Accelerated cheese ripening: a method for increasing the number of lactic starter bacteria in cheese without detrimental effect to the cheese-making process, and its effect on the cheese ripening

1975 ◽  
Vol 42 (2) ◽  
pp. 313-326 ◽  
Author(s):  
H.-E. Pettersson ◽  
G. Sjöström
Keyword(s):  
Heat Treatment ◽  
Adverse Effect ◽  
Trichloroacetic Acid ◽  
Detrimental Effect ◽  
Phosphotungstic Acid ◽  
Cheese Making ◽  
Cheese Ripening ◽  
Constant Ph ◽  
Cheese Curd ◽  
Number Of Cells

SummaryA method is outlined for accelerating ripening in Swedish semihard cheese by increasing the number of lactic starter bacteria present in the cheese without impairing characteristic texture and flavour. In addition to the normal starter inoculum, suitable lactic starter bacteria whose lactic-acid-producing activity had been greatly reduced by previous sublethal heat treatment, were added to the cheesemilk. When suspensions of streptococci and lactobacilli cultivated at a constant pH were heated at 59 and 69°C respectively acid production was retarded by 5–10 h, which was found to be sufficient for the cheese-making. Proteolysis was lowered only 10–30% by these heating temperatures. Bacterial cell suspensions, prepared by the methods outlined and added to the cheesemilk, were incorporated in cheese curd to extents depending on the amount added and the type of starter. The number in the final cheese could be increased to a maximum of 4–5 times that of control cheese. No adverse effect of the extra starter bacteria on pH, fat content and water content of cheeses 24-h old was observed. Proteolysis, measured as the increase in trichloroacetic acid and phosphotungstic acid (PTA)-soluble N, increased with increasing number of cells in the cheese. Organoleptic judgements showed a positive correlation (r= 0·81) between taste and PTA-soluble N, which in turn was influenced by the number of cells in the final cheeses.

Denaturation of porcine pepsin during Cheddar cheese manufacture

1977 ◽  
Vol 44 (2) ◽  
pp. 335-343 ◽  
Author(s):  
A. M. O'Keeffe ◽  
P. F. Fox ◽  
C. Daly
Keyword(s):  
Cheddar Cheese ◽  
Porcine Pepsin ◽  
Cheese Making ◽  
Temperature Range ◽  
Cheese Ripening ◽  
Cheese Curd

SummaryPorcine pepsin was rapidly denatured in phosphate buffers, pH 6·4–6·7, in the temperature range 31–39 °C and was only slightly more stable in milk under similar conditions. However, the enzyme was considerably more stable in Cheddar cheese curd in which the extent of denaturation was very markedly influenced by the pH of the milk at setting. Under normal cheese-making conditions, porcine pepsin was about equally stable with chymosin. Two modifications of the cheesemanufacturing procedure were developed which permit the manufacture of cheese almost free of coagulant and suitable for the assessment of the contribution of starter proteinases to proteolysis during cheese ripening.

644. The influence of penicillin on the manufacture and ripening of Cheddar cheese

1956 ◽  
Vol 23 (3) ◽  
pp. 355-360 ◽  
Author(s):  
H. R. Whitehead ◽  
D. J. Lane
Keyword(s):  
Adverse Effect ◽  
Direct Effect ◽  
Acid Production ◽  
Cheddar Cheese ◽  
Poor Quality ◽  
Large Excess ◽  
Ripening Process ◽  
Cheese Making ◽  
Cheese Curd ◽  
Short Time

The addition of penicillin to cheese milk had the effect of delaying acid production by starter in the cheese curd; any effect on cheese quality could be traced to the delay in acid production and to a high final pH in the cheese. There was no indication of any direct effect of penicillin on the ripening process.A concentration of 0·10 unit/ml. of penicillin in the cheese milk was a borderline amount with the particular starters which were used. Cheese quality was sometimes adversely affected. A smaller concentration (0·05 unit/ml.) delayed the cheese-making process slightly but had no adverse effect in final cheese quality. Higher concentrations regularly resulted in poor quality cheese.Penicillinase added to cheese milk neutralized any penicillin present but with a short time of contact of about 30 min., a large excess of penicillinase had to be used.

The Preservation of Specialization by Dispersed Steer Thyroidal Cells in Long-Term Culture

1971 ◽  
Vol 9 (1) ◽  
pp. 49-69
Author(s):  
E. SIEGEL
Keyword(s):  
Standard Deviation ◽  
Trichloroacetic Acid ◽  
Doubling Time ◽  
Ultrastructural Level ◽  
Thyroid Stimulating Hormone ◽  
Linear Variation ◽  
Thyroid Cells ◽  
Long Acting ◽  
Number Of Cells

