scholarly journals Rennet coagulation of heated milk: A review

2021 ◽  
pp. 105179
Author(s):  
Michel Britten ◽  
Hélène J. Giroux
Keyword(s):  
Heated Milk ◽  
Rennet Coagulation

scholarly journals Rennet coagulation properties of heated milk

1993 ◽  
Vol 2 (5) ◽  
pp. 361-369
Author(s):  
J. A. Lucey ◽  
C. Gorry ◽  
P. F. Fox
Keyword(s):  
Raw Milk ◽  
Low Ph ◽  
Ph Values ◽  
Heated Milk ◽  
Rennet Coagulation ◽  
Low Concentrations ◽  
And Storage

Heating impaired the rennet coagulation properties of milk which deteriorated further during storage, i.e. rennet hysteresis occurred. Acidification to pH values ≤ 6.2 or addition of low concentrations of CaCl2 greatly improved the rennet coagulation properties of heated milk. Acidification of heated milk to pH values < 5.5 followed by neutralization to pH 6.6 to produce reformed micelles, resulted in greatly improved rennet coagulation properties except for severely heated milks (120°C for 10 min) which were not coagulable even after acidification/neutralization. Acidification of heated milk to pH values < 5.5 and storage at the low pH for 24 h before neutralization resulted in a further improvement in the rennet coagulation properties. Dialysis of heated milk that had been acidified and reneutralized against an excess of normal milk resulted in a dramatic deterioration of its rennet coagulability. Reheating milk that had been heated, acidified and reneutralized resulted in little change in RCT or gel firmness. Addition of heated milk to raw milk resulted in an increase in RCT of the latter and a reduction in gel firmness.

The rennet hysteresis of heated milk

1969 ◽  
Vol 36 (3) ◽  
pp. 333-341 ◽  
Author(s):  
P. A. Morrissey
Keyword(s):  
Calcium Phosphate ◽  
Calcium Ions ◽  
Calcium Ion ◽  
Heating Process ◽  
Second Stage ◽  
Heated Milk ◽  
Rennet Coagulation ◽  
Micellar Casein ◽  
Induced Changes ◽  
Β Lactoglobulin

SummaryThe phenomenon of rennet hysteresis in heated milk is essentially due to reversible heat-induced changes of calcium phosphate equilibrium which affect the second or calcium ion stage of the rennet coagulation. The phenomenon is shown not only by heated milk but also by all heated caseinate systems provided they contain sufficient calcium to permit of coagulation with rennet and enough phosphate to ensure some degree of colloidal phosphate precipitation during the heating process; its occurrence does not require the presence of micellar casein or of β-lactoglobulin, or the initial presence of colloidal phosphate. Nevertheless, rennet hysteresis is greatly increased in these heated systems if β-lactoglobulin is present owing to the formation of a calcium caseinate/β-lactoglobulin complex which in its renneted condition is much less sensitive to calcium ions than is calcium para-caseinate. The resulting relative prolongation of the second stage of the rennet coagulation renders this phenomenon more apparent by increasing the proportion of the total time occupied by the hysteresis effect.

Rheological properties of milk gels formed by a combination of rennet and glucono-δ-lactone

2000 ◽  
Vol 67 (3) ◽  
pp. 415-427 ◽  
Author(s):  
JOHN A. LUCEY ◽  
MICHELLE TAMEHANA ◽  
HARJINDER SINGH ◽  
PETER A. MUNRO
Keyword(s):  
Heat Treatment ◽  
Rheological Properties ◽  
Large Scale ◽  
Whey Proteins ◽  
Skim Milk ◽  
Rheological Behaviour ◽  
Intermolecular Forces ◽  
Heated Milk ◽  
Rennet Coagulation ◽  
Tan Δ

The effects of heat treatment of milk, and a range of rennet and glucono-δ-lactone (GDL) concentrations on the rheological properties, at small and large deformation, of milk gels were investigated. Gels were made from reconstituted skim milk at 30 °C, with two levels each of rennet and GDL. Together with controls this gave a total of sixteen gelation conditions, eight for unheated and eight for heated milk. Acid gels made from unheated milks had low storage moduli (G′) of < 20 Pa. Heating milks at 80 °C for 30 min resulted in a large increase in the G′ value of acid gels. Rennet-induced gels made from unheated milk had G′ values in the range ∼ 80–190 Pa. However, heat treatment severely impaired rennet coagulation: no gel was formed at low rennet levels and only a very weak gel was formed at high levels. In gels made with a combination of rennet and GDL unusual rheological behaviour was observed. After gelation, G′ initially increased rapidly but then remained steady or even decreased, and at long ageing times G′ values increased moderately or remained low. The loss tangent (tan δ) of acid gels made from heated milk increased after gelation to attain a maximum at pH ∼ 5·1 but no maximum was observed in gels made from unheated milk. Gels made by a combination of rennet and GDL also exhibited a maximum in tan δ, indicating increased relaxation behaviour of the protein–protein bonds. We suggest that this maximum in tan δ was caused by a loosening of the intermolecular forces in casein particles caused by solubilization of colloidal calcium phosphate. We also suggest that in combination gels made from unheated milk a low value for the fracture stress and a high tan δ during gelation indicated an increased susceptibility of the network to excessive large scale rearrangements. In contrast, combination gels made from heated milk formed firmer gels crosslinked by denatured whey proteins and underwent fewer large scale rearrangements.

