INFLUENCE OF CITRUS AND CELERY PECTINS ON PHYSICOCHEMICAL AND SENSORY CHARACTERISTICS OF FERMENTED DAIRY PRODUCTS

Abstract

The aim of the current study was to improve the nutritional value, rheological quality and sensory characteristics of yoghurt prepared with high-esterified citrus and celery pectins. Comparative studies of physicochemical characteristics of yoghurt with incorporated pectin isolated from celery (Apium graveolens var. rapaceum D. C.) tubers and commercially available citrus pectin were conducted. The celery pectin extracted by ammonium oxalate was characterized as highly methoxylated (HM) with a degree of esterification (DE) 75 % and anhydrouronic acid content (AUАC) 66 %, respectively. The rate of lactic acid formation, rheological, and sensory characteristics of the resulting yoghurts were also studied. It was found, that the addition of high-esterified celery pectin in the milk in an amount of 0.3 % decreased syneresis of the acid coagulum and led to a slight increase in viscosity. The addition of pectins in the concentration from 0.1 to 0.3 % caused alterations in sensory perception, which was positively evaluated by the panellists. However, the highest scores from sensory evaluation of resulting yoghurts demonstrated these prepared with 0.2 % celery pectin. This study suggested that the highly esterified celery pectin presents an alternative source of soluble dietary fibre for the enrichment of yoghurt and the production of a functional product with potential health effects.

Keywords

• ftir spectra
• high methylated celery pectin
• high methylated citrus pectin
• sensory evaluation
• viscosity
• yoghurt