Serially propagated cells derived from the steer thyroid gland preserve several specialized characteristics, some demonstrable for as long as 8 months (over 15 passes). For about 5 passes (3 months), follicular-like arrays of cells develop. Thyroid-stimulating hormone (TSH) or thyrotropin (1 and 10 mu./ml) induces the formation of supernumerary nucleoli, and promotes at the ultrastructural level the prompt (within 10 min) appearance of microvilli, pseudopodia, and intracytoplasmic droplets. These cells have a mean plating efficiency (PE) of 16.5 ± 4.5% (standard deviation) and with 3x104 cells as the standard inoculum, a mean doubling time (Td) of 43.7 ± 1.2 h. The linear variation of Td with the number of cells seeded probably signifies strong cell-cell interactions. TSH (1-5o mu./ml) influences both PE and Td, with 1 mu./ml producing the maximum stimulation. TSH (0.001-100 mu./ml) also induces the discharge of incorporated radio-iodide from the cultured thyroid cells, achieving a peak by 2-4 h, titres of 0.1-1 mu./ml being most potent. Long-acting thyroid stimulator (LATS) (0.2 u./ml) likewise effects release of 131I into growth medium (1 experiment), but over a more protracted period. After labelling with [3H]leucine, radioautographs demonstrate that the synthesis of proteins is stimulated by exposure to TSH (1 mu./ml). Precipitation with trichloroacetic acid indicates that these cells persist in synthesizing 131I-tagged iodoproteins, an activity optimally stimulated by 1 mu./ml TSH and marked by 3 h. Hence, such thyroidal cell lines afford a useful model for studying differentiation and hormonal effects.

scholarly journals Effect of Trichloroacetic Acid Hydrogel on Self-Etch Adhesive Bond Strength to Dental Tissues

2013 ◽  
Vol 14 (3) ◽  
pp. 375-380
Author(s):  
Maryam Khoroushi ◽  
Kamyar Fathpour
Keyword(s):  
Bond Strength ◽  
Trichloroacetic Acid ◽  
Detrimental Effect ◽  
Adhesive Bond ◽  
Study Groups ◽  
Test Machine ◽  
Dental Tissues ◽  
Adhesive Bond Strength ◽  
Self Etch

ABSTRACT Introduction Trichloroacetic acid (TCA) is a soft tissue cauterizing agent applied to gingival margins prior to cervical tooth-colored restorations. The present in vitro study evaluated the effects of two different concentrations of TCA hydrogel as a hemostatic/preconditioning agent on the shear bond strength (SBS) of a self-etch adhesive to tooth structures. Materials and methods Thirty-six flat enamel and 36 flat dentin surfaces were prepared using human molars; each group was subdivided into three subgroups (n = 12). The groups were made ready as follows: In groups 1 (E1 and D1), the enamel (E) and dentin (D) surfaces were designated as control groups and remained intact. In groups 2 (E2 and D2), 35% TCA gel was applied to enamel and dentin surfaces for 30 seconds. In groups 3 (E3 and D3), 50% TCA gel was applied to enamel and dentin surfaces for 30 seconds. Clearfil SE Bond and Z100 composite resin were applied to the surfaces according to manufacturers¡¦ instructions. After 24 hours of incubation and thermocycling, the composite cylinders underwent an SBS test in a DARTEC test machine. Data were analyzed using the ANOVA and Scheffé's test (α = 0.05). Results The mean SBS ± SD in the study groups were 34.73 ± 5.66, 35.32 ± 7.3, 23.75 ± 9.67, 20.94 ± 9.84, 19.32 ± 6.20, 23.50 ± 6.63 MPa in the E1, E2, E3, D1, D2 and D3 groups, respectively. ANOVA revealed significant differences between the SBS values of enamel groups (p = 0.001). There were no significant differences between the dentin groups (p = 0.425). Conclusion Application of 35 and 50% concentrations of TCA to dentin had no detrimental effect on the bond produced by two-step self-etch adhesive under study; however, application of only 35% TCA to enamel did not result in a detrimental effect on the same adhesive. How to cite this article Fathpour K, Khoroushi M. Effect of Trichloroacetic Acid Hydrogel on Self-Etch Adhesive Bond Strength to Dental Tissues. J Contemp Dent Pract 2013; 14(3):375-380.

scholarly journals The COVID-19 pandemic, remittances and financial inclusion in the Philippines

2021 ◽  
Vol 57 (1) ◽  
pp. 18-41
Author(s):  
Eiji Yamada ◽  
Satoshi Shimizutani ◽  
Enerelt Murakami
Keyword(s):  
Adverse Effect ◽  
Developing Countries ◽  
Detrimental Effect ◽  
Recent Literature ◽  
The Philippines ◽  
Financial Inclusion ◽  
Rural Regions ◽  
Household Level ◽  
Remittance Flows ◽  
Substantial Decline

Recent literature has revealed that financial inclusion enhances economic opportunities and security in developing countries. Moreover, a greater inflow of remittances can promote inclusiveness. In this paper, we explore the potential impacts of the COVID-19 outbreak on financial inclusion by focusing on its detrimental effect on remittance flows to developing countries. Using a household-level dataset collected in rural regions of the Philippines prior to the outbreak, we confirm that remittances are associated with financial inclusion, particularly for women. We discuss the potential impacts of the pandemic on financial inclusion through the change in the flow of remittances. We show that a substantial decline in remittances caused by the COVID-19 crisis may have an adverse effect on financial inclusion in the Philippines.

