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Journal of Food Engineering 82 (2007) 128–134

Gelling properties and lipid oxidation of kamaboko gels from grasscarp (Ctenopharyngodon idellus) influenced by chitosan

Linchun Mao *, Tao Wu

Department of Food Science and Nutrition, College of Biosystem Engineering and Food Science, Zhejiang University, Hangzhou 310029, China

Received 6 December 2006; received in revised form 17 January 2007; accepted 21 January 2007Available online 4 February 2007

Abstract

Chitosan was applied to kamaboko gels made from grass carp (Ctenopharyngodon idellus), and the correlative influences on gellingquality and lipid oxidation were evaluated by color, texture, expressible water, TBA (2-thiobarbituric acid) and peroxide values. White-ness, hardness, springiness, cohesiveness, chewiness, adhesiveness, TBA value increased, while expressible water and peroxide valuedecreased when 1% chitosan was added in gels. Addition with 1% chitosan was considered as a promising approach in the processingof grass carp gels to improve thermal gelling properties and delay lipid oxidation.� 2007 Elsevier Ltd. All rights reserved.

Keywords: Chitosan; Grass carp; Kamaboko gel; Gelling property; Lipid oxidation

1. Introduction

Grass carp (Ctenopharyngodon idellus) is one of the mainfreshwater fish species in China. The potential of this fish asa source of low fat, high protein food has not yet been fullyutilized due to the limited processing, distribution sphereand storage period. Surimi is a high quality myofibrillarprotein concentrate that obtained from fish muscle, withhigh commercial value and extensive application in seafoodproduction. Therefore, surimi processing is the effectiveway to utilize those fish species with low commercial value.Functional properties such as color and texture are themajor factors responsible for the final acceptance of sur-imi-based products by consumers. When high quality sur-imi is the predominant component of a surimi-basedproduct, the resulting texture tends to be rubbery (Lee,Wu, & Okada, 1992). Another restriction of surimi prod-ucts is the oxidation of lipid. Fish lipids are well knownto have a high content of polyunsaturated fatty acids, suchas eicosapentanoic acid (EPA) and docosahexaenoic acid(DHA) which have health promotion and cardiovascular

0260-8774/$ - see front matter � 2007 Elsevier Ltd. All rights reserved.

doi:10.1016/j.jfoodeng.2007.01.015

* Corresponding author. Tel./fax: +86 571 86091584.E-mail address: linchun@zju.edu.cn (L. Mao).

effects. But they are fairly susceptible to oxidation, leadingto a number of complex chemical changes that eventuallygive rise to the development of off-flavors, as well as thegeneration of harmful oxidation products (Fritsche &Johnston, 1988; Hsieh & Kinsella, 1989; Shahidi, 1998).To better suit the textural and healthy preferences of con-sumers, natural ingredients is commonly added to surimi,to improve the functional properties and inhibit lipid oxi-dation of surimi products (Lee et al., 1992; Lee, Lee,Chung, & Lavery, 1992).

Protein–carbohydrate interactions affects the functionalproperties in foods such as solubility, surface activity, con-formational stability, gel forming ability, emulsifying andfoaming properties, where proteins are the major ingredi-ents, such as meat and fish processed products (Chin, Kee-ton, Longnecker, & Lamkey, 1998). Some biopolymerssuch as starch (Kim & Lee, 1987) and cellulose (Yoon &Lee, 1990) have been reported to contribute to surimi gelproperties. Chitosan is a low-acetyl-substituted form ofchitin, which has been reported to have a number of func-tional properties that make it technically and physiologi-cally useful as a kind of dietary fibre (Shahidi, Arachchi,& Jeon, 1999; Jeon, Kamil, & Shahidi, 2002; Borderıas,Sanchez-Alonso, & Perez-Mateos, 2005). There have been

