Influences of structural characteristics of phenolic compounds on the properties of potato starch were investigated, and their effects on the quality, function, and digestion of potato starch noodles ...were further determined. All testing phenolic compounds (including protocatechuic acid PA, naringin NA, and tannic acid TA) exhibited the significant capability to modify the thermal properties, rheological properties, and enzymatic hydrolysis of potato starch. The high amount of hydroxyl groups, the presence of glycoside structure, appropriate molecular size, and steric hindrance were beneficial to enhance their effects on potato starch. In addition, by changing the microstructure of starch hydrocolloids, PA, NA, and TA could affect the color, texture properties, and cooking properties of potato starch noodles. Meanwhile, PA and TA could endow potato starch noodles with remarkable antioxidant activity. Furthermore, the in vitro digestion of potato starch noodles was obviously inhibited by phenolic compounds, especially for TA. All present results suggested that structural characteristics of phenolic compounds affected their interaction affinity and combination degree with potato starch molecules, so as to modify the properties of starch and affect the quality, function, and digestion of starchy foods, which showed the valuable applications in food and chemical industries.
Practical Application
The property, function, and digestion characteristics of potato starch show the significant effects on the quality of potato starch products in food industry. In present study, the thermal properties, rheological properties, and enzymatic hydrolysis of potato starch were modified by different phenolic compounds (including protocatechuic acid, naringin, and tannic acid) in varying degrees, whereas the quality, antioxidant activity, and digestion characteristic of potato starch noodles were modified by phenolic compounds with different structures. All results showed the potential application and interaction regularities of phenolic compounds as natural additives for potato starch processing in food industry.
A functional yogurt was prepared with Ligustrum robustum (Rxob.) Blume extract (LRE), while its antioxidant and hypoglycemic activities were evaluated and its action mechanism was further explored. ...With the cofermentation of LRE, the yogurt showed the fine quality characteristics, including pH, titratable acidity, texture, syneresis susceptibility, color, microbiological content, and chemical composition. Meanwhile, the yogurt exhibited the remarkable antioxidant capability to enhance the activities of antioxidant enzymes and reduce the malondialdehyde level in animal serums. In addition, the yogurt showed the obvious hypoglycemic activity to inhibit the decrease of glucose tolerance and the increase of postprandial hyperglycemia of diabetes mice. Furthermore, using the analysis of molecular docking, the main compounds of LRE could combine tightly with α‐amylase and α‐glucosidase by hydrogen bond and hydrophobic interaction, so as to change their spatial structure and inhibit their biocatalytic activity in glucose metabolism. All present results suggested that LRE showed the potential value to be used as supplement to enhance the quality and functions of yogurt in food industry.
Practical Application
The hypoglycemic and antioxidant activities of a functional yogurt cofermented with LRE were found and its relative action mechanism was also explored. This work provide the experimental and theoretical basis for the application of this yogurt as nutraceuticals to protect human health in food industry.
The effects and action mechanism of tea polyphenols (TP) on the quality of rapeseed oil during frying process were investigated. Results showed that compared with control, TP (0.04%, w/w) exhibited ...the remarkable ability to inhibit the deterioration of acid value, peroxide value, anisidine value, viscosity, and color of frying oil. By using gas chromatography‐mass spectrometry, frying oil with TP showed the higher content of unsaturated fatty acids (72.79%) and lower content of trans fatty acids (3.36%) than those of control. Meanwhile, frying oil with TP had a higher total phenolic content than control at the same frying time. In addition, the thermo gravimetric‐differential scanning calorimetry results showed that TP could increase the oxidation stability of rapeseed oil. Furthermore, according to the Fourier transform infrared and molecular dynamic simulation results, TP could reduce the breaking degree of = C–H bond, C–O–C bond, and C = C bond in oil molecules, and inhibit the oxidation of oil components by inhibiting the generation of free radicals and eliminating free radicals. All present results suggested that TP showed the potential value to be used for protecting the quality of oil during the frying process in food and chemical industries.
Practical Applications
The inhibitory effect of tea polyphenols on the deterioration of quality of rapeseed oil during frying was found and the mechanism had also preliminarily interpretation. This work provided a method for monitoring the quality of fry oil and provided the theoretical basis for the use of tea polyphenols in frying.