Virus-like particles and lytic plaque formation in lawns of Candida albicans

1982 ◽  
Vol 152 (1) ◽  
pp. 502-505
Author(s):  
R J Mehta ◽  
C H Nash ◽  
J J Bozzola
Keyword(s):  
Heat Treatment ◽  
Candida Albicans ◽  
Phosphotungstic Acid ◽  
Uv Light ◽  
Electron Microscopic Examination ◽  
Plaque Formation ◽  
Spherical Particles ◽  
Electron Microscopic ◽  
Ultrathin Sections ◽  
Aculeacin A

The antifungal agent Aculeacin A at subinhibitory levels induced lytic plaques in lawns of Candida albicans. Electron microscopic examination of plaque lysates suspended in phosphotungstic acid revealed the presence of spherical particles 12, 18, and 28 to 30 nm in size. Particles were also found in ultrathin sections of treated C. albicans cells. The plaque lysate lost infectivity after treatment with UV light, heat treatment at 80 degrees C for 10 min, or being held at pH 2 for 30 min.

Histamine Production in Low-Salt Cheddar Cheese

1991 ◽  
Vol 54 (11) ◽  
pp. 852-860 ◽  
Author(s):  
JAYNE E. STRATTON ◽  
ROBERT W. HUTKINS ◽  
STEVE L. TAYLOR
Keyword(s):  
Low Temperature ◽  
Trichloroacetic Acid ◽  
Phosphotungstic Acid ◽  
Cheddar Cheese ◽  
Ripening Period ◽  
Histamine Production ◽  
Low Salt ◽  
Histamine Formation ◽  
Low Levels ◽  
Control Milk

To assess the potential for histamine production in low-salt Cheddar cheese, pasteurized milk was inoculated with Lactobacillus buchneri St2A at levels of 102, 103, and 104 microorganisms per ml of milk. One additional vat was uninoculated and served as a control. Milk was then manufactured into low-salt (0.40%) Cheddar cheese. After 180 d of aging at 7°C, levels of L. buchneri St2A had increased approximately 100-fold in the inoculated cheese. Proteolysis, expressed as μmoles free glycine per g cheese, increased from 40 to 150 (trichloroacetic acid soluble) and from 25 to 130 (phosphotungstic acid soluble) during the ripening period. Histamine levels, however, remained low in the inoculated cheeses (<5 mg/100 g), suggesting that the potential for histamine formation may be minimal in low-salt Cheddar cheese. It was concluded that the relatively low levels of proteolysis and low temperature of storage were primarily responsible for inhibiting histamine production.

Heat treatment of cheese milk: effect on proteolysis during cheese ripening

2001 ◽  
Vol 11 (4-7) ◽  
pp. 567-574 ◽  
Author(s):  
Connie Benfeldt ◽  
John Sørensen
Keyword(s):  
Heat Treatment ◽  
Cheese Ripening

Assessment of swine, bovine and chicken pepsins as rennet substitutes for Cheddar cheese-making

1972 ◽  
Vol 39 (2) ◽  
pp. 261-273 ◽  
Author(s):  
Margaret L. Green
Keyword(s):  
Cheddar Cheese ◽  
Cheese Making ◽  
Stomach Mucosa ◽  
Milk Clotting ◽  
Cheese Ripening ◽  
Cheese Flavour ◽  
The Cost ◽  
Substrate Ph ◽  
Milk Clotting Activity

SummaryThree enzymes were assessed as rennet substitutes for cheese-making. The bovine and chicken pepsins used were relatively crude extracts of bovine stomach mucosa and chicken proventriculae respectively; the swine pepsin was a partially purified commercial product. The ratios of milk-clotting activity to general proteolytic activity were high for rennet and bovine pepsin and low for swine and chicken pepsins. Both bovine mucosa and chicken stomach gave low milk-clotting activities compared with calf stomach. For all the enzymes the chemical reactions causing milk clotting appeared to be the same. The milk-clotting activity showed a decrease with increase in substrate pH for all the enzymes, although they were all still active at pH 6·81.Duplicate cheeses were made from each of the swine, bovine and chicken pepsins, with rennet as a standard in each trial. The cheese-making process was similar with each enzyme, but differences appeared during ripening. The chicken-pepsin cheeses had poor body and weak Cheddar-cheese flavour, with many and intense off-flavours. The cheeses made with bovine and swine pepsins were only slightly inferior in quality and intensity of Cheddar-cheese flavour to the rennet cheeses. From a simulated cheese-making experiment it was concluded that 30–40 % of the added rennet, bovine pepsin and chicken pepsin was probably inactivated during the cheese-making process and that most or all of the swine pepsin was lost. These results provide an explanation for the variations observed in cheese ripening.It was concluded that chicken pepsin would not prove a suitable rennet substitute for making Cheddar cheese because of the quality of the cheese produced, and that bovine pepsin would not prove suitable because of the cost of preparing a suitable extract. Swine pepsin would appear to be suitable if the ripening time were to be lengthened or if another enzyme were to be added to assist ripening; it is cheaper than rennet and other rennet substitutes.

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