Week 14-Sunflower Oil PDF

SUNFLOWER OIL 1 A- INTRODUCTION  Two basic types of sunflower: (1)oilseed type: oilseed types bore small black seeds with a thin hull (representing 20–25% of total seed weight) with a 40% oil content. (2)nonoil type: larger seeds with a thicker black-and- white-striped hull. Supplying the bird me...

SUNFLOWER OIL 1 A- INTRODUCTION  Two basic types of sunflower: (1)oilseed type: oilseed types bore small black seeds with a thin hull (representing 20–25% of total seed weight) with a 40% oil content. (2)nonoil type: larger seeds with a thicker black-and- white-striped hull. Supplying the bird meal and confectionary markets. These seeds contain 30% of oil.  The size of oil-type seeds varies according to cultivar and according to the seed’s position in the head, those on the periphery being larger. Besides affecting the oil content (internal seeds contain less oil than those in intermediate or external zones), the position of seeds in the head in fluences the fatty acid composition (the content of linoleic and palmitic acids increases, and the content of oleic acid decreases from the perimeter 2  Hull composition Kernel composition 3  Harvesting time affect the oil composition (linoleic acid content increases from the fourteenth day after flowering while the oleic acid content decreases).  Temperature and light, affect the oil composition of sunflower seeds (linoleic acid increased proportionally with increasing temperature difference, the oleic acid content is lower (average: 19.4%) and that the linoleic acid content is higher (average: 68.4%) for seeds sown in August (lowest mean temperature from flowering to maturity,  An 18°C). increase in temperature resulted in a decrease in the linoleic acid content and an increase in the oleic acid content. The linoleic acid content ranged from 48.7% in seeds grown in warmer weather in the south of Spain to 70.2% for colder weather plantations. An increase in temperature also leads to a slight decrease in the stearic acid content (suggestions: 4 stearic  oleic). B- CHEMICAL AND PHYSICAL PROPERTIES OF REGULAR SUNFLOWER OIL 1) Composition of Regular Sunflower Oil a) Sunflower Fatty AcidsMajor fatty acids of sunflower oil  High concentration of linoleic acid, followed by oleic acid.  Palmitic acid and stearic  SFA of acid < 15% regular sunflower oil < cottonseed (maximum 32%) < peanut (maximum 28%)< corn (maximum 22%) < soybean (maximum 20%) oils  SFA of regular sunflower oil > safflower (maximum 12%) and rapeseed (maximum 12%) oils.  LnA of regular sunflower oil is fairly low (always lower than 0.3%), giving the oil a good oxidative stability. 5 b) Triacylglycerol composition  This TAG distribution is responsible for the low solidification point of regular sunflower oil (16°C to 19°C), allowing, for example, storage of mayonnaise manufactured with regular sunflower oil in a refrigerator without 6 breakage of the emulsion (unlike the case of other oils such as peanut oil). c) Nonacylglycerol components of regular sunflower oil Phospholipids. The content of crude sunflower oil ranges between 0.5% and 1.2%.  Oils extracted by solvent generally have a higher content of phosphlipids than those obtained by pressing.  Most phospholipids are hydratable and may be removed from the crude oil through a water-degumming process Tocopherols. Vitamine E activity, antioxidant effect as free radical scavenger, Levels of Tocopherols and Tocotrienols in Crude Regular Sunflower Oil (ppm), 7  Maximum values of major tocopherols (ppm) of crude sunflower, peanut, soybean, corn, and cottonseed oils, according to the Codex Alimentarius 8  Levels of desmethylsterols in crude Sterols. regular sunflower oil, as a percentage of total sterols and total sterol content (ppm)  Regular sunflower oil is characterized by a medium sterol content.  The main component is β- sitosterol, followed by -7-stigmasterol. The latter may be used as a tracer for detection of adulterations in sunflower oil, as most vegetable oils (except safflower oil) have fairly low amounts 9 of -7-stigmasterol (