L. Mao, T. Wu / Journal of Food Engineering 82 (2007) 128–134 129

a few studies describing addition of chitosan to tofu (Kim& Han, 2002), meat products (Jo, Lee, Lee, & Byun, 2001;Lin & Chao, 2001; Sagoo, Board, & Roller, 2002) and fishmuscle (Kataoka, Ishizaki, & Tanaka, 1998; Benjakulet al., 2000; Benjakul, Visessanguan, Phatchrat, & Tanaka,2003; Kamil, Jeon, & Shahidi, 2002). A number of studies(Kamil et al., 2002; Shahidi, Kamil, Jeon, & Kim, 2002;Gomez-Guillen, Montero, Solas, & Perez-Mateos, 2005)report that chitosan inhibits lipid oxidation, and that thisinhibition is dependent on concentration and type of chito-san (different viscosity or molecular weight). As a naturalpolysaccharide material with texturizing properties (Benja-kul et al., 2003), antioxidant activity (Kamil et al., 2002;Lin & Chou, 2004; Kim & Thomas, 2007) and antibacterialproperties (Chung, Wang, Chen, & Li, 2003), chitosantherefore appears to be a promising use in fish surimi prod-ucts to improve gelling properties and prevent lipidoxidation.

The objective of this study was to investigate the effectsof chitosan with different molecular weights and concentra-tions on the gelling properties and inhibition of lipid oxida-tion of kamaboko gels prepared from grass carp.

2. Materials and methods

2.1. Surimi and chemicals

Fresh grass carp (C. idellus) was obtained from a fishmarket in Hangzhou, China. Fifty fresh fishes (ca.50 kg) were washed and kept in ice until processing. Sur-imi was obtained after fishes were headed, gutted, andwashed in cold water (below 10 �C), removing skin andbones. After dewatering with cheesecloth as filtering mate-rial, surimi was mixed with 8% sucrose as cryoprotectant,then packed into polyethylene bags (2 kg each), frozen at�70 �C in a ultra freezer (Forma Scientific R404A, USA)for 5 h and stored at �20 �C until needed. Commercialchitosans (MW 300 kDa and MW 10 kDa, 95% deacetyla-tion) were obtained from Dingguo Bio-Technology Com-pany (Hangzhou, China). All other chemicals used wereof analytical grade and supplied by Sigma Company(Sigma Co., USA).

Table 1Experimental formula (grams) of kamaboko gels from grass carp

Ingredients Control 0.5% HC 1% HC 0.

Surimi 675 660 635 6Ice water 255 265 285 2NaCl 20 20 20Egg white 10 10 10Starch 40 40 40HC 0 5 10LC 0 0 0Total 1000 1000 1000 10

HC: 300 kDa chitosan (high molecular weight chitosan); LC: 10 kDa chitosan (w). All formulations were standardized at 78% water and 22% solids.

2.2. Preparation of kamaboko gels

Formulations of kamaboko gels are shown in Table 1.The frozen surimi was partially thawed at room tempera-ture for approximately 2 h before being cut into 4 cmcubes. Surimi cubes were chopped for several minutes.First, salt (2%) was added and the mixture was choppedfor 1.5 min, and then ice water was added and the mixturewas chopped for 1 min, forming a very viscous and tackypaste. Starch (4%) and dried egg white (1%) were addedand the mixture was chopped for another 4 min, then dif-ferent chitosans (MW 300 kDa, MW 10 kDa, 1:1 mixtureof MW 300 kDa and MW 10 kDa chitosans) were dis-persed with a little 1% acetic acid and added to the mixture.The final concentrations of chitosan were 0.5% and 1%,respectively. The MW 300 kDa chitosan was described asrelative high molecular weight chitosan (HC), the MW10 kDa chitosan was described as relative low molecularweight chitosan (LC), their 1:1 mixture was described asHC + LC. All formulations were standardized at 78%moisture, 22% solids and 2% NaCl (Park, 2000). Gels with-out chitosan were served as control.

