Polyphenol-enriched berry extracts naturally modulate reactive proteins in model foods

Bioactive Dairy-Fermented Products and Phenolic Compounds: Together or Apart

Fermented dairy products (e.g., yogurt, kefir, and buttermilk) are significant in the dairy industry. They are less immunoreactive than the raw materials from which they are derived. The attractiveness of these products is based on their bioactivity and properties that induce immune or anti-inflammatory processes. In the search for new solutions, plant raw materials with beneficial effects have been combined to multiply their effects or obtain new properties. Polyphenols (e.g., flavonoids, phenolic acids, lignans, and stilbenes) are present in fruit and vegetables, but also in coffee, tea, or wine. They reduce the risk of chronic diseases, such as cancer, diabetes, or inflammation. Hence, it is becoming valuable to combine dairy proteins with polyphenols, of which epigallocatechin-3-gallate (EGCG) and chlorogenic acid (CGA) show a particular predisposition to bind to milk proteins (e.g., α-lactalbumin β-lactoglobulin, αs1-casein, and κ-casein). Reducing the allergenicity of milk proteins by combining them with polyphenols is an essential issue. As potential 'metabolic prebiotics', they also contribute to stimulating the growth of beneficial bacteria and inhibiting pathogenic bacteria in the human gastrointestinal tract. In silico methods, mainly docking, assess the new structures of conjugates and the consequences of the interactions that are formed between proteins and polyphenols, as well as to predict their action in the body.

Food Allergens: When Friends Become Foes-Caveats and Opportunities for Oral Immunotherapy Based on Deactivation Methods

Food allergies represent a serious health concern and, since the 1990s, they have risen gradually in high-income countries. Unfortunately, the problem is complex because genetic, epigenetic, and environmental factors may be collectively involved. Prevention and diagnoses have not yet evolved into efficacious therapies. Identification and control of allergens present in edible substances hold promise for multi-purpose biomedical approaches, including oral immunotherapy. This review highlights recent studies and methods to modify the otherwise innocuous native proteins in most subjects, and how oral treatments targeting immune responses could help cancel out the potential risks in hypersensitive individuals, especially children. We have focused on some physical methods that can easily be conducted, along with chemo-enzymatic modifications of allergens by means of peptides and phytochemicals in particular. The latter, accessible from naturally-occurring substances, provide an added value to hypoallergenic matrices employing vegetal wastes, a point where food chemistry meets sustainable goals as well.

Dairy-Protein-Based Aggregates as Additives Enriched with Tart Cherry Polyphenols and Flavor Compounds

Nowadays, the development of innovative food products with positive health effects is on the rise. Consequently, the aim of this study was a formulation of aggregates based on tart cherry juice and dairy protein matrix to investigate whether different amounts (2% and 6%) of protein matrix have an impact on the adsorption of polyphenols as well as on the adsorption of flavor compounds. Formulated aggregates were investigated through high-performance liquid chromatography, spectrophotometric methods, gas chromatography and Fourier transform infrared spectrometry. The obtained results revealed that with an increase in the amount of protein matrix used for the formulation of aggregates, a decrease in the adsorption of polyphenols occurred, and, consequently, the antioxidant activity of the formulated aggregates was lower. The amount of protein matrix additionally affected the adsorption of flavor compounds; thus the formulated aggregates differed in their flavor profiles in comparison with tart cherry juice. Adsorption of both phenolic and flavor compounds caused changes in the protein structure, as proven by recording IR spectra. Formulated dairy-protein-based aggregates could be used as additives which are enriched with tart cherry polyphenols and flavor compounds.

Boosting the Bioaccessibility of Dietary Bioactives by Delivery as Protein-Polyphenol Aggregate Particles

Protein-polyphenol aggregate particles concurrently fortify a functional food product with healthy dietary proteins and concentrated polyphenols. However, what impact does ingestion of aggregate particles have on ultimate health relevance of either the polyphenolic molecules in the matrix or the protein molecules? Because human health benefits are contingent on bioavailability after ingestion, the fate of these molecules during transit in the gastrointestinal tract (GIT) will dictate their utility as functional food ingredients. This brief review explores diverse applications of protein-polyphenol particles in the food industry and the bioaccessibility of both bioactive polyphenolic compounds and edible proteins. Evidence to date suggests that complexation of phytoactive polyphenolics effectively enhances their health-relevant impacts, specifically because the phytoactives are protected in the protein matrix during transit in the GIT, allowing intact, non-degraded molecules to reach the colon for catabolism at the gut microbiome level, a prerequisite to realize the health benefits of these active compounds.

