161. Studies in Cheddar cheese. VI. The degradation of milk proteins by lactic acid bacteria isolated from cheese, alone, with sterile rennet and with whole rennet

It has been shown by experiments in milk that the enzymes of commercial rennet in conjunction with the lactic acid bacteria occurring in Cheddar cheese can bring about protein breakdown similar in extent to that found in the ripe cheese as far as the non-protein nitrogen is concerned. The amino nitrogen produced is, however, much less than in cheese. This may be ascribed to the higher pH of cheese as compared with that of the milk cultures, since acidity adversely affects the peptidases present. Attention is drawn to the differences between the conditions.

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207. Protein metabolism and acid production by the lactic acid bacteria in milk. Influence of yeast extract and chalk

Journal of Dairy Research ◽

10.1017/s0022029900002685 ◽

1939 ◽

Vol 10 (1) ◽

pp. 20-34 ◽

Cited By ~ 9

Author(s):

M. Braz ◽

L. A. Allen

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Proteolytic Activity ◽

Yeast Extract ◽

Protein Metabolism ◽

Acid Production ◽

Single Species ◽

Soluble Nitrogen ◽

Protein Breakdown ◽

Protein Nitrogen

Though the lactic acid bacteria are recognized primarily as saccharolytic, several workers have recorded observations on their slow proteolytic activity. Von Freudenreich(1) was the first to record the fact that cultures of these organisms in milk, to which chalk had been added to neutralize the acidity, formed appreciable amounts of soluble nitrogen, and these findings were confirmed by Orla-Jensen (2), Barthel(3), and Barthel & Sandberg(4). Anderegg & Hammer (5), in a study of a large number of strains ofStr. Lactis, found an increase in soluble nitrogen in some cases and a decrease in others, while occasionally the same strain differed in different tests. In general, cultures which clotted rapidly were more inclined to proteolysis than those which were slower in forming acid.Str. citrovorusandStr. paracitrovorusdid not cause protein breakdown. Addition of 0·3% peptone to the milk tended to retard proteolysis or to increase negative values while addition of chalk resulted in more extensive proteolysis. Barthel & Sadler (6) found that starters consisting of mixed cultures of streptococci produced more extensive proteolysis than single species, indicating a symbiotic effect. Sherwood & Whitehead (7) tested the proteolytic powers of several strains ofStr. cremorisin chalk milk cultures and found some active and some comparatively inactive. Two strains appear to have formed surprisingly large amounts of non-protein nitrogen. In general they found that acid-producing power was linked with proteolytic power.

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Co-Microencapsulated Black Rice Anthocyanins and Lactic Acid Bacteria: Evidence on Powders Profile and In Vitro Digestion

Molecules ◽

10.3390/molecules26092579 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2579

Author(s):

Carmen-Alina Bolea ◽

Mihaela Cotârleț ◽

Elena Enachi ◽

Vasilica Barbu ◽

Nicoleta Stănciuc

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Oryza Sativa L ◽

Milk Proteins ◽

Ethanolic Extract ◽

Dry Weight ◽

Hot Water ◽

Raw Material ◽

Black Rice

Two multi-functional powders, in terms of anthocyanins from black rice (Oryza sativa L.) and lactic acid bacteria (Lactobacillus paracasei, L. casei 431®) were obtained through co-microencapsulation into a biopolymer matrix composed of milk proteins and inulin. Two extracts were obtained using black rice flour as a raw material and hot water and ethanol as solvents. Both powders (called P1 for aqueous extract and P2 for ethanolic extract) proved to be rich sources of valuable bioactives, with microencapsulation efficiency up to 80%, both for anthocyanins and lactic acid bacteria. A higher content of anthocyanins was found in P1, of 102.91 ± 1.83 mg cyanindin-3-O-glucoside (C3G)/g dry weight (DW) when compared with only 27.60 ± 17.36 mg C3G/g DW in P2. The morphological analysis revealed the presence of large, thin, and fragile structures, with different sizes. A different pattern of gastric digestion was observed, with a highly protective effect of the matrix in P1 and a maximum decrease in anthocyanins of approximatively 44% in P2. In intestinal juice, the anthocyanins decreased significantly in P2, reaching a maximum of 97% at the end of digestion; whereas in P1, more than 45% from the initial anthocyanins content remained in the microparticles. Overall, the short-term storage stability test revealed a release of bioactive from P2 and a decrease in P1. The viable cells of lactic acid bacteria after 21 days of storage reached 7 log colony forming units (CFU)/g DW.

