A laboratory study of continuous fermentation of skim-milk for the production of sour curd cheese

SummaryThe feasibility of 2-stage continuous fermentation of skim-milk to produce sour curd cheese (quarg) has been established. The first stage was a stirred pH-stat fermenter, operated at pH 5·4, 5·6, 5·8 and 6·0, in which the operating pH was maintained by inflowing fresh milk. The remaining fermentation down to pH 4·7 was carried out by a procedure which simulated a second-stage plug flow fermenter (i.e. one in which forward velocity was as constant as possible at all points of the crosssection).Skim-milk powder was dissolved to give 8, 10, 14 and 20% solids in the reconstituted milk. Maximum productivity of fermented milk solids was obtained with reconstituted milk containing 20% solids and operation of the first-stage fermenter at pH 5·4. This 2-stage continuous fermentation gave a total residence time of about 5 h, which represents a rate of production 4·8 times that obtainable in 24 h in a batch fermenter of the same fluid capacity filled once daily with the same reconstituted milk.

Download Full-text

Improvement in the quality of the dried fermented milk product, oggtt

Journal of Dairy Research ◽

10.1017/s0022029900025619 ◽

1987 ◽

Vol 54 (3) ◽

pp. 429-435 ◽

Cited By ~ 10

Author(s):

Ibrahim M. Al-Ruqaie ◽

Hamza M. El-Nakhal ◽

Ahmed N. Wahdan

Keyword(s):

Arabian Peninsula ◽

Milk Powder ◽

Skim Milk ◽

Fermented Milk ◽

Skim Milk Powder ◽

Milk Product ◽

Keeping Quality ◽

Reconstituted Milk ◽

Fermented Milk Product

SummaryOggtt is a dried fermented milk product made and marketed primitively under uncontrolled conditions in the Arabian peninsula. By applying controlled conditions for production, the keeping quality of oggtt was greatly improved. The two types (cooked and salted) were produced from fresh pasteurized goats' or cows' milk or from skim milk powder. Oggtts flavoured with chocolate, date, mint or different fruits were also produced. Chemical composition and organoleptic properties of the final products were evaluated. Taste panel results indicated that the plain products, including those made from reconstituted milk, were acceptable, but flavoured oggtts, with the exception of date flavour, were not popular.

Download Full-text

Influence of the emulsion droplet type on the rheological characteristics and microstructure of rennet gels from reconstituted milk

Journal of Dairy Research ◽

10.1017/s002202990900418x ◽

2009 ◽

Vol 76 (3) ◽

pp. 349-355 ◽

Cited By ~ 10

Author(s):

Zafir Gaygadzhiev ◽

Arthur Hill ◽

Milena Corredig

Keyword(s):

Elastic Modulus ◽

Milk Fat ◽

Milk Powder ◽

Skim Milk ◽

Skim Milk Powder ◽

Tween 20 ◽

Gel Structure ◽

Ionic Equilibrium ◽

Fat Globules ◽

Reconstituted Milk

Rheological and microstructural properties of rennet-induced milk gels containing different fat globules were studied. Recombined milks were prepared by mixing reconstituted low-heat skim milk powder and anhydrous milk fat emulsified with reconstituted skim milk powder (SMP), sodium caseinate (NaCas), whey protein isolate (WPI) or Tween 20. Final elastic modulus of the rennet gels containing WPI- or Tween 20-stabilized fat globules showed significantly lower values compared with those prepared with SMP-emulsified fat globules. SMP-stabilized fat globules interacted with the continuous casein network reinforcing the gel structure. Confocal micrographs supported the rheological data revealing that gels containing SMP-stabilized fat globules formed a tighter network relative to other treatments. Microscopy images also showed some degree of droplet flocculation in the case of gels containing WPI- or Tween 20-stabilized fat globules, and this was most likely the cause of the increase of elastic modulus of these systems. Contrary to reports for acid-induced casein gels, NaCas-stabilized fat globules hindered the formation of rennet gels. These results illustrate that rennet gel structure is affected by droplet-droplet and droplet-casein interactions, which in turn are determined by the composition of the oil-water interface as well as the ionic equilibrium in the reconstituted milk gels.

Download Full-text

Fermentation of reconstituted milk by Streptococcus thermophilus: Effect of irradiation on skim milk powder

International Dairy Journal ◽

10.1016/j.idairyj.2013.02.004 ◽

2013 ◽

Vol 31 (2) ◽

pp. 139-149 ◽

Cited By ~ 5

Author(s):

Irina Stulova ◽

Natalja Kabanova ◽

Tiina Kriščiunaite ◽

Anastassia Taivosalo ◽

Tiiu-Maie Laht ◽

...

Keyword(s):

Milk Powder ◽

Skim Milk ◽

Streptococcus Thermophilus ◽

Skim Milk Powder ◽

Reconstituted Milk

Download Full-text

Influence of concentration of milk solids on the dissociation of micellar κ-casein on heating reconstituted milk at 120°C

Journal of Dairy Research ◽

10.1017/s0022029900033549 ◽

1991 ◽

Vol 58 (1) ◽

pp. 99-105 ◽

Cited By ~ 28

Author(s):

Harjinder Singh ◽

Lawrence K. Creamer

Keyword(s):

Gel Electrophoresis ◽

Milk Powder ◽

Skim Milk ◽

Skim Milk Powder ◽

Heating Time ◽

Total Solids ◽

Solids Content ◽

Milk Solids ◽

Reconstituted Milk

SummarySkim milks were prepared from skim milk powder at several concentrations between 10 and 25% total solids and portions were pH-adjusted to between pH 6·3 and 7·1 and heated at 120°C. After ultracentrifugation (88000 g for 90 min), the supernatants were analysed using gel electrophoresis to determine the concentrations of β-lactoglobulin, α-lactalbumin and κ-casein. The dissociation of κ-casein from the micelles was dependent on both the pH and the total solids content of milk before heating. Both higher pH (in the range 6·5–7·l) and higher concentration increased the extent of dissociation. A further series of samples were heated for 2–11 min at 120°C at pH 6·55. κ-Casein dissociation increased with concentration and with heating time. It was concluded that as the milk increased in concentration, the pH at which micellar κ-casein dissociated on heating was lowered.

