Ascorbic acid induced degradation of polysaccharide from natural products: a review

Journal Pre-proof An overview on ascorbic acid induced degradation of polysaccharide from natural products

Ming-Yue Zou, Shao-Ping Nie, Jun-Yi Yin, Ming-Yong Xie PII:

S0141-8130(19)40598-9

DOI:

https://doi.org/10.1016/j.ijbiomac.2020.02.193

Reference:

BIOMAC 14810

To appear in:

International Journal of Biological Macromolecules

Received date:

4 January 2020

Revised date:

9 February 2020

Accepted date:

17 February 2020

Please cite this article as: M.-Y. Zou, S.-P. Nie, J.-Y. Yin, et al., An overview on ascorbic acid induced degradation of polysaccharide from natural products, International Journal of Biological Macromolecules(2018), https://doi.org/10.1016/j.ijbiomac.2020.02.193

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

© 2018 Published by Elsevier.

Journal Pre-proof

An overview on ascorbic acid induced degradation of polysaccharide from natural products Ming-Yue Zou 1, Shao-Ping Nie 1,**, Jun-Yi Yin 1,*, Ming-Yong Xie 1,2

1

State Key Laboratory of Food Science and Technology, China-Canada Joint Lab of Food Science and Technology (Nanchang), Nanchang University, Nanchang, Jiangxi Province, 330047, China 2

of

National R&D Center for Freshwater Fish Processing, Jiangxi Normal University, Nanchang, Jian gxi 330022, China *

Corresponding Authors: Professor Jun-Yi Yin, PhD (E-mail: [email protected]) Corresponding Authors: Professor Shao-Ping Nie, PhD (E-mail: [email protected])

Jo ur

na

lP

re

-p

ro

**

1

Journal Pre-proof ABSTRACT：Polysaccharide derived from natural products has a wide range of sources and mild properties, and exhibit various bioactivities. Ascorbic acid is one of the most important nutrients in fruits and vegetables, as well as their products. Ascorbic acid and polysaccharide coexist in many systems during food production and processing. Many studies have found that ascorbic acid at low concentrations degrades polysaccharide derived from natural products via hydroxyl radical. In this paper, the research progress on ascorbic acid induced polysaccharide degradation is summarized from four aspects: mechanism of action, analytical methods, influencing

of

factors and bioactivity of degradation products. It is expected to provide a theoretical

ro

basis for further research.

Jo ur

na

lP

re

-p

KEYWORDS：Ascorbic acid; Polysaccharide; Degradation; Mechanism

2

Journal Pre-proof

1 Introduction Food is a complex system composed of macromolecules (carbohydrate, lipid and protein), and small molecules (vitamin, polyphenol and mineral). Its multi-scale structural characteristics are the material basis of food quality and function. Clarifying interactions such as intermolecular association, aggregation, chemical bonding and

of

degradation between food components and related mechanisms, which helps to clarify

ro

the basis of food quality and functional materials based on multi-scale structural

-p

characteristics, is a major concern in the field of food chemistry in recent years [1-5].

re

Polysaccharide is a very important class of carbohydrate in foods, usually formed

lP

by the attachment of aldehyde group and keto group from more than 10

na

monosaccharide molecules via glycosidic bonds. In addition to providing necessary energy (like starch), polysaccharide have good bioactivities, including immune

Jo ur

regulation [6-10], anti-tumor [11-16], anti-oxidation [17-19], blood sugar lowering [20-24] and intestinal microbiota regulation [25-28]. L-ascorbic acid (AA), also known as Vitamin C (Vc), is a naturally occurring organic compound and an important food additive. It also plays a significant biological role in anti-oxidation [29], anti-aging [30], anti-cancer [31, 32], immune regulation [33], gene regulation [34], and reduction of atherosclerosis [35]. When added as an antioxidant to foods rich in polysaccharide such as juice, beverage and pasta, ascorbic acid with low concentrations may exhibit an effect of promoting oxidation thereby affecting the functional properties, such as viscosity of

3

Journal Pre-proof

polysaccharide in foods [36, 37]. Studies have confirmed that there is a certain interaction between ascorbic acid and polysaccharide. Polysaccharide can reduce [38] or promote [39] the degradation of ascorbic acid, while ascorbic acid also has a widely effect on the functional properties of polysaccharide in preventing radiation degradation [40], changing the

of

morphology and functional properties of starch [41, 42], and improving the properties of films and coatings [43, 44].

However, the pro-oxidation of ascorbic acid is often

ro

overlooked, while the coexistence system of polysaccharide-ion-ascorbic acid is

-p

common in plant and food systems [45]. Most of the extensive studies on interaction

re

between polysaccharide and ascorbic acid are report on the degradation of

lP

polysaccharide by ascorbic acid [46-49], which indicates that ascorbic acid at low

na

concentrations has a tendency to promote oxidation degradation of polysaccharide via hydroxyl radical. Nevertheless, there is little review in this regard. Therefore, this

Jo ur

paper summarizes the research progress of ascorbic acid induced degradation of polysaccharide from natural product from four aspects: mechanism of action, analytical methods, influencing factors and activity of degradation products. It will provide a theoretical basis for intensive experimental research.

2 Mechanism of ascorbic acid induced polysaccharide degradation The addition of ascorbic acid to the polysaccharide causes a series of changes in properties of the polysaccharide, such as lower apparent viscosity, smoother apparent morphology, and fewer particles [45, 50, 51]. Through the molecular weight

4

Journal Pre-proof

measurement, it was found that the molecular weight of the polysaccharide product after the addition of ascorbic acid was remarkably lowered [52-55]. However, the results of FT-IR, NMR and monosaccharide composition analysis showed that the structure of major functional group of the degradation product did not undergo changes compared with that before degradation, and the monosaccharide composition

of

remained basically unchanged [50, 52, 53, 56]. Further research found that this change is due to the fact that ascorbic acid generates hydroxyl radicals based on the

ro

Fenton reaction, and then hydroxyl radicals attack polysaccharide molecules, causing

-p

a series of reactions such as depolymerization, resulting in a decrease in molecular

re

weight [48, 49, 51, 55, 57, 58]. The degradation can be inhibited by radical

lP

scavengers and prevented by catalase [45, 49]. Ascorbic acid (AH2) can reduce

na

oxygen to hydrogen and simultaneously reduce metal ions (Reactions 1 and 2) [51, 59]. The hydroxyl radical can be formed by a Fenton reaction between the reduced

Jo ur

metal ion and hydrogen peroxide, or produced by oxidation of ascorbic acid by hydrogen peroxide, which will produce 2,3-diketogu-lonic acid (DKG) (Reactions 3 and 4) [60-62]. These hydroxyl radicals are very reactive and will react with the hydrogen atoms of polysaccharide (hydrogen abstraction reaction), which causes the glycoside bond cleavage [46]. Figure 1 illustrates the degradation of polysaccharide by free radicals using xyloglucan as an example [63]. This process could be shown with the following equations: AH2+ O2 →A + H2O2 AH2+ Fe3+/Cu2+ →A+2H++2Fe2+/Cu+ AH2 + H2O2 → •OH + H2O + DKG

(1) (2) (3) 5

Journal Pre-proof (4)

ro

of

Fe2+/Cu+ + H2O2 → •OH + -OH + Fe3+/Cu2+ (Fenton reaction)

re

from ref [63]. Copyright 2010 Elsevier.

-p

Figure 1. Proposed mechanism for free-radical degradation of xyloglucan. Reprinted with permission

lP

Whether the attack of polysaccharide by hydroxyl radicals is targeted is also studied by researchers. Research has shown that the oxidation with ascorbic acid

na

mainly resulted in glycosidic bond cleavage [64]. In addition, it also has been found

Jo ur

that free radicals preferentially act on the GalA backbone of pectin in the HG region and maintain the RG-I region [53]. Nevertheless, the oxidation degradation of polysaccharide by ascorbic acid is still considered to be random and non-specific. Besides, little research has been done on whether there is a linkage between ascorbic acid, molecular weight/ functional group and performance, which remains to be further studied.

