Ultrasound pretreatment for improving the quality and protein digestibility of stir-frying chicken gizzards

The quality and protein digestibility of chicken gizzards influenced by ultrasound pretreatment and stir-frying time were investigated. The results indicated that with the extension of stir-frying time, the yield, springiness, tenderness and protein digestibility of samples significantly decreased (P < 0.05), while they increased after ultrasound pretreatment. When the stir-frying time was 5 min, the shear force of samples treated with ultrasound decreased by 25.4% and the protein digestibility increased by 65.3% and 34.7% compared with the non-ultrasound. Additionally, the samples stir-fried for 5 min after ultrasound pretreatment (U-5) had the highest overall acceptance score and best flavor. Hierarchical cluster analysis was applied to all the obtained data, which described the main characteristics of stir-frying chicken gizzard samples from different treatment groups. In conclusion, ultrasound pretreatment is an effective method to improve the quality and promote protein digestion of stir-frying chicken gizzards.