Modification of insoluble dietary fiber from rice bran with dynamic high pressure microfluidization: Cd(II) adsorption capacity and behavior

The aim of the study is to improve the physicochemical and Cd(II) adsorption properties of rice bran insoluble dietary fiber (RBIDF). Dynamic high pressure microfluidization (DHPM) (0–150 MPa for 2 times) was investigated as a modification process for RBIDF, determining its effects on physicochemical, structural and Cd(II) adsorption properties. After a 30 MPa treatment, the flake-like surface of RBIDF changed into a fluffy and slightly expanded morphology. However, DHPM-treated RBIDFs at 60, 90 MPa were fragmented and separated into smaller chips. DHPM increased the RBIDF specific surface area and total negative charge. Among all samples, DHPM-treated RBIDF at 150 MPa exhibited the highest Cd(II) adsorption capacity (60.5 μmol/g at pH 2.0), which was 1.46 times that of the untreated sample. Cd(II) adsorption was well described by the pseudo-second-order kinetics and Langmuir isotherms models, and Cd(II) removal rate was as high as 56.9% in the simulated small intestine. In conclusion, DHPM shows great potential for enhancing the Cd(II) adsorption capacity by RBIDF.Industrial relevanceThis research deals with the modification of RBIDF by DHPM treatments. The treatments at 120 or 150 MPa obviously increased Cd(II) adsorption capacity by unfolding the stiff structure to expose more oxygen-containing functional groups. DHPM is thus a safe and eco-friendly method to improve the physicochemical and adsorbent properties of RBIDF, which is a promising ingredient for use in food applications.     

Insights into the effects of dynamic high-pressure microfluidization on the structural and rheological properties of rapeseed protein isolate

The application of dynamic high-pressure microfluidization (DHPM) provides interesting modifications in food structures. However, the effects of DHPM on the structural and rheological properties of rapeseed protein isolate (RPI) were scarcely investigated. In this study, the average hydrodynamic size of RPI treated by DHPM significantly declined from 239.2 nm to 170 nm with the pressure and time rising to 60 MPa and 2 min. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis found that DHPM did not affect the molecular mass of the RPI. The changes in the intrinsic fluorescence and circular dichroism spectra showed that tertiary and secondary structures of RPI were altered, as proved by the higher fluorescence intensity and greater conversion of random coils and β-sheets into α-helices compared with the control (unprocessed RPI). The spatial unfolding of the RPI structure and the dissociation of chemical bonds influenced its rheological behavior. All RPI suspensions (15%, w/v) processed by DHPM had lower apparent viscosity, moduli, higher gelling temperature (up to 69.7 °C) than control, and the differences in rheological performance were closely dependent on the treatment pressure and time. In conclusion, through this study of the effects of DHPM on RPI, DHPM was shown to be a potential method for modifying proteins and reducing the consistency of high-protein fluid foods.     

Combination of high-pressure homogenization and ultrasound improves physiochemical,interfacial and gelation properties of whey protein isolate

The main purpose of this work was to investigate the influence of high-pressure homogenization (HPH, 60, 90, and 120 MPa, three cycles) combined with ultrasound (US, 120, 360, and 600 W, 30 min) on the physiochemical, interfacial, and gelation properties of whey protein isolate (WPI). Compared with an individual application of HPH or US, a combined HPH-US treatment can further reduce average particle size (D_4,3) and turbidity of WPI, while significantly ameliorating its surface hydrophobicity, fluorescence intensity, and free sulfhydryl content. Compared with that of an untreated WPI, the emulsifying ability index (EAI) of WPI was increased by 8.54% after a 120 MPa HPH and by 7.63% after a 600 W US, whereas it increased by 13.97% after a combined treatment of 120 MPa and 600 W HPH-US. Accordingly, the foaming ability (FA) and the foaming stability (FS) were enhanced by 26.10% and 118.18% at 120 MPa and 600 W, respectively. The hardness of WPI gel was also increased by 170.45% at 120 MPa and 600 W compared to the untreated WPI. Therefore, the combination of HPH and US could make a remarkable improvement in the physicochemical functional characteristics of WPI, providing basic data support for the food industry to obtain excellent novel WPI ingredients.     

