Interactions of β-Conglycinin (7S) with Different Phenolic Acids—Impact on Structural Characteristics and Proteolytic Degradation of Proteins

Abstract

p-Coumalic acid (PCA), caffeic acid (CA), gallic acid (GA) and chlorogenic acid (CGA) are the major phenolic acids that co-exist with soy protein components in foodstuffs. Surprisingly, there are only a handful of reports that describe their interaction with β-Conglycinin (7S), a major soy protein. In this report, we investigated the interaction between phenolic acids and soy protein 7S and observed an interaction between each of these phenolic acids and soy protein 7S, which was carried out by binding. Further analysis revealed that the binding activity of the phenolic acids was structure dependent. Here, the binding affinity of CA and GA towards 7S was found to be stronger than that of PCA, because CA and GA have one more hydroxyl group. Interestingly, the binding of phenolic acids with soy protein 7S did not affect protein digestion by pepsin and trypsin. These findings aid our understanding of the relationship between different phenolic acids and proteins in complex food systems.

Characterization of Whey Protein Isolate Covalently Modified with Phenolic Compounds 2: Physiochemical and Emulsifying Properties

“…This means that the contents of tryptophan were decreased by 58.7 and 85 % for WP-CA and WP-RA, respectively. These results are in line with the literatures (You et al 2012, Ali et al 2013, Gan et al 2016. Moreover, the possibility of the interaction of different phenolics with tryptophan has been found , Rawel et al 2002b, Rohn et al 2005, Ali et al 2013).…”

“…Where, the recorded values were -10.97 ±1.31, -11.13 ±1.32, and -11.35 ±0.65 for UWP, WP-CA, and WP-RA, respectively. All values of zeta potential were negative because the proteins were dissolved in PBS buffer pH 7, this observation is in accordance with Gbassi et al (2012) and Wilde et al (2016). The increase in zeta potential of WP modified by RA was slightly higher than the WP modified by CA.…”

“…Emulsions prepared with modified whey proteins by allyl isothiocyanate and chlorogenic acid showed no significant changes in the emulsifying properties (Rade-Kukic et al 2011, Ali et al 2013. Other researchers have studied the covalent interactions between the plant-derived compounds and protein and they found that the formed conjugates may modify the main properties of protein (Aewsiri et al 2009, You et al 2012, Gan et al 2016, Abd El-Maksoud et al 2018, Karefyllakis et al 2018. However, according to our research, no studies on the effect of rosmarinic acid on whey protein isolate emulsions were done, while the influence of the enzymatic and alkaline modifications on the antimicrobial, antioxidant, and antiviral properties of whey protein isolate were studied in our previous studies Elsharkawy 2018, Ali et al 2018).…”

The Role of Dietary Phenolic Compounds in Protein Digestion and Processing Technologies to Improve Their Antinutritive Properties

“…Although there was no difference in peanut allergen digestibility, IgE‐binding to pepsin‐resistant peptides of Ara h 6 was dramatically reduced (Plundrich and others ). Treatment of soy protein 7S with p ‐coumaric acid, caffeic acid, gallic acid, and chlorogenic acid did not inhibit protein degradation by pepsin at pH 2 and pH 4, and trypsin at pH 7.5, even when the mass ratio of phenolic acids to soy protein 7S reached 10:1 (Gan and others ). Yu and others () demonstrated that casein digestion by pepsin increased with increasing grape seed polyphenol extract (GSP) concentration until GSP concentration reached 0.04 mg/mL, and then decreased.…”

Covalent Whey Protein–Rosmarinic Acid Interactions: A Comparison of Alkaline and Enzymatic Modifications on Physicochemical, Antioxidative, and Antibacterial Properties

“…In addition, they are also one of the most popular natural antioxidant sources in food industry, as they are label free (clean label); (Xie et al 2017). As discussed previously, phenolic compounds can interact with proteins and these protein-phenol interactions are likely to alter the physiochemical and functional properties of proteins such as the antioxidant activity and surface hydrophobicity, which opens new opportunities for functional ingredients (Ali et al, 2013;Cao & Xiong, 2017;Cao, Xiong, Cao, & True, 2018;Gan et al, 2016;Jia et al, 2016).…”