Biopolymer complexes fabricated by proteins and neutral polysaccharides have some specific and innovative functionalities. A better understanding of the interactions among these biopolymers might provide new insight into the applications of the complexes. Therefore, this study aimed to investigate the structural characteristics and molecular interaction mechanisms of whey protein isolates (WPI) and Auricularia auricular polysaccharides (APs). The turbidity analysis confirmed that the pH value and mixing ratio of the two polymers had strong effects on the formation of the APs-WPI complexes. All dispersions formed soluble complexes at approximately pH = 6.0 (pHc). APs-WPI self-assembles exhibited physically cross-linked networks under higher APs proportions, while they formed spherical complexes at higher WPI ratios. The addition of APs could alter the secondary structure of WPI, and the most noticeable changes were located in the regions of β-sheet and β-turn as confirmed by circular dichroism (CD) analysis. A molecular docking study showed that the amino acid residues of β-lactoglobulin complexed with the –COOH and –OH groups of APs. Hydrogen bonds and hydrophobic interactions, which were nonbonding contributions, played a key role in the formation of the APs-WPI complex. This study provided a basis for the development and application of APs in WPI-based beverages.
L. Gentile, Protein-polysaccharide interactions and aggregates in food formulations, Curr. Opin. Colloid. In. 48 (2020) 18–27. https://doi.org/10.1016/j.cocis.2020.03.002.
J. Carpentier, E. Conforto, C. Chaigneau, et al., Complex coacervation of pea protein isolate and tragacanth gum: comparative study with commercial polysaccharides, Innov. Food Sci. Emerg. 69 (2021). https://doi.org/10.1016/j.ifset.2021.102641.
E. Dickinson, Biopolymer-based particles as stabilizing agents for emulsions and foams, Food Hydrocoll. 68 (2017) 219–231. https://doi.org/10.1016/j.foodhyd.2016.06.024.
Y. Lan, B. Chen, J. Rao, Pea protein isolate-high methoxyl pectin soluble complexes for improving pea protein functionality: effect of pH, biopolymer ratio and concentrations, Food Hydrocoll. 80 (2018) 245–253. https://doi.org/10.1016/j.foodhyd.2018.02.021.
S. S. N. Chakravartula, M. Soccio, N. Lotti, et al., Characterization of composite edible films based on pectin/alginate/whey protein concentrate, Materials 12 (2019) 2454. https://doi.org/10.3390/ma12152454.
F. Alavi, L. Chen, Complexation of nanofibrillated egg white protein and low methoxy pectin improves microstructure, stability, and rheology of oil-in-water emulsions, Food Hydrocoll. 124 (2022). https://doi.org/10.1016/j.foodhyd.2021.107262.
J. Ye, X. Hua, W. Zhang, et al., Emulsifying capacity of peanut polysaccharide: improving interfacial property through the co-dissolution of protein during extraction, Carbohydr. Polym. 273 (2021). https://doi.org/10.1016/j.carbpol.2021.118614.
J. Cheng, Y. Ma, X. Li, Effects of milk protein-polysaccharide interactions on the stability of ice cream mix model systems, Food Hydrocoll. 45 (2015) 327–336. https://doi.org/10.1016/j.foodhyd.2014.11.027.
W. Chen, W. Wang, X. Ma, et al., Effect of pH-shifting treatment on structural and functional properties of whey protein isolate and its interaction with (–)-epigallocatechin-3-gallate, Food Chem. 274 (2019) 234–241. https://doi.org/10.1016/j.foodchem.2018.08.106.
B. G. Carter, E. A. Foegeding, M. A. Drake, Invited review: astringency in whey protein beverages, J. Dairy Sci. 103 (2020) 5793–5804. https://doi.org/10.3168/jds.2020-18303.
J. Hu, T. F. Zhao, S. J. Li, Stability, microstructure, and digestibility of whey protein isolate-Tremella fuciformis polysaccharide complexes, Food Hydrocoll. 89 (2019) 379–385. https://doi.org/10.1016/j.foodhyd.2018.11.005.
Z. Jiang, Y. Gao, J. Li, et al., Consecutive pH-shift and ultrasound treatment modify the physicochemical properties of whey protein isolate, Int. Dairy J. 127 (2022) 105211. https://doi.org/10.1016/j.idairyj.2021.105211.
F. Cui, D. J. McClements, X. Liu, et al., Development of pH-responsive emulsions stabilized by whey protein fibrils, Food Hydrocoll. 122 (2022) 107067. https://doi.org/10.1016/j.foodhyd.2021.107067.