The increasing concerns about health have led to a growing demand for high‐quality fried foods. The potential uses of Ligustrum robustum (Rxob.) Blume, a traditional tea in China, as natural ...additives to enhance the quality of starchy food during frying was studied. Results indicated that L. robustum polyphenols extract (LREs) could improve the quality of fried starchy food, according to the tests of color, moisture content, oil content, texture property, and volatile flavor. The in vitro digestion results demonstrated that LRE reduced the final glucose content from 11.35 ± 0.17 to 10.80 ± 0.70 mmol/L and increased the phenolic content of fried starch foods from 1.23 ± 0.04 to 3.76 ± 0.14 mg/g. The appearance and polarizing microscopy results showed that LRE promoted large starch bulges on the surface of fried starchy foods. Meanwhile, X‐ray diffraction results showed that LRE increased the intensity of characteristic diffraction peak of fried starch with a range of 21.8%–28%, and Fourier transform infrared results showed that LRE reduced the damage to short‐range order structure of starch caused by the frying process. In addition, LRE increased the aggregation of starch granules according to the SEM observation and decreased the enthalpy of starch gelatinization based on the differential scanning calorimetry results. The present results suggest that LREs have the potential to be utilized as a natural additive for regulating the quality of fried starchy food in food industries.
Practical Application
The enhancement of L. robustum polyphenols on the quality of starchy food during frying was found, and its mechanisms were also explored. This work indicated that L. robustum might be used as a novel economic natural additive for producing high‐quality fried foods.
Effect of tea polyphenols (TP) on the quality of Chinese steamed bun (CSB) was investigated, while the interaction and action mechanism between TP and vital wheat gluten (VWG, constitutive proteins ...of flour) were further explored. With a low concentration (1%) of TP, CSB showed positive changes in quality, and the hardness of CSB decreased by 33.95%, while its specific volume, springiness, and resilience separately increased by 1.8%, 11.9%, and 5.5%, whereas the higher concentrations of TP (2% and 4%) caused an adverse impact. By observation of scanning electron microscope, VWG formed a fluffier structure with a low concentration of TP, while the structure deteriorated at high concentration of TP. In addition, the secondary and tertiary structures of VWG were both changed by TP. Along with the results of thermodynamic analysis (thermogravimetric and differential scanning calorimetry measurements), TP could induce the structural rearrangement of VWG. Further, a lower amidogen and sulfhydryl contents of VWG were obtained in TP groups, which illustrated that peptide and disulfide bonds of VWG were not possibly interrupted by TP. Instead, hydrophobic residues of VWG were bonded to form a more hydrophilic structure. Moreover, according to molecular docking results, epigallocatechin‐3‐gallate interacted tightly with VWG by hydrogen bonds and hydrophobic actions, and the action sites were mainly at hydrophobic and hydrophilic residues. All results suggested that the VWG structure was affected greatly by TP, and a low dose of TP might be potential to improve the quality of flour products.
Practical Application
The physicochemical properties of gluten show the significant effects on the quality of flour products in food industry. In the present study, a low dose of tea polyphenols exhibited a strengthened effect on gluten, so as to ameliorate the texture of Chinese steamed bun (CSB) due to their tight interactions with gluten, while the color of CSB was changed to brown as tea polyphenols. All results suggested that a low dose of tea polyphenols could be potentially utilized to improve flour quality and enhance gluten strength in food industry.
► Polysaccharides from Auricularia auricular (AAP) were extracted using MAE. ► Influence of MAE to structure and antioxidant activity of AAP was determined. ► The structure of AAP was elucidated by ...chemical and instrumental analysis. ► AAP showed the significant antioxidant activity in vitro systems. ► MAE can improve the antioxidant activity of AAP with no obvious change in structure.
