Extraction, Production and Quality Evaluation of Margarine from Oil Extracted from Waste Biomass Peels of Avocado and Virgin Coconut Oil, Using Chitosan from Reared Shells as Preservative

The production and consumption of avocado pears generates tons of wastes, mainly the pear peels which are usually discarded, although they have been reported to contain important phyto-chemicals with biological activities. The adverse health effect associated with the consumption of saturated lipid based foods has ignited research on reformulation of lipid based foods to eliminate Trans Fatty Acids (TFAs). This study was thus aimed at the extraction and characterization of oil from Avocado Peels (APO) and evaluation of the quality of margarine produced from it. Five verities of pear were used for oil extraction by soxhlet method and physiochemical, oxidative, functional and antioxidant characterization was done. Margarines were formulated using a central composite design using oil blends of APO and Virgin Coconut Oil (VCO) with an oil ratio of 10:90, 40:60, 70:30 respectively, varied blending speed, blending time, and chitosan concentration. Samples were characterized and the effect of process parameters on the physiochemical and functional properties of the margarine studied. Optimized conditions were used to produce samples for sensory evaluation. Color, spreadability, aroma, taste and general acceptability was evaluated using ranking difference test. The results showed that the yield, density, and iodine values of APOs oils ranged from 14.91 ± 0.18 to 11.76 ± 0.46;0.93 ± 0.001 to 0.99 ± 0.1;46.63 ± 1.70 to 52.4 ± 0.63, their acid values, TBA and PV values ranged from 1.42 ± 0.39 to 1.97 ± 0.5;0.11 ± 0.002 to 0.18 ± 0.04;and 2.72 ± 0.14 to 4.43 ± 0.36 respectively, with Brogdon avocado peel variety having the overall best properties prepared blends of trans-free APO margarines showed that increase in APO ratio decreased melting point, increased oxidative stability and reduced moisture content of margarine samples. Chitosan addition leads to decrease moisture content and increase functional properties. VCO lead to increase in phenolic and flavonoid content of the margarines. Samples were spreadable and palatable with R20 being most palatable and the most accepted being R26 with a mean score of 7.07 ± 0.70. Decrease in color intensity increased acceptability. This study therefore demonstrated that avocado peel waste biomass can be valorized by using it as raw material for oil extraction, which can serve as good material for the production of trans-free margarines with good oxidative stability, functional and antioxidant properties.

A Comparative Study of the Fatty Acid Composition of Dairy Products and Margarines with Reduced or Substituted Fat Content

The objective of this study was to survey the fatty acid profiles of fat spreads, margarines, shortenings, vegetable fat ice creams, vegetable fat milk-based cream substitutes, vegetable fat cheese substitutes, and reduced-fat cheeses on the Finnish market. The evaluation of the nutritional quality of fat in these products is of significance to dieticians and to the development of fat products with enhanced nutritional value. Remarkable differences between fatty acid profiles of vegetable fat products were found. Vegetable fat ice creams may have a lot of saturated fat and, in addition, the proportion of polyunsaturated fatty acids may be very low. Vegetable fat half creams had, in general, less saturated fat and more polyunsaturated fatty acids than cream. The spreads and shortenings studied contained less than 2% trans fatty acids of total fatty acids. Consumption of reduced-fat cheese in place of full-fat cheese does not negatively affect the nutritional quality of the consumed fat.

Impact of dietary oils and fats on lipid peroxidation in liver and blood of albino rats

Objective:To investigate the effects of different dietary fat and oils(differing in their degree of saturation and unsaturation)on lipid peroxidation in liver and blood of rats.Methods:The study was conducted on SO albino rats that were randomly divided into 5 groups of 10 animals.The groups were fed on dietary butter(Group I),margarine(Croup II),olive oil(Group III),sunflower oil(Group IV)and com oil(Group V)for 7 weeks.After 12 h of diet removal,livers were excised and blood was collected to measure malondialdehyde(MDA)levels in the supernatant of liver homogenate and in blood.Blood superoxide dismutase activity(SOD),glutathione peroxidase activity(GPx),serum vitamin E and total antioxidant capacity(TAC)levels were also measured to determine the effects of fats and oils on lipid peroxidation.Results:The results indicated that no significant differences were observed in SOD activity,vitamin E and TAC levels between the five groups.However,there was significant decrease of GPx activity in groups IV and V when compared with otlier groups.The results indicated that feeding corn oil caused significant increases in liver and blood MDA levels as compared with other oils and fats.There were positive correlations between SOD and GPx,vitamin E and TAC as well as between GPx and TAC(r:0.743;P<0.001)and between blood MDA and liver MDA(r:0.897;P<0.00l).The results showed also negative correlations between blood MDA on one hand and SOD,GPx,vitamin E and TAC on the other hand.Conclusions:The results demonstrated that feeding oils rich in polyunsaturated fatly acids(PUFA)increases lipid peroxidation significantly and may raise the susceptibility of tissues to free radical oxidative damage.