X. Du, X. Huang, L. Wang, et al., Nanosized niosomes as effective delivery device to improve the stability and bioaccessibility of goat milk whey protein peptide, Food Res. Int. 161 (2022) 111729. https://doi.org/10.1016/j.foodres.2022.111729.
J. Aschemann-Witzel, P. Varela, A. Peschel, Consumers’ categorization of food ingredients: do consumers perceive them as ‘clean label’ producers expect? An exploration with projective mapping, Food Qual. Prefer. 71 (2019) 117–128. https://doi.org/10.1016/j.foodqual.2018.06.003.
M. Sarraf, S. Naji-Tabasi, A. Beig-Babaei, Influence of calcium chloride and pH on soluble complex of whey protein-basil seed gum and xanthan gum, Food Sci. Nutr. 9 (2021) 6728–6736. https://doi.org/10.1002/fsn3.2624.
W. Wijaya, S. Turan, A. Diah, et al., Effect of low-methoxy pectin on interfacial and emulsion stabilizing properties of heated whey protein isolate (WPI) aggregates, Food Struct. 26 (2020) 100159. https://doi.org/10.1016/j.foostr.2020.100159.
Wusigale, L. Liang, Y. C. Luo, Casein and pectin: structures, interactions, and applications, Trends Food Sci. Tech. 97 (2020) 391–403. https://doi.org/10.1016/j.jpgs.2020.01.027.
F. Du, Y. Qi, H. Huang, et al., Stabilization of o/w emulsions via interfacial protein concentrating induced by thermodynamic incompatibility between sarcoplasmic proteins and xanthan gum, Food Hydrocoll. 124 (2022). https://doi.org/10.1016/j.foodhyd.2021.107242.
D. Liu, P. Zhou, T. Nicolai, Effect of kappa carrageenan on acid-induced gelation of whey protein aggregates. Part I: potentiometric titration, rheology and turbidity, Food Hydrocoll. 102 (2020). https://doi.org/10.1016/j.foodhyd.2019.105589.
J. Miao, J. M. Regenstein, J. Qiu, et al., Isolation, structural characterization and bioactivities of polysaccharides and its derivatives from Auricularia: a review, Int. J. Biol. Macromol. 150 (2020) 102–113. https://doi.org/10.1016/j.ijbiomac.2020.02.054.
S. Xu, X. Xu, L. Zhang, Branching structure and chain conformation of water-soluble glucan extracted from Auricularia auricula-judae, J. Agric. Food Chem. 60 (2012) 3498–3506. https://doi.org/10.1021/jf300423z.
P. Shao, J. Feng, P. Sun, et al., Recent advances in improving stability of food emulsion by plant polysaccharides, Food Res Int. 137 (2020) 109376. https://doi.org/10.1016/j.foodres.2020.109376.
N. Chen, H. Zhang, X. Zong, et al., Polysaccharides from Auricularia auricula: preparation, structural features and biological activities, Carbohydr. Polym. 247 (2020) 116750. https://doi.org/10.1016/j.carbpol.2020.116750.
H. Bao, S. You, L. Cao, et al., Chemical and rheological properties of polysaccharides from fruit body of Auricularia auricular-judae, Food Hydrocoll. 57 (2016) 30–37. https://doi.org/10.1016/j.foodhyd.2015.12.031.
Y. Zhao, D. Shui, S. Li, et al., Complexation behavior of Auricularia auriculapolysaccharide and whey protein isolate: characterization and potential beverage application, J. Food Process Pres. 46 (2022) e16340. https://doi.org/10.1111/jfpp.16340.
J. Shang, J. Ritian, W. Yang, et al., The effect of different edible fungal polysaccharides on the stability of whey protein isolate solution near isoelectric point, Int. J. Food Sci. Tech. (2023) 16259. https://doi.org/10.1111/ijfs.16259.
B. Fataneh, M. A. R. Seyed, H. Joyner, Mechanisms of whey protein isolate interaction with basil seed gum: influence of pH and protein-polysaccharide ratio, Carbohydr. Polym. 232 (2020) 115775. https://doi.org/10.1016/j.carbpol.2019.115775.
J. Shang, M. Liao, R. Jin, et al., Molecular properties of Flammulina velutipes polysaccharide-whey protein isolate (WPI) complexes via noncovalent interactions, Foods 10 (2020) 1. https://doi.org/10.3390/foods10010001.
H. Li, T. Wang, Y. Hu, et al., Designing delivery systems for functional ingredients by protein/polysaccharide interactions, Trends Food Sci. Technol. 119 (2022) 272–287. https://doi.org/10.1016/j.jpgs.2021.12.007.