3 Analytical methods Methods for studying ascorbic acid induced polysaccharide degradation can be roughly divided into two aspects. On the one hand, it is to study the degradation 6

Journal Pre-proof

mechanism, mainly to detect the formation of hydroxyl radicals in the reaction by electron spin resonance (ESR) technique [47, 65], and to verify the formation by using hydroxyl radical scavengers or inhibitors [45, 51]. Li et al. used ESR-electron spin capture technology to find that the addition of ascorbic acid significantly increased the amount of free radicals in the reaction system (Figure 2D) [53]. On the

of

other hand, it is to study the degradation products of polysaccharide, mainly using colorimetry, HPSEC, HPLC, FT-IR, NMR and SEM to analyze the molecular

ro

properties and structure of the oxidative degradation products of polysaccharide

-p

(Figure 2A, B and C). It was found that the degradation behavior of polysaccharide

re

followed first-order reaction kinetics [52, 66]. The degree of deacetylation of

lP

degraded chitosan samples obtained by an acid-base titration method did not appear to

na

change with decreasing molecular weight, suggesting that the N-acetyl-glucosamine is stable enough during degradation and that glycosidic bonds might be randomly

Jo ur

cleaved [66]. However, in view of the fact that the current research on the degradation of ascorbic acid itself is very extensive [67-69], relatively little is known about the degradation process of ascorbic acid in the ascorbic acid-induced polysaccharide degradation reaction. Also, thermal gravimetric analysis and differential scanning calorimetry (DSC) can be used to explore the interaction between ascorbic acid and polysaccharides.

Besides,

methylation

has

been

widely used

to

analysis

polysaccharide structure [70-73], but not used for analysis ascorbic acid induced polysaccharide degradation, while should be strengthened. These remains to be further studied in future research. Table 1 summarizes common methods for the 7

Journal Pre-proof

analysis of ascorbic acid induced polysaccharide degradation. Table 1. Analytical methods for degradation of polysaccharide by ascorbic acid Items

Reference

ESR

[47, 53, 66]

Thin-layer chromatography

Free radical analysis

(TLC)

Carbonyl analysis

[55]

Paper electrophoresis (PE)

[55]

Fluorescent labeling

[64, 65]

GPC

[52, 53, 66]

APC-MALS

[50]

Purity and molecular

HPSEC

[75]

AsFlFFF

[54]

GC

[50]

HPLC

[53, 76]

HPAEC-PAD

[64]

re

Composition and proportion of

lP

monosaccharide

[51, 54, 74]

GPC-HPLC

-p

weight analysis

of

mechanism

ro

Degradation

Methods

Colorimetric reaction

[46, 50, 75]

FT-IR

[52, 53]

NMR

[64, 76]

MS

[75]

Acid hydrolysis

[55]

Rheometry

[47, 51, 77]

Viscometry

[41, 45, 63]

Crystal structure

XRD

[66]

analysis

WXRD

[41]

Morphological analysis

SEM

[41, 50]

Zeta (ζ) potential

[50]

na

Degradation products

Jo ur

Structure analysis

Rheological behavior

Stability analysis of colloidal dispersion system

8

-p

ro

of

Journal Pre-proof

re

Figure 2. SEM images of A) polysaccharide purified from Lycium barbarum L. leaves (LP) and B) LP treated with 50 mM ascorbic acid and 50mM H 2O2 (LP6). Reprinted with permission from ref [50]. Copyright 2019 Elsevier. C) IR spectra of unfractionated heparin (UFH) and low molecular

lP

weight heparins (LMWHs) prepared by ultrasound/H2O2/ascorbic acid process. Reprinted with permission from ref [52]. Copyright 2019 Elsevier. D) ESR spectra of pectin solution under different

affecting

ascorbic

acid

induced

degradation

of

Jo ur

4 Factors

na

reaction systems. Reprinted with permission from ref [53]. Copyright 2019 Elsevier.

polysaccharide 4. 1 Oxidation system

The oxidation system is an important factor affecting the degradation of polysaccharide by ascorbic acid. At present, main oxidation systems used for the study of ascorbic acid oxidized polysaccharide are divided into three categories: the first one is ascorbic acid alone (including hydrogen peroxide assist), the second is metal ion assist and the third is ultrasound assisted. The first type of reaction is to add a certain concentration of ascorbic acid or

9

Journal Pre-proof

ascorbic acid-hydrogen peroxide mixture to the polysaccharide solution for oxidative degradation, of which the advantage is that the product is of high purity, but the reaction rate is not as fast as the latter two systems. Many studies have used an oxidation system with only hydrogen peroxide to degrade the polysaccharide via Fenton reaction [55, 78-84]. When ascorbic acid is added to the polysaccharide

of

solution alone, the viscosity of the polysaccharide solution can be rapidly decreased to achieve a significant degradation [41, 45, 49, 65]. Moreover, when hydrogen peroxide

ro

is added together with ascorbic acid, the degradation rate of the polysaccharide is

-p

considerably increased [54]. In addition, the degradation products of this type of

re

oxidation system are of high purity because ascorbic acid decomposes during the

lP

reaction, thereby achieving an efficient ecofriendly degradation process.

na

The second type of reaction is the oxidative degradation involving metal ions with high reaction rate, but it is necessary to remove metal ions by using metal

Jo ur

chelating agent or the like to obtain a high-purity degradation product. Cu2+ and Fe2+ ions participating in the Fenton reaction are the common metal ions involved in the ascorbic acid induced polysaccharide degradation, which accelerates the rate of hydroxyl radical generation [54, 64, 74, 75, 85]. However, β-glucan will bind to ferrous iron at pH 4.7, which affects the rate of earlier degradation of β-glucan [86]. Notably, when Fe2+ and hydrogen peroxide coexists in the oxidation system, the degradation products may contain formic acid, which was proposed to result from Ruff degradation where oxidised glucose (gluconic acid) is decarboxylated to form arabinose [64]. 10

Journal Pre-proof

The third category, the ultrasound-assisted degradation reaction, is a mild, effective and environmentally friendly method, which greatly enhances the degradation efficiency based on the first type. Ultrasound has been widely studied on the degradation of polysaccharide [87-89], and the synergistic use of ultrasound and ascorbic acid can improve the oxidation efficiency of ascorbic acid on polysaccharide.

of

It is widely acknowledged that the mechanism of low frequency ultrasonic degradation of chitosan has been attributed mainly to the action of shear forces

ro

(mechanical effect) caused during the collapse of cavitation bubbles [90, 91]. Besides,

-p

ultrasound induces acoustic cavitation and the subsequent violent collapse of

re

cavitation at multiple locations in the system can increase the temperature and

lP

pressures significantly in the collapsing bubble and close vicinity of the bubble, which

na

gives rise to generation of •OH and •H radicals that can subsequently form hydrogen peroxide [92-94]. For example, ultrasound can be used to assist in the decomposition

Jo ur

of sulfated polysaccharide clusters in fucosyl chondroitin sulfate, and then the ascorbic acid-hydrogen peroxide oxidation system produces hydroxyl radicals to induce polysaccharide depolymerization (Figure 3) [76].

11

Journal Pre-proof Figure 3. The schematic diagram of native fucosylated chondroitin sulfate degradation path by ultrasound/H2O2/ascorbic acid system. Reprinted with permission from ref [76]. Copyright 2019

re

-p

ro

of

Elsevier.

