Encapsulation of Antibiotic Alternatives for Pathogen Control in Poultry Intestinal Tract
The misuse of antibiotics has led to antibiotic resistance which threatens public health. Antibiotic alternatives are thought to replace antibiotics for a healthier production of meat animals. Both essential oils and polyphenols are significantly mentioned due to their antibacterial effect against pathogens. The combination of the two compounds may exhibit a synergistic effect on growth inhibition of pathogenic bacteria in animals. However, these compounds have strong unpleasant smell and taste. Encapsulation is applied to mask the taste of these compounds and ensure the controlled release of core materials in the intestinal tract. This research focuses on encapsulating essential oils (EO), carvacrol and thymol, and polyphenols (PP) extracted from grape pomace, evaluating their synergistic antimicrobial effect, and determining encapsulation efficiency and releasing profile using in vitro methods. Ratios between essential oils and polyphenols were optimized (unencapsulated) based on minimum inhibition concentration (MIC) of pathogenic bacteria found in poultry intestinal tract; E.coli, Salmonella typhimurium, Enterococcus cloacae, as well as a probiotic bacterium, Lactobacillus Plantarum. Best ratios were encapsulated by spray drying (SD) and freeze drying (FD). Encapsulation efficiency was analyzed by determining free EO and PP at the particle surface. Encapsulates were digested in vitro to determine releasing profile. MIC was determined spectrophotometrically using 96 well plates on a plate reader. The optimized ratio between EO and PP was determined at 1:1 which gave MIC on pathogenic bacteria at 125 -250ppm while promoting the growth of the probiotic, 62.5ppm. FD yielded 88.3% with encapsulation efficiency (EE) of 88.9%. SD yielded 72.5% with EE of 83.9%. FD released 0.026 – 0.204mg/ml Gallic acid equivalent (GAE) compared to SD released 0.024 – 0.198mg/ml from 0 to 5 h, which indicated that FD may provide better protection of the core compounds in poultry intestinal tract.
Cosmas Mwendwa Muasya,
"Encapsulation of Antibiotic Alternatives for Pathogen Control in Poultry Intestinal Tract"
ETD Collection for Tennessee State University.