Role of Enterococci in Cheddar Cheese: Organoleptic Considerations1

1975 ◽  
Vol 38 (3) ◽  
pp. 142-145 ◽  
Author(s):  
JANE P. JENSEN ◽  
G. W. REINBOLD ◽  
C. J. WASHAM ◽  
E. R. VEDAMUTBU
Keyword(s):  
Lactic Acid ◽  
Fatty Acid ◽  
Citric Acid ◽  
Free Fatty Acid ◽  
Cheddar Cheese ◽  
Streptococcus Faecalis ◽  
Growth And Survival ◽  
Respective Control ◽  
Significant Difference

Eight lots of Cheddar cheese were manufactured with two strains each of Streptococcus faecalis and Streptococcus durans and subjected to combinations of two early cooling treatments (air vs. brine cooling) and two curing temperatures (7.2 and 12.8 C). The enterococcus cultures were used as supplemental starters in combination with a commercial lactic culture. These cheeses were analyzed for microbiological growth and survival, proteolysis, lactic acid development, free fatty acid appearance, and citric acid utilization—each being compared with a control cheese made without enterococci. Results were presented in three previous articles. This series is concluded with the results of organoleptic ana1ysis of the cheeses. Cheeses made with S. faecalis were either comparable to or less desirable than their respective control cheeses. Those made with S. durans, however, were in all instances more desirable than their controls. Cheeses cured at 7.2 C were always given the better scores, but there was no statistically significant difference between air- and brine-cooled cheeses.

Role of Enterococci in Cheddar Cheese: Free Fatty Acid Appearance and Citric Acid Utilization1

1975 ◽  
Vol 38 (2) ◽  
pp. 78-83 ◽  
Author(s):  
JANEP. JENSEN ◽  
G. W. REINBOLD ◽  
C. J. WASHAM ◽  
E. R. VEDAMUTHU
Keyword(s):  
Fatty Acid ◽  
Citric Acid ◽  
Free Fatty Acid ◽  
Fatty Acid Content ◽  
Cheddar Cheese ◽  
Gas Production ◽  
Lower Content ◽  
Biochemical Effects ◽  
Neutral Compounds

Eight lots of Cheddar cheese were manufactured to determine the microbiological response and biochemical effects of two strains each of Streptococcus faecalis and Streptococcus durans used as supplemental starters in combination with a commercial lactic culture. Each lot consisted of a control vat of cheese manufactured with the 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 environmental effects on the cheeses. Cheeses manufactured with S. faecalis had a somewhat lower content of free fatty acids than did control cheeses, possibly because of early conversion of acids to neutral compounds. Cheeses manufactured with S. durans showed a fluctuating, but consistent, free fatty acid content among treatments, with overall amounts being greater than in the control cheeses or in cheeses made with S. faecalis. Cheeses cured at 12.8 C showed greater free fatty acid liberation, but the effects of early cooling rates were not significant. Citric acid in cheeses made with S. faecalis and in control cheeses was utilized most rapidly in 30 days at 12.8 C and extending to 60 days when cured at 7.2 C, after which no more breakdown seemed to occur. Cheeses made with S. durans 9–20 followed approximately the same pattern although some utilization took place between 90 and 180 days. In cheeses made with S. durans 15–20, however, citric acid utilization was continuous up to 180 days, and in cheeses cured at 12.8 C, citric acid was nearly depleted at 180 days. Cheeses made with S. durans 15–20 and cured at 12.8 C exhibited excessive gas production.

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

1975 ◽  
Vol 38 (1) ◽  
pp. 3-7 ◽  
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.

Effect of pH, Acidulant, Time, and Temperature on the Growth and Survival of Listeria monocytogenes

1989 ◽  
Vol 52 (8) ◽  
pp. 571-573 ◽  
Author(s):  
KENT M. SORRELLS ◽  
DAVIN C. ENIGL ◽  
JOHN R. HATFIELD
Keyword(s):  
Antimicrobial Activity ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Citric Acid ◽  
Hydrochloric Acid ◽  
Malic Acid ◽  
Incubation Temperature ◽  
Growth And Survival ◽  
Ph Values