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Lactic Acid Bacteria in Cheddar Cheese Made with Sodium Chloride, Potassium Chloride or Mixtures of the Two Salts

Journal of Food Protection ◽

10.4315/0362-028x-58.1.62 ◽

1995 ◽

Vol 58 (1) ◽

pp. 62-69 ◽

Cited By ~ 14

Author(s):

K. ANJAN REDDY ◽

ELMER H. MARTH

Keyword(s):

Lactic Acid ◽

Sodium Chloride ◽

Lactic Acid Bacteria ◽

Potassium Chloride ◽

Starter Culture ◽

Cheddar Cheese ◽

Starter Cultures ◽

Detectable Effect ◽

Agar Media ◽

Cheese Curd

Three different split lots of Cheddar cheese curd were prepared with added sodium chloride (NaCl) potassium chloride (KCl) or mixtures of NaCl/KCl (2:1 1:1 1:2 and 3:4 all on wt/wt basis) to achieve a final salt concentration of 1.5 or 1.75%. At intervals during ripening at 3±1°C samples were plated with All-Purpose Tween (APT) and Lactobacillus Selection (LBS) agar. Isolates were obtained of bacteria that predominated on the agar media. In the first trial (Lactococcus lactis subsp. lactis plus L. lactis subsp. cremoris served as starter cultures) L. lactis subsp.lactis Lactobacillus casei and other lactobacilli were the predominant bacteria regardless of the salting treatment Received by the cheese. In the second trial (L. lactis subsp. lactis served as the starter culture) unclassified lactococci L. lactis subsp. lactis unclassified lactobacilli and L. casei predominated regardless of the salting treatment given the cheese. In the third trial (L. lactis subsp. cremoris served as the starter culture) unclassified lactococci unclassified lactobacilli L. casei and Pediococcus cerevisiae predominated regardless of the salting treatment applied to the cheese Thus use of KCl to replace some of the NaCl for salting cheese had no detectable effect on the kinds of lactic acid bacteria that developed in ripening Cheddar cheese.

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Encapsulation of a Lactic Acid Bacteria Cell-Free Extract in Liposomes and Use in Cheddar Cheese Ripening

Foods ◽

10.3390/foods2010100 ◽

2013 ◽

Vol 2 (1) ◽

pp. 100-119 ◽

Cited By ~ 7

Author(s):

Alice Nongonierma ◽

Magdalena Abrlova ◽

Kieran Kilcawley

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Cheddar Cheese ◽

Cell Free Extract ◽

Cheese Ripening

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Nonstarter Lactic Acid Bacteria Biofilms and Calcium Lactate Crystals in Cheddar Cheese

Journal of Dairy Science ◽

10.3168/jds.s0022-0302(06)72213-5 ◽

2006 ◽

Vol 89 (5) ◽

pp. 1452-1466 ◽

Cited By ~ 30

Author(s):

S. Agarwal ◽

K. Sharma ◽

B.G. Swanson ◽

G.Ü. Yüksel ◽

S. Clark

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Cheddar Cheese ◽

Calcium Lactate ◽

Nonstarter Lactic Acid Bacteria

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Role of Enterococci in Cheddar Cheese: Proteolytic Activity and Lactic Acid Development1

Journal of Milk and Food Technology ◽

10.4315/0022-2747-38.1.3 ◽

1975 ◽

Vol 38 (1) ◽

pp. 3-7 ◽

Cited By ~ 18

Author(s):

JANE P. JENSEN ◽

G. W. REINBOLD ◽

C. J. WASHAM ◽

E. R. VEDAMUTHU

Keyword(s):