The chopping procedure was carried out in a coolroom (4 �C) to keep the paste below 8 �C. The mixturewas extruded into plastic tubes (25 mm diameter,120 mm length) where both ends were plugged with rub-ber pistons. The interior wall of the tubes was coated witha film of vegetable oil to prevent gel adhesion. The gelwas cooked in a water bath at 90 �C for 20 min after set-ting at 25 �C for 3 h. After heating, surimi mixturebecame stronger and non-transparent gel, called kam-aboko gel (Benjakul et al., 2000), which were removedfrom the tubes and stored at 4 �C in polystyrene bags,prior to measurements.

2.3. Proximate analysis

Moisture, ash, and crude protein (N � 6.25) wereassayed as described by AOAC (1995). Lipid content wasdetermined as described by Folch, Lee, and Sloane-Stanley(1957). The proximate analysis was based on the muscle offresh grass carp.

5% LC 1% LC 0.5% HC + LC 1% HC + LC

60 635 660 63565 285 265 28520 20 20 2010 10 10 1040 40 40 400 0 2.5 55 10 2.5 5

00 1000 1000 1000

low molecular weight chitosan); HC + LC: mixture of HC and LC (1:1, w/

130 L. Mao, T. Wu / Journal of Food Engineering 82 (2007) 128–134

2.4. Color measurement

Color measurements of gels were performed in a colormeter (SPSIC WSC-S, China) at ambient temperature.The equipment was standardized with a standard-whitereflection plate. The most important color parameter insurimi gels is whiteness, which was calculated using the for-mula: W = L – 3b, where L is the lightness from black towhite, b is the scale from yellow to blue (Park, 1994).

2.5. Texture profile analysis

Texture profile analysis (TPA) of gels was performed atambient temperature with a TA-XT2i Texture Analyser(SMS, UK) and a 25 kg load cell. The Texture ExpertExceed version 1.22 computer program by Stable MicroSystem was used for data collection and calculation. Gelswere cut in cylinders of 25 mm diameter � 25 mm length.Each cylinder was compressed axially in two consecutivecycles of 25% compression, 5 s apart, with a flat plunger50 mm in diameter (SMS-P/50). The cross-head moved ata constant speed of 1 mm/s. From the TPA curves, the fol-lowing texture parameters were obtained: hardness at 25%of deformation, springiness, cohesiveness, adhesiveness,and chewiness (Pons, 1996).

2.6. Expressible water

The amount of expressible water (EW) for each treat-ment was measured. Samples of 3 g (±0.2 g) of fish gelswere weighed and put between two layers of filter paper.Samples were placed at the bottom of 50 ml centrifugetubes and centrifuged at 1000g for 15 min at 15 �C (Uresti,Ramırez, Lopez-Arias, & Vazquez, 2003). Immediatelyafter centrifugation, the fish gel samples were weighedand the EW was calculated as: expressible water(%) = (Wi �Wf)/Wi � 100, where Wi is the initial weightof gel, Wf is the final weight of gel.

2.7. TBA test

Method was based on Gomes, Silva, Nascimento, andFukuma (2003). The TBA (2-thiobarbituric acid) solutionwas prepared by weighing 0.3 g of TBA and transferringin a 100 ml beaker with 90 ml distilled water. The beakerwas placed in a water bath (80 �C) until complete dissolu-tion. The solution was then quantitatively transferred toa 100 ml volumetric flask and the volume completed withdistilled water so as to achieve a 0.021 M TBA solution.

Minced sample (50 g) was blended after the addition of6 ml of ethanolic solution of butylated hydroxytoluene(BHT, 1 g/l) to prevent autoxidation. Aliquots of homoge-nized sample (10 g) were transferred to a flat-bottomedflask and one drop of silicone anti-foaming agent addedplus 2.5 ml of 4 N HCl and 97.5 ml of distilled water. Thissample was then distilled and the first 50 ml of distillatecollected. Distillation was carried out in triplicate. Then

5 ml of the distillate plus 0.6 ml of BHT (1 g/l) were addedto 5 ml of 0.021 M TBA solution into a screw-cap test tubeand heated in a water bath (90 �C) for 40 min for pinkcolor development. The test tube was then cooled and theoptical density was determined at 532 nm on a spectropho-tometer (Spectrum-cn 722E, China) using control solutioncontaining 5 ml distilled water, 5 ml TBA solution and0.6 ml BHT. TBA values were expressed as mg of malondi-aldehyde (MDA) per kg of sample. The concentration ofMDA was calculated from a standard curve using1,1,3,3-tetraethoxy-propane (TEP) as the standardcompound.

