Recently, Prof. Taihua Mu’s research team, Potato and Sweet Potato Processing and Quality Control Research Team, wrote a review on nanocomplexation of important bioactive compounds in sweet potato aimed to enhance the industrial application as functional food supplements in the food and pharmaceutical industry. The relevant research results were published in the journal of Food Chemistry (IF: 7.514) with the title “Functionalization of sweet potato leaf polyphenols by nanostructured composite β-lactoglobulin particles from molecular level complexations: A review”.

Nowadays, the research community in the food, biochemistry and pharmaceutical disciplines are interested in bringing natural alternatives to synthetic antioxidants. This is due to increasing evidence and consumer awareness of the benefits of natural antioxidants. Consumption of raw natural plant foods or minimally processed foods with high levels of bioactive compounds is becoming a trend worldwide. β-lactoglobulin (βlg) is a highly regarded whey protein. Sweet potato leaf polyphenols (SPLPs) have shown potential health benefits as evidenced by several in vitro, ex vivo, and in vivo studies.  βlg can interact with SPLPs at the molecular level to form reversible or irreversible nanocomplexes (NCs). A complete understanding of the functionalization mechanisms of SPLPsβlgNCs as well as their characteristics are essential to construct novel supplements. In this review, the composition and structure of SPLPs and βlg, as well as methods of molecular complexation and mechanisms of formation of SPLPsβlgNCs, are revisited. The modified functionalities of SPLPsβlgNCs, especially protein conformational structures, antioxidant activity, solubility, thermal stability, emulsifying, and gelling properties including allergenic potential, digestibility, and practical applications are discussed. The molecular level functionalization of SPLPsβlgNCs results from non-covalent (hydrophobic bridging, hydrogen bonding, and ionic interactions) or covalent interactions brought about by enzymatic or non-enzymatic pathways. Besides, optimization of fabrication conditions such as pH, temperature, amount of added polyphenol or protein is important to produce complexes with tailored functionalities. Thus, the synergistic mechanisms of SPLPsβlgNCs show the potential to construct associated food products with desired functionalities.

Our PhD student Shadrack Isaboke Makori is the first author, and Professor Taihua Mu and Associate Professor Hongnan Sun are corresponding authors. This work was supported by the Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences (grant number CAAS-ASTIP-202X-IFST); the Central Public-Interest Scientific Institution Basal Research Fund (grant number S2020JBKY-17); the National Key R&D Program of China (grant number 2016YFE0133600); and the Natural Science Funding of China (grant number 31701614).

Fig. 1. The 3D structure of bovine β-lactoglobulin showing the position of two tryptophan (Trp) residues i.e. Trp 19 and Trp 61, and one free thiol group (Cys 121) (A). Primary structure and amino acid sequence of β-lactoglobulin (B). Key: H1–H4, helical segments; A1–I, beta sheets; β, beta turn; γ, gamma turn; 1 = 2, disulfide bonds. Figures adapted from Broersen (2020) and Sengupta et al. (2018). 

Fig. 2. Fig. 3 Schematic representation of sweet potato leaf functionalization.

Link to the paper: https://authors.elsevier.com/c/1dvLr16Ds1oPk0

DOI: https://doi.org/10.1016/j.foodchem.2021.131304