The effect of non-starter bacteria on the chemical composition and the flavour of Cheddar cheese

1976 ◽  
Vol 43 (1) ◽  
pp. 117-125 ◽  
Author(s):  
B. A. Law ◽  
Marisi Castañón ◽  
M. Elisabeth Sharpe
Keyword(s):  
Fatty Acids ◽  
Chemical Composition ◽  
Free Fatty Acids ◽  
Raw Milk ◽  
Methyl Ketones ◽  
Gram Negative ◽  
Fresh Cheese ◽  
Cheese Curd ◽  
Bacterial Groups ◽  
Made In

SummaryDifferences in flavour scores and in the concentrations of free fatty acids, methyl ketones and H2S were measured in Cheddar cheeses containing various groups of non-starter bacteria or starter streptococci alone, made under controlled bacteriological conditions by the aseptic vat technique. The non-starter bacteria were made up of lactobacilli, leuconostocs, pediococci, micrococci and Gram-negative rods isolated in commercial creameries from raw milk or fresh cheese curd. These were added to the experimental cheese as single groups or as complete floras (reference floras). Several bacterial groups influenced the measured concentrations of the flavour compounds, but flavour differences were not correlated with these chemical differences. Only cheese containing a curd-derived whole reference flora or cheese made in open vats in the N.I.R.D. Experimental Dairy had significantly better flavour than starter-only cheese, but this improvement was not attributable to any particular group of bacteria.

scholarly journals The Effect of Lipolytic Enzymes of Bacillus spp. on Quality of Ultra-High-Temperature-Treated Milk

2006 ◽  
Vol 75 (3) ◽  
pp. 427-435 ◽  
Author(s):  
B. Janštová ◽  
L. Vorlová ◽  
M. Dračková
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Storage Temperature ◽  
Lipolytic Activity ◽  
Storage Period ◽  
Raw Milk ◽  
Model Case ◽  
Number Of Microorganisms ◽  
Bacillus Spp ◽  
Initial Content

Lipolysis was monitored based on determining the concentration of free fatty acids in milk, on the model case of UHT milk contamination with spores of 15 B. licheniformis, B. subtilis and B. cereus strains isolated from farm environment and raw milk. Lipolysis was not recorded at storage temperature of 4 °C, whereas significant changes in levels of free fatty acids were shown at storage temperature of 24 °C. After 3 weeks of storage the initial content of 41.97 mmol·kg-1 of fat rose to as much as 1,617.22 mmol·kg-1 of fat. The extent of the change depended mainly on the Bacillus spp. species and the storage period and, to a certain degree, also on the initial number of microorganisms. Significant lipolytic activity was detected in association with B. licheniformis and B. cereus species. It was found that spores of resistant B. licheniformis strains may survive 100 °C/10 min and 135 °C/5 s heating and show lipolytic activity.

scholarly journals The effect of cold storage, time and the population of Pseudomonas species on milk lipolysis

2019 ◽  
Vol 70 (2) ◽  
pp. 300
Author(s):  
F. A.B. Pereira ◽  
L. L. Luiz ◽  
S. R. Bruzaroski ◽  
R. C. Poli-Frederico ◽  
R. Fagnani ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Pseudomonas Putida ◽  
Pseudomonas Fluorescens ◽  
Cold Storage ◽  
Storage Time ◽  
Raw Milk ◽  
Lower Index ◽  
Whole Milk

The aim of this study was to evaluate the lipolytic index (LI) of Pseudomonas fluorescens and Pseudomonas putida (2, 5, 6 log CFU/mL) in milk during 96 h by the Lipo R method. The strains were isolated from refrigerated raw milk (30 °C, 48 h), and species were confirmed by PCR, inoculated in reconstituted whole milk, and stored at 2 °C, 4 °C, and 8 °C. The storage time (ST) and temperature were associated with LI of P. putida. The interaction among lipolysis, temperature, and ST occurs even with a low population of P. putida and these variables combined together contributed to about 77% of the free fatty acids (FFA) in milk. The ST, temperature, and population of P. fluorescens showed a significant effect on its LI, and the variables contributed to about 43% of FFA. LI was about 224% higher in milk with P. fluorescens than with P. putida. The reduc-tion in ST and milk temperature resulted in a decrease in lipid lysis and a lower index of FFA by P. putida and P. fluorescens, with P. fluorescens showing a higher lipolytic capacity.

scholarly journals Evaluation of development in indirect determination of milk fat free fatty acids in Czech Republic