Figure 4. Possible mechanism of sonolysis assisted H2O2/Vc action on the chitosan chain. Reprinted

lP

with permission from ref [66]. Copyright 2016 RSC Publishing.

na

4. 2 Concentration of ascorbic acid

Jo ur

Ascorbic acid concentration is an important factor affecting the degradation of polysaccharide. Ascorbic acid is generally present in the form of an antioxidant, but it is more likely to exist as a pro-oxidant at a low concentration [95]. It has been proved when add ascorbic acid to crude water-soluble polysaccharide from the seeds of P. asiatica L. [56]. For oxidation systems containing ascorbic acid and hydrogen peroxide, the ratio of this two also has an effect on the rate of degradation reaction. When the ratio of hydrogen peroxide to ascorbic acid is 1:1 (30-50 mM), the degradation rate is highest. Excessive ascorbic acid does not increase the degradation rate [66]. However, some studies have found that when degrading pectin, the degradation rate was the highest when the ratio is 5:1 (50 mM: 10 mM). When the 12

Journal Pre-proof

ratio reached 1:1, the degradation rate was not significantly promoted as the concentration of ascorbic acid increased [53]. The reason is consistent with the above that ascorbic acid has a tendency to promote oxidation at low concentrations. The mechanism of that perhaps is because that under these reaction conditions, excess ascorbic acid (AH2) is susceptible to autoxidation to generate dehydroascorbic acid

of

anions (Reactions 5 and 6) that react with •OH generated from H2O2/ascorbic acid oxidation system (Reaction 7) [36], leading to a reduction in the degradation rate of

-p

re

(5) (6) (7)

lP

AH2 → AH−+ H AH− + O2 → •A− + O2− + H+ AH− + •OH → •A− + H2O

ro

polysaccharide.

The difference in the above conclusions may be due to differences in the type of

na

polysaccharide and the oxidation system or other experimental conditions such as the

Jo ur

difference in polysaccharide types. 4. 3 Polysaccharide types

The polysaccharide species has a significant effect on the ascorbic acid oxidized polysaccharide.

Most

of

polysaccharide

studied

at

present

are

viscous

biomacromolecules, and the polysaccharide with deeper studies include β-glucan, pectin and chitosan. When treated with ultrasonic assisted H2O2/ascorbic acid, the scission of the glycosidic bond of chitosan was predominantly from H abstraction at C-1 and C-4, resulting in cleavage of glycosidic bonds without changing the chemical structure of chitosan and no carboxyl group formation (Figure 4) [66]. For

13

Journal Pre-proof mixed-linked (1→3), (1→4)-β-D-glucans, the radical-mediated cleavage of mid-chain glucose residues create new reducing termini [55]. However, there is a lack of in-depth research on glucomannan, arabinoxylan and other common polysaccharide from natural product sources. Table 2 summarizes the types of polysaccharide and their degradation parameters that have been studied in the past decade.

Polysaccharide

of

Table 2. Types of polysaccharide degraded by ascorbic acid, corresponding oxidation system and method for collecting degradation products Degradation products collect

Oxidation conditions

methods

ro

type

Reference

Dialysis with a 500 Da cutoff

chondroitin sulfate

U-H-A

25℃，90 min

membrane for 72 h, concentrated

[76]

-p

Fucosylated

and subsequently lyophilized.

Heparin

re

Under different U-H-A

temperature

-

[52]

-

[53]

U-H-A

Wheat starch

U-H-A

25℃

Jo ur

Chitosan

Xyloglucan

30℃，60 min

na

Pectin

lP

（0℃-45℃）

H-A

A

Precipitated with absolute ethanol, then the chitosan precipitate was filtered, washed with ethanol

[66]

several times and lyophilization.

80℃

-

[63]

Poured in large stainless-steel trays with thickness of 2 to 3 mm and 40℃，8 min Ambient

dried in a cabinet drier at 50 ℃ for 2 h, then the dried starch was

temperature，8 min

[41]

hammer milled and sieved to obtain particle sizes in the range of 120 to 200 μm.

Starch Xylan Galactoglucomanna n

The copper was removed by metal M (Cu)-A (Na salt)

55℃，20 h

mixture was then concentrated to

[74]

dryness.

Dextran β-glucan

ion chelator and the reaction

A

Room temperature

14

Precipitated and washed thoroughly

[65]

Journal Pre-proof Polysaccharide

Degradation products collect

Oxidation conditions

type

methods

Reference

Precipitated with ethanol to remove the oxidation reagents. After M (Fe)-A

Room temperature

centrifugation, the samples were

[64]

washed twice with ethanol and finally dried at room temperature.

M (Cu)-H-A

M (Fe)-H-A

Room temperature， 16 h

Reagents were removed by dialysis, and aliquots were

[55]

freeze-dried.

Room temperature

-

[58]

of

Note: A: Ascorbic Acid; H: H2O2; U: Ultrasonic; M: Metal; -, not provided

ro

4. 4 Temperature and pH

-p

Due to the poor stability of ascorbic acid, the temperature and pH value can

re

easily have a significant impact on it [96]. As the temperature increases, the ascorbic

lP

acid induced degradation rate of the polysaccharide increases [76]. However, when the temperature rises to a certain extent, the degradation rate of polysaccharide is not

na

significantly affected by the continued temperature rise, which maybe because

Jo ur

ascorbic acid begins to decompose at high temperature and leading to a slowdown of free radical production rate therefore reducing the impact on polysaccharide degradation [52, 53].

For pH, acidic environment is more conducive to the degradation of polysaccharide by ascorbic acid [45]. Studies have shown that xyloglucan has the highest degradation rate at pH 4.5, because ascorbic acid exists in the form of single anion with strong reducibility under this condition (pKa=4.2) [49]. Thus, it can reduce molecular oxygen to hydrogen peroxide, and then produce hydroxyl radical to attack polysaccharide. The difference between these findings may be due to diversity of the

15

Journal Pre-proof

types of polysaccharide, experimental conditions and other factors. 4. 5 Others Polysaccharide extracted from natural products or polysaccharide in complex environmental system are easily contacted with many other substances, some of which have varying degrees of influence during the oxidation of polysaccharide by

of

ascorbic acid. In terms of small molecules, the addition of glucose and mannitol can

ro

delay the reduction of the viscosity of β-glucan extracted from grains added with

-p

ascorbic acid [45]. However, phytate promotes the degradation of polysaccharide by

re

ascorbic acid [45, 80]. In addition to small molecular substances, macromolecules also have a significant effect on ascorbic acid induced degradation of polysaccharide.

lP

Different iron-binding proteins have different effects. Lactoferrin has no effect on the

na

reaction, apotransferrin promotes the formation of hydroxyl radicals and promotes

Jo ur

degradation, and ovotransferrin completely blocks formation of hydroxyl radicals in the system [77]. In addition to protein, polysaccharide can also have an effect on the degradation, such as xanthan gum can prevent ascorbic acid from reducing β-glucan viscosity. There are two possible reasons, one of that is xanthan gum reacts with free radicals thus reduces the attack of free radicals on β-glucan thereby protecting β-glucan. The other one is xanthan gum and β-glucan interacts in aqueous solution and form double-strand or something therefore reducing the chance of free radical attack and protecting β-glucan [97]. Although there are so many substances that affect ascorbic acid induced polysaccharide degradation, the exact conclusion on how small molecules, protein and other substances affect has not been drawn, and further 16

Journal Pre-proof

research is still needed.

