PhD student Oils and Fats Laboratory - University of Campinas Campinas, Sao Paulo, Brazil
The elimination of the use of partially hydrogenated fat has instigated increase in the content of saturated fatty acids (SFA) in foods. This study aimed to develop and characterize emulsions with organogels (emulgels) for application in margarines of low and high lipid content. Emulgels were developed in the proportions 65:35 and 40:60 water:oil (w/w), with soybean-oil structured with candelilla wax, fully hydrogenated palm oil and monoacyglycerols, using a central composite rotatable design (CCRD). The optimal points obtained by CCRD were evaluated during three months stored at 5 ºC: thermal stability, particle size by nuclear magnetic resonance, texture properties, peroxide index and fatty acid composition. The emugels developed showed thermal stability to 35°C/48h. Emulgels with low and high lipid content presented similar particle size, approximately 5.3 μm and 5.5 μm, respectively. Values were close to the commercial margarines (d3.3 < 4.3 μm), indicating ideal particle size for application in both margarines. In order for a product not to be considered as oxidized, its peroxide index must be less than 10 meq O2/kg. After 3 months, the evaluated systems were characterized: 2.69±0.57 meq O2/kg in emulgels 40:60 and 1.08±0.22 meq O2/kg in 65:35. Emulgels 60:40 showed higher hardness and lower spreadability. Therefore, structurants act differently in systems with different water content. However, both showed lower values than commercial margarines, since the emulgels have less SFA content (<13%) affecting the texture properties. In conclusion, the use of emulgels was satisfactory in the preparation of stable, zero trans and reduced in saturated fat margarines.