2013 ◽  
Vol 61 (6) ◽  
pp. 1669-1679 ◽  
Author(s):  
Oto Hanuš ◽  
Eva Samková ◽  
Jan Říha ◽  
Marcela Vyletělová Klimešová ◽  
Petr Roubal
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Milk Fat ◽  
Raw Milk ◽  
Important Indicator ◽  
Indirect Determination ◽  
Milk Samples ◽  
Bulk Milk ◽  
Instrumental Values

Free fatty acids (FFAs) in fat are important indicator of raw milk quality. Result reliability of FFAs is important. Aim was to verify MIR–FT (mid infrared spectroscopy with Fourier’s transformations) method for its calibration to determine FFAs, time stability of MIR–FT FFA calibration and calibration levelling in laboratory networks. Reference (RE) milk samples (1 set = 8) were prepared according to CSN 57 0533 (FFAs in mmol.100g−1 of fat). MIR–FT instruments were: 1 LactoScope FTIR (DE); 2 Bentley FTS (BE); 2 MilkoScan FT 6000 (FO). 3 calibrations of MIR–FT (5) in 3 laboratories were performed. Bulk milk samples came from 4 herds and 2 breeds. These 4 samples were used for calibration in native and modified form. Modification increased FFAs by cca 100%. Calibration set had 8 samples. 1 between calibration interval was checked monthly by proficiency testing (PT). PT set had 10 samples. 5 samples were with native milk and 5 had modified fat content, lower and higher. Maximal value of difference variability for calibration quality validation is x (sd of difference MIR–FT and RE) plus 1.64 multiple of sd (on 95% level), 1.0613 mmol.100g−1. Mean validation correlation coefficient (r) between MIR–FT and RE results was 0.802 ± 0.082 (P < 0.001), from 0.666 to 0.945. Minimal value at calibration is x minus 1.64 multiple of sd (0.668). Correlations between MIR–FT results were higher by 8.4% (0.869 (P < 0.001) > 0.802). Example PT with 10 and 5 milk samples had similar results of r 0.887 and 0.953 (P < 0.001 and P < 0.05). There is possibility to construct a levelling programme for calibrated instruments. Some equation between PT reference and instrumental values could correct MIR–FT results for their better comparability.

The Anal Sac Secretion of Viverrids from the Genus Genetta

1986 ◽  
Vol 41 (3) ◽  
pp. 325-336 ◽  
Author(s):  
Jürgen Jacob ◽  
Harald Schliemann
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acids ◽  
Liquid Chromatography ◽  
Chemical Composition ◽  
Free Fatty Acids ◽  
Gas Liquid Chromatography ◽  
Anal Sac Secretion ◽  
Anal Sac ◽  
Anal Sacs

The chemical composition of the secretions from the anal sacs of three species from the genus Genetta has been analysed by means of gas-liquid chromatography and mass spectrometry. The main constituents of the secretion are free fatty acids, hydrocarbons, mono- and diester waxes, triglycerides, alkane diols, and free alcohols. Composition of the secretion in the three species is fundamentally similar, but there are some remarkable quantitative differences of the components m entioned. Some of the alkane-1,2-diols in these secretions have never been found before in nature.

scholarly journals Fatty Acids as Biomarkers of the Production Season of Caciocavallo Palermitano Cheese

Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2675
Author(s):  
Giuseppe Maniaci ◽  
Antonino Di Grigoli ◽  
Adriana Bonanno ◽  
Cristina Giosuè ◽  
Vincenzo Ilardi ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Multivariate Analysis ◽  
Chemical Composition ◽  
Wheat Bran ◽  
Vaccenic Acid ◽  
Four Seasons ◽  
In Trans ◽  
Total Pufa ◽  
Trans Vaccenic Acid ◽  
Made In

This experiment aims to evaluate the potential of fatty acids (FA) of Caciocavallo Palermitano cheese as biomarkers of production season and pasture-based diet. A total of 48 cheeses were made in the four seasons with milk from two farms that raised cows of Cinisara breed. The animals were fed on pasture with supplementation of wheat bran and wheat straw in the barn, and in summer also with Opuntia ficus-indica cladodes. The chemical composition and FA profile of cheese were influenced by the season and not by the farm. In particular, cheeses produced in spring were characterized by higher protein and lower fat, and showed higher contents in trans-vaccenic acid, α-linolenic acid, rumenic acid, n-3 polyunsaturated FA (PUFA), and total PUFA. In winter, the lower availability of grazing forage, requiring a higher level of feeding integration, was responsible for an increase of saturated FA (SFA). The multivariate analysis distinguished clearly the cheeses made in winter and spring, while those produced in autumn and summer showed some overlapping points. Further investigations should be carried out to evaluate the effects of type and level of feeding integration on the presence of FA more suitable to be used as biomarkers of period and diet.

