Polysaccharide selection and mechanism for prevention of protein-polyphenol haze formation in beverages

Investigation of the interaction mechanism of citrus pectin-polyphenol-protein complex

Citrus pectin is an anionic polysaccharide in citrus, which may improve the stability of citrus juices. This study investigated the influence of citrus pectin on the stability of protein-polyphenol complexes in the citrus juice model system and its interaction mechanism by multispectral and molecular dynamics (MD) simulations. Dynamic light scattering (DLS) and differential scanning calorimetry (DSC) showed that the citrus pectin-proanthocyanidin-zein complex improved the model citrus juices' cloud and thermal stability. Molecular dynamics (MD) simulations suggested that both pectin and proanthocyanidin bound to the U-shaped cavity of the zein molecules. Electrostatic and van der Waals forces were predominant in citrus pectin-zein. In contrast, van der Waals forces predominantly drove in proanthocyanidin-zein. This study indicated that citrus pectin could stabilize juice by delaying the onset of protein-polyphenol haze formation, which may provide new strategies for improving the quality, stability, and nutritional profile of fruit juice systems.

Effect and mechanism of calcium ions on the astringency in green tea infusion and epigallocatechin gallate solution: An in vitro oral soft tribology study

In this study, the effect of calcium ions (Ca2+) on the astringency sensation in green tea infusion was explored using sensory evaluation, in vitro oral soft tribology, and targeted metabolomics. Ca2+ enhanced the astringency intensity (from 2 to 6) and the turbidity (from 10.0 to 83.3), and decreased the particle size (from 1468.0 to 817.65) in cold-brewing tea. Catechins influenced the astringent sensation in the presence of Ca2+ and the content of (-)-Epicatechin, (-)-Epigallocatechin, and (-)-Epigallocatechin gallate (EGCG) solution in green tea infusion after oral processing all reduced. The friction coefficient of hot-brewed tea (μ, 1.6-2.8) was greater than that of cold-brewed tea (μ, 1.0-2.6), and EGCG increased with the enlarged Ca2+ concentrations. Ca2+ increased the astringency mainly through catechins and saliva lubrication. The in vitro soft oral tribology could be usefully explored the enlarged astringency sensation by Ca2+, and applied to the astringency regulation of beverages.

Mathematical modeling and optimization of pasteurization for the internal pressure and physical quality of canned beer

Globally, beer is the most popular alcoholic beverage. To accomplish microbial stabilization and extend the shelf life of beer, it is typically subjected to in-package pasteurization using a tunnel pasteurizer. However, high internal pressure can cause can bulging during pasteurization, leading to significant product loss. In this study, an empirical mathematical model was constructed to describe the effects of can thickness (0.245-0.270 mm), fill volume (320-338 mL), carbon dioxide content (5.70-6.10 g/L), and pasteurization temperature (59-66 °C) on the internal pressure inside canned beer. A laboratory-scale pasteurization setup was used to pasteurize samples based on the worst-case scenario of commercial pasteurization. The mathematical model (R2 = 0.90) showed that all parameters significantly influenced the internal pressure of pasteurized canned beer (p < 0.05). Additionally, the physical, chemical, and biological properties of pasteurized canned beer were assessed. All values fell within an acceptable range of industrial standards. A simplified 2nd-order polynomial equation (R2 = 0.90) was created and verified for industrial use. The data are well represented by the simplified model, which suggests that it could be used for optimization of product- and process parameters to reduce the occurrence of can bulging in commercial pasteurization of canned beer.

Comparison in structural, physicochemical and functional properties of sweet potato stems and leaves polysaccharide conjugates from different technologies

In order to better understand the influences of extraction techniques on the yield, characteristics, and bioactivities of polysaccharide conjugates, hot reflux extraction (HRE), ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE), complex enzymolysis extraction (CEE), ultra-high pressure extraction (UPE), ultrasonic complex enzymes extraction (UEE) were used to extract sweet potato stems leaves polysaccharide conjugates (SPSPCs), and their physicochemical characteristics, functional properties, antioxidant and hypoglycemic activities were compared. Results showed that compared with HRE conjugate (HR-SPSPC), the yield, content of uronic acid (UAC), total phenol (TPC), total flavonoid (TFC) and sulfate group (SGC), water solubility (WS), percentage of glucuronic acid (GlcA), galacuronic acid (GalA) and galactose (Gal), antioxidant and hypoglycemia activities of UEE polysaccharide conjugates (UE-SPSPC) significant increased, while its molecular weight (Mw), degree of esterification (DE), content of protein (PC) and percentage of glucose (Glc) declined, but monosaccharides and amino acid types, and glycosyl linkages were not much different. Indeed, UE-SPSPC possessed the highest antioxidant activities and hypolipidemic activities among six SPSPCs, which might be due to the high UAC, TPC, TFC, SGC, GlcA, GalA and WS, low Mw, DE and Glc of UE-SPSPC. The results reveal that UEE is an effective extraction and modification technology of polysaccharide conjugates.

Hawthorn Juice Simulation System for Pectin and Polyphenol Adsorption Behavior: Kinetic Modeling Properties and Identification of the Interaction Mechanism

The interaction between polyphenols and polysaccharides plays an important role in increasing the turbidity stability of fruit juice and improving unpleasant sensory experiences. The binding adsorption behavior between hawthorn pectin (HP) and polyphenols (epicatechin and chlorogenic acid) accorded with the monolayer adsorption behavior driven by chemical action and were better fitted by pseudo-second order dynamic equation and Langmuir model. The HP binding sites (Qm) and adsorption capacity (Qe) to epicatechin were estimated at 75.188 and 293.627 μg/mg HP, respectively, which was about nine and twelve times higher than that of chlorogenic acid. The interaction between HP and polyphenols exhibited higher turbidity characteristics, particle size and lower zeta potential than epicatechin and chlorogenic acid alone. Meanwhile, according to Fourier Transform Infrared Spectroscopy (FT-IR) analysis, it could be speculated that the interaction between HP and polyphenols resulted in chemical combination. Moreover, ΔH < 0 and TΔS < 0, which indicated that the interaction between HP and polyphenols was mainly driven by hydrogen bonds and van der Waals forces.

Removal of astringency from persimmon paste via polysaccharide treatment

Non-astringent persimmon (Diospyros kaki Thunb.) paste is typically produced by treating astringent persimmon fruit with alcohol or dry ice (to remove tannins) followed by abrasion. However, considering the large yield of astringent persimmons harvested in a short time, this long, laborious method has hindered the use of persimmon paste in food processing. Herein, the addition of polysaccharides was used to produce a non-astringent persimmon paste while maintaining its quality. Among the nine evaluated polysaccharides, high- (HM) and low-methoxyl (LM) pectins, carrageenan, xanthan gum, and sodium alginate exhibited high astringency removal efficiencies. No astringency recurrence was observed after freezing when HM or LM pectin, guar gum, carrageenan, or sodium alginate were added. Moreover, the addition of HM pectin, or LM pectin, or sodium alginate prevented astringency upon heating. Additionally, guar, xanthan, tara gum, or carrageenan effectively inhibited syneresis. Thus, high-quality pastes could be easily and efficiently produced using a combination of polysaccharides.