Effects of ultrasound-assisted alkaline extraction on the physiochemical and functional characteristics of chicken liver protein isolate

Abstract

This research investigated the physiochemical and functional characteristics of chicken liver protein isolate, which was extracted by alkali (CLPI) and ultrasound-assisted alkali (UCLPI), respectively. Protein yield of UCLPI was increased by 55.4% over that of CLPI (P < 0.05). Several amino acids were significantly higher and methionine was lower in UCLPI (P < 0.05). Ultrasound treatment reduced the particle size and prolonged the stability of the protein isolate during 7 d storage. Lower pH and a higher amount of total solubilized proteins (68.5%) were found in UCLPI by comparison with CLPI (61.8%). Surface hydrophobicity increased greatly by 63.0% compared with CLPI, but the total/reactive sulfhydryl groups and the primary structure molecular weight profile between them were not significantly different (P > 0.05). However, the enthalpy of denaturation in UCLPI decreased by 41.7%, which was related to the changes in its second structure. This resulted in better water/oil holding capacity and emulsifying properties for UCLPI. The changed physiochemical characteristics and improved functional properties of UCLPI demonstrated the potential utilization of ultrasound-assisted alkaline extraction in the food industries.

Effect of ultrasound power on extraction kinetic model, and physicochemical and structural characteristics of collagen from chicken lung

“…The lungs were then cut into slices (~1.0 × 0.5 cm), stirred in a high-speed mixer until they were well homogenized. The mixture was then kept at − 20°C according to the method described previously by Zou et al (2017). Pepsin (4000 U mg − 1 , dry matter), the standard L -hydroxyproline ( L -(OH)C 4 H 7 N(COOH)), and dimethylaminobenzaldehyde ((CH 3 ) 2 NC 6 H 4 CHO) were bought from Sigma-Aldrich (St. Louis, MO, USA).…”

Comparison on the emulsion properties of normal colour and discolouration fresh chicken liver

“…Other factors except for protein denaturation, the pH of raw chicken livers also effects cooking loss. Xiong et al (2017) reported that DCCLs' pH (6.18) is close to the isoelectric point for the majority of muscle proteins, causing the protein solubility decrease (Zou et al 2017). The pH plays a positive role in gel information, and indirectly effects the water retention ability of chicken livers (Ramirezsuarez and Xiong 2003;Omura et al 2020).…”

Effect of ultrasound‐assisted extraction on the structure and emulsifying properties of peanut protein isolate

“…Ultrasound has been used widely in the food industry because of its simple manipulation, speed, and environment‐friendly nature. Ultrasound can be used to improve extraction efficiency by the rapid formation and collapse of cavitation bubbles, which induce high cavitation and mechanical effects, causing plant cell walls to rupture and accelerating the release of intracellular substances into the solvent 8,9 . Furthermore, the cavitation and mechanical effects can damage the non‐covalent interactions between protein particles, break peptide bonds, and change the molecular weight and particle size of proteins 10 .…”