Minimal processing of underutilised ingredients for food gel applications

Tools

Kremmyda, Alexandra (2024) Minimal processing of underutilised ingredients for food gel applications. PhD thesis, University of Nottingham.

[thumbnail of corrections]
Preview
 PDF (corrections) (Thesis - as examined) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Available under Licence Creative Commons Attribution.
Download (6MB) | Preview

Abstract

Finding an alternative to chemical ways to modify the functional properties of food materials has increased over the last few years. Ball milling has been used recently as a method of physical modification of isolated components (starch, protein) from various botanical sources using mechanical force (centrifugal, impact).

This research introduces ball milling as a method of physical modification of non-fractionated flours from lentils and pearl millet. The impact of the ball mill on the physicochemical and functional properties as well as the morphology of the legume and cereal flours was studied between the native flours and over 2 and 4 hours of ball milling.

Ball milling decreased the birefringence, crystallinity and onset starch gelatinisation temperature of the lentils suggesting the disruption of the starch molecules’ intermolecular bonds and the loss of radial orientation. Lower solubility and hydrophobicity as well as the observation of protein aggregates indicated partial denaturation and aggregation of the lentils’ proteins after ball milling. Protein aggregation was responsible for decreasing the viscosity of the lentils after ball milling by inhibiting starch hydration and swelling. However, such changes were not observed for the pearl millet indicating a more resistant structure to the ball milling forces.

Having identified the impact of ball milling on the pasting of lentils, the research continued with the application of the ball-milled material on gel formation. Starch was the major component in lentil flours and responsible for the gel network formation. However, protein aggregation induced by the ball milling forces impacted the formation of a strong starch-based gel in lentils by disrupting amylose retrogradation. Lentils formed softer gels showing either a starch-based or a protein-starch (interpenetrating) gel network after ball milling.

This research has highlighted the use of ball milling on non-isolated flour modification and the potential advantages of using these flours for food gel applications.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Gould, Joanne
Di Bari, Vincenzo
Keywords: minimal processing, milling, pasting, gelation, legumes, cereals, food, proteins, starch
Subjects: T Technology > TP Chemical technology > TP 368 Food processing and manufacture
Faculties/Schools: UK Campuses > Faculty of Science > School of Biosciences
Item ID: 79876
Depositing User: Kremmyda, Alexandra
Date Deposited: 13 Dec 2024 04:40
Last Modified: 13 Dec 2024 04:40
URI: https://eprints.nottingham.ac.uk/id/eprint/79876

Actions (Archive Staff Only)

Edit View Edit View