Multi-functional fibres as bio-based food binders, selectively modified using green technologies and enzymes

The current trend in the food and innovation sector is the drive for more sustainable foods and its alternatives in an attempt to combat the negative effects unsustainable approaches have on the environment (Saari et al., 2021). This is embodied in profound consumer shifts to vegan foods and plant proteins. There is an abundance of grain proteins which can be blended in mixtures offering tailored composition and flavour (Jiménez-Munoz et al., 2021). The technological and physicochemical properties are, however, challenging to be controlled. Normally, binding agents - food grade molecules with protein binding capability - are required to achieve the structure and the stability that is expected in a food formulation, e.g., a vegan meal. Traditional binding agents, like gelatine, lecithin, or gums are either not vegan friendly or can induce allergies or simply not optimised to synergistically work with plant proteins. Some legume or seed starches used are either expensive or unsustainable to mass produce. Currently, the golden standard is methyl cellulose (E461), that is derived from wood fibres and includes chemical modifications. Conveniently, the thermogelation properties of this polysaccharide provides firmness above 60 degrees C simulating the texture of meat (Nasatto et al., 2015). However, it is perceived as artificial and non-sustainable, an unpopular choice for health and environmentally conscious consumers and thus, there is a drive by food suppliers to develop alternative sustainable and clean label solutions. One of the most sustainable alternative sources are biotechnologically produced fibres sourced from by-products of the agri-food sector. Fibres can have multiple functionalities, including binding agent, rheology modifier, bulking material, emulsifier, and fat mimic as ingredients in food products. Therefore, there is a clear need and considerable market opportunity to develop alternative sustainably sourced fibrous binder using green technologies with similar, to the competition, capacity but achieving a clean label and a low environmental footprint.

Aims and objectives:
The aim is to develop novel 'clean label' food binding agents through the modification of cellulosic (Curran) and hemicellulosic polymers extracted from agri-food residues and by-products.
The aim of the study is to investigate and provide the basis for understanding and developing novel, vegan-friendly fibrous binding agents derived from agri-food by-product streams using green (bio)processing technologies.
Specifically:
-To Screen various natural sources, starting from micro-fibrillated cellulose and expanding to other sustainable biopolymers including hemicellulosic fractions to evaluate their fit for purpose.
-To explore chemical modification of the fibrous biopolymers using a variety of green processing technologies (ultra-sonication, cold plasma, microwave processing and high-pressure processing).

- To investigation enzymatic modification of fibrous molecules of various molecular weights though oxidation reaction or grafting.
- To characterize the rheology, texture, gel formation, emulsifying and binding properties of the candidate molecules on their own and in model systems with other ingredients (characterization will be done checking their binding capacity, rheology, emulsification, water holding capacity, thermogelation properties).
- To select the most favorable material for their inclusion in reformulated food applications, such as vegan meat alternatives.
- To determine the structure of the biopolymers using size exclusion and ion exchange chromatography, matrix-assisted laser desorption ionization, nuclear magnetic resonance.