The effect of dynamic high-pressure microfluidization on the activity,stability and conformation of trypsin

Dynamic high-pressure microfluidization (DHPM) treatment of trypsin showed no significant effects with relative activities of 98.5% (80 MPa), 98.3% (100 MPa), 97.8% (120 MPa) and 97% (160 MPa). However, DHPM treatment enhanced the pH and thermal stability of trypsin. After 100 min of incubation at 45 °C, the residual activity of trypsin treated at 80 MPa was still as high as 96% while the untreated trypsin retained only 86% of its original activity. The optimum pH of trypsin maintained surprising consistency (pH = 7.6); nevertheless, the relative activities were about 97%, 102% and 103% at 80, 100 and 120 MPa, respectively. In addition, DHPM-induced conformational changes of trypsin were observed. The unfolding of trypsin, induced by DHPM treatment, was reflected in the increase in maximum emission fluorescence intensity and exposed SH contents, as well as the decrease in total SH contents, UV absorbance and α-helix intensity.     

动态高压微射流协同糖基化对β-乳球蛋白乳化性和结构的影响

采用动态高压微射流（dynamic high pressure microfluidization,DHPM）协同糖基化处理β-乳球蛋白,研究改性β-乳球蛋白乳化性、乳化稳定性和结构的变化。研究发现DHPM协同糖基化处理过程中β-乳球蛋白结构变化与其乳化性能可能存在关联;DHPM协同糖基化处理能显著提高β-乳球蛋白的乳化性和乳化稳定性。0、40、120 MPa糖基化处理后β-乳球蛋白的乳化活性指数（emulsifying activity index,EAI）分别为136.3、168.1、177.9 m2/g。0 MPa协同糖基化处理后β-乳球蛋白的乳化稳定指数（emulsifying stability index,ESI）为52.3 min;随着压强逐渐增加至40 MPa和120 MPa,协同糖基化处理后ESI值分别升高为56.4 min和59.0 min。通过表征分析β-乳球蛋白结构变化发现：不同压力DHPM协同糖基化处理后,β-乳球蛋白分子质量升高;巯基含量升高;表面疏水性降低;二级结构变化以及氨基酸三维空间构象暴露程度发生变化。这些变化说明β-乳球蛋白与低聚半乳糖发生共价交联时改变了蛋白质结构,造成β-乳球蛋白表面亲水基团的增加,从而导致其乳化性能显著提高。     

Effects of high hydrostatic pressure treatment on structural,allergenicity, and functional properties of proteins from ginkgo seeds

The effects of high hydrostatic pressure (HHP) treatment on the structural, allergenicity and functional properties of ginkgo seed protein (GSP) were investigated. GSP was treated under pressures of 100, 200, 300, 400, 500, 600 and 700 MPa. Western blotting and ELISA assay revealed that HHP treatment at pressure ranges from 300 up to 700 MPa can significantly reduce the allergenicity of GSP. Meanwhile, SDS-PAGE, MALDI-TOF-MS, CD spectra, fluorescence spectra and UV absorption spectra analysis revealed that, after HHP treatment, the GSP disintegrated into proteins with small molecular weights ranging from 4 to 30 kDa; the secondary structures of α-helices and β-sheet were largely destroyed and turned into random coil; and the UV absorption intensity, surface hydrophobicity and sulfhydryl group (SH) content of GSP were significantly increased. Moreover, the HHP-treated GSP showed markedly improved heat stability and emulsifying properties compared to the untreated GSP.Industrial relevanceAs a traditional food and medicine source, the seeds of Ginkgo biloba were used in china for several thousand years. Ginkgo seeds could be added to desserts, glazed fruit, beverages and tipple, also ginkgo seeds, as a traditional Chinese medicinal material, have been recorded in the Compendium of Materia Medical. Research shows that ginkgo seeds have a relatively high content (10%–15%) of proteins, which possess rich and reasonable composition of amino acids, and much higher content of essential amino acids than the recommended FAO/WHO standard, belonging to the high-quality protein. Ginkgo seeds proteins (GSP) have many biological activities, including anti-oxidation, anti-aging, anti-tumor, and anti-bacterial, so it has high value of nutrition and medicine. However, eating GSP could result in allergic reaction to humans, infant, or children are more sensitive to GSP, the clinical symptoms such as nausea, vomiting, bellyache, diarrhea, dysphoria, exanimation, convulsions, dyspnea, and mydriasis, and sometimes even death can occur.In the study, we used the method of high hydrostatic pressure (HHP) treatments, which can significantly improve the functional properties and reduce the antigenicity of GSP. After the HHP treatment, GSP can be transformed into proteins with small molecular weights ranging from 4 to 30 kDa, the antigenicity of GSP can be reduced by more than 95%, and the heat stability and emulsifying properties of GSP can be markedly improved. Thus, this study is very helpful for designing the hypoallergenic and improved functional GSP, which could have a relevant practical application for their use as base ingredients of food.     