5 Biological activity of degradation products The polysaccharide itself has many biological activities as mentioned above. However, the bioactivity of polysaccharide after degradation will vary to varying degrees. Many researchers have found that degradation of polysaccharide by different

of

methods (such as enzymatic hydrolysis, thermal hydrolysis, oxidative degradation,

ro

ultrasonic degradation, microwave degradation, etc.) can improve the biological

-p

activities of polysaccharide in different degrees, such as antioxidant, anticancer,

re

anti-glycosylation, repair of cell oxidative damage, lowering blood lipids, and

lP

improving lipid metabolism disorders in liver cells [85, 98-107]. There are not many

na

reports about the changes in biological activity of ascorbic acid-degraded polysaccharide products, and we summarized them as follows:

Jo ur

5. 1 Anticancer activity

The degradation products of polysaccharides treated with ultrasound/hydrogen peroxide/ascorbic acid showed enhanced anticancer activity [52, 53]. Low molecular weight fucosylated chondroitin sulfate (fCS) produced by ascorbic acid combined with ultrasound and hydrogen peroxide showed better anti-proliferative effect than native fCS at higher concentrations on A549 lung cancer cells, which may be due to the higher molar concentration, the more stiff molecular chains, and the more number of active sites caused by depolymerization [76]. Interestingly, current research on anticancer activity is based on the ultrasound-assisted degradation, and the other two 17

Journal Pre-proof

oxidation systems are almost absent, which remains to be studied more extensively. 5. 2 Antithrombotic activity The anticoagulant activity of polysaccharide products treated with ascorbic acid and hydrogen peroxide was significantly enhanced. Depolymerized fragments from Costaria costata polysaccharide showed better anticoagulant activity and affect both

of

the intrinsic and extrinsic mechanisms of coagulation [75]. In addition, degradation of

ro

polysaccharide purified from Lycium barbarum L. leaves (LP) could significantly

-p

enhance the anticoagulant activity, especially the antiplatelet activity. LP with the

re

highest degradation degree had a higher inhibition effect on platelet aggregation caused by arachidonic acid and thrombin than aspirin [50]. Similarly, current studies

lP

on anticoagulation lack the rest of the oxidation system, which remains to be studied

na

in depth.

Jo ur

5. 3 Antioxidant activity

Ascorbic acid-treated polysaccharide degradation products also exhibit enhanced antioxidant activity. The antioxidative activity of degradation products of Tremella fuciformis polysaccharide after Fe2+/ascorbic acid/H2O2 treatment is significantly improved, and lower molecular weight polysaccharide show stronger scavenging activity on superoxide radicals, which probably due to the more free hydroxyl groups, better water solubility and more surface area of lower molecular weight sample [46]. Current research on antioxidants is also very limited and needs further research. Most of the experimental results showed that degradation could enhance the bioactivity of polysaccharide, which might be different between each other due to 18

Journal Pre-proof

various polysaccharide types, degradation systems and experimental conditions. At present, studies on the activity of ascorbic acid-degrade polysaccharide products mainly focus on the aspects of anti-cancer and anti-oxidation as mentioned above, and more extensive researches are needed on other activity. Moreover, whether there is a difference of bioactivity of polysaccharide degradation products between ascorbic

of

acid and other degradation methods still remains to be further studied.

ro

6 Conclusions

-p

Both ascorbic acid and polysaccharide are compounds that are widely present in

re

natural plants and interact with each other. The mechanism of ascorbic acid induced

lP

polysaccharide degradation is mainly through the formation of hydroxyl radicals to

na

attack polysaccharide molecules, thereby to degrade polysaccharide. The degradation process and products of polysaccharide are mainly analyzed by ESR, HPSEC, HPLC,

Jo ur

FT-IR, NMR and SEM. The oxidation system involved in the degradation consists of ascorbic acid (include hydrogen peroxide assisted) system, metal ion added system, and ultrasound assisted system. The mainly investigated polysaccharide includes β-glucan, xyloglucan, chitosan, fucosyl chondroitin sulfate and so on. Both temperature and pH have a great impact on the degradation. Although the degradation rate of polysaccharide increases with the rise of temperature, the excessive temperature tends to cause decomposition of ascorbic acid and reduce the reaction rate. pH 4.5 is the most suitable condition for degradation of polysaccharide by ascorbic acid. In addition, the existence of glucose, mannose, phytic acid, protein and

19

Journal Pre-proof

other substances also affect the degradation. The products of ascorbic acid induced polysaccharide degradation have stronger anti-tumor, anti-coagulation, anti-oxidation and other functional activities to some extent. In general, the degradation of polysaccharide by ascorbic acid is environmentally friendly and efficient. However, current research on ascorbic acid induced degradation

of

of polysaccharide has not been elaborated on the mechanism of how specific conditions affect the degradation, the degradation of ascorbic acid in this process and

ro

whether the degradation products will continue to interact with polysaccharide.

-p

Meanwhile, the research on the types of polysaccharide and the activity of

re

degradation products is still limited. It is still unknown whether the degradation is

lP

specific and whether there is a linkage between ascorbic acid, molecular weight/

na

functional group and performance. Furthermore, whether the free radicals that degrade the polysaccharide are likely to be mainly produced by air, and ascorbic acid

Jo ur

only plays a supporting role. These are all needed to be studied comprehensively by future researchers.

Conflicts of interest

The authors declared that there were no conflicts of interest

Acknowledgments The financial supports from the National Key R&D Program of China (2017YFD0400104), National Natural Science Foundation of China (31571826,

20

Journal Pre-proof

21564007 & 31871755) and Scientific and Technological Innovation Foundation for Distinguished Young Scholars of Jiangxi Province (20192BCB23005) were gratefully acknowledged. The authors appreciate helpful comments and language revision on the text from Dr. Wei Zou (Commonwealth Scientific and Industrial Research

Jo ur

na

lP

re

-p

ro

of

Organization, Australia).

21

Journal Pre-proof

References: [1]

C. Lv, G. Zhao, Y. Ning, Interactions between plant proteins/enzymes and other food

components, and their effects on food quality, Crit. Rev. Food Sci. Nutr. 57 (2017) 1718-1728. https://doi.org/10.1080/10408398.2015.1023762. [2]

J. Parada, J.L. Santos, Interactions between starch, lipids, and proteins in foods: Microstructure

control for glycemic response modulation, Crit. Rev. Food Sci. Nutr. 56 (2016) 2362-2369. https://doi.org/10.1080/10408398.2013.840260. [3]

C. Le Bourvellec, C.M. Renard, Interactions between polyphenols and macromolecules:

quantification methods and mechanisms, Crit. Rev. Food Sci. Nutr. 52 (2012) 213-248. [4]

of

https://doi.org/10.1080/10408398.2010.499808. N. Bordenave, B.R. Hamaker, M.G. Ferruzzi, Nature and consequences of non-covalent

https://doi.org/10.1039/c3fo60263j.

M. Hyldgaard, T. Mygind, R.L. Meyer, 2012. Essential oils in food preservation: mode of action,

synergies,

and

interactions

with

food

matrix

https://doi.org/10.3389/fmicb.2012.00012.

Front.

Microbiol.

3,

12.

L. Liu, S. Nie, M. Xie, Tumor microenvironment as a new target for tumor immunotherapy of

polysaccharides,

Crit.

re

[6]

components,

-p

[5]

ro

interactions between flavonoids and macronutrients in foods, Food Funct. 5 (2013) 18-34.

Rev.

Food

Sci.

Nutr.

56

(2016)

S85-S94.

[7]

lP

https://doi.org/10.1080/10408398.2015.1077191.

S. Kang, H. Min, Ginseng, the 'Immunity Boost': the effects of Panax ginseng on immune

system, J. Ginseng Res. 36 (2012) 354-368. https://doi.org/10.5142/jgr.2012.36.4.354. J.E. Ramberg, E.D. Nelson, R.A. Sinnott, 2010. Immunomodulatory dietary polysaccharides: a

na

[8]

systematic review of the literature, Nutr. J. 9, 54. https://doi.org/10.1186/1475-2891-9-54. [9]

B.A. Cobb, Q. Wang, A.O. Tzianabos, D.L. Kasper, Polysaccharide processing and presentation

Jo ur

by the MHCII pathway, Cell 117 (2004) 677-687. https://doi.org/10.1016/j.cell.2004.05.001. [10] L. Li, W. Li, W. Zhen, F. Wang, L. Wang, M. Pan, J. Lv, Y. Yao, S. Nie, M. Xie, Ganoderma atrum polysaccharide ameliorates ROS generation and apoptosis in spleen and thymus of immunosuppressed

mice,

Food

Chem.

Toxicol.

99

(2017)

199-208.

https://doi.org/10.1016/j.fct.2016.11.033. [11] X. Chen, J. Xie, W. Huang, S. Shao, Z. Wu, L. Wu, Q. Li, Comparative analysis of physicochemical characteristics of green tea polysaccharide conjugates and its decolored fraction and their

effect

on

HepG2

cell

proliferation,

Ind.

Crops

Prod.

