Tailor-Made Conversion of Mango Seed Husks to Obtain Hemicellulose Suitable for the Production of Thermally Stable Films

Mango seed husks were fractionated to obtain hemicellulose extracts with varied xyloglucan (XGN) and xylan (XLN) ratios that suit the formulation of thermally stable and self-supporting films. A strategy for obtaining the suitable XGN/XLN composition involved optimizing extraction temperatures (40–90 °C), NaOH concentrations (1–2 M), and time (2–4 h) in central composite design experiments, based on the yield, XGN/XLN ratio, uronic acid, and lignin contents. Through desirability analysis, the optimal process conditions (1.92 M NaOH, 86.0 °C, and 3.84 h) for suitable XGN/XLN composition were achieved, which gave hemicellulose yield, XGN/XLN ratio, uronic acids, lignin, and Zeta potential of 46.24%, 0.13, 12.02%, 16.73%, and − 16.1 mV, respectively. Permethylation analysis and Gas chromatography/Mass spectroscopy confirmed the presence of 1,4 linked glucan backbone for xyloglucan in the hemicellulose, with xylose residues branching at the non-reducing end. The molecular weight and maximum degradation temperature of the hemicellulose extract were higher (70,189 g mol−1 & ≈ 330 °C, respectively) than of beechwood XLN (27,235 g mol−1 & 290 °C, respectively). The hemicellulose extract formed self-supporting thermally stable (290 °C) biocomposite films, with potential application in food packaging. Customizing extraction of the hemicellulose with tunable functional properties, from the mango seed husk, is a novel approach for value addition to food waste that can be integrated into a biorefinery set-up.