The effect of different acids, pH, incubation time, and incubation temperature on the growth and survival of four strains of Listeria monocytogenes in tryptic soy broth was compared. Hydrochloric acid (HCl), acetic acid (AA), lactic acid (LA), malic acid (MA), and citric acid (CA) were used to acidify tryptic soy broth to pH values 4.4, 4.6, 4.8, 5.0, and 5.2 pH. Incubation times were 1, 3, 7, 14, and 28 d at 10, 25, and 35°C. The inhibition of L. monocytogenes in the presence of high acidity appears to be a function of acid and incubation temperature. Based on equal pH values, the antimicrobial activity is AA > LA > CA ≥ MA > HCl at all incubation times and temperatures. When based on equal molar concentration, the activity appeared to be CA ≥ MA > LA ≥ AA > HCl at 35 and 25°C, and MA > CA > AA ≥ LA > HCl at 10°C. Greatest antimicrobial activity occurred at 35°C. Greatest survival occurred at 10°C and greatest growth occurred at 25°C. Final pH of the medium was as low as 3.8 in HCl at 28 d. All strains grew well at pH values lower than the minimum previously reported (5.5–5.6).

Regulation of free fatty acid metabolism by insulin in humans: role of lipolysis and reesterification

2006 ◽  
Vol 263 (6) ◽  
pp. E1063-E1069 ◽  
Author(s):  
P. J. Campbell ◽  
M. G. Carlson ◽  
J. O. Hill ◽  
N. Nurjhan
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Acid Metabolism ◽  
Insulin Dose ◽  
Healthy Humans ◽  
Constant Rate ◽  
Free Fatty Acid Metabolism ◽  
Plasma Ffa ◽  
Maximal Suppression

The regulation of lipolysis, free fatty acid appearance into plasma (FFA R(a)), an FFA reesterification and oxidation were examined in seven healthy humans infused intravenously with insulin at rates of 4, 8, 25, and 400 mU.m-2.min-1. Glycerol and FFA R(a) were determined by isotope dilution methods, and FFA oxidation was calculated by indirect calorimetry or by measurement of expired 14CO2 from infused [1-14C]palmitate. These measurements were used to calculate total FFA reesterification, primary FFA reesterification occurring within the adipocyte, and secondary reesterification of circulating FFA molecules. Lipolysis, FFA R(a), and secondary FFA reesterification were exquisitely insulin sensitive [the insulin concentrations that produced half-maximal suppression (EC50), 106 +/- 26, 91 +/- 20 vs. 80 +/- 16 pM, P = not significant] in contrast to insulin suppression of FFA oxidation (EC50, 324 +/- 60, all P < 0.01). The absolute rate of primary FFA reesterification was not affected by the increase in insulin concentration, but the proportion of FFA molecules undergoing primary reesterification doubled over the physiological portion of the insulin dose-response curve (from 0.23 +/- 0.06 to 0.44 +/- 0.07, P < 0.05). This served to magnify insulin suppression of FFA R(a) twofold. In conclusion, insulin regulates FFA R(a) by inhibition of lipolysis while maintaining a constant rate of primary FFA reesterification.

scholarly journals Free Fatty acids receptors (FFAR2 and FFAR3) control cell proliferation by regulating cellular glucose uptake

2019 ◽  
Author(s):  
Mohammad Aziz ◽  
Saeed Al Mahri ◽  
Amal Alghamdi ◽  
Maaged AlAkiel ◽  
Monira Al Aujan ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Fatty Acids ◽  
Cell Proliferation ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Free Fatty Acids ◽  
Glucose Uptake ◽  
Microarray Data ◽  
Free Fatty Acid Receptors

Abstract Background Colorectal cancer is a worldwide problem which has been associated with changes in diet and lifestyle pattern. As a result of colonic fermentation of dietary fibres, short chain free fatty acids are generated which activate Free Fatty Acid Receptors 2 and 3 (FFAR2 and FFAR3). FFAR2 and FFAR3 genes are abundantly expressed in colonic epithelium and play an important role in the metabolic homeostasis of colonic epithelial cells. Earlier studies point to the involvement of FFAR2 in colorectal carcinogenesis. Methods Transcriptome analysis console was used to analyse microarray data from patients and cell lines. We employed shRNA mediated down regulation of FFAR2 and FFAR3 genes which was assessed using qRT-PCR. Assays for glucose uptake and cAMP generation was done along with immunofluorescence studies. For measuring cell proliferation, we employed real time electrical impedance based assay available from xCelligence. Results Microarray data analysis of colorectal cancer patient samples showed a significant down regulation of FFAR2 gene expression. This prompted us to study the FFAR2 in colorectal cancer. Since, FFAR3 shares significant structural and functional homology with FFAR2, we knocked down both these receptors in colorectal cancer cell line HCT 116. These modified cell lines exhibited higher proliferation rate and were found to have increased glucose uptake as well as increased level of GLUT1. Since, FFAR2 and FFAR3 signal through G protein subunit (Gαi), knockdown of these receptors was associated with increased cAMP. Inhibition of PKA did not alter the growth and proliferation of these cells indicating a mechanism independent of cAMP/PKA pathway. Conclusion: Our results suggest role of FFAR2/FFAR3 genes in increased proliferation of colon cancer cells via enhanced glucose uptake and exclude the role of protein kinase A mediated cAMP signalling. Alternate pathways could be involved that would ultimately result in increased cell proliferation as a result of down regulated FFAR2/FFAR3 genes. This study paves the way to understand the mechanism of action of short chain free fatty acid receptors in colorectal cancer.

