scholarly journals Utjecaj tehnološkog postupka i skladištenja na profil masnih kiselina u mliječnim proizvodima

Author(s):  
Lina Laučienė ◽  
Loreta Šernienė ◽  
Laima Urbšienė ◽  
Artūras Kašauskas ◽  
Ingrida Sinkevičienė ◽  
...  

In the present study fatty acid (FA) composition in four main groups of dairy products was determined to investigate their development during processing and storage. Fresh cheese, sour cream, butter, and ultra-high temperature (UHT) milk representing differences in technological approach were chosen for the study. Fatty acids methyl esters (FAME) were quantified using a gas chromatograph (GC) equipped with a mass spectrometer (MS) and a capillary column SP-2560. The concentrations and profile of FA in final products were primarily dependent on the FA content of raw milk for UHT milk and fresh cheese production or in the raw cream for sour cream and butter. The shelf life had a significant impact (P<0.05) only in UHT milk and butter, whereby unsaturated fatty acids (UFA) and polyunsaturated fatty acids (PUFA) decreased significantly in UHT milk, while PUFA decreased significantly in butter.

2009 ◽  
Vol 66 (4) ◽  
pp. 481-485 ◽  
Author(s):  
Bruna Marcatti ◽  
Ana Mônica Quinta Barbosa Habitante ◽  
Paulo José do Amaral Sobral ◽  
Carmen Sílvia Favaro-Trindade

Effective incorporation of a probiotic into foods requires the culture to remain viable all along processing and storage, without adverse alterations to sensory characteristics. The objective of this work was developing Minas-type fresh cheese with probiotic properties from buffalo milk. Four batches of Minas-type fresh cheese were prepared using buffalo milk: batch T1 in which neither culture nor lactic acid added; batch T3 in which only lactic acid added; batches T2 and T4 , both added of Lactobacillus acidophilus LAC 4, but T4 was also acidified. Resulting cheeses were evaluated for probiotic culture stability, texture profile, sensory acceptance, and changes in pH. The T4 probiotic cheese presented hardness, gumminess, and chewiness significantly lower than the other treatments. However, values for springiness and cohesiveness did not differ between all cheeses, and no sensory differences (p > 0.05) were found between treatments for texture, taste, and overall acceptance. The addition of probiotic to the acidified cheese (T4) yielded best aroma. The populations of L. acidophilus were greater than 10(6) CFU g-1 after 28 days of storage all products. Minas-type fresh cheese from buffalo milk is a suitable food for the delivery of L. acidophilus, since the culture remained viable during the shelf life of the products and did not negative affect analysed parameters.


2021 ◽  
Vol 51 (2) ◽  
pp. 262-270
Author(s):  
I.M. Boldea ◽  
C. Dragomir ◽  
M.A. Gras ◽  
M. Ropotă

The objective of this research was to assess the effects of including oil-rich feedstuffs in diets for lactating goats on the fatty acid (FA) profile of their milk. Thirty-six Murciano-Granadina goats were randomly assigned to three treatment groups, namely a control diet (CTRL), a diet based on whole rapeseed (RS), and a diet based on pumpkin seed cake (PSC). The diets were composed of 1 kg hay (70 % Italian ryegrass, 30% alfalfa) and 1.24 kg concentrate, and were formulated to be isoenergetic and isonitrogenous. Milk yield and its contents of protein, fat and lactose did not differ significantly among the groups. However, including oil-rich feeds in the diet altered the fatty acid profile of the milk significantly, decreasing its saturated fatty acid (SFA) content and increasing its content of unsaturated fatty acids (UFAs). Effects on polyunsaturated fatty acids (PUFAs), conjugated linoleic acid (CLA), and the n-6 to n-3 ratio depended on the source of dietary lipids. The PSC augmented diet increased the relative amount of PUFAs and fatty acid methyl esters (FAME) in milk (+25 %) significantly In comparison with CTRL, whereas the RS diet produced a limited and statistically insignificant increase (+7.5%). The concentration of CLA was higher in milk from does fed the PSC diet, whereas the n-6 to n-3 ratio was lower in milk from does fed RS. These preliminary results form the basis for developing premium dairy products that are enriched in fatty acids that are more favourable for human health.


Separations ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 118
Author(s):  
Meiqing Chen ◽  
Yangdong Zhang ◽  
Fengen Wang ◽  
Nan Zheng ◽  
Jiaqi Wang

The determination of C18 fatty acids (FAs) is a key and difficult aspect in FA profiling, and a qualified method with good chromatographic separation and high sensitivity, as well as easy methylation, is required. A GC-MS method was established to simultaneously determine C18 FAs in milk. To simplify the methylation protocol for milk samples, besides a base-catalyzation methylation (50 °C for 20 min), the necessity of an additional acid-catalyzation was also studied using different temperatures (60 °C, 70 °C, 80 °C, and 90 °C) and durations (90 min and 150 min). The results showed that the chromatographic resolution was improved, although three co-eluted peaks existed. The base-catalyzation was sufficient, and an additional acid-catalyzation was not necessary. The proposed method was validated with good sensitivity, linearity, accuracy, and precision, and then applied in determining C18 FAs in 20 raw milk and 30 commercial milk samples. UHT milk presented a different profile of C18 FAs from raw milk and PAS milk samples, which indicated that excessive heating could change the profile. Overall, the proposed method is a high-throughput and competent approach for the determination of C18 FAs in milk, and which presents an improvement in chromatographic resolution and sensitivity, as well as a simplification of methylation.