Influence of microwave-assisted extraction (MAE) to the characterization and corresponding antioxidant activity of polysaccharides from Auricularia auricula (AAP) was determined. According to gas chromatography–mass spectrometry, high performance size exclusion chromatography, Fourier transform infrared spectroscopy, partial acid hydrolysis, periodic acid oxidation, Smith degradation, methylation analysis and atomic force microscopy, AAP was a heteropolysaccharide (composed of glucose, galactose, mannose, arabinose and rhamnose at the molar ratio of 37.53:1:4.32:0.93:0.91) with the molecular weight of 2.77×104Da, observed as a spherical lump, and the backbone of AAP was mainly composed by glucose with (1→3) linked. Moreover, AAP exhibited significant in vitro antioxidant activity in scavenging free radicals (ABTS, DPPH, superoxide and hydroxyl radicals), in lipid peroxidation and reducing power assays. The present result suggested that AAP by MAE had low molecular weight and remarkable antioxidant capability.
The interaction and action mechanism of starch with different phenolic compounds were investigated. By using scanning electron microscope, nuclear magnetic resonance, Fourier transform infra-red ...spectroscopy and thermogravimetric analysis, phenolic compounds exhibited the significant effects on the morphology, intensity of hydrogen bond, crystalline structure and thermal stability of starch, respectively. Furthermore, according to the analysis of molecular dynamics simulation by using short-chain glucose (SGS) as model, phenolic compounds could change the spatial configuration of starch, and had the obvious effects on the formation of hydrogen bonds (including intra- and intermolecular hydrogen bonds) and the strength of binding free energy. Meanwhile, epigallocatechin gallate possessed the strongest capacity to change the spatial configuration of starch with the consistent hydrogen bond occupancy and the lowest binding free energy. All present results suggested that phenolic compounds might be potentially utilised for improving the quality of starch in food industry.
Effects of tea polyphenols (TP) on the physical properties, barrier properties and functionality of potato starch-based film were determined, while the interaction mechanism between TP and starch in ...film and the application of this film in fruit packaging were further evaluated. TP exhibited different effects on the physical properties of potato starch-based film, including thickness (0.083 to 0.087 mm), moisture content (9.27% to 9.68%), color (Δ
value: 5.41 to 10.55), light transmittance (51% to 62%), tensile properties and thermal properties, and improved its barrier properties, including water vapor permeability (9.68 to 11.84 × 10
g m
s
Pa
),oxygen permeability (1.25 to 2.78 × 10
g m
s
Pa
) and antioxidant activity. According to the determination of wide-angle X-ray diffraction, Fourier transform infrared and scanning electron microscope, TP could interact with starch chains via hydrogen bonds to form non-crystal complexes, thus affecting the cross-linking among starch chains and further changing the microstructure of film. Furthermore, film incorporated with TP could improve the storage quality (including weight and texture) of blueberries, and inhibit the enzymatic browning of fresh-cut bananas during storage. All present results suggested that tea polyphenols had potential to enhance the properties and function of potato starch-based film, and the film exhibited the application prospect in fruit packaging and preservation.
The effect of tea polyphenols (TP) on the rice starch (RS) was investigated and the interaction mechanism between TP and RS was further analyzed. TP exhibited a remarkable capacity to affect the ...processing properties (including the texture property and color) of RS in cold rice cake. Meanwhile, TP exhibited a significant effect on the solubility, swelling power, gelatinization property, rheological property, gel property, and microstructure of RS. Furthermore, according to the molecular dynamics simulation using epigallocatechin gallate (EGCG) and two parallel short‐chain glucose (SGS) as a testing model, EGCG could interact with two SGS chains by hydrogen bonds, and could change the SGS‐wound form and molecular force (including intra‐ and intermolecular hydrogen bonds) in heating and cooling period. All results suggested that TP had the obvious effects on starch food by affecting its gelatinization and retrogradation.
Practical applications
There are many kinds of starch food, which are important energy sources for the human body. However, during the processing and storage periods, the unfavorable changes in the starch property may cause the quality deterioration of starch food, which can affect the taste, nutrition, and sale of starch food. In the present study, tea polyphenols (TP) were used as supplement fortified in starch to affect the color, taste, and quality of starch food, and the action mechanism of molecular interaction was also revealed. The present study suggested that TP showed the potential value to ameliorate the quality of starch food and extended its shelf life during its processing and storage in the food industry.
