Beneficial effects of high pressure processing on the interaction between RG-I pectin and cyanidin-3-glucoside

The mechanism of pectin in improving anthocyanin stability and the application progress of their complexes: A review

Improving anthocyanin stability is a major challenge for the food industry. Studies have revealed that the interaction with pectin through non-covalent bonds can improve the anthocyanin stability, thus showing the potential to alleviate the above challenges. However, the interactions are highly complex and diverse. Thus, analyzing the effect of this interaction on anthocyanin stability is essential to promote anthocyanin-pectin complexes application in functional foods. Pectin can interact with anthocyanins through covalent and non-covalent interactions, and these interactions are affected by their structure, the external environment, and the processing methods. Through their interaction with pectin, the thermal, color, and storage stability of anthocyanins are improved, enhancing their bioavailability in the gastrointestinal and facilitating their application range in food processing. This review provides a theoretical reference for improving anthocyanin stability and increasing the application range of anthocyanin-pectin complexes.

Antioxidant Activity and Structural Characterization of Anthocyanin-Polysaccharide Complexes from Aronia melanocarpa

Anthocyanins and polysaccharides are among the primary components of numerous foodstuffs, and their interaction exerts a considerable influence on the texture and nutritional value of foods. In order to improve the antioxidant properties and stability of anthocyanins as well as their bioavailability, in this study, anthocyanin-polysaccharide complexes with varying compounding ratios (1:0.5, 1:1.0, 1:1.5, 1:2.0, 1:2.5, 1:3.0) were prepared from Aronia melanocarpa anthocyanins and polysaccharides derived from the fruit pomace of Aronia melanocarpa. These compounds were characterized, and their antioxidant capacity was determined. The findings demonstrated that the antioxidant activity of anthocyanins was markedly enhanced through the process of compounding with polysaccharides. The most efficacious antioxidant effect was determined by measuring the IC50 of the antioxidant activity of mixtures at different anthocyanin/polysaccharide complexing ratios. The results of ultraviolet-visible spectroscopy, infrared spectroscopy, and scanning electron microscopy revealed the features of the anthocyanin-polysaccharide complexes with ratios of 1:0.5, 1:1.0, 1:1.5, and 1:2.5. The anthocyanins and polysaccharides were observed to enhance the intensity of ultraviolet absorption with respect to that of the individual molecules, and it was noted that they were able to bond to each other through hydrogen bonding. Additionally, the morphology of the compositions differed from that of the individual components. This provides a theoretical foundation for the structural design of anthocyanin-polysaccharide-containing foods and the development and utilization of novel food ingredients.

Effect of high-pressure-homogenisation on the interaction between pomegranate peel pectin fractions and anthocyanins in acidic environment

In this study, changes in the basic composition and structural characterisation of water-soluble pectin (WSP), homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) from pomegranate peel were investigated after high-pressure-homogenisation (HPH) at 50 MPa and 300 MPa. The interactions between three pectin and anthocyanin (ACN) complex were also studied. The three pectin fractions were mainly composed of galacturonic acid (34.95%-87.69%), all with low degrees of methyl-esterification ≤41.20%. HPH at 300 MPa increased the binding ratios of ACN to three pectin fractions by 34.22%-34.59%. Changes in the structural characterisation results of pectin confirmed that the depolymerisation and breakdown of the side chains of pectin after HPH promoted electrostatic interactions, hydrogen bond and hydrophobic interaction between pectin and ACN. Correspondingly, the thermal and storage stabilities of ACN in the complex was boosted after HPH at 300 MPa. This study provides insights into the interaction between pectin and ACN under HPH.

Impact of thermal treatment on proanthocyanidin-pectin binary complexes: Insights from structural, rheological, antioxidant, and astringent properties

In this study, the effects of thermal treatments on the structural, rheological, water mobility, antioxidant, and astringency properties of proanthocyanidin (PA)-pectin binary complexes were investigated. Thermal treatments (25, 63, or 85 °C) significantly decreased the particle size but increased the molecular weight of PA-pectin complexes, which indicated that heating altered the intermolecular and intramolecular interactions between PA and pectin. The thermal treatments reduced the apparent viscosity of both pectin and PA-pectin complexes, but the presence of proanthocyanidins (PAs) increased the apparent viscosity and water mobility of the PA-pectin complexes. Antioxidant activity analysis showed that the presence of pectin slightly reduced the antioxidant activity of the PAs, but there were no significant changes in the total phenolic content and antioxidant activity after thermal treatment. Finally, we found that pectin reduced the astringency of the PAs by forming PA-pectin complexes. Moreover, the thermal treatments also significantly reduced the astringency of the PA-pectin complexes.

