 min after rennet addition to milk averaged 22.66 min, 5.53 min and 16.79 mm, respectively. The most abundant minerals were P (1495 mg kg−1) and Ca (1344 mg kg−1), and the least abundant Mg (141 mg kg−1). Compared to their older contemporaries, early-lactating younger animals yielded milk that was more favourable for cheese production (i.e. with shorter coagulation time and stronger curd firmness). Mineral contents were lower in milk of primiparous than multiparous cows, except for Na. Moreover, Ca, Mg, P and Na contents decreased from parturition to peak of lactation and increased thereafter, except for K, which exhibited an opposite trend. Our results showed that Pinzgauer breed produced milk with better coagulation properties and mineral content, from a technological point of view, in first than later parities and in early than late lactation. The characterization of milk coagulation properties and mineral content in autochthonous breeds is important to increase their value and marketability of their products.


Author(s):  
А.Г. КРУЧИНИН ◽  
С.Н. ТУРОВСКАЯ ◽  
Е.Е. ИЛЛАРИОНОВА ◽  
А.В. БИГАЕВА

Потребность в увеличении количества и качества производимой молочной продукции стимулирует исследования, направленные на повышение эффективности переработки молочного сырья, что, в свою очередь, невозможно без изучения технологических свойств молока и функционально необходимых ингредиентов, применяемых в производстве различной молочной продукции. На основе научно-технической информации международных и российских баз данных, систематизированной в рамках изучаемой тематики, представлен обзор научных работ о коагулянтах белков молока различного происхождения, применяемых при кислотной, кислотно-сычужной и сычужной коагуляции. Установлено, что в российской и международной производственной практике востребованы коагулянты животного, микробного и рекомбинантного происхождения. Наибольшим спросом среди коагулянтов животного происхождения пользуется химозин, получаемый из желудков телят. Ферменты микробного и рекомбинантного происхождения отличаются более стабильным качеством и низкой стоимостью, но их производство, основанное на методах генной инженерии, вызывающих предубеждение у большинства потребителей, практически полностью сосредоточено за рубежом. При условии повышения лояльности потребителей ферменты рекомбинантного происхождения могут стать наиболее перспективными функциональными ингредиентами. Исследования потенциала различных протеолитических ферментов растительного происхождения выявили невысокий технологический эффект их применения. Рассмотренный материал позволяет прогнозировать перспективность научных исследований по выявлению механизмов коагуляции молока и новых эффективных и универсальных коагулянтов совокупно с селекционной практикой отбора животных, направленной на улучшение технологических свойств молочного сырья. The need to increase the quantity and quality of dairy products encourages research aimed at improving the efficiency of processing dairy raw materials, which, in turn, is impossible without studying the technological properties of milk and functionally necessary ingredients used in the production of various dairy products. On the basis of scientific and technical information from international and Russian data bases, systematized within the framework of the subject under study, a review of scientific works on milk protein coagulants of various origins used in acid, acid-rennet and rennet coagulation is presented. It is established that coagulants of animal, microbial and recombinant origin are in demand in the Russian and international production practice. The greatest demand among coagulants of animal origin is chymosin, obtained from the stomachs of calves. Microbial and recombinant enzymes are characterized by more stable quality and lower cost, but their production, based on genetic engineering methods that cause prejudice among most consumers, is almost entirely concentrated abroad. If consumer loyalty is increased, recombinant enzymes may become the most promising functional ingredients. Studies of the potential of various proteolytic enzymes of plant origin revealed a low technological effect of their use. The considered material allows us to predict the prospects of scientific research to identify the mechanisms of milk coagulation and new effective and universal coagulants together with the breeding practice of animal selection, aimed at improving the technological properties of dairy raw materials.


2008 ◽  
Vol 16 (3) ◽  
pp. 222 ◽  
Author(s):  
I. JÕUDU ◽  
M. HENNO ◽  
S. VÄRV

The genetic variation of ás1-, â- and ê-caseins and b-lactoglobulin was determined and their effects on the rennet coagulation properties were examined using 335 milk samples from 118 Estonian Native (EN) cows. We found 16 aggregate casein genotypes (ás1-, â-, ê-caseins), of which four . namely, BB A2A2 AA (21.2%), BB A1A2 AB (16.9%), BB A1A2 AA (14.4%), and BB A2A2 AB (10.2%) – occurred among nearly two-thirds of the analysed cows. Aggregate casein genotype had a significant overall effect on rennet coagulation parameters. Better rennet coagulation properties were found for aggregate casein genotypes CC A2A2 AB and BC A1A2 BB, among frequent genotypes for BB A1A2 AB. Of the cattle breeds raised in Estonia, milk from EN had the best coagulation properties and highest frequency of favourable ê-Cn B allele.;


2001 ◽  
Vol 68 (1) ◽  
pp. 63-70 ◽  
Author(s):  
PRIMO MARIANI ◽  
ANDREA SUMMER ◽  
PAOLA DI GREGORIO ◽  
ANDREA RANDO ◽  
ENRICO FOSSA ◽  
...  

