THE EFFECT OF AMARANTH SEEDS ON THE CHEMICAL, MICROBIOLOGICAL AND SENSORY QUALITY OF YOGURT

  • GJORE NAKOV
    Technical University of Sofia, College of Sliven, 59 Burgasko Shose Blvd, Sliven, Bulgaria
    gnakov@tu-sofia.bg
  • NASTIA IVANOVA
    Technical University of Sofia, College of Sliven, 59 Burgasko Shose Blvd, Sliven, Bulgaria
  • VIOLETA RAYKOVA
    Technical University of Sofia, College of Sliven, 59 Burgasko Shose Blvd, Sliven, Bulgaria
  • NADYA NINOVA-NIKOLOVA
    LB Bulgaricum PLC, Research & Development Center, 1225 Sofia, Bulgaria
  • BILJANA TRAJKOVSKA
    University “St. Kliment Ohridski”, Faculty of Biotechnical Sciences, Partizanska bb, 7000, Bitola, R.N. Macedonia

Abstract

The objective of this study was to investigate the chemical, microbiological, and sensory characteristics of yogurt enriched with amaranth seeds, stored at a temperature range of 5 ± 1 °C for 21 days. The quantity of amaranth incorporated into the yogurt was 5 % and 10 %. The changes were regularly observed and recorded every 7 days. Statistically significant results (p ≤ 0.05) show that as storage time increases, pH values decrease, and acidity increases. The fat content remains consistent regardless of the amount of amaranth stored. The inclusion of amaranth seeds in yogurt resulted in a statistically significant increase (p ≤ 0.05) in the protein content of the final product. All yogurt samples demonstrate the absence of Enterobacteriaceae, yeast and molds, Coagulase-positive staphylococci, Salmonella spp. and Listeria monocytogenes after 21 days of storage, ensuring product safety. Sensory quality was evaluated based on color, taste, aftertaste, texture, and overall acceptability at 1, 7, 14, and 21 days. The results indicate that the sensory quality of yogurt decreases as the concentration of amaranth seeds increases. Except for the control sample (without amaranth seeds), yogurt with 5 % amaranth seeds exhibited superior sensory quality compared to yogurt with 10 % amaranth seeds.

Cuvinte cheie

amaranth functional food storage quality yogurt