2.8. Peroxide value

Gel samples (0.5 g) were mixed with 25 ml of a solutionof glacial acetic acid and chloroform (3:2 v/v) in a conicalflask, and then 1 ml of saturated potassium iodide wasadded. The mixture was kept in the dark for about10 min, and then 30 ml of distilled water and 1 ml of freshlyprepared 1% starch were added. After shaking, the sampleswere titrated with 0.01 M sodium thiosulfate. The peroxidevalues were expressed in units of meq/kg of sample (Egan,Kirk, & Sawyer, 1981).

2.9. Statistical analysis

All analyses were run in triplicate for each replicate(n = 2 � 3). Results are reported as mean values of sixdeterminations ± standard deviation (SD). Analysis of var-iance was performed by ANOVA procedures (SPSS 12.0for Windows). Differences among the mean values of thevarious treatments and storage periods were determinedby the least significant difference (LSD) test, and the signif-icance was defined at P < 0.05.

3. Results and discussion

3.1. Proximate composition of grass carp muscle

Proximate analysis showed that grass carp muscle con-tains 18.95 ± 0.53% total protein, 77.57 ± 0.37% moisture,1.83 ± 0.12% total lipid, and 1.19 ± 0.09% ash. Grass carpmuscle has a low lipid, intermediate protein, and highmoisture content, similar to previous reports (Bakir, Mel-ton, & Wilson, 1993).

3.2. Gel color

Color measurements of grass carp gels were shown inTable 2. Gels with chitosan exhibited higher L (80.08–83.68) than that of control (78.33) (P < 0.05). Significantdifferences of L values between gels containing high molec-ular weight chitosan (HC) or low molecular weight chito-san (LC) were not observed. However, L value increasedsignificantly in gels when the mixture of high molecularweight chitosan and low molecular weight chitosan

Table 2Color parameters of grass carp gels with or without chitosan

Chitosan Chitosan levels (%) Lightness (L) Yellowness (b) Whiteness (W)

Control 0 78.33 ± 0.52c 4.84 ± 0.11a 63.81 ± 0.69d

HC 0.5 80.19 ± 0.71b 4.56 ± 0.09b 66.51 ± 0.72c1 80.08 ± 0.69b 4.51 ± 0.11b 66.54 ± 0.87c

LC 0.5 80.35 ± 0.54b 4.18 ± 0.10c 67.81 ± 0.78b1 80.11 ± 0.34b 4.17 ± 0.13c 67.60 ± 0.63b

HC + LC 0.5 83.29 ± 0.81a 3.83 ± 0.13d 71.79 ± 0.90a1 83.68 ± 0.65a 3.81 ± 0.10d 72.26 ± 0.75a

HC: 300 kDa chitosan (high molecular weight chitosan); LC: 10 kDa chitosan (low molecular weight chitosan); HC + LC: mixture of HC and LC (1:1, w/w). Means in columns followed by different letters are statistically different using LSD (a = 0.05).

L. Mao, T. Wu / Journal of Food Engineering 82 (2007) 128–134 131

(HC + LC) was added (P < 0.05). The concentration ofchitosan had no obvious effect on the lightness of gels. Yel-lowness (b) of gels decreased by the addition of chitosan,especially HC + LC (P < 0.05). The concentration of chito-san had no significant influence on yellowness of gels. Thewhiteness of grass carp gels varied from 63.81 to 72.26, andwas improved by adding chitosan (P < 0.05). Difference inwhiteness was also found within different molecularweights chitosan (P < 0.05). Gels containing HC + LCexhibited the highest whiteness.