131

(2019)

243-249.

https://doi.org/10.1016/j.indcrop.2019.01.061. [12] X. Meng, H. Liang, L. Luo, Antitumor polysaccharides from mushrooms: a review on the structural characteristics, antitumor mechanisms and immunomodulating activities, Carbohydr. Res. 424 (2016) 30-41. https://doi.org/10.1016/j.carres.2016.02.008. [13] H. Zhang, W. Zhang, P. Xu, Pectin in cancer therapy: A review, Trends Food Sci. Technol. 44 (2015) 258-271. https://doi.org/10.1016/j.tifs.2015.04.001. [14] A. Zong, H. Cao, F. Wang, Anticancer polysaccharides from natural resources: A review of recent

research,

Carbohydr.

Polym.

https://doi.org/10.1016/j.carbpol.2012.07.026. 22

90

(2012)

1395-1410.

Journal Pre-proof [15] X. Chen, Z. Zhang, Z. Gao, Y. Huang, Z. Wu, Physicochemical properties and cell-based bioactivity of Pu'erh tea polysaccharide conjugates, Int. J. Biol. Macromol. 104 (2017) 1294-1301. https://doi.org/10.1016/j.ijbiomac.2017.03.183. [16] P. Gao, J. Bian, S. Xu, C. Liu, Y. Sun, G. Zhang, D. Li, X. Liu, Structural features, selenization modification, antioxidant and anti-tumor effects of polysaccharides from alfalfa roots, Int. J. Biol. Macromol. 149 (2020) 207-214. https://doi.org/10.1016/j.ijbiomac.2020.01.239. [17] Q. Wu, L. Liu, A. Miron, B. Klimova, D. Wan, K. Kuca, The antioxidant, immunomodulatory, and anti-inflammatory activities of Spirulina: an overview, Arch. Toxicol. 90 (2016) 1817-1840. https://doi.org/10.1007/s00204-016-1744-5. [18] I.C.F.R. Ferreira, S.A. Heleno, F.S. Reis, D. Stojkovic, M.J.R.P. Queiroz, M.H. Vasconcelos, M. Sokovic, Chemical features of Ganoderma polysaccharides with antioxidant, antitumor and antimicrobial

activities,

Phytochemistry

114

38-55.

of

https://doi.org/10.1016/j.phytochem.2014.10.011.

(2015)

[19] Y. Chen, M. Xie, S. Nie, C. Li, Y. Wang, Purification, composition analysis and antioxidant

ro

activity of a polysaccharide from the fruiting bodies of Ganoderma atrum, Food Chem. 107 (2008) 231-241. https://doi.org/10.1016/j.foodchem.2007.08.021.

-p

[20] J. Wang, W. Jin, W. Zhang, Y. Hou, H. Zhang, Q. Zhang, Hypoglycemic property of acidic polysaccharide extracted from Saccharina japonica and its potential mechanism, Carbohydr. Polym. 95

re

(2013) 143-147. https://doi.org/10.1016/j.carbpol.2013.02.076.

[21] K. Zhu, S. Nie, C. Li, W. Li, S. Lin, M. Xing, D. Gong, M. Xie, A newly identified polysaccharide from Ganoderma atrum attenuates hyperglycemia and hyperlipidemia, Int. J. Biol.

lP

Macromol. 57 (2013) 142-150. https://doi.org/10.1016/j.ijbiomac.2013.03.009. [22] Q. Luo, Y. Cai, J. Yan, M. Sun, H. Corke, Hypoglycemic and hypolipidemic effects and antioxidant activity of fruit extracts from Lycium barbarum, Life Sci. 76 (2004) 137-149.

na

https://doi.org/10.1016/j.lfs.2004.04.056.

[23] X. Chen, Y. Fang, K. Nishinari, H. We, C. Sun, J. Li, Y. Jiang, Physicochemical characteristics

Jo ur

of polysaccharide conjugates prepared from fresh tea leaves and their improving impaired glucose tolerance, Carbohydr. Polym. 112 (2014) 77-84. https://doi.org/10.1016/j.carbpol.2014.05.030. [24] H. Chen, Q. Nie, J. Hu, X. Huang, W. Huang, S. Nie, 2020. Metabolism amelioration of Dendrobium officinale polysaccharide on type II diabetic rats, Food Hydrocolloids 102, 105582. https://doi.org/10.1016/j.foodhyd.2019.105582. [25] H.J. Flint, E.A. Bayer, M.T. Rincon, R. Lamed, B.A. White, Polysaccharide utilization by gut bacteria: potential for new insights from genomic analysis, Nat. Rev. Microbiol. 6 (2008) 121-131. https://doi.org/10.1038/nrmicro1817. [26] F. Cuskin, E.C. Lowe, M.J. Temple, Y. Zhu, E.A. Cameron, N.A. Pudlo, N.T. Porter, K. Urs, A.J. Thompson, A. Cartmell, A. Rogowski, B.S. Hamilton, R. Chen, T.J. Tolbert, K. Piens, D. Bracke, W. Vervecken, Z. Hakki, G. Speciale, J.L. Munoz-Munoz, A. Day, M.J. Pena, R. McLean, M.D. Suits, A.B. Boraston, T. Atherly, C.J. Ziemer, S.J. Williams, G.J. Davies, D.W. Abbott, E.C. Martens, H.J. Gilbert, Human gut Bacteroidetes can utilize yeast mannan through a selfish mechanism, Nature 517 (2015) 165-186. https://doi.org/10.1038/nature13995. [27] J. Larsbrink, T.E. Rogers, G.R. Hemsworth, L.S. McKee, A.S. Tauzin, O. Spadiut, S. Klinter, N.A. Pudlo, K. Urs, N.M. Koropatkin, A.L. Creagh, C.A. Haynes, A.G. Kelly, S.N. Cederholm, G.J. Davies, E.C. Martens, H. Brumer, W.S.C. Wallenberg, Centra, F.B.B. Skolan, KTH, Glykovetenskap, F.K.C. Skolan, A discrete genetic locus confers xyloglucan metabolism in select human gut 23

Journal Pre-proof Bacteroidetes, Nature 506 (2014) 498-502. https://doi.org/10.1038/nature12907. [28] J. Hu, S. Nie, Q. Wu, C. Li, Z. Fu, J. Gong, S.W. Cui, M. Xie, Polysaccharide from seeds of Plantago asiatica L. affects lipid metabolism and colon microbiota of mouse, J. Agric. Food Chem. 62 (2014) 229-234. https://doi.org/10.1021/jf4040942. [29] M. Valko, K. Jomova, C.J. Rhodes, K. Kuča, K. Musílek, Redox- and non-redox-metal-induced formation of free radicals and their role in human disease, Arch. Toxicol. 90 (2016) 1-37. https://doi.org/10.1007/s00204-015-1579-5. [30] R.R.F. Cathcart, Vitamin C: the nontoxic, nonrate-limited, antioxidant free radical scavenger, Med. Hypotheses 18 (1985) 61-77. https://doi.org/10.1016/0306-9877(85)90121-5. [31] J.D. Schoenfeld, Z.A. Sibenaller, K.A. Mapuskar, M.D. Bradley, B.A. Wagner, G.R. Buettner, V. Monga, M. Milhem, D.R. Spitz, B.G. Allen, Redox active metals and H 2O2 mediate the increased efficacy of pharmacological ascorbate in combination with gemcitabine or radiation in pre-clinical

of

sarcoma models, Redox Biol. 14 (2018) 417-422. https://doi.org/10.1016/j.redox.2017.09.012. [32] J. Du, J.J. Cullen, G.R. Buettner, Ascorbic acid: Chemistry, biology and the treatment of cancer, Biophys.

Acta,

Rev.

Cancer

1826

ro

Biochim.

https://doi.org/10.1016/j.bbcan.2012.06.003.

(2012)

443-457.

