Food emulsions with amidated pectin from celery (Apium graveolens var. rapaceum D.C.) tubers

Iv. Petrova1, N. Petkova2*, M. Ognyanov3, Ap. Simitchiev4, M. Todorova2, P. Denev2

1Department of Catering and Tourism, Faculty of Economic, University of Food Technologies, 4002 Plovdiv, Bulgaria
2Department of Organic Chemistry and Inorganic Chemistry, Technological Faculty, University of Food Technologies, 4002 Plovdiv, Bulgaria 3Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Laboratory of Biologically Active Substances, 4000 Plovdiv, Bulgaria
4Department of Machinery for Food Industry, Technical Faculty, University of Food Technologies, 4002 Plovdiv, Bulgaria

(Manuscript received 29 May 2017; accepted for publication 22 August 2017)

Abstract. Hydrocolloids, especially polysaccharides from traditional plant sources and their derivatives possessed significant emulsifying properties. Pectin was isolated from celery tubers by accelerated “green” method for extraction based on ultrasonic irradiation. Further chemical modification of celery pectin was performed with 4 mol/L NH3. The amidated celery pectin was obtained with the following characteristics: the degree of esterification (DE) 31%, the degree of amidation (DA) 16%, degree of acetylation (DAc) 2% and anhydrouronic acid content (AUAC) 68%. This modified pectin was incorporated in preparation of model30,40and50%oil-in-wateremulsions.Theeffectofamidationofcelerypectinonthestabilityofemulsionswasinvestigated. Theresultsshowedthat amidation increased the emulsifying properties of pectic polysaccharides. It affected also the rheological characteristics of model emulsion. The current study demonstrated preparation of emulsion with low-caloric amidated pectin as proper alternative to the traditional emulsifiers.

Investigation the influence of dietary fiber on the rheological properties of alginate beads

Z. Manev1*, N. Petkova2, P. Denev2, D. Ludneva1, S. Zhelyazkov1

1Food Research and Development Institute, 154 Vasil Aprilov, 4003 Plovdiv, Bulgaria
2Department of Organic Chemistry, Technological Faculty, University of Food Technologies, 26 Maritza, 4002 Plovdiv, Bulgaria

Abstract. During the current investigation experiments for the preparation of alginate beads with aqueous solutions of sodium alginate, calcium lactate or calcium dichloride and dietary fiber in different concentrations: inulin with varying degrees of polymerization, wheat bran and amidated apple pectin were carried out. The sodium alginate solutions were at constant concentration 3%, while calcium salts in 7% were applied for bead formation. It was proven that the rupture force of alginate beads was always higher than the pure model system regardless of the chemical structure of dietary fibers used. In the result of the carried research the dependence at a certain concentration was established at which the rupture force and deformation of the beads increased gradually.

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