Effect of dynamic high-pressure microfluidization at different temperatures on the antigenic response of bovine β-lactoglobulin

The antigenic response of β-lactoglobulin (β-Lg), treated by dynamic high-pressure microfluidization (DHPM) at different temperatures, was determined by an indirect competitive enzyme-linked immunosorbent assay using polyclonal antibodies from rabbit serum. DHPM treatment causes changes in the protein structure and may influence the antigenicity of β-Lg. DHPM treatment of β-Lg at 90 °C showed significant effects with the antigenic response of 5.2 μg mL⁻¹ (untreated), 45 μg mL⁻¹ (40 MPa), 79 μg mL⁻¹ (80 MPa), 132 μg mL⁻¹ (120 MPa), and 158 μg mL⁻¹ (160 MPa). In combination with temperature treatment (70–90 °C), the antigenic response enhanced as the temperature increased at 160 MPa. The β-Lg antigenicities were about 14, 108, and 158 μg mL⁻¹ at 70, 80, and 90 °C, respectively. However, the influence of DHPM pressures on the antigenic response of β-Lg standards was different. DHPM modified β-Lg standards showed a remarkable increase in antigenicity when treated to 80 MPa. Above 80 MPa, the antigenic response decreased.     

动态高压微射流处理顺序对果胶-乳铁蛋白复合物结构及性质的影响

采用动态高压微射流（dynamic high pressure microfluidization,DHPM）分别以不同的处理顺序：DHPM预处理乳铁蛋白（lactoferrin,LF）后与果胶（pectin,P）混合（MLFP）、DHPM预处理果胶后与乳铁蛋白混合（MPLF）以及乳铁蛋白与果胶混合后再经DHPM处理（MLFP）,制备3 种乳铁蛋白-果胶复合物,探究DHPM的处理顺序对复合物结构及性质的影响。结果表明：DHPM处理使复合物的分散性增大,乳化性减小。且经DHPM处理后的3 种复合物中,MLFP的分散性和乳化性最强,而MLFP的分散性和乳化性最低,这与界面张力测定结果一致。经DHPM处理后复合物粒径也显著减小（P＜0.05）,且MPLF＜MLFP ＜MLFP＜空白对照组复合物。ζ-电位和荧光光谱结果表明,果胶和LF复合物主要通过两者间静电作用结合,且DHPM处理促进果胶与LF的相互作用。本研究为探讨食品组分在食品加工过程中的结构和性质变化提供一定的理论依据。     

Effect of industry-scale microfluidization on structural and physicochemical properties of potato starch

A recently designed “industry-scale microfluidizer” (ISM) was applied to treat potato starch, then the structural and physicochemical properties of potato starch treated at different ISM pressure (30, 60, 90, and 120 MPa) were investigated. As ISM pressure increased, starch granule size was firstly increased, and subsequently declined at 120 MPa. A remarkable destruction of starch granules was observed, and all the large granules disintegrated into irregular block-like structures after treatment at 120 MPa. Both crystalline and short-range ordered structure were progressively disrupted with the increase of pressure. The structural destruction was attributed to starch gelatinization, which depended on ISM pressure. ISM treatment could arbitrarily adjust pasting viscosity and increase setback value of potato starch. Moreover, moduli and mechanical rigidity of starch pastes were enhanced by ISM treatment. These results implied that ISM treatment could be a potential choice to modify starch containing large granules at an industrial level.Industrial relevanceMicrofluidization was an available physical technique to improve functional properties of starch. However, it was difficult for conventional microfluidizer to treat starch containing big granule sizes both in laboratory and industrial scale owing to the drawbacks of devices. A recently designed “industry-scale microfluidizer” (ISM) in our laboratory could be applied to treat potato starch containing large granules. This preliminary study gave important indications that the practical industrial applications of potato starch could be widen by safe and simple microfludization technology, and ISM may be used for processing whole grains flour to obtain nutritional products.     