-p

[33] A. Carr, S. Maggini, 2017. Vitamin C and immune function, Nutrients 9, 1211. https://doi.org/10.3390/nu9111211.

re

[34] E.A. Minor, B.L. Court, J.I. Young, G. Wang, Ascorbate induces ten-eleven translocation (Tet) methylcytosine dioxygenase-mediated generation of 5-hydroxymethylcytosine, J. Biol. Chem. 288 (2013) 13669-13674. https://doi.org/10.1074/jbc.C113.464800.

lP

[35] M. Moser, O. Chun, 2016. Vitamin C and heart health: A review based on findings from epidemiologic studies, Int. J. Mol. Sci. 17, 1328. https://doi.org/10.3390/ijms17081328. [36] G.R. Buettner, B.A. Jurkiewicz, Catalytic metals, ascorbate and free radicals: Combinations to

na

avoid, Radiat. Res. 145 (1996) 532-541. https://doi.org/10.2307/3579271. [37] R. Kivela, L. Nystrom, H. Salovaara, T. Sontag-Strohm, Role of oxidative cleavage and acid

Jo ur

hydrolysis of oat beta-glucan in modelled beverage conditions, J. Cereal Sci. 50 (2009) 190-197. https://doi.org/10.1016/j.jcs.2009.04.012. [38] D. Sun-Waterhouse, B.G. Smith, C.J. O Connor, L.D. Melton, Effect of raw and cooked onion dietary fibre on the antioxidant activity of ascorbic acid and quercetin, Food Chem. 111 (2008) 580-585. https://doi.org/10.1016/j.foodchem.2008.04.023. [39] L. Hung, Y. Horagai, Y. Kimura, S. Adachi, Decomposition and discoloration of L-ascorbic acid freeze-dried with saccharides, Innovative Food Sci. Emerging Technol. 8 (2007) 500-506. https://doi.org/10.1016/j.ifset.2007.02.003. [40] A.J. Aliste, N.L. Del Mastro, Ascorbic acid as radiation protector on polysaccharides used in food industry, Colloids Surf., A 249 (2004) 131-133. https://doi.org/10.1016/j.colsurfa.2004.08.064. [41] M. Majzoobi, M. Radi, A. Farahnaky, T. Tongdang, Effects of L-ascorbic acid on physicochemical

characteristics

of

wheat

starch,

J.

Food

Sci.

77

(2012)

C314-C318.

https://doi.org/10.1111/j.1750-3841.2011.02586.x. [42] P. Sriburi, S.E. Hill, J.R. Mitchell, Effects of L-ascorbic acid on the conversion of cassava starch, Food Hydrocolloids 13 (1999) 177-183. https://doi.org/10.1016/S0268-005X(98)00080-0. [43] K.S. Özdemir, V. Gökmen, Extending the shelf-life of pomegranate arils with chitosan-ascorbic acid coating, LWT-Food Sci. Technol. 76 (2017) 172-180. https://doi.org/10.1016/j.lwt.2016.10.057. [44] S.Y. Park, H.J. Park, B.I. Lee, S.T. Jung, Biopolymer composite films based on κ-carrageenan 24

Journal Pre-proof and chitosan, Mater. Res. Bull. 36 (2001) 511-519. https://doi.org/10.1016/S0025-5408(01)00545-1. [45] R. Kivelä, L. Nyström, H. Salovaara, T. Sontag-Strohm, Role of oxidative cleavage and acid hydrolysis of oat beta-glucan in modelled beverage conditions, J. Cereal Sci. 50 (2009) 190-197. https://doi.org/10.1016/j.jcs.2009.04.012. [46] Z. Zhang, X. Wang, M. Zhao, H. Qi, Free-radical degradation by Fe2+/Vc/H2O2 and antioxidant activity of polysaccharide from Tremella fuciformis, Carbohydr. Polym. 112 (2014) 578-582. https://doi.org/10.1016/j.carbpol.2014.06.030. [47] A.M. Faure, J. Werder, L. Nyström, Reactive oxygen species responsible for beta-glucan degradation, Food Chem. 141 (2013) 589-596. https://doi.org/10.1016/j.foodchem.2013.02.096 [48] G. Tabbì, S.C. Fry, R.P. Bonomo, ESR study of the non-enzymic scission of xyloglucan by an ascorbate-H2O2-copper system: the involvement of the hydroxyl radical and the degradation of ascorbate, J. Inorg. Biochem. 84 (2001) 179-187. https://doi.org/10.1016/S0162-0134(00)00235-X.

of

[49] S.C. FRY, Oxidative scission of plant cell wall polysaccharides by ascorbate-induced hydroxyl radicals, Biochem. J. 332 (1998) 507-515. https://doi.org/10.1042/bj3320507.

ro

[50] S. Lin, M. AL-Wraikat, L. Niu, F. Zhou, Y. Zhang, M. Wang, J. Ren, J. Fan, B. Zhang, L. Wang, Degradation enhances the anticoagulant and antiplatelet activities of polysaccharides from Lycium L.

leaves,

Int.

J.

Biol.

Macromol.

133

(2019)

674-682.

-p

barbarum

https://doi.org/10.1016/j.ijbiomac.2019.04.147.

re

[51] R. Kivelä, F. Gates, T. Sontag-Strohm, Degradation of cereal beta-glucan by ascorbic acid induced oxygen radicals, J. Cereal Sci. 49 (2009) 1-3. https://doi.org/10.1016/j.jcs.2008.09.003. [52] X. Shen, Z. Liu, J. Li, D. Wu, M. Zhu, L. Yan, G. Mao, X. Ye, R.J. Linhardt, S. Chen, anti-metastasis

property,

Int.

lP

Development of low molecular weight heparin by H2O2/ascorbic acid with ultrasonic power and its J.

Biol.

Macromol.

133

(2019)

101-109.

https://doi.org/10.1016/j.ijbiomac.2019.04.019.

na

[53] J. Li, S. Li, Y. Zheng, H. Zhang, J. Chen, L. Yan, T. Ding, R.J. Linhardt, C. Orfila, D. Liu, X. Ye, S. Chen, Fast preparation of rhamnogalacturonan I enriched low molecular weight pectic

Jo ur

polysaccharide by ultrasonically accelerated metal-free Fenton reaction, Food Hydrocolloids 95 (2019) 551-561. https://doi.org/10.1016/j.foodhyd.2018.05.025. [54] N. Mäkelä, T. Sontag-Strohm, N.H. Maina, The oxidative degradation of barley β-glucan in the presence of ascorbic acid or hydrogen peroxide, Carbohydr. Polym. 123 (2015) 390-395. https://doi.org/10.1016/j.carbpol.2015.01.037. [55] A. Iurlaro, G. Dalessandro, G. Piro, J.G. Miller, S.C. Fry, M.S. Lenucci, Evaluation of glycosidic bond cleavage and formation of oxo groups in oxidized barley mixed-linkage β-glucans using tritium labelling, Food Res. Int. 66 (2014) 115-122. https://doi.org/10.1016/j.foodres.2014.09.008. [56] O. Li, L. Wang, X. Liu, J. Yin, S. Nie, 2020. Interactions between ascorbic acid and water soluble polysaccharide from the seeds of Plantago asiatica L.: Effects on polysaccharide physicochemical

properties

and

stability,

Food

Hydrocolloids

99,

105351.

https://doi.org/10.1016/j.foodhyd.2019.105351. [57] K. Uchida, S. Kawakishi, Oxidative Depolymerization of polysaccharides induced by the ascorbic

acid-copper

ion

systems,

Agric.

Biol.

Chem.

