adinehpour F, Jafari S M, Sadeghi A, Khomeiri M, khalili S. Microencapsulation of Streptococcus thermophilus and Lactobacillus bulgaricus bacteria on the physicochemical and sensory properties of yogurt. FSCT 2025; 21 (156) :137-149
URL:
http://fsct.modares.ac.ir/article-7-74769-en.html
1- gorgan university , fateme.adinepoor@gmail.com
2- gorgan university
3- Noshirvani university
Abstract: (207 Views)
The aim of the current research was microencapsulation of Streptococcus thermophilus and Lactobacillus bulgaricus bacteria by coacervation complex method and sodium caseinate and pectin coatings. Sodium caseinate and pectin have electrostatic attraction together at pH=4 and form a complex. Using a scanning electron microscope, the morphology of coacervates was investigated. The properties of pectin and sodium caseinate complexes were investigated by infrared spectrometry tests and measuring the size and distribution of particles. Physicochemical characteristics such as water absorption, pH and acidity and sensory characteristics were also investigated. The results showed that the efficiency of microencapsulation of bacteria by coacervation method was 66.6%. The particle size was 1.565 micrometers and the zeta potential was reported as -16 mV. Electron microscope images showed spherical coacervate without holes and wrinkles on the surface. The results of infrared spectroscopy also showed the creation of electrostatic interactions between pectin and sodium caseinate. Also, microencapsulation of bacteria caused a significant change (p>0.05) in pH (4.6 ± 0.091) and yogurt acidity (1.1 ± 0.03) compared to pH (4.6 ± 0.1). And the acidity of yogurt (0.8±0.01) produced with free bacteria did not. The water content of yogurts produced with microencapsulated bacteria (40±1.1) was reduced compared to yogurts produced with free bacteria (45±0.9) (p<0.05). Bacterial encapsulation has a negative effect on color sensory characteristics. It did not have the smell and taste of the produced yogurts (p>0/05), but a significant difference was observed in the texture of the yogurts produced with microencapsulated bacteria compared to the yogurts produced with free bacteria (p<0/05).
Article Type:
Original Research |
Subject:
Food Microbiology Received: 2024/04/21 | Accepted: 2024/07/3 | Published: 2025/01/20