Comparison of Faba Bean Protein Ingredients Produced Using Dry Fractionation and Isoelectric Precipitation: Techno-Functional, Nutritional and Environmental Performance
School of Food and Nutritional Sciences, University College Cork, T12 YN60 Cork, Ireland
Department of Food Science, University of Copenhagen, 1958 Frederiksberg C., Denmark
Fraunhofer Institute for Process Engineering and Packaging, Giggenhauser Str. 35, D-85354 Freising, Germany
IFEU-Institut für Energie-und Umweltforschung Heidelberg GmbH, Im Weiher 10, 69121 Heidelberg, Germany
APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland
Author to whom correspondence should be addressed.
Foods 2020, 9(3), 322; https://doi.org/10.3390/foods9030322
Received: 2 February 2020 / Revised: 2 March 2020 / Accepted: 5 March 2020 / Published: 11 March 2020
(This article belongs to the Special Issue Milk Alternatives and Non-Dairy Fermented Products)
Dry fractionated faba bean protein-rich flour (FPR) produced by milling/air classification, and faba bean protein isolate (FPI) produced by acid extraction/isoelectric precipitation were compared in terms of composition, techno-functional properties, nutritional properties and environmental impacts. FPR had a lower protein content (64.1%, dry matter (DM)) compared to FPI (90.1%, DM), due to the inherent limitations of air classification. Of the two ingredients, FPR demonstrated superior functionality, including higher protein solubility (85%), compared to FPI (32%) at pH 7. Foaming capacity was higher for FPR, although foam stability was similar for both ingredients. FPR had greater gelling ability compared to FPI. The higher carbohydrate content of FPR may have contributed to this difference. An amino acid (AA) analysis revealed that both ingredients were low in sulfur-containing AAs, with FPR having a slightly higher level than FPI. The potential nutritional benefits of the aqueous process compared to the dry process used in this study were apparent in the higher in vitro protein digestibility (IVPD) and lower trypsin inhibitor activity (TIA) in FPI compared to FPR. Additionally, vicine/convicine were detected in FPR, but not in FPI. Furthermore, much lower levels of fermentable oligo-, di- and monosaccharides, and polyols (FODMAPs) were found in FPI compared to FPR. The life cycle assessment (LCA) revealed a lower environmental impact for FPR, partly due to the extra water and energy required for aqueous processing. However, in a comparison with cow’s milk protein, both FPR and FPI were shown to have considerably lower environmental impacts.