50

(1986)

2579-2583.

https://doi.org/10.1080/00021369.1986.10867785. [58] A.M. Faure, M.L. Andersen, L. Nyström, Ascorbic acid induced degradation of beta-glucan: Hydroxyl radicals as intermediates studied by spin trapping and electron spin resonance spectroscopy, Carbohydr. Polym. 87 (2012) 2160-2168. https://doi.org/10.1016/j.carbpol.2011.10.045. 25

Journal Pre-proof [59] M.B. Davies, J. Austin, D.A. Partridge, Vitamin C: Its chemistry and biochemistry, Royal Society of Chemistry, Cambridge, 1991. [60] M. Curcio, F. Puoci, F. Iemma, O.I. Parisi, G. Cirillo, U.G. Spizzirri, N. Picci, Covalent insertion of antioxidant molecules on chitosan by a free radical grafting procedure, J. Agric. Food Chem. 57 (2009) 5933-5938. https://doi.org/10.1021/jf900778u. [61] M.J. Burkitt, Chemical, biological and medical controversies surrounding the Fenton reaction, Prog. React. Kinet. Mech. 28 (2003) 75-103. https://doi.org/10.3184/007967403103165468. [62] J.C. Deutsch, Ascorbic acid oxidation by hydrogen peroxide, Anal. Biochem. 255 (1998) 1-7. https://doi.org/10.1006/abio.1997.2293. [63] A. Pillay Narrainen, P.A. Lovell, Mechanism and kinetics of free-radical degradation of xyloglucan

in

aqueous

solution,

Polymer

51

(2010)

6115-6122.

https://doi.org/10.1016/j.polymer.2010.10.049.

of

[64] N. Makela, T. Sontag-Strohm, S. Schiehser, A. Potthast, H. Maaheimo, N.H. Maina, Reaction https://doi.org/10.1016/j.carbpol.2016.11.060.

ro

pathways during oxidation of cereal beta-glucans, Carbohydr Polym 157 (2017) 1769-1776. [65] R. Kivelä, U. Henniges, T. Sontag-Strohm, A. Potthast, Oxidation of oat β-glucan in aqueous during

processing,

Carbohydr.

https://doi.org/10.1016/j.carbpol.2011.08.028.

Polym.

87

(2012)

589-597.

-p

solutions

re

[66] T. Wu, C. Wu, Y. Xiang, J. Huang, L. Luan, S. Chen, Y. Hu, Kinetics and mechanism of degradation of chitosan by combining sonolysis with H 2O2/ascorbic acid, RSC Adv. 6 (2016) 7628-76287. https://doi.org/10.1039/c6ra11197a. ascorbic

acid,

lP

[67] M. Peleg, M.D. Normand, W.R. Dixon, T.R. Goulette, Modeling the degradation kinetics of Crit.

Rev.

Food

Sci.

Nutr.

58

(2018)

1478-1494.

https://doi.org/10.1080/10408398.2016.1264360.

na

[68] J.L. Gębicki, M. Szymańska-Owczarek, B. Pacholczyk-Sienicka, S. Jankowski, Ascorbyl radical disproportionation in reverse micellar systems, Radiat. Phys. Chem. 145 (2018) 174-179.

Jo ur

https://doi.org/10.1016/j.radphyschem.2017.10.019. [69] S. Tewari, R. Sehrawat, P.K. Nema, B.P. Kaur, 2017. Preservation effect of high pressure processing on ascorbic acid of fruits and vegetables: A review, J. Food Biochem. 41, e12319. https://doi.org/10.1111/jfbc.12319.

[70] Y. Wang, J. Yin, X. Huang, S. Nie, 2020. Structural characteristics and rheological properties of high viscous glucan from fruit body of Dictyophora rubrovolvata, Food Hydrocolloids 101, 105514. https://doi.org/10.1016/j.foodhyd.2019.105514. [71] X. Xiao, C. Tan, X. Sun, Y. Zhao, J. Zhang, Y. Zhu, J. Bai, Y. Dong, X. Zhou, 2020. Effects of fermentation on structural characteristics and in vitro physiological activities of barley β-glucan, Carbohydr. Polym. 231, 115685. https://doi.org/10.1016/j.carbpol.2019.115685. [72] M. Zhang, G. Wang, F. Lai, H. Wu, Structural characterization and immunomodulatory activity of a novel polysaccharide from Lepidium meyenii, J Agric Food Chem. 64 (2016) 1921-1931. https://doi.org/10.1021/acs.jafc.5b05610. [73] A. Bouallegue, A. Casillo, F. Chaari, A. La Gatta, R. Lanzetta, M.M. Corsaro, R. Bachoual, S. Ellouz-Chaabouni, Levan from a new isolated Bacillus subtilis AF17: Purification, structural analysis and

antioxidant

activities,

Int.

J.

Biol.

Macromol.

144

(2020)

316-324.

https://doi.org/10.1016/j.ijbiomac.2019.12.108. [74] J. Rahkila, F.S. Ekholm, R. Leino, CuI-mediated degradation of polysaccharides leads to 26

Journal Pre-proof fragments

with

narrow

polydispersities,

Eur.

J.

Org.

Chem.

2018

(2018)

1449-1454.

https://doi.org/10.1002/ejoc.201800033. [75] N. Hou, M. Zhang, Y. Xu, Z. Sun, J. Wang, L. Zhang, Q. Zhang, Polysaccharides and their depolymerized fragments from Costaria costata: Molecular weight and sulfation-dependent anticoagulant and FGF/FGFR signal activating activities, Int. J. Biol. Macromol. 105 (2017) 1511-1518. https://doi.org/10.1016/j.ijbiomac.2017.06.042. [76] J. Li, S. Li, L. Wu, H. Yang, C. Wei, T. Ding, R.J. Linhardt, X. Zheng, X. Ye, S. Chen, Ultrasound-assisted fast preparation of low molecular weight fucosylated chondroitin sulfate with antitumor activity, Carbohydr. Polym. 209 (2019) 82-91. https://doi.org/10.1016/j.carbpol.2018.12.061. [77] A.M. Faure, L. Nystrom, Effect of apotransferrin, lactoferrin and ovotransferrin on the hydroxyl radical

mediated

degradation

of

beta-glucan,

Food

Chem.

204

(2016)

1-6.

https://doi.org/10.1016/j.foodchem.2016.02.075.

of

[78] N. Lamas De Souza, J. Bartz, E. Da Rosa Zavareze, P. Diaz De Oliveira, A. Da Silveira Moreira, W. Schellin Vieira Da Silva, A.R. Guerra Dias, 2017. Functional, physiological, and rheological Preserv. 41, e13169. https://doi.org/10.1111/jfpp.13169.

ro

properties of oat β-glucan oxidized with hydrogen peroxide under soft conditions, J. Food Process.

-p

[79] N. Mäkelä, N.H. Maina, P. Vikgren, T. Sontag-Strohm, Gelation of cereal β-glucan at low concentrations, Food Hydrocolloids 73 (2017) 60-66. https://doi.org/10.1016/j.foodhyd.2017.06.026. oxidative

degradation

of

re

[80] Y. Wang, R. Zhan, T. Sontag-Strohm, N.H. Maina, The protective role of phytate in the cereal

beta-glucans,

Carbohydr.

Polym.

169

(2017)

220-226.

https://doi.org/10.1016/j.carbpol.2017.04.016.

lP

[81] A.M. Faure, A. Sánchez-Ferrer, A. Zabara, M.L. Andersen, L. Nyström, Modulating the structural properties of β-d-glucan degradation products by alternative reaction pathways, Carbohydr. Polym. 99 (2014) 679-686. https://doi.org/10.1016/j.carbpol.2013.08.022. oxidation

processes,

na

[82] A.D. Bokare, W. Choi, Review of iron-free Fenton-like systems for activating H2O2 in advanced J.

Hazard.

Mater.

275

(2014)

121-135.