Lactic Acid ◽

Proteolytic Activity ◽

Statistical Difference ◽

Cheddar Cheese ◽

Protein Breakdown ◽

Streptococcus Faecalis

Eight lots of Cheddar cheese were manufactured by using two strains of Streptococcus faecalis and Streptococcus durans in combination with a commercial lactic culture. Each lot consisted of a control vat of cheese, manufactured with lactic starter only, and an experimental vat of cheese containing the lactic starter and one of the enterococcus strains. Combinations of two curing temperatures (7.2 and 12.8 C) and two early cooling treatments (air vs. brine cooling) were used for cheeses from each vat to determine the effects of these handling procedures, as well as of enterococcus addition, on proteolysis and lactic acid development. These characteristics were monitored from milling to up to 6 months of curing. Cheeses manufactured with S. faecalis exhibited more protein breakdown than did the control cheeses and those made with S. durans, the latter two being nearly identical in the extent of proteolysis. More proteolysis was consistently observed in those cheeses cured at 12.8 C. No statistical difference was observed inproteolytic activity between air- and brine-cooled cheeses. Cheeses made with S. durans had a higher final percentage of lactic acid than did controls and cheeses made with S. faecalis. Cheeses manufactured with enterococci exhibited a more rapid initial production of lactate. Cheeses cured at 12.8 C had greater percentages of lactic acid compared with those cured at 7.2 C. Air-cooled cheeses also developed significantly higher levels of lactic acid than did brine-cooled cheeses.

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104. Studies in Cheddar Cheese. IV. Observations on the Lactic Acid Flora of Cheddar Cheese made from Clean Milk

Journal of Dairy Research ◽

10.1017/s0022029900001321 ◽

1935 ◽

Vol 6 (2) ◽

pp. 175-190 ◽

Cited By ~ 25

Author(s):

John Gilbert Davis

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Osmotic Pressure ◽

Slow Growth ◽

Carbon Sources ◽

Lactate Concentration ◽

Cheddar Cheese ◽

Titratable Acidity ◽

Distinct Species ◽

Litmus Milk

1. The lactic acid flora of Cheddar cheese made from milk of certified quality form a well-defined, physiologically homogeneous group of bacteria, growing best over a temperature range of from 22 to 37° C. They may be classified into four well-defined types, Str. lactis, Str. cremoris, Sbm. plantarum and Sbm. casei, and have been studied over a period of five years. It appears from the evidence found that Str. lactis and Str. cremoris are distinct species, but that Sbm. casei and Sbm. plantarum represent different stages in the adaptation of a common progenitor to conditions in a ripening cheese. Both the streptococci and the streptobacteria appear to be unable to oxidise sugars and may thus be considered indifferent to molecular oxygen.2. A study of their frequency distribution from the curd at making to an 18 months old cheese has shown that Str. lactis and Str. cremoris are equally viable during the first month, after which the rod forms begin to predominate, Sbm. plantarum and, later, Sbm. casei being found. The former lactobacillus is only found when the cheese is from 1 to 5 months old, the flora consisting entirely of Sbm. casei after this time. The general vigour of all strains decreases with increasing age of the cheese. There is a marked correlation between the shape of the cell, the viability of the organism in cheese and its resistance to acids and lactates.3. The factors controlling the sequence of flora in Cheddar cheese are discussed. There is no evidence that titratable acidity, oxygen tension and differential carbon sources are responsible for the sequence. It is suggested that lactate concentration, the extent of protein degradation and osmotic pressure are factors responsible for the gradual replacement of the streptococci by the rod forms.4. The significance of sugar fermentations by the lactic 'acid bacteria studied is discussed. The slow production of lactase is shown to be the reason for the slow growth of weakened strains in litmus milk.5. Str. cremoris predominates over Str. lactis in the depth of the cheese in the early stages of ripening, whereas near the surface the reverse holds. Certain strains of Str. cremoris isolated from the depth of the cheese were particularly vigorous in growth in litmus milk, forming gas and beginning to peptonise the milk in about 3 days. Such strains consisted of very long chains of large cells of peculiar morphology. It is suggested that this finding is related to the known greater rate of ripening in the depth of the cheese.

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