PHYSICOCHEMICAL AND EMULSIFYING PROPERTIES MODIFICATIONS OF HIGH-PRESSURED EGG YOLK LOW DENSITY LIPOPROTEIN

MARIE DE LAMBALLERIE; MARIA CECILIA PUPPO; FRANCISCO SPERONI; ROMUALD CHERET; MARC ANTON

Praga Republica Checa

Congreso; 44th European High Pressure Research Group Meeting; 2006

European High Pressure Research Group

PHYSICOCHEMICAL AND EMULSIFYING PROPERTIES MODIFICATIONS OF HIGH-PRESSURED EGG YOLK LOW DENSITY LIPOPROTEIN Marie de Lamballerie1, Maria Cecilia Puppo2, Francisco Speroni2, Romuald Cheret1, Marc Anton3 1ENITIAA, GEPEA, BP 82225, 44322 Nantes Cedex 3, France 1ENITIAA, GEPEA, BP 82225, 44322 Nantes Cedex 3, France 1, Maria Cecilia Puppo2, Francisco Speroni2, Romuald Cheret1, Marc Anton3 1ENITIAA, GEPEA, BP 82225, 44322 Nantes Cedex 3, FranceENITIAA, GEPEA, BP 82225, 44322 Nantes Cedex 3, France 2CIDCA (UNLP CONICET) - 47 - 116, 1900 La Plata, ArgentinaCIDCA (UNLP CONICET) - 47 - 116, 1900 La Plata, Argentina 3INRA-BIA, Interface et Systemes Disperses, BP71627, 44316 Nantes cedex 3, France Egg yolk low density lipoprotein (LDL) are mainly responsible for the emulsifying properties of egg yolk, because of their ability to make up an interfacial film. Moreover LDL are very sensitive to heating, since denaturation and gelation occur from 70 degrees C, and heat denatured LDL do not have any emulsifying properties. Then non thermal stabilization processes are of a great interest to sanitize egg yolk industrial products. To evaluate the effect of high pressure treatment, LDL dispersions were pressured at 200, 400 or 600 MPa, at pH 3.0 and 8.0. Solubility, aggregation, and emulsifying properties (oil droplet size and flocculation) were then analysed. Results put in evidence that high pressure treatment did not modify physicochemical and emulsifying properties at pH 3.0, but that at pH 8.0 LDL were denatured and aggregated without losing their ability to adsorb at the interface between oil and aqueous dispersion, and with a decrease of oil droplets flocculation. Then high pressure treatments do not modify emulsifying properties of egg yolk low density lipoprotein at acidic pH, and lead to an improvement of emulsions stability at alkaline pH. As a result high pressure treatment could be considered to stabilize industrial egg yolk products. Egg yolk low density lipoprotein (LDL) are mainly responsible for the emulsifying properties of egg yolk, because of their ability to make up an interfacial film. Moreover LDL are very sensitive to heating, since denaturation and gelation occur from 70 degrees C, and heat denatured LDL do not have any emulsifying properties. Then non thermal stabilization processes are of a great interest to sanitize egg yolk industrial products. To evaluate the effect of high pressure treatment, LDL dispersions were pressured at 200, 400 or 600 MPa, at pH 3.0 and 8.0. Solubility, aggregation, and emulsifying properties (oil droplet size and flocculation) were then analysed. Results put in evidence that high pressure treatment did not modify physicochemical and emulsifying properties at pH 3.0, but that at pH 8.0 LDL were denatured and aggregated without losing their ability to adsorb at the interface between oil and aqueous dispersion, and with a decrease of oil droplets flocculation. Then high pressure treatments do not modify emulsifying properties of egg yolk low density lipoprotein at acidic pH, and lead to an improvement of emulsions stability at alkaline pH. As a result high pressure treatment could be considered to stabilize industrial egg yolk products. INRA-BIA, Interface et Systemes Disperses, BP71627, 44316 Nantes cedex 3, France Egg yolk low density lipoprotein (LDL) are mainly responsible for the emulsifying properties of egg yolk, because of their ability to make up an interfacial film. Moreover LDL are very sensitive to heating, since denaturation and gelation occur from 70 degrees C, and heat denatured LDL do not have any emulsifying properties. Then non thermal stabilization processes are of a great interest to sanitize egg yolk industrial products. To evaluate the effect of high pressure treatment, LDL dispersions were pressured at 200, 400 or 600 MPa, at pH 3.0 and 8.0. Solubility, aggregation, and emulsifying properties (oil droplet size and flocculation) were then analysed. Results put in evidence that high pressure treatment did not modify physicochemical and emulsifying properties at pH 3.0, but that at pH 8.0 LDL were denatured and aggregated without losing their ability to adsorb at the interface between oil and aqueous dispersion, and with a decrease of oil droplets flocculation. Then high pressure treatments do not modify emulsifying properties of egg yolk low density lipoprotein at acidic pH, and lead to an improvement of emulsions stability at alkaline pH. As a result high pressure treatment could be considered to stabilize industrial egg yolk products. Email of the presenting author: anton@enitiaa-nantes.fr