Jo ur

https://doi.org/10.1016/j.jhazmat.2014.04.054. [83] O.E. Mäkinen, R. Kivelä, L. Nyström, M.L. Andersen, T. Sontag-Strohm, Formation of oxidising species and their role in the viscosity loss of cereal beta-glucan extracts, Food Chem. 132 (2012) 2007-2013. https://doi.org/10.1016/j.foodchem.2011.12.040. [84] Y. Hou, J. Wang, W. Jin, H. Zhang, Q. Zhang, Degradation of Laminaria japonica fucoidan by hydrogen peroxide and antioxidant activities of the degradation products of different molecular weights, Carbohydr. Polym. 87 (2012) 153-159. https://doi.org/10.1016/j.carbpol.2011.07.031. [85] Y. Xu, X. Niu, N. Liu, Y. Gao, L. Wang, G. Xu, X. Li, Y. Yang, Characterization, antioxidant and hypoglycemic activities of degraded polysaccharides from blackcurrant (Ribes nigrum L.) fruits, Food Chem. 243 (2018) 26-35. https://doi.org/10.1016/j.foodchem.2017.09.107. [86] A.M. Faure, W.H. Koppenol, L. Nyström, Iron (II) binding by cereal beta-glucan, Carbohydr. Polym. 115 (2015) 739-743. https://doi.org/10.1016/j.carbpol.2014.07.038. [87] Q. Zheng, W. Li, S. Liang, H. Zhang, H. Yang, M. Li, Y. Zhang, Effects of ultrasonic treatment on the molecular weight and anti-inflammatory activity of oxidized konjac glucomannan, CyTA--J. Food 17 (2019) 1-10. https://doi.org/10.1080/19476337.2018.1541195. [88] S. Trzciński, D.U. Staszewska, Kinetics of ultrasonic degradation and polymerisation degree distribution of sonochemically degraded chitosans, Carbohydr. Polym. 56 (2004) 489-498. https://doi.org/10.1016/j.carbpol.2004.03.017. 27

Journal Pre-proof [89] S. Baxter, S. Zivanovic, J. Weiss, Molecular weight and degree of acetylation of high-intensity ultrasonicated

chitosan,

Food

Hydrocolloids

19

(2005)

821-830.

https://doi.org/10.1016/j.foodhyd.2004.11.002. [90] T. Wu, S. Zivanovic, D.G. Hayes, J. Weiss, Efficient reduction of chitosan molecular weight by high-intensity ultrasound: underlying mechanism and effect of process parameters, J. Agric. Food Chem. 56 (2008) 5112-5119. https://doi.org/10.1021/jf073136q. [91] M.R. Kasaai, J. Arul, G. Charlet, Fragmentation of chitosan by ultrasonic irradiation, Ultrason. Sonochem. 15 (2008) 1001-1008. https://doi.org/10.1016/j.ultsonch.2008.04.005. [92] C. Leonelli, T.J. Mason, Microwave and ultrasonic processing: Now a realistic option for industry, Chem. Eng. Process. 49 (2010) 885-900. https://doi.org/10.1016/j.cep.2010.05.006. [93] R. Czechowska-Biskup, B. Rokita, S. Lotfy, P. Ulanski, J.M. Rosiak, Degradation of chitosan and

starch

by

360-kHz

ultrasound,

Carbohydr.

Polym.

(2005)

175-184.

of

https://doi.org/10.1016/j.carbpol.2004.12.001.

60

[94] P.R. Gogate, A.L. Prajapat, Depolymerization using sonochemical reactors: A critical review,

ro

Ultrason. Sonochem. 27 (2015) 480-494. https://doi.org/10.1016/j.ultsonch.2015.06.019. [95] L.J. Bai, J.Y. Wang, The ESR spin trapping studies of reaction between ascorbic acid with

-p

hydrogen peroxide, Chem. J. Chinese U. 19 (1998) 890-894.

[96] Y. Li, Y. Yang, A.N. Yu, K. Wang, Effects of reaction parameters on self-degradation of https://doi.org/10.1007/s10068-016-0014-x.

re

L-ascorbic acid and self-degradation kinetics, Food Sci. Biotechnol. 25 (2016) 97-104. [97] E. Paquet, S.L. Turgeon, S. Lemieux, Effect of xanthan gum on the degradation of cereal

lP

β-glucan by ascorbic acid, J. Cereal Sci. 52 (2010) 260-262. https://doi.org/10.1016/j.jcs.2010.06.003. [98] J. Li, S. Li, S. Liu, C. Wei, L. Yan, T. Ding, R.J. Linhardt, D. Liu, X. Ye, S. Chen, Pectic oligosaccharides hydrolyzed from citrus canning processing water by Fenton reaction and their potentials,

Int.

J.

Biol.

na

antiproliferation

Macromol.

124

(2019)

1025-1032.

https://doi.org/10.1016/j.ijbiomac.2018.11.166.

Jo ur

[99] Y. Xu, X. Zhang, X. Yan, J. Zhang, L. Wang, H. Xue, G. Jiang, X. Ma, X. Liu, Characterization, hypolipidemic and antioxidant activities of degraded polysaccharides from Ganoderma lucidum, Int. J. Biol. Macromol. 135 (2019) 706-716. https://doi.org/10.1016/j.ijbiomac.2019.05.166. [100] R. Zhu, X. Zhang, Y. Wang, L. Zhang, C. Wang, F. Hu, C. Ning, G. Chen, Pectin oligosaccharides

from

hawthorn

(Crataegus

pinnatifida

characterization and potential antiglycation activities,

Bunge.

Var.

major):

Molecular

Food Chem. 286 (2019) 129-135.

https://doi.org/10.1016/j.foodchem.2019.01.215. [101] X. Sun, H. Zhang, J. Liu, J. Ouyang, Repair activity and crystal adhesion inhibition of polysaccharides with different molecular weights from red algae Porphyra yezoensis against oxalate-induced oxidative damage in renal epithelial cells, Food Funct. 10 (2019) 3851-3867 https://doi.org/10.1039/c8fo02556h. [102] H. Zhang, X.T. Cai, Q.H. Tian, L.X. Xiao, Z. Zeng, X.T. Cai, J.Z. Yan, Q.Y. Li, Microwave-assisted degradation of polysaccharide from Polygonatum sibiricum and antioxidant activity, J. Food Sci. 84 (2019) 754-761. https://doi.org/10.1111/1750-3841.14449. [103] D. Shi, J. Qi, H. Zhang, H. Yang, Y. Yang, X. Zhao, Comparison of hydrothermal depolymerization and oligosaccharide profile of fucoidan and fucosylated chondroitin sulfate from Holothuria

floridana,

Int.

J.

Biol.

https://doi.org/10.1016/j.ijbiomac.2019.03.127. 28

Macromol.

132

(2019)

738-747.

Journal Pre-proof [104] Y. Xu, N. Liu, X. Fu, L. Wang, Y. Yang, Y. Ren, J. Liu, L. Wang, Structural characteristics, biological, rheological and thermal properties of the polysaccharide and the degraded polysaccharide from

raspberry

fruits,

Int.

J.

Biol.

Macromol.

132

(2019)

109-118.

https://doi.org/10.1016/j.ijbiomac.2019.03.180. [105] A. Rani, R. Baruah, A. Goyal, Prebiotic chondroitin sulfate disaccharide isolated from chicken keel bone exhibiting anticancer potential against human colon cancer cells, Nutr. Cancer 71 (2019) 825-839. https://doi.org/10.1080/01635581.2018.1521446. [106] E. Li, S. Yang, Y. Zou, W. Cheng, B. Li, T. Hu, Q. Li, W. Wang, S. Liao, D. Pang, 2019. Purification, characterization, prebiotic preparations and antioxidant activity of oligosaccharides from mulberries, molecules 24, 2329. https://doi.org/10.3390/molecules24122329. [107] Z. Zhi, J. Chen, S. Li, W. Wang, R. Huang, D. Liu, T. Ding, R.J. Linhardt, S. Chen, X. Ye, 2017. Fast preparation of RG-I enriched ultra-low molecular weight pectin by an ultrasound accelerated

Jo ur

na

lP

re

-p

ro

of

Fenton process, Sci. Rep. 7, 541. https://doi.org/10.1038/s41598-017-00572-3.

29

Journal Pre-proof Highlights

Hydroxyl radical existed during ascorbic acid degradation of polysaccharide.



Ascorbic acid could reduce the molecular weight of polysaccharide.



Degradation would not cause any significant changes on polysaccharide structure.



The biological activity of degraded products had been improved to some extent.

Jo ur

na

lP

re

-p

ro

of



30