Rennet coagulation of heated milk: influence of pH adjustment before or after heating

1988 ◽  
Vol 55 (2) ◽  
pp. 205-215 ◽  
Author(s):  
Harjinder Singh ◽  
Samweul I. Shalabi ◽  
Patrick F. Fox ◽  
Albert Flynn ◽  
Anne Barry
Keyword(s):  
Heat Treatment ◽  
Adverse Effect ◽  
Adverse Effects ◽  
Skim Milk ◽  
Ph Adjustment ◽  
Milk Samples ◽  
Heated Milk ◽  
Rennet Coagulation ◽  
Low Concentrations ◽  
Influence Of Ph

SummaryThe rennet coagulation times of infant milk formulae or fresh skim milk (milk) samples heated at temperatures in the range 70–140 °C for 1–10 min decreased on acidification, usually to pH < 6·0. Heated milk samples acidified to pH 5·5 and reneutralized to pH 6·6 retained good rennet coagulability. Acidification of such milk samples before heating also reduced the adverse effect of severe heat treatment (95 °C for 1 min) on rennet coagulation. Addition of low concentrations of CaCl2 to heated milks offset the adverse effects of heating. Acidification of heated milks increased the [Ca2+], and reneutralization of acidified milk only partly restored the [Ca2+], i.e. acidified/reneutralized milk had a higher [Ca2+] than normal milk, suggesting this as the mechanism via which acidification/neutralization improves the rennet coagulability of heated milk. Approximately 50% of the whey protein can be incorporated into rennet gels in heated milks while retaining good coagulability and curd tension; this may be a useful technique for increasing cheese yield.

Rennet coagulation of heated milk concentrates

2000 ◽  
Vol 80 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Regina Schreiber ◽  
J�rg Hinrichs
Keyword(s):  
Heated Milk ◽  
Rennet Coagulation

Effects of high pressure treatment on the rennet coagulation and cheese-making properties of heated milk

2005 ◽  
Vol 6 (3) ◽  
pp. 279-285 ◽  
Author(s):  
Thom Huppertz ◽  
Katharina Hinz ◽  
Mathias R. Zobrist ◽  
Therese Uniacke ◽  
Alan L. Kelly ◽  
...  
Keyword(s):  
High Pressure ◽  
Pressure Treatment ◽  
High Pressure Treatment ◽  
Cheese Making ◽  
Heated Milk ◽  
Rennet Coagulation

Whey as an indicator for standardizing cow’s milk fat percentage for cheese production

2020 ◽  
pp. 33-39
Author(s):  
Prof. Asoc. Dr. Shurki MAXHUNI ◽  
Prof.Asiss.Dr.Nerimane BAJRAKTARI
Keyword(s):  
Milk Fat ◽  
Economic Indicator ◽  
Peculiar Feature ◽  
Cow’S Milk ◽  
Fat Percentage ◽  
Cow's Milk ◽  
Physical Chemical ◽  
Heated Milk ◽  
Sweet Whey ◽  
Acid Whey

The dairy industry seems to have convinced the food industry that whey is a miracle product. The list of supposed benefits it gives to food is as long as your arm. Some of the benefits may be real. Whey is the liquid remaining after milk has been curdled and strained. It is a by-product of the manufacture of cheese or casein and has several commercial uses. To produce cheese, rennet or an edible acid is added to heated milk. This makes the milk coagulate or curdle, separating the milk solids (curds) from the liquid whey. Sweet whey is the byproduct of rennet-coagulated cheese and acid whey (also called sour whey) is the byproduct of acid-coagulated cheese. Sweet whey has a pH greater than or equal to 5.6, acid whey has a pH less than or equal to 5.1. Whey is also a great way to add sweetness to a product without having to list sugar as an ingredient as whey contains up to 75% lactose. And it sounds healthy. This study is done to research the examinations for the production of mozzarella cheese from Cow’s milk, after research and analyses of a physical-chemical peculiar feature of whey from coagulum. We have followed the processes from the drying of whey from the coagulum analyzer's physical-chemical peculiar feature. We carried out three experiments. For every experiment, we took three patterns and analyzed the physical-chemical. The calculation was appraised statistically. This paper deals with the research of% of whey fat during the process of milk production from standardized to non-standardized milk. Where% of whey fat should be an economic indicator for standardizing milk for dairy production.

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