Unveiling the impact of high-pressure processing on anthocyanin-protein/polysaccharide interactions: A comprehensive review

Anthocyanins, natural plant pigments responsible for the vibrant hues in fruits, vegetables, and flowers, boast antioxidant properties with potential human health benefits. However, their susceptibility to degradation under conditions such as heat, light, and pH fluctuations necessitates strategies to safeguard their stability. Recent investigations have focused on exploring the interactions between anthocyanins and biomacromolecules, specifically proteins and polysaccharides, with the aim of enhancing their resilience. Notably, proteins like soy protein isolate and whey protein, alongside polysaccharides such as pectin, starch, and chitosan, have exhibited promising affinities with anthocyanins, thereby enhancing their stability and functional attributes. High-pressure processing (HPP), emerging as a non-thermal technology, has garnered attention for its potential to modulate these interactions. The application of high pressure can impact the structural features and stability of anthocyanin-protein/polysaccharide complexes, thereby altering their functionalities. However, caution must be exercised, as excessively high pressures may yield adverse effects. Consequently, while HPP holds promise in upholding anthocyanin stability, further exploration is warranted to elucidate its efficacy across diverse anthocyanin variants, macromolecular partners, pressure regimes, and their effects within real food matrices.

Effect of ultrasonic modification on the binding ability of pectin to anthocyanin

BACKGROUND

Pectin was considered as a potential candidate to improve the thermal stability of anthocyanins, and the binding ability of pectin to anthocyanins was influenced by its structure. In this study, sunflower pectins, modified by ultrasound (40 kHz) for different periods of time, were prepared and used to bind with anthocyanins, extracted from purple sweet potato.

RESULTS

Characterization and thermal stability of pectin-anthocyanin complexes were investigated. The ultrasonic modification of pectin resulted in many changes in pectin chemical structure, including degradation of neutral sugar side chains, breakage of methoxyl groups, and increased molecular flexibility. Extension of ultrasonic modification time led to greater changes in pectin chemical structure. Analysis of the binding ability, as determined by Fourier transform infrared spectroscopy and molecular dynamics simulations, revealed that the interaction between pectin and anthocyanins was driven by hydrogen bonding, electrostatic interaction, and hydrophobic interaction. Pectins with different ultrasonic modification times bound with anthocyanins to different extents, mainly resulting from an increase in the number of hydrogen bonds. According to high-performance liquid chromatographic analysis, during heating at 90 °C the stronger the binding ability of pectin and anthocyanin complex, the better was its thermal stability.

CONCLUSION

Ultrasonic modification of pectin could effectively enhance its binding ability to anthocyanin. © 2023 Society of Chemical Industry.

Tunable interactions in starch-anthocyanin complexes switched by high hydrostatic pressure

Native starches usually have poor polyphenol-binding efficiency despite remarkable architectural structures. In this study, the interaction between cyandin-3-O-glucose (C3G) and three starches under high hydrostatic pressure was investigated. Pressure (200-550 MPa) was found to promote the binding rate of potato starch from 31.6% to 47.0% but reduced that of corn and pea starch to below 10% at 550 MPa. Microscopy results showed that pressurized corn and pea starch-C3G complexes partially or completely lost spatial structures, whereas potato starch-C3G complexes retained structural integrity. The former had decreased zeta potentials and increased particle sizes at 550 MPa, suggesting surface charges and specific surface area losses caused poor binding. Potato starch-C3G complexes, however, exhibited unchanged zeta potential and particle size but the strongest fluorescence at 200 MPa, indicating a positive binding shift from surface to interior. Overall, high hydrostatic pressure can regulate the interactions of native starches with anthocyanins via spatial structural changes.

Effects of sunflower pectin on thermal stability of purple sweet potato anthocyanins at different pH

The present study aimed to examine the impact of sunflower pectin (SFP) on the thermal stability and antioxidant activity of purple sweet potato anthocyanins (PSPA) at varying pH levels. It was observed that the pH value significantly influenced the ability of pectin to protect anthocyanins from thermal degradation, which was found to be associated with the rate of binding between PSPA and SFP. The binding rate of PSPA-SFP was observed to be highest at pH 4.0, primarily due to the influence of electrostatic interaction and hydrogen bonding. Monoacylated anthocyanins exhibited a binding rate approximately 2-4 % higher than that of diacylated anthocyanins. The PSPA-SFP demonstrated its highest thermal stability at pH 4.0, with a corresponding half-life of 14.80 h at 100 °C. Molecular dynamics simulations indicated that pectin had a greater affinity for the flavylium cation and hemiketal form of anthocyanins. The antioxidant activity of anthocyanins in PSPA and PSPA-SFP increased with increasing pH, suggesting that anthocyanins at high pH had higher antioxidant activity than anthocyanins at low pH.

Characterize the physicochemical properties and microstructure of pectin from high-pressure and thermal processed cloudy hawthorn (Crataegus pinnatifida) juice based on acid heating extraction

Physicochemical properties and morphological features of pectin in high-pressure-processing (JHPP) and thermal-processing (JTP) treated cloudy hawthorn juice were investigated based on acid heating extraction. Pectin from hawthorn juice was identified as low methoxy pectin (41.77%), which was significantly reduced to 34.56%-39.51% from JHPP, while pectin esterification degree (DE) from JTP increased to 45.58%, which can also be confirmed by Fourier transform infrared spectroscopy. In comparison to control, pectin linearity of JHPP and JTP significantly decreased with more highly branched-chains. However, no significate difference was observed in thermostability, crystallinity and main functional groups. Interestingly, a large number of aggregations was observed in JHPP pectin, and the intermodular distance of JTP pectin was enhanced, which was consistent with the results of viscosity, molecular weight and DE. These findings provided insights into utilization of hawthorn pectin and application of high-pressure processing (HPP) for improving quality property of fruit products by pectin modification.