Generally, gels with high lightness, low yellowness andhigh whiteness are highly demanded by consumers (Hsu& Chiang, 2002). This study confirmed that addition ofchitosan improved the gel color. Rearrangement and inter-action of water, protein and polysaccharide moleculescaused by the addition of chitosan could be the responsiblefor this improvement. The chitosan–chitosan interactionand protein–chitosan covalent crosslinking seems to mod-ify the gel network, exhibiting a more lustrous and trans-parent appearance, and thus modifying the lightness offish gels.

3.3. Textural properties

Texture parameters including hardness, chewiness,springiness, cohesiveness, and adhesiveness were shown inTable 3. Addition of chitosan improved hardness andchewiness, with higher hardness and chewiness of HC or

Table 3Texture parameters of grass carp gels with or without chitosan

Chitosan Chitosan levels (%) Hardness Springi

Control 0 601 ± 19f 0.94 ± 0

HC 0.5 857 ± 22b 0.96 ± 01 898 ± 26a 0.99 ± 0

LC 0.5 681 ± 23e 0.95 ± 01 811 ± 21c 0.98 ± 0

HC + LC 0.5 761 ± 24d 0.95 ± 01 887 ± 27a 0.99 ± 0

HC: 300 kDa chitosan (high molecular weight chitosan); LC: 10 kDa chitosan (w). Values in the same column followed by a different letter are significantly d

HC + LC than LC (P < 0.05). Concentration of chitosanhad a significant effect on the hardness of gels in all treat-ments (P < 0.05), when concentration increased from 0.5%to 1%. Grass carp gels had high springiness values. Afterthe first compression, they almost recovered their originalheight, a typical characteristic of viscoelastic materials.At the concentration of 0.5%, chitosan showed no signifi-cant effect on the springiness value of fish gels when com-pared with that of control except HC. When theconcentration of chitosan increased to 1%, springinessincreased significantly (P < 0.05). Exhibition of cohesive-ness was very close to that of springiness, only when theconcentration of chitosan at 1%, cohesiveness of gels withchitosan was higher than that of gels without chitosan(P < 0.05), regardless of different type of chitosan. Adhe-siveness values were significantly higher in gels containingLC or HC + LC than gels without chitosan (P < 0.05).There is no significant difference between the adhesivenessvalues of gels with different concentrations of chitosan.

Influences of chitosan on texture of fish gels observed inthis study were similar as previous reports in walleye pollock(Kataoka et al., 1998) and barred garfish (Benjakul et al.,2000; Benjakul et al., 2003). In the presence of chitosan, pro-tein–polysaccharide conjugates would be formed betweenthe reactive amino group of glucosamine and the glutaminylresidue of myofibrillar proteins. Bonds between chitosanand myofibrillar proteins could be associated with improv-ing of texture properties in gels with the final structure

ness Cohesivene Chewiness Adhesiveness

.02c 0.86 ± 0.01b 483 ± 20e �25.3 ± 5.2c

.01b 0.86 ± 0.01b 700 ± 23b �33.3 ± 6.7d

.01a 0.91 ± 0.01a 804 ± 32a �34.7 ± 7.2d

.01bc 0.86 ± 0.02b 559 ± 37d �17.4 ± 4.2b

.01a 0.92 ± 0.01a 725 ± 23b �18.1 ± 4.6b

.01bc 0.87 ± 0.02b 633 ± 29c �6.1 ± 1.3a

.01a 0.92 ± 0.01a 808 ± 32a �5.5 ± 1.1a

low molecular weight chitosan); HC + LC: mixture of HC and LC (1:1, w/ifferent (P < 0.05).

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Control HC LC HC+LC

TB

A (

mg

MD

A/k

g) 0 day 15 days

Fig. 1. Thiobarbituric acid (TBA) values of grass carp gels stored at 4 �Cfor 0 and 15 days. Gels added with 1% 300 kDa chitosan (HC), 1% 10 kDachitosan (LC), 1% mixture of HC and LC chitosans (HC + LC) or withoutchitosan (control).