scholarly journals Free Fatty Acid Receptor 4 (GPR120) Stimulates Bone Formation and Suppresses Bone Resorption in the Presence of Elevated n-3 Fatty Acid Levels

Endocrinology ◽  
2016 ◽  
Vol 157 (7) ◽  
pp. 2621-2635 ◽  
Author(s):  
Seong Hee Ahn ◽  
Sook-Young Park ◽  
Ji-Eun Baek ◽  
Su-Youn Lee ◽  
Wook-Young Baek ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Bone Resorption ◽  
Bone Loss ◽  
Bone Formation ◽  
High Fat Diet ◽  
Wild Type ◽  
High Fat ◽  
Free Fatty Acid Receptor

Free fatty acid receptor 4 (FFA4) has been reported to be a receptor for n-3 fatty acids (FAs). Although n-3 FAs are beneficial for bone health, a role of FFA4 in bone metabolism has been rarely investigated. We noted that FFA4 was more abundantly expressed in both mature osteoclasts and osteoblasts than their respective precursors and that it was activated by docosahexaenoic acid. FFA4 knockout (Ffar4−/−) and wild-type mice exhibited similar bone masses when fed a normal diet. Because fat-1 transgenic (fat-1Tg+) mice endogenously converting n-6 to n-3 FAs contain high n-3 FA levels, we crossed Ffar4−/− and fat-1Tg+ mice over two generations to generate four genotypes of mice littermates: Ffar4+/+;fat-1Tg−, Ffar4+/+;fat-1Tg+, Ffar4−/−;fat-1Tg−, and Ffar4−/−;fat-1Tg+. Female and male littermates were included in ovariectomy- and high-fat diet-induced bone loss models, respectively. Female fat-1Tg+ mice decreased bone loss after ovariectomy both by promoting osteoblastic bone formation and inhibiting osteoclastic bone resorption than their wild-type littermates, only when they had the Ffar4+/+ background, but not the Ffar4−/− background. In a high-fat diet-fed model, male fat-1Tg+ mice had higher bone mass resulting from stimulated bone formation and reduced bone resorption than their wild-type littermates, only when they had the Ffar4+/+ background, but not the Ffar4−/− background. In vitro studies supported the role of FFA4 as n-3 FA receptor in bone metabolism. In conclusion, FFA4 is a dual-acting factor that increases osteoblastic bone formation and decreases osteoclastic bone resorption, suggesting that it may be an ideal target for modulating metabolic bone diseases.

ROLE OF ENTEROCOCCI IN CHEDDAR CHEESE: GROWTH OF ENTEROCOCCI DURING MANUFACTURE AND CURING1

1973 ◽  
Vol 36 (12) ◽  
pp. 613-618 ◽  
Author(s):  
Jane P. Jensen ◽  
G. W. Reinbold ◽  
c. J. Washam ◽  
E. R. Vedamuthu
Keyword(s):  
Cheddar Cheese ◽  
Rapid Decrease ◽  
Growth Patterns ◽  
Population Differences ◽  
Streptococcus Faecalis

Eight lots of Cheddar cheese were manufactured to determine the microbiological response of two strains each of Streptococcus faecalis and Streptococcus durans when used as supplemental starters in combination with a commercial lactic culture. Each lot consisted of a control vat of cheese manufactured with the 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 environmentally-induced variability. Growth patterns were monitored throughout the manufacture period up to the end of pressing, and during curing up to 6 months. Enterococcus populations showed little or no decrease when the cheeses were being pressed, whereas populations in control cheeses decreased over the same period. During curing, control cheeses cured at 7.2 C showed marked population decreases over the 6 months; those cured at 12.8 C showed a rapid decrease followed by an upsurge in population. Populations of S. faecalis in the experimental cheeses decreased only slightly, and S. durans showed almost no decrease. Generally, cheeses cured at 7.2 C showed the greatest numerical survival and there appeared to be no population differences caused by early cooling treatment.

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