Study of the Stability at Coalescence in Mucilage Emulsions

C. QUINZIO; M. CORVALÁN; B.A. LÓPEZ DE MISHIMA; L. ITURRIAGA

Joas Pessoa

Congreso; V International Cactus Pear Congress; 2007

International Society for Horticultural Science

AbstractMucilage is a mucopolysaccharide found in cacti cladodes (Opuntia ficusindica(L.) Mill) and the same as hydrocolloids modify food functional properties.Presence of a low molecular weight protein fraction has been reported. It is knownthat polysaccharides such as the xanthan (XG) and guar gums (GG) are used in theformulation of emulsions. Since the latter has a 1-2% protein content that conveys itthose amphyfilic characteristics needed for the stabilising activity, the Opuntia spp.mucilage might be used as an emulsifying agent. Thus, this work was aimed atevaluating stability at coalescence in emulsions prepared using mucilage andcomparing them against that of commercial hydrocolloids emulsions. Isoviscoussolutions of freeze-dried mucilage (FM), GG, XG, and carboxy methyl cellulose(CMC) were prepared. In turn, 1:5 emulsions (v:v; oil: solution) were prepared usingthe NATURA® commercial oil and a polysaccharide solution, and homogenised witha blender for 4 min. Emulsion stability (ES) at coalescence was evaluated bycentrifugation at 10.000 rpm for 10 min and registering the lipid phase retained. Inaddition the native mucilage-based emulsion stability was evaluated and apparentviscosities were determined using the TA Instruments AR 1000 rotational rheometer.The results showed that both XG and FM were the best stabilizing agents with 100%ES. The CMC displayed a 12% ES, while the GG and native mucilage (2%) at 89-90% one. They all indicate that the mucilage has stabilizing properties similar to thoseof the hydrocolloids under study.