Functionalization of sweet potato leaf polyphenols by nanostructured composite β-lactoglobulin particles from molecular level complexations: A review

Sweet potato leaf polyphenols (SPLPs) have shown potential health benefits in the food and pharmaceutical industries. Nowadays, consumption of SPLPs from animal feeds to foodstuff is becoming a trend worldwide. However, the application of SPLPs is limited by their low bioavailability and stability. β-lactoglobulin (βlg), a highly regarded whey protein, can interact with SPLPs at the molecular level to form reversible or irreversible nanocomplexes (NCs). Consequently, the functional properties and final quality of SPLPs are directly modified. In this review, the composition and structure of SPLPs and βlg, as well as methods of molecular complexation and mechanisms of formation of SPLPsβlgNCs, are revisited. The modified functionalities of SPLPsβlgNCs, especially protein conformational structures, antioxidant activity, solubility, thermal stability, emulsifying, and gelling properties including allergenic potential, digestibility, and practical applications are discussed for SPLPs future development.

Adsorption of Quercetin on Brown Rice and Almond Protein Matrices: Effect of Quercetin Concentration

Plant-based proteins are very often used as carriers of different phenolic compounds. For that purpose, complexation of quercetin with almond and brown rice protein matrices was investigated. The amount of protein matrices was constant, while the concentration of quercetin varied (1 mM, 2 mM or 5 mM) during complexation. Dried complexes were investigated for quercetin amount (HPLC analysis) and antioxidant activity (DPPH, FRAP and CUPRAC methods). Additionally, complexation was proven by DSC and FTIR-ATR screening. An increase in the concentration of quercetin in the initial complexation mixture resulted in the increase in the adsorption of quercetin onto protein matrices. For the brown rice protein matrices, this increase was proportional to the initial quercetin concentration. Adsorption of quercetin caused the change in thermal stability of microparticles in comparison to corresponding protein matrices that have been proven by DSC. FTIR-ATR analysis revealed structural changes on microparticles upon adsorption of quercetin.

Extraction of functional extracts from berries and their high quality processing: a comprehensive review

Berry fruits have attracted increasing more attention of the food processing industry as well as consumers due to their widely acclaimed advantages as highly effective anti-oxidant properties which may provide protection against some cancers as well as aging. However, the conventional extraction methods are inefficient and wasteful of solvent utilization. This paper presents a critical overview of some novel extraction methods applicable to berries, including pressurized-liquid extraction, ultrasound-assisted extraction, microwave-assisted extraction, supercritical fluid extraction, enzyme-assisted extraction as well as some combined extraction methods. When combined with conventional methods, the new technologies can be more efficient and environmentally friendly. Additionally, high quality processing of the functional extracts from berry fruits, such as refined processing technology, is introduced in this review. Finally, progress of applications of berry functional extracts in the food industry is described in detail; this should encourage further scientific research and industrial utilization.

A Comprehensive Review on the Interaction of Milk Protein Concentrates with Plant-Based Polyphenolics

Functional properties and biological activities of plant-derived polyphenolic compounds have gained great interest due to their epidemiologically proven health benefits and diverse industrial applications in the food and pharmaceutical industry. Moreover, the food processing conditions and certain chemical reactions such as pigmentation, acylation, hydroxylation, and glycosylation can also cause alteration in the stability, antioxidant activity, and structural characteristics of the polyphenolic compounds. Since the (poly)phenols are highly reactive, to overcome these problems, the formulation of a complex of polyphenolic compounds with natural biopolymers is an effective approach. Besides, to increase the bioavailability and bioaccessibility of polyphenolic compounds, milk proteins such as whey protein concentrate, sodium caseinate, and milk protein concentrate act as natural vehicles, due to their specific structural and functional properties with high nutritional value. Therefore, milk proteins are suitable for the delivery of polyphenols to parts of the gastrointestinal tract. Therefore, this review reports on types of (poly)phenols, methods for the analysis of binding interactions between (poly)phenols-milk proteins, and structural changes that occur during the interaction.