动态高压微射流对茎菠萝蛋白酶性质和构象的影响

以茎菠萝蛋白酶为原料,研究动态高压微射流(DHPM)对其活性、稳定性和构象的影响。结果显示：DHPM 对茎菠萝蛋白酶具有钝化作用,但活力并不随着压力的升高而降低。压力为60、80、100、120MPa 时,茎菠萝蛋白酶的相对酶活力分别是94%、93%、98% 及92%。DHPM 不同压力对茎菠萝蛋白酶的最适反应温度的影响不同,但对最适pH 值几乎没有影响。然而经DHPM 60、120MPa 处理后,茎菠萝蛋白酶在pH8.0 的稳定性显著增强。在pH8.0 保温40min 后,60、120MPa 处理的茎菠萝蛋白酶相对酶活力分别为85% 和82%,分别比未经处理的高14% 和11%。可见,DHPM 60、120MPa 处理极大地提高了茎菠萝蛋白酶在pH8.0 时的稳定性。此外,紫外光谱和荧光光谱的结果表明：DHPM 导致茎菠萝蛋白酶部分去折叠,分子中赖氨酸和色氨酸残基所处的微环境发生了变化;红外光谱结果显示：DHPM 处理后茎菠萝蛋白酶二级或三级结构发生了变化。     

Effects of high hydrostatic pressure on microstructure,physicochemical properties and in vitro digestibility of oat starch/β-glucan mixtures

Oats do not contain gluten protein, and oat dough structure is formed mainly through the hydrogen bonding of starch and β-glucan. As a non-thermal processing technology, high hydrostatic pressure (HHP) is mainly used to modify starch and protein in food processing. This study investigated the effects of HHP treatment on the morphological, structural, thermal, pasting and in vitro digestion properties of oat starch/β-glucan mixtures. Results showed that β-glucan interconnects with amylose through hydrogen bonding and has a protective effect on the crystalline region of oat starch. Effect of HHP treatment on the crystal structure of mixture system goes through crystal structure perfection stage, crystallisation disintegration and gelatinisation stage. After 300–400 MPa treatment, the changes in particle surface were not obvious, the phase transition temperature, the ΔH_gel and the PT of mixtures increased, while the particle size, viscosity and BD values decreased. After 500–600 MPa treatment, mixtures were completely gelatinised, most of the particles swelled and deformed, the particle size increased significantly. The principal component analysis results show that the complexes were distributed in the same region with similar properties after the 300–400 MPa and 500–600 MPa treatments, respectively.     

Effect of high hydrostatic pressure on the structure,physicochemical and functional properties of protein isolates from cumin (Cuminum cyminum) seeds

The effect of high hydrostatic pressure (HHP) treatment on the structure, physicochemical and functional properties of cumin protein isolate (CPI) was investigated. More aggregates, pores, irregular conformations and bigger particle size were observed for HHP-treated CPI. HHP resulted in an increase in α-helix, a decrease in β-strand and fluorescence intensity of CPI. Surface hydrophobicity (H_o) of CPI significantly increased after HHP treatment, from 343.35 for native CPI to 906.22 at 600 MPa (P < 0.05). HHP treatment at 200 MPa reduced zeta-potential and solubility of CPI, while had little effect at 400 and 600 MPa. Emulsifying activity and stability of CPI decreased after HHP treatment, of which droplet size of emulsions significantly increased (P < 0.05). HHP-treated CPI could form heat-induced gelation at lower temperature (68.5 °C) and improved storage modulus (G′) comparing to native one (80.6 °C), suggesting that CPI might be potential protein resources as gelation substitute in food system.     

Aggregation and conformational changes of bovine β-lactoglobulin subjected to dynamic high-pressure microfluidization in relation to antigenicity

Our previous research indicated that dynamic high-pressure microfluidization (DHPM) had a significant effect on the antigenicity of β-lactoglobulin (β-LG). In this study, aggregation and conformational changes subjected to DHPM (0.1-160 MPa) were investigated in relation to antigenicity. When DHPM pressure increased from 0.1 to 80 MPa, disaggregation of β-LG samples and partial unfolding of the molecule were accompanied by an increase in β-LG antigenicity, which was reflected in the decrease of particle size, increase of free sulfhydryl (SH) contents and β-strands contents, and slight exposure of aromatic amino acid residues. At pressures above 80 MPa, the reaggregation of β-LG may contribute to the decrease in antigenicity, which was reflected by an increase in particle size, the formation of aggregates, a decrease of in SH and β-strands contents, and slight changes in aromatic amino acid residues. Aggregation and conformational changes of β-LG under DHPM was related to its antigenicity.     

