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

食品和创新部门目前的趋势是推动更可持续的食品及其替代品，以应对不可持续的方法对环境的负面影响（Saari等人，2021年）。这体现在消费者对纯素食品和植物蛋白的深刻转变中。存在丰富的谷物蛋白质，其可以混合在混合物中，提供定制的组成和风味（Jiménez-Munoz等人，2021年）。然而，工艺和物理化学性质是具有挑战性的控制。通常，需要结合剂-具有蛋白质结合能力的食品级分子-来实现食品制剂中预期的结构和稳定性，例如，素食餐传统的粘合剂，如明胶、卵磷脂或树胶，要么对素食主义者不友好，要么会引起过敏，要么根本没有优化与植物蛋白协同作用。使用的一些豆类或种子淀粉要么昂贵，要么无法大规模生产。目前，黄金标准是甲基纤维素（E461），它来源于木纤维，包括化学改性。方便地，这种多糖的热凝胶化性质提供高于60 ℃的硬度，模拟肉的质地（Nasatto等人，2015年）。然而，它被认为是人造的和非可持续的，对于具有健康和环保意识的消费者来说是一个不受欢迎的选择，因此，食品供应商推动开发替代的可持续和清洁标签解决方案。最可持续的替代来源之一是来自农业食品部门副产品的生物技术生产的纤维。纤维可以具有多种功能，包括粘合剂、流变改性剂、填充材料、乳化剂和脂肪模拟物作为食品中的成分。因此，开发替代的可持续来源的纤维粘合剂是一个明确的需求和相当大的市场机会，使用绿色技术，具有与竞争对手类似的能力，但实现清洁标签和低环境足迹。目的和目标：本研究的目的是通过对从农业食品残渣和副产品中提取的纤维素（Curran）和半纤维素聚合物进行改性，开发新型的“清洁标签”食品粘合剂。使用绿色（生物）加工技术从农业食品副产品流中获得的素食友好型纤维粘合剂。具体而言：-筛选各种天然来源，从微纤化纤维素开始，扩展到其他可持续的生物聚合物，包括半纤维素部分，以评估其适用性。-探索使用各种绿色加工技术（超声波处理、冷等离子体、微波加工和高压加工）对纤维生物聚合物进行化学改性。研究不同分子量纤维分子通过氧化反应或接枝的酶改性。表征候选分子本身以及在具有其他成分的模型系统中的流变学、质地、凝胶形成、乳化和结合特性（将进行表征，检查其结合能力、流变学、乳化、持水能力、热凝胶化特性）。选择最有利的材料，将其纳入重新配制的食品应用中，例如纯素肉类替代品。采用分子排阻色谱、离子交换色谱、基质辅助激光解吸电离、核磁共振等方法测定生物大分子的结构。

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.