Chemical Composition of the Secretion from the Anal Sacs of Civettictis civetta (Schreber, 1776)

1983 ◽  
Vol 38 (5-6) ◽  
pp. 497-500 ◽  
Author(s):  
Jürgen Jacob ◽  
Harald Schliemann
Keyword(s):  
Fatty Acids ◽  
Chemical Composition ◽  
Free Fatty Acids ◽  
Functional Significance ◽  
Volatile Components ◽  
Cholesterol Esters ◽  
Anal Sac Secretion ◽  
Anal Sac ◽  
Chain Lengths ◽  
Anal Sacs

The chemical composition of the secretion from the anal sacs of a female of Civettictis civetta is analysed using gas- liquid chromatographical and mass spectrometrical tech­niques. The secretion mainly consists of cholesterol esters, monoester waxes, cholesterol, and free fatty acids of chain lengths not under C12; highly volatile components were not traceable. The functional significance of the anal sac secretion is discussed. `

scholarly journals Effects of lipolytic enzymes Pseudomonas fluorescens on liberation of fatty acids from milk fat

2000 ◽  
Vol 18 (No. 5) ◽  
pp. 175-182 ◽  
Author(s):  
M. Vyletělová ◽  
J. Ficnar ◽  
O. Hanuš
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Pseudomonas Fluorescens ◽  
Milk Fat ◽  
Storage Temperature ◽  
Raw Milk ◽  
Lipolytic Enzymes ◽  
Pasteurized Milk ◽  
Milk Samples

Effects of thermostable lipolytic enzymes Pseudomonas fluorescens 66 ZB in pasteurized milk on concentration of free fatty acids (VMK) in milk were studied in selected milk samples. Identical bulk milk samples were analysed by the method specified in previous papers (Vyletělová et al. 1999a, b, 2000). Reference milk samples (without bacterial strains) and the experimental ones (containing Ps. fl. 150 th. CFU/ml and 2800 th. CFU/ml, resp.) were stored at 6.5°C and 14°C and analysed at regular time intervals (24 h) – Table 1. An extractive-titric method (Kadlec et al. 1996; Table 2 and Fig. 2) was used for monitoring of fatty acid (MK) liberation. Precise analyses of MK and VMK were made by the chromatographic method (Figs. 1, 3 and 4). Medium-chain fatty acids (C12–C16) are liberated first of all; short-chain acids (C6–C10) were found sporadically or in very small quantities (Table 2). Dissociation constant of the specific fatty acid liberated from milk fat affects principally relationships between pH and free fatty acid concentration. The predominating proportion of long-chain acids in liberated fatty acid formation is associated with lower reduction of pH as compared to the predomination of fatty acids with shorter chains associated with more substantial reduction of pH. In our study, a rapid decrease of pH was noted before 168 h (Table 24); this corresponds to low concentrations of short-chain free fatty acids. Vyletělová et al. (2000) found significant relations between pH and contents of VMK (measured by the extractive-titric method); in some samples, correlation coefficients amounted to r = –0.93*** (P £ 0.001). The extractive-titric method analysing VMK concentrations (mmol/kg milk fat) provides results characterized by a systematic rise (e.g., 32.0 mmol/kg instead of 13.0 mmol/kg in raw milk). According to Kratochvíl (1992) 20 mmol VMK/kg milk fat signalized the starting point characterizing flavour degradation of milk caused by activities of fatty acids C12–C14 above all; the transformed value (respecting specifics of the extractive-titric method) amounts to 49 mmol/kg. In case of higher storage temperature a significant break is found after 144 h; in case of lower temperature this break is after 192 h (Table 2). Limits determining potential lipolytic modifications of milk flavour (RLZCHV) as related to specific samples and temperatures at VMK levels amounting to 49 mmol/kg or 20 mmol/kg are outlined in Fig. 2. Milk samples No. 5 and No. 6 stored at higher temperature surpassed this risk limit at 56 h and 64 h, respectively (Table 2, Fig. 2). On the contrary, milk samples stored temperatures corresponding to the standard storage temperature (storage of raw milk, transport, storage of pasteurized milk) surpass the mentioned risk level after 90 h and 140.5 h. Obtained results document the predominant role of storage temperature in the whole complex (production and processing of milk as a raw material or an intermediate product); evident differences in contamination rates (105 an 106) can be characterized as secondary effects in this case (Table 2). As related to practical conditions, the mentioned facts imply immediate processing of raw milk and pasteurized milk. This postulate must be respected namely by dairy plants producing delicate milk products. Vyletělová et al. (2000) found a notable VMK increase/24 h (7–11 mmol/kg milk fat) under specific temperatures and microbial contamination.

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