Encapsulation of Cinnamic Acid on Plant-Based Proteins: Evaluation by HPLC, DSC and FTIR-ATR

Plant-based protein matrices can be used for the formulation of delivery systems of cinnamic acid. Pumpkin, pea and almond protein matrices were used for the formulation of dried complexes. The matrices were used in varying amounts (1%, 2%, 5% and 10%) whilst the amount of cinnamic acid was maintained constant. The obtained complexes were analyzed by HPLC, DSC and FTIR-ATR. The highest amounts of cinnamic acid were determined on complexes prepared by the lowest amounts of protein matrices, regardless of their type. The highest affinity for cinnamic acid adsorption was determined for the pumpkin protein matrix. DSC analysis revealed that adsorption of cinnamic acid caused an increase in the thermal stability of the almond protein matrix, while the other two matrices had the opposite behavior. The complexation of protein matrices and cinnamic acid was proven by recording the IR spectra. The obtained complexes could have potential applications in food products to achieve enrichment with cinnamic acid as well as proteins.

Pea protein isolate characteristics modulate functional properties of pea protein-cranberry polyphenol particles

Plant polyphenols have a natural binding affinity for proteins, and their interaction can be exploited to form diverse aggregate particles. Protein-polyphenol particles utilized as food ingredients allow consumers to incorporate more health-benefiting plant bioactives into their diets. The functional properties of the protein-polyphenol particles can be influenced by many factors, including complexation conditions and starting material properties. Here, cranberry polyphenols extracted from pomace were complexed with nine pea protein isolate starting materials with different physical (particle size and protein content) and chemical (hydrolyzed and oxidized) properties to investigate the impact of protein characteristics on particle functionality. Chemical differences between proteins affected polyphenol binding; oxidized protein isolate (specifically, VegOtein N) bound 12%-27% more polyphenols than other isolates. Polyphenol binding to proteins decreased digestion rates in vitro, averaging 25% slower gastric (pepsin) digestion and a 35% slower intestinal (pancreatin) digestion. Physical differences in protein starting materials affected digestibility; isolate with the largest particle size (specifically, Nutralys F85G) produced particles with the lowest digestion rate. Solubility was impacted by both the process of forming particles and by polyphenol binding; control particles were 56% less soluble, and protein-polyphenol particles up to 75% less soluble, than unmodified proteins. The solubility of unmodified protein isolate starting materials varied widely according to the manufacturing process, but, after complexation, protein-polyphenol particles produced from all protein sources exhibited a similar depressed level of solubility. The desired functional properties of the protein-polyphenol particle food ingredients will be considerably influenced by the properties of the protein isolate starting material.

Comparison of berry juice concentrates and pomaces and alternative plant proteins to produce spray dried protein-polyphenol food ingredients

Spray dried functional food ingredients were prepared by complexing alternative plant protein sources - buckwheat flour alone or blended with pea and rice proteins, with polyphenol sources - blueberry, cranberry and purple muscadine grape extracts from juice concentrates and pomaces - to create colloidal aggregate powders. When fruit pomaces (rather than juice concentrates) were used as polyphenol resources, solid recovery was significantly enhanced, especially for matrices made with pea protein, buckwheat flour or pea-buckwheat blends (over two fold for pea protein-berry pomace aggregates). Polyphenol content and DPPH radical scavenging capacity were, in general, significantly greater for pomace-derived protein-polyphenol aggregates compared to those made with juice concentrates. In particular, the particles produced with muscadine grape pomace presented the highest (p < 0.05) phenolic content (147.3-174.3 mg g-1, 19.4-20.4 mg g-1 and 16.3-21.4 mg g-1 for total phenolic content, anthocyanins and proanthocyanidins respectively), and antioxidant activity (408.9-423.3 μmol TE per g) as well as good spray drying yield (38.6-63.4%). Buckwheat flour, despite its relatively low protein content (13.7%) relative to pea and rice protein isolates (84% and 89%, respectively) still demonstrated high capacity for sorption of flavonoid phytoactive compounds from the berry fruits. These results suggest an efficient plant-based approach to produce value-added protein-polyphenol aggregates with broad utility as healthy food ingredients.