Whey Protein-Pectin Conjugate by Wet-Dry Heating: Optimization using Response Surface Methodology with Box-Behnken Design

The recent progress in glycation of proteins utilizing saccharides through the Maillard reaction has garnered substantial attention, with a specific emphasis on Whey Protein Concentrate (WPC). Conjugation mode is frequently intricate and poses challenges when scaling up for large-scale production. Consequently, this investigation sought to optimize the conditions of the WPC-pectin conjugation process using Response Surface Methodology (RSM) in conjunction with Box-Behnken design (BBD). The experimentation was executed employing a cabinet dryer, incorporating both wet and dry heating procedures to yield a WPC-pectin conjugate exhibiting favorable functional properties. The independent variables investigated encompassed pectin concentration (ranging from 0 to 1%), pH (ranging from 6 to 8), and drying time (ranging from 2 to 6 hours), The measured responses encompassed the emulsion stability index (ESI), emulsifying activity index (EAI), and solubility. Analyzing the experimental data underwent scrutiny for model sufficiency through diagnostic plots, and a second-order polynomial equation was fitted through multi-response regression analysis, resulting in a high coefficient of determination (R 2 ) value. The most effective parameters were identified as a pectin concentration of 0.49%, pH 6.7, and a drying duration of 4.12 hours, yielding a peak ESI of 452.267 minutes, EAI measuring 49.95 m 2 g -1 , and solubility reaching 48.09%. Further experiments were conducted to validate these outcomes, and the presence of the Maillard reaction was confirmed using Fourier Transform Infrared Spectrum (FTIR). The et-dry method demonstrated efficacy in producing WPCpectin conjugates with commendable functional properties

A review on nuclear Overhauser enhancement (NOE) and rotating-frame Overhauser effect (ROE) NMR techniques in food science : basic principles and applications

Background: The characterization of the original chemical structure and induced changes of micro- and macromolecules using analytical techniques with concise and detailed outcomes is potentially one of the major challenges for food scientists. To this end, the non-invasive nuclear magnetic resonance (NMR) technique can play a significant role through employment of different NMR methods. The Nuclear Overhauser effect (NOE) and rotating-frame Overhauser effect (ROE) techniques are powerful NMR methods that have attracted great interest because they provide precise information about the three dimensional spatial structure of the molecules, as well as about possible chemical reactions and interactions. Scope and approach: In this article, we reviewed the basic principles as well as applications of two NMR techniques: Nuclear Overhauser effect spectroscopy (NOESY) and rotating-frame Overhauser effect spectroscopy (ROESY). Hereby, we focused mainly on the applications and importance of these techniques in food science research. Both the structural (configuration and conformation) changes and the complexes formed by interacting compounds could be better studied using these techniques. Key findings and conclusions: The inter- and intra-molecular interactions within food-based ingredient mixtures, as well as configurational and conformational analyses can be more efficiently studied with the aid of NOESY and ROESY. These methods as complementary analysis tools can be exploited for the straightforward elucidation of the spatial proximity of either novel, native or modified compounds. In the future, these techniques may be helpful to better understand the interaction between polymers, such as protein-polysaccharide interactions

Whey protein-polysaccharide conjugates obtained via dry heat treatment to improve the heat stability of whey protein stabilized emulsions

Background: As the demand for "clean label emulsions" and natural emulsifiers is increasing, whey proteins have a big potency to be used as an emulsifier in food emulsions. However, in order to enable their application, whey proteins should withstand high temperature processing. Hence, the limited heat stability of whey proteins is a major drawback: they are highly heat labile and thus prone to heat induced protein denaturation and aggregation. As this phenomenon highly impacts their functionality, it is of utmost importance to increase the heat stability of whey proteins to broaden their application in the food industry, which requires a thorough knowledge of the heat stability properties of whey proteins. Scope and approach: To better understand the heat stabilizing activity of whey protein-polysaccharides conjugates, studies on the heat stability of whey proteins and whey protein stabilized emulsions, as well as approaches to improve their heat stability, especially using the dry heat treatment method are reviewed. Key findings and conclusions: Chemical modification by combining whey proteins and polysaccharides has been reported to successfully improve the heat stability of the obtained conjugates. Hence, this new whey protein-polysaccharide material is promising to be used as a natural emulsifier

Electrostatic-Maillard formation of coconut protein Concentrate-Pectin conjugate for Oil-in-Water Emulsion: Effects of Ratio, Temperature, and pH

Polysaccharide protein conjugate is usually prepared by electrostatic interactions or Maillard reaction. In this study, coconut protein concentrate (CPC)-pectin conjugate was synthesized by a combination between the electrostatic and early stage Maillard reaction. The objective was to evaluate the effect of CPC-pectin ratio, temperature, and pH on emulsion stability index (ESI) and emulsion activity index (EAI). Furthermore, the obtained conjugate was used to stabilize the red palm oil emulsion. The conjugate was prepared by mixing CPC and pectin solution, and dried in a cabinet dryer. Factors, such as CPC-pectin ratio (1:3, 1:2, 1:1, 2:1, 3:1), incubation temperature (50, 60, 70, 80, 90 °C), and pH (3; 3.5; 4; 4.5; 5) were evaluated. The result show that CPC contained 67.40% ± 0.93 protein. ESI and EAI of CPC was not detected. CPC-pectin ratio, temperature, and pH had a significant effect on ESI and EAI, except temperature was not significant effect on EAI. Early stage Maillard reaction was confirmed by FTIR analysis since the peak intensity of amida I increased and amida II decreased. The best CPC-pectin conjugate was found at CPC-pectin ratio of 1:2 (w/w), incubation temperature of 80 °C, and pH of 4. ESI, EAI, droplet size and zeta potential of red palm oil emulsion were 165.263 min; 72.314 m2/g; 553.4 nm and −45.5 mV, respectively. The emulsion droplets were uniform in size and equally dispersed. In summary, drying of conjugate on cabinet dryer induced early stage Maillard reaction and the conjugate can be used to stabilize red palm oil emulsion