Download Full-text

Identification and Effects of Skim Milk-Derived Bioactive Antihypertensive Peptides

Biologics ◽

10.3390/biologics2010001 ◽

2021 ◽

Vol 2 (1) ◽

pp. 1-14

Author(s):

Fatah B. Ahtesh ◽

Lily Stojanovska ◽

Vijay Mishra ◽

Osaana Donkor ◽

Jack Feehan ◽

...

Keyword(s):

Blood Pressure ◽

Bioactive Peptides ◽

Milk Powder ◽

Skim Milk ◽

Fermented Milk ◽

Skim Milk Powder ◽

Angiotensin Converting Enzyme Inhibition ◽

Blood Pressure Lowering Effect ◽

Spontaneously Hypertensive ◽

Freeze Dried

Bioactive peptides are generated during milk fermentation or enzymatic hydrolysis. Lactobacillus (L) helveticus is commonly used to produce some types of fermented milk products. Fermented milk derived bioactive peptides are known to be beneficial in human health. Anti-hypertensive peptides play a dual role in the regulation of hypertension through the production of the vasoconstrictor angiotensin II and its inactivation of the vasodilator bradykinin. MALDI MS/MS, nano-LC/MS/MS and RP-HPLC were used to isolate peptides showing angiotensin converting enzyme inhibition (ACE-I) from 12% fermented skim milk using a combination of L. helveticus and Flavourzyme®. The fermentation procedure facilitated the identification of 133 anti-hypertensive peptides and 75% short chain amino acids, and the three with the highest ACE-I activity reduced blood pressure in a rat model of hypertension. The freeze- dried extract was supplemented in rodent chow. In this study 14-week-old male spontaneously hypertensive rats were fed for 10 weeks with the identified peptides added to chow and compared to controls supplemented with skim milk powder. Blood pressure (BP) decreased significantly (p < 0.05) from 6 to 10 weeks of FS groups (120/65 mmHg) compared with the NFS control groups, where the BP increased significantly (220/150 mmHg) (p < 0.05). The F6 fraction provided bioactive peptides with stronger antihypertensive properties than other fractions. Skim milk fermented by L. helveticus and Flavourzyme® generates several bioactive peptides which have a blood pressure lowering effect in hypertensive disease.

Download Full-text

Partial substitution of 40 g/100 g fresh milk with reconstituted low heat skim milk powder in high-moisture mozzarella cheese production: Rheological and water-related properties

LWT ◽

10.1016/j.lwt.2020.110391 ◽

2021 ◽

Vol 137 ◽

pp. 110391

Author(s):

Flavio Tidona ◽

Marcello Alinovi ◽

Salvatore Francolino ◽

Gianluca Brusa ◽

Roberta Ghiglietti ◽

...

Keyword(s):

Milk Powder ◽

Skim Milk ◽

Skim Milk Powder ◽

Partial Substitution ◽

Mozzarella Cheese ◽

High Moisture ◽

Fresh Milk ◽

Cheese Production

Download Full-text

QUALITY OF PROTEIN IN MILK REPLACERS FOR YOUNG CALVES. I. FACTORS AFFECTING IN VITRO CURD FORMATION BY RENNET (CHYMOSIN, RENNIN) FROM RECONSTITUTED SKIM MILK POWDER

Canadian Journal of Animal Science ◽

10.4141/cjas76-037 ◽

1976 ◽

Vol 56 (2) ◽

pp. 317-325 ◽

Cited By ~ 17

Author(s):

D. B. EMMONS ◽

E. E. LISTER

Keyword(s):

Heat Treatment ◽

Milk Powder ◽

Skim Milk ◽

High Heat ◽

Skim Milk Powder ◽

Factors Affecting ◽

Fresh Milk ◽

Milk Solids ◽

Milk Replacers

Fresh milk coagulates with chymosin (rennin) in the calf stomach to form relatively strong curds. With respect to calf milk replacers it is of interest to study factors affecting curd formation of reconstituted skim milk powder by this enzyme. Curd firmness was increased by lower pH of the skim milk over a range of 5.6–6.6, higher concentration of skim milk solids over a range of 5–20%, higher concentrations of chymosin, lower temperatures of heat treatment of skim milk prior to spray drying, and higher temperature of coagulation, 37 vs. 30 C. Reconstitution of powder in water above 56 C for 2 min remarkedly reduced the firmness of the curd. The following coagulation conditions were selected for comparison of powders and milk replacers: addition of 1 ml of a 1:50 dilution of standard strength commercial rennet to 100 ml of milk previously adjusted to pH 6.1, 10% of nonfat solids in the aqueous nonfat phase, temperature of 37 C, and measurements of firmness 30 min after adding rennet. Commercially produced skim milk powders designated high-heat, medium-heat and roller products yielded soft curds. Commercial low-heat powders yielded strong curds. All coagulated in less than 4 min at pH 6.1, the time being relatively independent of heat treatment.

Download Full-text