The effect of ultrasound for 15 and 30 min (40 kHz, 130 W, 10% salt solution, 25°C) on dehydration kinetics and physicochemical, microbiological, structural and rehydration characteristics of tilapia cubes dehydrated at 35°C was evaluated. The ultrasound treatments decreased dehydration time in the range of 8.7–19.2%, in comparison with the control treatments (15 and 30 min, 10% salt solution, 25°C). Of the Wang and Singh, Lewis, Modified Page and Page models, the last one was the one that better described the dehydration kinetics. The ultrasound significantly (p < .05) increased the ash content and significantly (p < .05) decreased the a_w of the dehydrated tilapia cubes but did not have an effect on the microbiological characteristics. In addition, the tilapia cubes treated with ultrasound presented porous structures with large and irregular cavities, which increased the amount of moisture absorbed in the rehydration, in comparison with the control treatments.

The present study evaluates garlic powder (GP) effects on growth performance, feed utilization, gill parasitic treatment, and monogenean diversity. Thus, a trial was performed under controlled conditions with 84 juvenile Nile tilapia, Oreochromis niloticus (39.8 ± 8.8 g initial weight), from culture ponds with monogenean parasite presence for 30 days. Four balanced diets in protein (32.5%) and lipids (6.4%) with GP inclusion levels of 0%, 1%, 2%, and 3% were formulated, manufactured, and supplied daily at approximately 6.5% body weight/tank. The GP diets, compared to the Control (without GP), indicated that the three inclusion levels did not affect the water quality, survival, growth performance, and feed utilization parameters (p > 0.05). No differences were observed in the parasitological index of prevalence (20–25%), mean intensity (9.6–28), and mean abundance (2.7–5.3) among the experimental diets (p > 0.05), evidencing no effect by inclusion level. Efficacy among GP diets indicated a potential decrease in parasite number (13.4–45.6%) but not all monogenean gill parasites. In conclusion, GP diets did not affect the Nile tilapia survival, growth performance, and feed utilization parameters; therefore, its use is suggested as a preventive alternative for monogenean gill parasites.

Revisión del aceite de orégano spp. en salud y producción animal