Study On The Application Of Trans-free Special Oil

The deleterious health implications of trans fatty acids (TFA) has become a consensus all over the world, governments across the globe are passing comlulsory legislation to limit the use of trans fats. Researchers are trying to do all they can to reduce the content of trans fatty acids in hydrogenated oils or develop healthy substitutes now. Phytosterols and phytosterols esters can alternative part of TFA and saturate fatty acid (SFA) form the skeleton for oil structuring. The aim of this research was to study the application of healthy margarine which use trans-free fats and phytosterols as raw materials in bread baking.Gas chromatography was used to determination the content of trans-and saturated fatty acids in various oils. The results showed that the content of trans-and saturated fatty acids in three commercial butter were more than 2% and 70%, respectively. Palm oil and corn oil contain no trans fatty acids, saturate fatty acids content were 53% and 14%, respectively. so their mixture could be used as zero-trans margarine-based oil.The orthogonal trial with mixed levels was used as experiment design, the texture characteristics of healthy margarine was determined according to the TPA texture analysis.Results showed that the contents of phytosterols and saturated fatty acid of raw oil material have great impact on the margarine textural properties. The elasticity modulus of dough, the elasticity and viscosity of bread were stronger, and the viscous modulus of dough, the hardness and chewiness of bread were weaker when special oil and commercial butters were added.Several different emulsifiers were added in the margarine made in laboratory. Rheology measurements and TPA texture analysis indicated that emulsifier greatly improved the rheological properties of dough and the texture characteristics of bread during the storage period. Along with the increase additive amount of lecithin, monoglycerides and sucrose ester, the specific volume, elasticity and cohesiveness of bread significantly increased. In addition, the viscous modulus, hardness and chewiness of dough significantly reduced, but the extent were not clear when the additive amount above 0.35%(In flour weight, the same below). When added the same dosage,SSL improved the rheological characteristics of the dough, specific volume and texture characteristics of bread most significantly. The optimal dosage was 0.35%.Using nuclear magnetic resonance (NMR) analyses the effect of margarine with different emulsifiers on water-holding capacity of bread during storage. T21 proton density significantly increased and changed slowly during storage when added ecithin, monoglycerides and sucrose ester. With increasing additive amount of emulsifier, T21 proton density showed a increase trend until the additive amount arrived 0.35%--when the increase amplitude of T21 proton density is limited; the sucrose ester showed best effect on water-holding capacity of bread; The optimal dosage of SSL was 0.35%...