Edible Polysaccharides Stabilize Phenolic Compounds and Pigments in Food Formulations, Enhancing Bioaccessibility

The increasing demand for functional foods with enhanced bioactive compounds drives research into effective delivery systems, and a team led by Liliane Siqueira de Oliveira, Davi Vieira Teixeira da Silva, and Lucileno Rodrigues da Trindade, all from the Federal University of Rio de Janeiro, alongside Vitor Francisco Ferreira from the Federal Fluminense University, investigates the potential of edible polysaccharides to stabilise and deliver phenolic compounds and pigments. Their work demonstrates how these naturally occurring carbohydrates, such as starch, pectin, and chitosan, effectively encapsulate these beneficial compounds, protecting them during food processing and improving their availability within the body. This research highlights the ability of polysaccharide mixtures to create highly efficient microparticles, achieving up to 90% encapsulation through interactions like hydrogen bonding, and ultimately paving the way for more nutritious and stable food formulations. The findings represent a significant step towards harnessing the full potential of bioactive compounds in food, addressing a critical need for improved delivery systems and enhanced bioavailability.

Polysaccharide and Protein Microencapsulation for Bioactives

Researchers extensively investigate microencapsulation using polysaccharides and proteins to protect and deliver valuable bioactive compounds like polyphenols, anthocyanins, carotenoids, and oils. Combinations of polysaccharides and proteins leverage complementary properties; polysaccharides form protective films while proteins contribute to stability and controlled release. Frequently employed combinations include inulin with maltodextrin and gum arabic with whey protein or inulin, highlighting gum arabic’s excellent film-forming and emulsifying capabilities. Alginate and chitosan also combine, forming complexes with bioactive compounds through electrostatic interactions.

Polyphenols and anthocyanins are frequently encapsulated due to their sensitivity to degradation and recognized health benefits. Carotenoids, such as lycopene and beta-carotene, are also common targets, aiming to improve their stability and bioavailability. Encapsulation protects oils from oxidation and enhances their dispersibility. Spray drying is a common encapsulation technique, offering scalability and cost-effectiveness. Other techniques include extrusion/ionic gelation, frequently used with alginate and chitosan to create spherical microparticles, and freeze-drying, which produces powders with high stability and good dispersibility.

Particle sizes vary significantly, ranging from sub-micron to several hundred microns, depending on the materials and techniques used. Many studies report high encapsulation efficiencies, often exceeding 80%. A major goal is controlled release, and numerous studies demonstrate sustained release of bioactive compounds in vitro, simulating digestion. Some formulations release their payload in response to specific pH changes, such as in the intestine. Encapsulation generally improves the stability of bioactive compounds against degradation from oxidation, heat, and light during storage. The combination of materials proves crucial, with synergistic effects often observed. This research highlights the potential of microencapsulation to protect sensitive compounds, improve their stability, and enhance their bioavailability, offering innovative solutions for food, pharmaceutical, and cosmetic applications.

Polysaccharide Microencapsulation Enhances Bioactive Compound Stability

Researchers systematically investigated polysaccharide-based microencapsulation to enhance the stability and bioavailability of bioactive compounds like polyphenols and pigments. They pioneered spray drying and freeze-drying to produce microparticles, employing polysaccharides including starch and gum arabic as wall materials. These techniques entrap hydrophilic and hydrophobic compounds through physical interactions, forming a protective barrier around the core substance or directly binding to it. Intermolecular binding, governed by hydrogen bonds and electrostatic interactions, can achieve up to 90% encapsulation efficiency within the microparticle matrix.

Detailed analysis focused on maltodextrin, a starch hydrolysate, and its encapsulation capacity. Scientists generated maltodextrin polymers through controlled acid or enzymatic hydrolysis of starch, resulting in varying degrees of dextrose equivalent (DE), ranging from 3 to 20. These differing DE values produce polymers with distinct physical and chemical properties, influencing encapsulation performance. High DE maltodextrins (16-20) provide excellent stability to volatile compounds due to smoother surfaces and numerous hydroxyl groups facilitating hydrogen bonding. Maltodextrin forms a network of double helical chains and long-chain aggregates at high concentrations, creating a hydrophobic core capable of complexing with bioactive compounds.

Researchers successfully encapsulated annatto extracts with 86% efficiency, achieving 97% solubility and 60-day storage stability. Freeze-dried beetroot microparticles prepared with maltodextrin retained 88% of betalains and higher concentrations of phenolic acids. Spray drying and freeze-drying of black carrot juice using DE 20 maltodextrin yielded 98% encapsulation efficiency and an anthocyanin content of 1461. 23mg/100g, accompanied by an antioxidant capacity of 329. 40 mmol Trolox/g. Lower DE maltodextrins (DE10) can achieve 87% encapsulation of stevia extract, suggesting a complex relationship between hydrolysis degree and encapsulation performance. These findings highlight the potential of tailored polysaccharide compositions to optimize the delivery and bioactivity of functional food ingredients.

Polysaccharide Carriers Enhance Bioactive Compound Stability

This work demonstrates the remarkable potential of modified polysaccharides as effective carriers for bioactive compounds, significantly enhancing their stability and bioaccessibility. Intermolecular binding between polysaccharides and bioactive compounds, governed by hydrogen bonds and electrostatic interactions, can achieve up to 90% encapsulation efficiency. Mixtures of wall polysaccharides in microparticle synthesis favor solubility, storage stability, bioaccessibility, and bioactivity of encapsulated compounds. Experiments using hydrolyzed starch at a 1:1 wall-to-core ratio achieved 76% encapsulation of carotenoids from Psidium cattleianum Sabine extracts via spray drying, simultaneously improving retention of total phenolics, carotenoids, and anthocyanins.

This formulation also maintained antiradical activity as measured by DPPH• and ABTS•+ assays. Encapsulated compounds exhibited a half-life ranging from 23 to 37 days, demonstrating prolonged stability. Modified OSA-starch microparticles retained 67% of anthocyanins from Euterpe edulis Martius pulp, while promoting 83% water solubility. A combination of 66% OSA-starch, 16% maltodextrin, and 16% inulin proved optimal for maintaining anthocyanin stability and antioxidant polyphenol power after 38 days under unfavorable storage conditions. Porous corn starch, used as a coating material for curcumin and resveratrol, achieved encapsulation efficiencies exceeding 80%, although surface area saturation can limit polyphenol loading.

OSA-modified taro starch microparticles, produced at a 1:3 core-to-wall ratio, encapsulated 61% of total phytosterols and phenolic compounds from pomegranate seed oil. These microparticles released 6. 63% and 49. 8% of bioactive compounds under simulated gastric and intestinal conditions, indicating controlled release potential. These results confirm the ability of modified polysaccharides to protect sensitive compounds and enhance their delivery, opening avenues for improved food products and nutraceutical formulations.