Polyphenol-protein particles: A nutraceutical breakthrough in nutrition and food science

Recently, with increased longevity and extensive media attention on healthcare matters, there is a growing consciousness among the population regarding the potential advantages of nutritional assistance in managing and preventing diseases. Polyphenols are secondary metabolites of plants that are considered highly indispensable functional foods as well as nutraceuticals. Ulcerative colitis is an intestinal inflammatory disorder, whose foremost therapeutic strategy is epitomized by synthetic anti-inflammatory medicines. Nevertheless, they are frequently accompanied by many complications that brought the interest of the scientists towards natural products. In this context, several studies asserted the anti-inflammatory effects of polyphenols such as anthocyanins, epigallocatechin gallate (EGCG), catechins, tannic acid (TA), resveratrol, and proanthocyanidins (PAC) by inhibiting the levels proinflammatory mediators and stimulated the expression of Nrf-2 dependent enzymes. However, the practical applications of polyphenols are constrained due to their poor bioavailability, and inefficient delivery to target organs, tissues, and cells. Therefore, the polyphenol's interactions with proteins in the form of polyphenol-protein particles provide a strategy to curtail the enzymatic hydrolysis and oxidative disintegration of polyphenols in the gastrointestinal tract (GIT) while increasing the bioactivity. The potential to prompt therapeutic efficacy could be attributed at least in part, to enhanced bioavailability in the intestines. This review aims to provide evidence favoring the nutraceutical potential of polyphenol-protein particles in ulcerative colitis (UC) and their mechanism and EGCG-keratinocyte growth factor, EGCG-ovalbumin, resveratrol-β-lactoglobulin, curcumin, and resveratrol-zein and Chinese mesona polysaccharides, and dihydrocaffeic acid modified with hyaluronic acid, EGCG, and KPV based particles were found to be promising in the alleviation of this condition. It examines the mechanisms involved in the formation of these particles through covalent and non-covalent interactions, offering insights into their structural and functional characteristics. The discussion also extends to the nutraceutical potential of these particles, emphasizing their bioactivities such as anti-inflammatory, antioxidant, antidiabetic, antiallergic, and antihyperlipidemic effects. Additionally, their practical applications in food systems are evaluated, specifically their roles in stabilizing emulsions, delivering nutraceuticals, and serving as functional ingredients to enhance food quality, safety, and shelf life. The review further highlights emerging technologies for the development and preservation of polyphenol-protein particles, including advanced processing methods, nanotechnology, molecular interaction techniques, enzymatic modifications, polysaccharide cross-linking, and fermentation-based strategies. By integrating these aspects, the review aims to present an in-depth understanding of polyphenol-protein particles, addressing existing knowledge gaps and proposing future research directions, specifically as therapeutic agents for UC.