2016 ◽  
Vol 8 (6) ◽  
pp. 149 ◽  
Author(s):  
Cunfang Wang ◽  
Xinman Lou ◽  
Jianmin Wang

<p>In this study, the fatty acid profile and fat stability for seven consecutive days of raw milk and pasteurized milk from Laoshan goats have been evaluated by gas chromatography-mass spectrometry (GC-MS) after fatty acid methyl ester. The results showed that the concentrations of short chain fatty acids (SCFA) and saturated fatty acids (SFA) significantly increased by 47.36% and 11.68% after pasteurization respectively, while the concentrations of unsaturated fatty acids (UFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) decreased by 26.08%, 26.45% and 22.15% respectively. The C10:0 (5.39%-8.57%), C12:0 (3.13%-5.28%), C14:0 (8.12%-11.87%), C16:0 (25.59%-28.53%), C18:0 (14.60-13.69%) and C18:1 (33.91-24.92%) are the most predominant fatty acids of Laoshan goat milk with significant differences. Moreover, the fat stabillity for seven consecutive days of raw milk and pasteurized milk was detected by sedimentation rate (R). The fat stability in pasteurized milk was more stable than that in raw milk, the sedimentation rate of raw milk and pasteurized milk consisted in a progressive decrease in the seven days by 82.99% and 79.77% respectively. What’s more, significant difference was observed from 1st day to 4th day between raw milk and pasteurized milk, however, there was no significance from 5th to 7th. This is the first report to fully characterize the fatty acid contents and fat stability of Laoshan goat raw milk and its pasteurized milk and it provided a certain theoretical basis for the research and development of goat milk functional product.</p>


1971 ◽  
Vol 54 (6) ◽  
pp. 1288-1292
Author(s):  
Anita Huang ◽  
David Firestone

Abstract A study was made to compare the rapid method reported by Allen with the tentative method of the American Oil Chemists’ Society for the determination of isolated (unconjugated) trans isomers of unsaturated fatty acids. The rapid method was found to be less accurate. The accuracy of the rapid method can be improved by using an oil or methyl ester matrix with the same composition as the sample matrix for the determination of K-and f-values used for calculation of per cent trans isomers. Results obtained with both methods for methyl esters were more accurate than results for vegetable oils. An analysis of variance was performed to compare the methods.


2020 ◽  
Vol 10 (11) ◽  
pp. 4020
Author(s):  
Magdalena Michalak ◽  
Katarzyna Skrzypczak ◽  
Maciej Nastaj ◽  
Konrad Terpiłowski ◽  
Tomasz Skrzypek ◽  
...  

This paper reports the potential use of fermented curly kale juice in Feta-type cheese production. The rheological study and Turbiscan assay demonstrated that fermented curly kale juice coupled with rennet accelerated curd formation resulted in a stronger curd compared to the sample containing rennet alone. Laboratory-scale cheese was manufactured from cow’s milk with the use of fermented curly kale juice. Several parameters that affect the quality of cheese were investigated, including physicochemical, textural and microstructure characteristics. The content of amino acids and fatty acids was determined, surface properties were assessed and microbial enumeration of the experimental cheese was carried out before and after ripening. The values of pH and the content of lactose and protein significantly decreased as a result of maturation. In turn, an increase in LAB growth as well as saturated and unsaturated fatty acids was observed. The use of the fermented curly kale juice improved the textural characteristics and changed the microstructure of the obtained cheese. Finally, the ripening process enhanced the amino acid profile of the Feta-type cheese. These findings indicate that the fermented curly kale juice can be used for manufacture of cheese with improved characteristics and functional properties.


1963 ◽  
Vol 41 (1) ◽  
pp. 605-612 ◽  
Author(s):  
Joyce L. Beare ◽  
J. A. Campbell ◽  
C. G. Youngs ◽  
B. M. Craig

The effects of increasing the saturated fatty acids in a dietary vegetable oil composed mostly of unsaturated fatty acids were studied in rats. A mixture of palm oil and Swedish rapeseed oil fed for 4 weeks as 20% of a purified diet promoted weight gains which exceeded those obtained with Polish rapeseed oil of a similar content of erucic acid, and altered the proportion of saturated fatty acids in the tissues to reflect that of the diet. When methyl esters of saturated fatty acids were added to Swedish rapeseed oil, similar effects on weight gain were not observed, but methyl esters of fatty acids from corn oil and rapeseed oil were shown to be of less nutritional value than the original glycerides. From fatty acids of olive oil, glycerides containing 3% palmitic acid were prepared, and produced weight gains which did not differ significantly from those of rats fed Polish rapeseed oil with a similar content of palmitic acid and 20% erucic acid. The characteristic effects of rapeseed oil are, therefore, attributed to its low content of saturated fatty acids as well as its high content of erucic acid.


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