The aim of this research was to study the effects of the CSN1AG allele on the main rennet coagulation properties of milk. The study was carried out on individual milk samples with low αs1-casein obtained from 19 Italian Brown cows heterozygous for the CSN1AG allele (seventeen CSN1A BG and two CSN1A CG) from four herds in the province of Parma (Italy). Control cows (sixteen CSN1A BB and three CSN1A BC) giving milk with normal αs1-casein levels were chosen from within the same herds in order to establish pairs of cows with identical environment and management conditions, and comparable lactation stages and numbers. Individual milk samples from single pairs of cows with somatic cell counts and lactose and chloride levels within the normal ranges were collected and analysed in parallel. Rennet coagulation properties of milk were analysed using Formagraph and Gel Tester. Milk from low αs1-casein cows was characterized by lower casein content, lower titratable acidity and a higher proportion of κ-casein in total casein. The clotting time of this milk was ∼ 23% lower than that obtained with milk from normal αs1-casein cows. Rennet curd from low αs1-casein milk was obtained more rapidly and had a higher final firmness: curd-firming time was ∼ 35% lower and curd firmness measured 30 min after rennet addition was ∼ 27 % higher compared with that for normal αs1-casein milk. In addition, curd from low αs1-casein milk had a higher resistance to compression. These results suggest that, although a role for the CSN2 locus cannot be definitely excluded, the CSN1AG allele can considerably affect the main rennet coagulation properties of milk.


2019 ◽  
Vol 86 (3) ◽  
pp. 331-336 ◽  
Author(s):  
Maria L. Dettori ◽  
Michele Pazzola ◽  
Emanuela Pira ◽  
Giorgia Stocco ◽  
Giuseppe M. Vacca

AbstractWe investigated whether variation of the sheep Growth Hormone Receptor (GHR), Growth Hormone Releasing Hormone Receptor (GHRHR) and Insulin-Like Growth Factor 1 (IGF1) genes were associated with milk coagulation properties (MCP) in sheep. The GHR, GHRHR and IGF1 genes are part of the GH system, which is known to modulate metabolism, growth and reproduction as well as mammogenesis and galactopoiesis in dairy species. A total of 380 dairy Sarda sheep were genotyped for 36 SNPs mapping to these three genes. Traditional MCP were measured as rennet coagulation time (RCT), curd-firming time (k20) and curd firmness at 30 m (a30). Modeling of curd firming over time (CFt) was based on a 60 m lactodynamographic test, generating a total of 240 records of curd firmness (mm) for each milk sample. The model parameters obtained included: the rennet coagulation time as a result of modeling all data available (RCTeq, min); the asymptotic potential value of curd firmness (CFP, mm) at an infinite time; the CF instant rate constant (kCF, %/min); the syneresis instant rate constant (kSR, %/min); the maximum value of CF (CFmax, mm) and the time at achievement of CFmax (tmax, min). Statistical analysis revealed that variation of the GHR gene was significantly associated with RCT, kSR and CFP (P < 0.05). No other significant associations were detected. These findings may be useful for the dairy industry, as well as for selection programs.


1984 ◽  
Vol 51 (3) ◽  
pp. 397-406 ◽  
Author(s):  
Johan Schaar

SummaryThe effects of κ-casein genetic variants, lactation number, pH and casein content on the renneting properties of individual milks were studied. Rennet coagulation time (RCT) and curd firmness were determined with the aid of a lactodynamograph and the results statistically analysed. Renneting properties were strongly related to κ-casein variants and lactation number, with κ-casein B and higher lactation numbers giving shorter RCT and increased curd firmness, the effects on curd firmness being more pronounced. The effect of κ-casein variant on RCT could be eliminated by reducing pH and adding CaCl2 to the milk samples. The effect on curd firmness was not altered by this treatment, however. The results show that the renneting properties of individual milks are to a considerable degree genetically controlled.


Author(s):  
Borut Kolenc ◽  
Primož Treven ◽  
Mojca Simčič ◽  
Angela Cividini ◽  
Andreja Čanžek Majhenič ◽  
...  

