Optimization and physicochemical properties of nutritional protein isolate from pork liver with ultrasound‐assisted alkaline extraction

Abstract

The aim of this study was to investigate the optimal conditions of ultrasound-assisted alkaline extraction (UAAE) on pork liver protein isolate (UPLPI) and its physico-chemical properties. Response surface methodology was used to determine the optimal conditions for UAAE, which were at ultrasonic power 265 W, ultrasonic time 42 min, NaOH concentration 0.80%, temperature 50°C, and solvent/raw material ratio 70. The extraction yield and efficiency of UPLPI were significantly improved over the conventional alkaline extraction (PLPI). The results of amino acid composition showed that UAAE could increase serine (36.5 g/kg), arginine (38.1 g/kg), alanine (37.5 g/kg), proline (48.7 g/kg), phenylalanine (55.6 g/kg) and lysine (47.2 g/kg) elution amount. The changes in fourier transform infrared spectra indicated unfolding and destruction of the protein structure in UPLPI. The differential scanning calorimetry analysis presented UPLPI with a slightly lower onset and peak denaturation temperature over PLPI. Surface hydrophobicity increased and the microstructures presented larger and more pores of UPLPI, therefore, it had better in vitro digestibility than PLPI. Therefore, UPLPI might have a potential application prospect in the food field due to its changes on molecular structure as well as on the microstructure of protein by UAAE.

The influence of ultrasound and adenosine 5’-monophosphate marination on tenderness and structure of myofibrillar proteins of beef

“…The spectra of MPs from beef were recorded in the range from 190 to 250 nm using a circular dichroism (CD) spectropolarimeter (Jasco 1500, Jasco Corp., Tokyo, Japan) at 25°C. An optical path of quartz CD cuvette was 1.0 mm [17]. The sample concentrations of MPs were 200 μg/mL for chemical analysis, and the corresponding phosphate buffer solvent (20 mM, pH 7.0) without MPs was used as blank to provide a spectral background.…”

Optimization of Flavourzyme Hydrolysis Condition for the Preparation of Antioxidant Peptides from Duck Meat using Response Surface Methodology

“…RSM is a statistical method widely used in food science and research in recent years to simulate and optimize the response of a system to one or more factors (Zou et al 2017a;Hu et al 2014;Wang et al 2007;Kim et al 2013). In our present study, temperature, pH, and reaction time were selected as independent variables for further optimization of the Flavourzyme hydrolysis conditions because of their obvious effects on antioxidant activity.…”

“…In our present study, temperature, pH, and reaction time were selected as independent variables for further optimization of the Flavourzyme hydrolysis conditions because of their obvious effects on antioxidant activity. DPPH radical scavenging activities evaluated in a 3-level and 3-factor factorial design, which was adopted to optimize the hydrolysis conditions, are shown in The interactions of independent variables and their interactions with antioxidant activity can be observed from 3D response surfaces of multiple nonlinear regression models (Basu and Basu, 2015;Zou et al 2017a). Using the complete model established by Eq.…”

Optimization of goose breast meat tenderness by rapid ultrasound treatment using response surface methodology and artificial neural network

“…Response surface methodology was employed to evaluate the factors that affect the tenderness and this approach enabled the overall number of experiments and possible interaction effects between factors to be considered (Huang, Kuo, Chen, Liu, & Shieh, ; Wang & Shahidi, ; Zou et al., ). A three‐level‐three‐factor Box‐Behnken experimental design (BBD) was performed to optimize the parameters of ultrasound treatment conditions for improving the tenderization of goose breast meat.…”