The enhancement of gastrointestinal digestibility of β-LG by dynamic high-pressure microfluidization to reduce its antigenicity

Dynamic high-pressure microfluidization (DHPM) can increase the antigenicity of β-lactoglobulin (β-LG) in previous researches. We observed in this study that the antigenicity of DHPM-modified β-LG at pressures of 0.1, 80 and 160 MPa after in vitro digestion declined from 13.41 to 12.27 and 7.19 μg mL⁻¹, gradually. The enhancement of gastrointestinal digestibility of β-LG was related to the aggregation state and conformational changes induced by DHPM and was reflected by the electrophoretic bands of low molecular weight (5 and 10 kDa) shown in electrophoresis, the reduction of particle size, the generation of smaller peptide fragments (m/z 837.444, 955.492 and 1215.616) detected by mass spectrum and the increase in surface hydrophobicity. These changes contributed to the decrease in antigenicity. Simultaneously, a schematic diagram was proposed to demonstrate the conceivable mechanism of antigenicity changes of modified β-LG after in vitro digestion.     

Effect of γ-irradiation on structural,functional and antioxidant properties of β-glucan extracted from button mushroom (Agaricus bisporus)

In this study, β-d-glucan extracted from mushroom Agaricus bisporus were irradiated at 5, 10, 20, 30 and 50 kGy. The samples were characterized by ATR-FTIR spectroscopy, gel permeation chromatography (GPC) and quantitative estimation by Megazyme β-d-glucan assay kit. The average molecular weight of non-irradiated β-d-glucan was 181 kDa that decreased to 31.1 kDa at 50 kGy. The functional properties like swelling power and viscosity decreased while fat binding capacity, emulsifying properties, foaming properties, and bile acid binding capacity showed increased trend with the increase in irradiation doses. The antioxidant properties of irradiated β-d-glucan were carried out using six different assays like DPPH, reducing power, inhibition of lipid per oxidation, chelating ability on ferrous ion, FRAP and ABTS assay that also showed increased activity. In conclusion, the present study signifies the importance of irradiated β-d-glucan in various fields of food processing and pharmacy.Industrial RelevanceIn today's scenario, people are having a sedentary life style with increased risk factors of various diseases like hypercholestromia, cancers, obesity, etc. So they are looking for such type of food that has profound health benefits i.e., functional food. β-Glucan is one of the polysaccharide that can be incorporated into the food formulations and make it functional. However its high viscous nature and low solubility pose several restrictions to being applied widely in food industries. Gamma irradiation is one of the useful techniques that can be commercialized to overcome this problem and use irradiated β-glucan in various food formulations as an ingredient with enhanced antioxidant and functional properties.     

Effect of pH at pressure treatment on the acid gelation of skim milk

Skim milk at pH between 6.4 and 7.3 was pressure treated at 200–600 MPa for 30 min and then slowly acidified with glucono-δ-lactone to form acid gels. Milks at low pH produced acid gels with low elastic moduli (final G′) and yield stresses and those at higher pH produced acid gels with higher final G′ and yield stresses. Pressure treatment disrupted the casein micelles at all pH and transferred high levels of casein to the serum phase. Denaturation of α-lactalbumin occurred at a pressure of 600 MPa only, and the level of denaturation increased with increasing pH. Denaturation of β-lactoglobulin (β-LG) occurred at all pressures, with the level of denaturation increasing with the magnitude of the pressure treatment and with pH. The denaturation of the whey proteins and the disruption of the casein micelles could not entirely account for the changes in the rheological properties of the acid gels, as denaturation of up to 50% of the whey proteins produced acid gels with very low final G′ and yield stresses. It is proposed that the pH and the magnitude of the pressure treatment affect the interactions of the denatured β-LG with the casein proteins in the pressure-treated milks, and that this affects the ability of the denatured β-LG to participate in the acid gel structures.Industrial relevanceThe control and manipulation of the firmness of acid skim milk gels is important in many dairy food applications such as yogurts and some types of cheeses. This study has demonstrated that acid gel firmness can be substantially manipulated when the milk is pH adjusted and pressure treated before acidification, and that these effects are different to those obtained through heating. The commercial uptake of high pressure processing in the dairy industry is dependent on this technology producing unique functional properties in milk when compared with traditional processing. The results of this study indicates that high pressure processing of milk may offer unique functional properties in acid gel applications which could be used for the development of new or improved dairy products.     

