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Browsing by Subject "GDL"

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  • Faba bean protein gelling properties affected by wet fractionation processes with and without spray-drying 
    Niskakoski, Anni (2022)
    Previous studies have demonstrated that legume proteins have high potential to lose their native functional properties during conventional wet fractionation, since heating and drying in the processes can lead to protein aggregation and solubility reduction. However, the effect of this process on faba bean protein has not been investigated thoroughly before, according to the literature review. Therefore, the aim of this study was to investigate the influence of wet fractionation process with and without spray drying on faba bean protein gelling properties. The hypothesis was that protein isolate produced with isoelectric precipitation without spray drying would have better solubility and gelling properties than spray dried isolate. Faba bean protein concentrate (FBPC) was used to prepare faba bean protein isolate with alkaline extraction followed by isoelectric precipitation, which was then dispersed into water and neutralized (faba bean protein slurry, FBPS). Some of FBPS was spray-dried (pilot faba bean protein isolate, FBPI-P). Commercial faba bean protein isolate (FBPI-C) was used as a reference sample. Their (FBPC, FBPS, FBPI-P, FBPI-C) functionality was studied by measuring thermal denaturation (DSC), protein solubility, particle size and light microscope pictures. In addition, glucono delta lactone (GDL) induced oil-in-water emulsion gels were prepared from FBPS, FBPI-P and FBPI-C. Water holding capacity (WHC), rheological and texture properties were measured from the gel samples. Surprisingly the obtained results of faba bean in this study were different from previous research on other legume proteins. It was found that spray-dried FBPI-P showed better gelling properties than wet based FBPS. This might be due to differences in thermal denaturation. Based on DSC curves, FBPI-C was found to be fully denatured and in a poor solubility. Interestingly, GDL-induced gels had strongest gel properties, which might be highly related to industrial manufacturing process of FBPI-C. When considering the theoretical environmental impact of these processes, FBPS could show potential of being more environmentally friendly process, as it could be more energy efficient than processes which require drying and heating. It was demonstrated that FBPS showed almost as good functional properties as the pilot spray-dried isolate. Hence, FBPS could work as functional and more environmentally friendly option for food industry. Future study could be conducted in near future about FBPS safety, technological applications, process optimization and environmental impact.
  • The use of whole faba beans in emulsion gel 
    Wang, Jing (2015)
    The faba bean (Vicia faba L.) is an economical protein source used in food and feed worldwide. It has high protein content and well-balanced amino acid composition. Since the starch fraction of faba beans causes problems in protein gelation, it hinders the use of whole faba beans for tofu production. Due to economical, ecological and nutritional reasons, it is worthwhile to develop a new way for producing whole faba bean tofu without discarding any part of faba beans. The aim of this thesis work was to produce whole faba bean glucono-𝛿-lactone (GDL) tofu by the starch amylolysis treatment and to study the impact of starch hydrolysate on faba bean tofu properties. This research investigated the changes in faba bean emulsion and emulsion gel properties with or without the starch hydrolysate. The pH and soluble protein content of faba bean suspensions with different GDL concentrations were measured. The microstructure, particle size distribution and viscosity of faba bean emulsions were studied. Moreover, the rheological and textural properties, microstructure, water holding capacity and total solid content of faba bean emulsion gels (GDL tofu) were also investigated. In addition, the contribution of different protein-protein interactive forces to the maintenance of faba bean emulsion gels was evaluated by comparing the protein resolubilization extent of the gels immersed in different reagents. Whole faba bean GDL tofu was prepared by the starch amylolysis treatment, emulsification and gelation processes. The starch hydrolysate containing faba bean emulsion gel was less elastic and more viscous than the starch-free gel. The presence of the starch hydrolysate increased the pH and viscosity of faba bean emulsions, which resulted in weakened protein-protein interactions. The starch hydrolysate significantly reduced the contribution of disulfide bonds to the maintenance of faba bean gel networks, but it increased the contribution of non-covalent interactions. In addition, the microstructure of the starch hydrolysate containing faba bean emulsion gel was not as fine and uniform as that of the starch-free gel. The presence of the starch hydrolysate lowered the water holding capacity and decreased the gel strength of faba bean tofu. All in all, the quality of the whole faba bean GDL tofu containing the starch hydrolysate was not comparable to that of the starch-free faba bean tofu, and further improvements are still required to improve its quality.

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