FATTY ACID CONTENT OF YOGURT PRODUCED FROM THE MILK OF SHEEP REARED IN CENTRAL BALKAN MOUNTAINS

Gercho GERCHEV, Gyurga MIHAYLOVA

Abstract. The study was performed on bulk milk samples obtained monthly during the milking period from the Srednostaroplaninska and Teteven sheep breeds, reared on pasture in the region of Central Balkan mountains. The technological part of yogurt production was carried out at the laboratory. Extraction of fat from the milk samples was done per the Rose-Gottlieb method. The fatty acid content was established on a gas chromatograph with a flame-ionisation detector and a capillary column. Saturated fatty acids in the milk of Srednostaroplaninska and Teteven sheep had a relatively high content during the milking period – 71.793% and 70.698%, respectively, with myristic acid content of 10.778% and 10.873%, respectively. The total amount of polyunsaturated fatty acids in the examined milk was relatively low and with similar concentrations (4.145-4.437%) during the months of the grazing period. Monounsaturated acids were mostly represented by oleic acid (С18:1), and its values in the milk of Srednostaroplaninska and Teteven sheep was, respectively, 23.545% and 25.271%. No significant change in the content of fatty acids could be observed over the course of yogurt production, in comparison with raw sheep milk.

Key words: sheep milk, yogurt, fatty acids

ON THE THERMODYNAMICS OF FATTY ACID OXIDATION

Simon BROWN, David C. SIMCOCK

 Abstract. The energy yield from the combustion of fatty acids and the ATP yield of their oxidation increases with the length of the acyl chain and decreases with unsaturation. Simple expressions describing these relationships are compared with data from the literature, and expressions for the yield of ATP and reducing equivalents are given. From these we derive the corresponding expressions for the oxidation of triacylglycerol. These expressions are used to estimate the energy yields from the oxidation of selected fats and oils of known composition.

Keywords: fatty acids, combustion, oxidation, ATP yield, reducing equivalents.

SAFETY AND QUALITY OF SOME VEGETABLE OILS MARKETED LOCALLY IN THE GOVERNORATE OF AL–HASA, SAUDI ARABIA

Najat A. AL–ABBAD, Amany M. M. BASUNY

Abstract. The aim of this research to identify the pattern of consumption of vegetable oils to families in the Governorate of Al–Hasa, Saudi Arabia, also, examining the safety and quality of some varieties vegetable oil marketed locally, and compare the results obtained from physical and chemical properties of eight oil samples with Saudi Arabia and International standard specification. Data were collected by the survey form was distributed to the housewife and the form included questions about the types of oils most often used in cooking and frying. The results obtained indicated that the oil most commonly used in cooked and frying foods is sunflower oil (Noor brand) (51.20% and 48.00%), respectively. On the other hand, the results of physical and chemical properties showed the significant differences between different kinds of oils. Also, there are significant differences in the values of oxidative stability, which ranged from 7.04 hr. for sunflower oil to 44 hr. for palm oil. Also, found that there were clear differences in the composition of fatty acids of oil samples, where results showed that predominant unsaturated fatty acids are linoleic acid or oleic acid and predominant saturated fatty acids is palmitic in most oil samples. Also, found that the percentage of trans fatty acids had reached 1.17 % and 5.66% in olive oil (Al–Wazeir brand) and oil (Al–Arabi brand), respectively. These percentages more than allowed in the Saudi Arabia and International standard specifications. While, mineral content of oil samples did not exceed the permissible limits according to the specifications.

Key words: oils, fats, fatty acids, oxidative stability, trans fatty acids.

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