高压微射流处理对大豆分离蛋白结构功能特性及其乳液性质的影响

采用高压微射流技术在不同压力条件下对大豆分离蛋白(SPI)进行处理,分析处理前后SPI结构、功能特性以及乳液性质的变化。结果表明:低压均质处理可使SPI的粒径降低,当均质压力增加至一定程度时,蛋白间的相互作用增加,颗粒粒径增加;均质压力在0～95 MPa范围内随着压力逐渐升高,SPI的溶解性得到了显著改善,而当均质压力增加到125 MPa和155 MPa时,溶解性反而降低;高压均质处理对乳化性的影响与溶解性变化趋势基本吻合;表面疏水性随着压力的增大而增大;内源荧光光谱结果表明,随着均质压力的增大,最大吸收波长红移,荧光强度降低,色氨酸残基暴露于极性环境中; SPI乳液粒径随着均质压力的增大(95 MPa除外)整体依次变小,SPI乳液在压力65 MPa处理时油脂氧化速率最快,SPI乳液在压力125、155 MPa处理时的初级氧化速率要低于未处理的乳液。     

Effects of high hydrostatic pressure (HHP) on protein structure and digestibility of red abalone (Haliotis rufescens) muscle

The protein secondary structure modifications and digestibility of red abalone muscle subjected to high hydrostatic pressure (HHP) treatments (200, 300, 400, and 500 MPa for 5 min) were evaluated. The protein structure was analysed by Fourier-Transformed Infrared spectroscopy. Protein digestibility was evaluated based on the degree of hydrolysis (DH) and peptide size distributions under in vitro gastrointestinal conditions. The intermolecular β-sheet structure was disrupted at 200 MPa, compensated by the formation of the intramolecular β-sheet. At 300 and 400 MPa, the β-sheet structure can fold on itself from the interactions that stabilize the protein structure. The 3₁₀-helix structure was significantly looser at 300 MPa. Structural modifications were accompanied by β-turn formation at 300, 400, and 500 MPa. In vitro gastrointestinal digestion is improved by HHP independently of pressure level. The results suggest that high pressure improve the DH of red abalone as a consequence of β-sheet and β-turn conformations changes.Industrial relevanceThe seafood industry uses high hydrostatic pressure (HHP) technology to reduce undesirable sensory changes and preserve the functional and nutritional properties of compounds. The HHP experiments contributed to unravel the impact of the different level pressure on digestibility. HHP treatment can change the secondary structures of proteins and improve the protein digestibility as function the pressure level. The results of this study provide valuable information for the potential application of HHP on the development of red abalone with high-nutritional value.     

动态高压微射流对小麦面筋蛋白功能性质影响的研究

本文研究了动态高压微射流对小麦面筋蛋白功能性质的影响及其机理。结果表明:微射流对面筋蛋白功能性质的改变与其压力和蛋白浓度密切相关。随着压力的升高,在大于等于4%浓度时,溶解度先增大后减小,在80 MPa时达到最大值,在小于4%浓度时正好相反;蛋白浓度为4%时,起泡性减小,泡沫稳定性、乳化性和乳化稳定性增大,在100 MPa时达到最大,其他浓度例如2%和6%时正好相反。SDS-PAGE和DSC图谱显示,微射流使面筋蛋白大分子量亚基被破坏,形成新的具有更加紧凑的空间结构的水溶性聚集体,从而改变了面筋蛋白的功能特性。     

高压微射流处理对原花青素平均聚合度和抗氧化性能的影响

为提高原花青素的生物利用度,本研究采用高压微射流技术处理原花青素溶液,探究其对原花青素平均 聚合度及其抗氧化能力的影响。将原花青素在不同处理压力（100、140、180、220 MPa和260 MPa）下分别进行 1、2、3、4 次循环处理,结果表明：随着处理压力的升高,原花青素的平均聚合度基本不存在显著差异,220 MPa 下平均聚合度相对较低;处理次数为4条件下的平均聚合度相对较小。固定处理次数为4,选择不同处理压力的样 品进行抗氧化能力分析,抗氧化能力（包括铁还原力和清除1,1-二苯基-2-三硝基苯肼自由基能力）由大到小为： 220 MPa＞180 MPa＞140 MPa＞100 MPa＞260 MPa＞对照组＞VC;半抑制浓度的变化趋势与抗氧化能力大小顺序 相反,说明处理压力为220 MPa下的原花青素抗氧化能力最强。