D. A. González-Martínez, H. Carrillo-Navas, C. E. Barrera-Díaz, et al., Characterization of a novel complex coacervate based on whey protein isolate-tamarind seed mucilage, Food Hydrocoll. 72 (2017) 115–126. https://doi.org/10.1016/j.foodhyd.2017.05.037.
J. Wang, S. Nie, Application of atomic force microscopy in microscopic analysis of polysaccharide, Trends Food Sci. Technol. 87 (2019) 35–46. https://doi.org/10.1016/j.jpgs.2018.02.005.
X. Li, Y. Bai, H. Ji, et al., The binding mechanism between cyclodextrins and pullulanase: a molecular docking, isothermal titration calorimetry, circular dichroism and fluorescence study, Food Chem. 321 (2020) 126750. https://doi.org/10.1016/j.foodchem.2020.126750.
Y. Lv, Q. Liang, Y. Li, et al., Study of the binding mechanism between hydroxytyrosol and bovine serum albumin using multispectral and molecular docking, Food Hydrocoll. 122 (2022) 107072. https://doi.org/10.1016/j.foodhyd.2021.107072.
T. Dai, R. Li, C. Liu, et al., Effect of rice glutelin-resveratrol interactions on the formation and stability of emulsions: a multiphotonic spectroscopy and molecular docking study, Food Hydrocoll. 97 (2019) 105234. https://doi.org/10.1016/j.foodhyd.2019.105234.
Y. Xu, M. Shen, Y. Chen, et al., Optimization of the polysaccharide hydrolysate from Auricularia auricula with antioxidant activity by response surface methodology, Int. J. Biol. Macromol. 113 (2018) 543–549. https://doi.org/10.1016/j.ijbiomac.2018.02.059.
S. Cao, X. He, L. Qin, et al., Anticoagulant and antithrombotic properties in vitro and in vivo of a novel sulfated polysaccharide from marine green alga Monostroma nitidum, Mar. Drugs 17 (2019). https://doi.org/10.3390/md17040247.
R. Sánchez, C. Juan, J. Benavides, et al., The folin-ciocalteu assay revisited: improvement of its specificity for total phenolic content determination, Anal. Methods. 5 (2013) 5990–5999. https://doi.org/10.1039/C3AY41125G.
L. P. H. Bastos, C. W. P. de Carvalho, E. E. Garcia-Rojas, Formation and characterization of the complex coacervates obtained between lactoferrin and sodium alginate, Int. J. Biol. Macromol. 120 (2018) 332–338. https://doi.org/10.1016/j.ijbiomac.2018.08.050.
T. Wagoner, B. Vardhanabhuti, E. A. Foegeding, Designing whey protein-polysaccharide particles for colloidal stability, Annu. Rev. Food Sci. Technol. 7 (2016) 93–116. https://doi.org/10.1146/annurev-food-041715-033315.
Y. Lan, J. B. Ohm, B. Chen, et al., Phase behavior, thermodynamic and microstructure of concentrated pea protein isolate-pectin mixture: effect of pH, biopolymer ratio and pectin charge density, Food Hydrocoll. 101 (2020) 105556. https://doi.org/10.1016/j.foodhyd.2019.105556.
R. L. Shen, X. Y. Liu, J. L. Dong, et al., The gel properties and microstructure of the mixture of oat β-glucan/soy protein isolates, Food Hydrocoll. 47 (2015) 108–114. https://doi.org/10.1016/j.foodhyd.2015.01.017.
C. C. Chen, S. T. Chen, J. F. Hsieh, Proteomic analysis of polysaccharide-milk protein interactions induced by chitosan, Molecules 20 (2015) 7737–7749. https://doi.org/10.3390/molecules20057737.
V. Kontogiorgos, S. M. Tosh, P. J. Wood, Phase behaviour of high molecular weight oat β-glucan/whey protein isolate binary mixtures, Food Hydrocoll. 23 (2009) 949–956. https://doi.org/10.1016/j.foodhyd.2008.07.005.
M. Rabe, D. Verdes, S. Seeger, Understanding protein adsorption phenomena at solid surfaces, Adv. Colloid. Interface Sci. 162 (2011) 87–106. https://doi.org/10.1016/j.cis.2010.12.007.
Y. Lan, J. B. Ohm, B. Chen, Phase behavior and complex coacervation of concentrated pea protein isolate-beet pectin solution, Food Chem. 307 (2020) 125536. https://doi.org/10.1016/j.foodchem.2019.125536.
K. Hoda, E. Bahareh, K. Rassoul, et al., Effects of biopolymer ratio and heat treatment on the complex formation between whey protein isolate and soluble fraction of persian gum, J. Dispers. Sci. Technol. 38 (2017) 1234–1241. https://doi.org/10.1080/01932691.2016.1230064.