Goat’s daily diet is usually based on grazing, hay and/or feed supplements. Feed supplements are crucial in the diet of high productive goats to achieve their genetic potential and breeders must choose balanced feeding regime to produce large quantities of milk without affecting the technological quality of milk. In the present study, we evaluated the influence of two commercially available feed supplements on goat milk coagulation properties and rheological properties of yoghurts. Goats of the Slovenian Alpine breed (61) were fed with two feed supplements during the 3-year experiment. Feed supplement 1 (FS1) had higher proportions of barley and alfalfa, while feed supplement 2 (FS2) had added premix of minerals and vitamins and had higher proportions of wheat and sunflower meal. Con¬sequently, FS1 had more crude fibres, which is the most probable reason for approximately 15 % higher firmness, consistency and cohesiveness (P&lt;0.05) of yoghurts in FS1 group, compared to the FS2 group. Moreover, the rennet coagulation time (r) was shorter (P&lt;0.05) in the FS1 group, compared to the FS2 group. Curd firmness 30 min after enzyme addition (a30) was also higher in FS1 group although the results were not statistically significant. Taking together, our results indicate that goats fed with FS1 produced milk with better technological properties compared to those fed with FS2, despite the fact that there were no significant differences in chemical composition of milk from each group. We showed that careful selection of feed supplement’s constituents could improve technological properties of goat milk. However, further studies are needed to evaluate the mechanisms of the observed differences.


2012 ◽  
Vol 80 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Denis Pretto ◽  
Massimo De Marchi ◽  
Mauro Penasa ◽  
Martino Cassandro

The aim of this study was to assess the effect of chemical composition, coagulation properties, pH, and titratable acidity (TA, SH°/50 ml) of vat milk on Grana Padano cheese yield (CY) under field conditions. Twelve cheese-making sessions were carried out from February to December 2009 in a dairy cooperative of Grana Padano Consortium (Italy), for a total of 96 vats of milk processed. For each vat, samples of raw milk were collected and analysed for quality traits (fat, protein, and casein contents), pH, TA, and milk coagulation properties (MCP), measured as rennet coagulation time (RCT, min), curd-firming time (k20, min), and curd firmness (a30, mm). Cheese yield was expressed as kilograms of cheese per 100 kg milk transformed, and was measured after 2 d of drainage. Fat, protein, and casein contents were positively and strongly correlated with CY (coefficients of correlation, r = 0·72, 0·88, and 0·84, respectively; P < 0·001). Coagulation properties were moderately and significantly (P < 0·001) related to CY: milk that coagulated earlier and had stronger a30 was associated to greater CY. Cheese yield was analysed with a model that accounted for fixed effects of cheese-making day, fat and protein content, TA, and a30. Significance was found for all the effects (P < 0·05). Milk characterised by high values of a30 resulted in higher CY than milk with low values of a30, indicating that MCP could be used as indicators of cheese-making efficiency. Future research should investigate the relationships between MCP and quality of cheese, and explore the feasibility of including MCP in multiple component milk pricing system for Grana Padano cheese production.


Author(s):  
Ondřej Polák ◽  
Daniel Falta ◽  
Oto Hanuš ◽  
Gustav Chládek

On two farms (A and B), samples of bulk milk produced by dairy cows of the Holstein (H) and Czech Fleckvieh (CF) breeds were collected every week on the same day within the time interval of 36 weeks. The aim of this sampling was to determine the effect of barn airspace temperature on milk compositon and its technological parameters. The following average values of all bulk milk samples (n = 72) were recorded: barn airspace temperature (BAT) 12.08 °C; rennet coagulation time (RCT) 211 sec.; curd quality class (CQC) 1.53; titratable acidity (TA) 7.16 °SH; protein content (P) 3.46 %; fat content (F) 4.09 %; lactose content (L) 4.79 %; and solids non fat (SNF) 8.86 %. As compared with H, dairy cows of CF breed produced milk with statistically significantly higher (P < 0.01) contents of P (+0.27 %) and SNF (+0.26 %). The remaining differences were statistically insignificant (P > 0.05): BAT (−2 °C); RCT (−4 sec.); CQC (0 class); TA (+0.11 °SH); F (+0.05 %) and L (−0.03 %). As far as the effect of temperature was concerned, calculated correlation coefficients and plotted graphs indicated a marked effect of BAT on RCT; F and P. This effect was in all cases markedly negative: at lower BAT, F and P values were higher and RCT longer while at higher temperatures they were lower and shorter. These trends were similar in both breeds regardless to differences in average values of aforementioned parameters.


Sign in / Sign up

Export Citation Format

Share Document