C. J. F. Souza, E. E. Garcia-Rojas, Effects of salt and protein concentrations on the association and dissociation of ovalbumin-pectin complexes, Food Hydrocoll. 47 (2015) 124–129. https://doi.org/10.1016/j.foodhyd.2015.01.010.
J. Liu, J. Chai, T. Zhang, et al., Phase behavior, thermodynamic and rheological properties of ovalbumin/dextran sulfate: effect of biopolymer ratio and salt concentration, Food Hydrocoll. 118 (2021) 106777. https://doi.org/10.1016/j.foodhyd.2021.106777.
R. Zhang, X. Pang, J. Lu, Effect of high intensity ultrasound pretreatment on functional and structural properties of micellar casein concentrates, Ultrason. Sonochem. 47 (2018) 10–16. https://doi.org/10.1016/j.ultsonch.2018.04.011.
Q. Li, Z. Wang, C. Dai, Physical stability and microstructure of rapeseed protein isolate/gum arabic stabilized emulsions at alkaline pH, Food Hydrocoll. 88 (2019) 50–57. https://doi.org/10.1016/j.foodhyd.2018.09.020.
W. C. Zeng, Z. Zhang, H. Gao, et al., Characterization of antioxidant polysaccharides from Auricularia auricular using microwave-assisted extraction, Carbohydr. Polym. 89 (2012) 694–700. https://doi.org/10.1016/j.carbpol.2012.03.078.
H. Wang, L. Ke, J. Zhou, et al., Multi-spectroscopic, molecular docking and molecular dynamic simulation evaluation of hydroxychloroquine sulfate interaction with caseins and whey proteins, J. Mol. Liq. 367 (2022). https://doi.org/10.1016/j.molliq.2022.120460.
P. Guerrero, J. P. Kerry, K. de la Caba, FTIR characterization of protein-polysaccharide interactions in extruded blends, Carbohydr. Polym. 111 (2014) 598–605. https://doi.org/10.1016/j.carbpol.2014.05.005.
Y. G. Zhao, N. Khalid, G. F. Shu, et al., Complex coacervates from gelatin and octenyl succinic anhydride modified kudzu starch: insights of formulation and characterization, Food Hydrocoll. 86 (2019) 70–77. https://doi.org/10.1016/j.foodhyd.2018.01.040.
Y. P. Timilsena, B. Wang, R. Adhikari, et al., Preparation and characterization of chia seed protein isolate-chia seed gum complex coacervates, Food Hydrocoll. 52 (2016) 554–563. https://doi.org/10.1016/j.foodhyd.2015.07.033.
Y. Li, X. Zhang, Y. Zhao, et al., Investigation on complex coacervation between fish skin gelatin from cold-water fish and gum arabic: phase behavior, thermodynamic, and structural properties, Food Res. Int. 107 (2018) 596–604. https://doi.org/10.1016/j.foodres.2018.02.053.
Y. Wang, J. Zhang, L. F. Zhang, Study on the mechanism of non-covalent interaction between rose anthocyanin extracts and whey protein isolate under different pH conditions, Food Chem. 384 (2022) 132492. https://doi.org/10.1016/j.foodchem.2022.132492.
T. Zhao, B. Yang, S. Ji, et al., Effects of the structure and interaction force of phytosterol/whey protein isolate self-assembly complex on phytosterol digestion properties, Food Chem. 403 (2023) 134311. https://doi.org/10.1016/j.foodchem.2022.13431.
Y. P. Neo, S. Ray, J. Jin, et al., Encapsulation of food grade antioxidant in natural biopolymer by electrospinning technique: a physicochemical study based on zein-gallic acid system, Food Chem. 136 (2013) 1013–1021. https://doi.org/10.1016/j.foodchem.2012.09.010.
Z. Xu, N. Hao, L. Li, et al., Valorization of soy whey wastewater: how epigallocatechin-3-gallate regulates protein precipitation, ACS Sustain. Chem. Eng. 7 (2019) 15504–15513. https://doi.org/10.1021/acssuschemeng.9b03208.
X. T. Le, S. L. Turgeon, Rheological and structural study of electrostatic cross-linked xanthan gum hydrogels induced by β-lactoglobulin, Soft Matter 9 (2013) 3063–3073. https://doi.org/10.1039/C3SM27528K.
This study was funded by the Heilongjiang Province Natural Science Foundation of China (Nos. LH2021C075 and LH2022C075).
Food Science of Animal Products published by Tsinghua University Press. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).