132 L. Mao, T. Wu / Journal of Food Engineering 82 (2007) 128–134

formed by both covalent and non-covalent interactions. Theeffect would be also reportedly due to modification of theactivity of the endogenous transglutaminase partly (Kat-aoka et al., 1998; Benjakul et al., 2000).

3.4. Expressible water

Content of extracted water is inversely associated withthe water holding capacity. Control product showed13.56% expressible water (Table 4). Adding 0.5% chitosandid not decrease the amount of expressible water in gels.When 1% chitosan was added, a significantly decrease onthe amount of expressible water was observed (P < 0.05),indicating that 1% chitosan improves the water holdingcapacity of restructured products. However, there wereno differences between HC, LC and HC + LC. Theseresults suggest that during the gelling of fish surimi con-taining chitosan, an increase of chitosan–water interactionsmight be induced.

3.5. TBA and peroxide values

Lipid oxidation, corresponding to the oxidative deterio-ration of polyunsaturated fatty acids in fish muscle, leadsto the production of off-flavors and off-odors, therebyshortening the shelf-life of food (Ramanathan & Das,1992). The TBA value and peroxide value are both well-established methods for determining oxidation products(Kulas & Ackman, 2001).

There were significant differences (P < 0.05) in the TBAvalues between the control and samples added with 1%chitosan, with contents of 0.184, 0.135, 0.095 and0.114 mg MDA/kg in the control, 1%HC gels, 1%LC gelsand 1%HC + LC gels, respectively (Fig. 1). After 15 daysof storage, TBA values in the control, HC gels, LC gelsand HC + LC gels increased to 1.181, 0.609, 0.352 and0.424 mg MDA/kg, respectively (Fig. 1). TBA values ofsamples without chitosan were significantly higher thanthose with chitosan (P < 0.05).

Peroxide values of samples with chitosan were signifi-cantly lower than that of control (P < 0.05). Changes of

Table 4Expressible water of grass carp gels with or without chitosan

Chitosan Chitosan levels (%) Expressible water (%)

Control 0 13.56 ± 0.83b

HC 0.5 13.76 ± 0.73ab1 6.58 ± 0.68c

LC 0.5 14.63 ± 0.88a1 7.27 ± 0.92c

HC + LC 0.5 13.49 ± 0.81b1 6.44 ± 0.90c

HC: 300 kDa chitosan (high molecular weight chitosan); LC: 10 kDachitosan (low molecular weight chitosan); HC + LC: mixture of HC andLC (1:1, w/w). Means in columns followed by different letters are statis-tically different using LSD (a = 0.05).

peroxide values were similar to TBA values, with contentsof 1.01, 0.79, 0.61 and 0.65 meq/kg in the control, 1%HC,1%LC and 1%HC + LC gels, respectively (Fig. 2). After 15days of storage, TBA values in the control, HC gels, LCgels and HC + LC gels increased to 13.56, 8.98, 5.23 and7.62 meq/kg, respectively (Fig. 2). As compared with thedifferent molecular weight chitosans, inhibitory effect onlipid oxidation was as follows: 10 kDa chito-san > 300 kDa + 10 kDa chitosan > 300 kDa chitosan.This observation is indicative of the inhibitory effect onlipid oxidation in grass carp gels by chitosan, and this effectseems to have relations with its molecular weight. Theresults of our study are in agreement with those of Kamilet al. (2002) who found that among the different molecularweight chitosans, chitosan of lower molecular weight wasmore effective than the higher molecular weight chitosansin preventing lipid oxidation.

Antioxidant activities of different molecular weights ofchitosan in grass carp gels may be attributed to theirmetal-binding capacities. Several sources of protein-boundiron exist in fish tissues, the iron bound to these proteinsmay be released during gel formation and storage, thusactivating oxygen and initiating lipid oxidation (St.Angelo, 1996). Chitosan may retard lipid oxidation by che-lating ferrous ions present in the system, thus eliminatingtheir peroxidant activity or their conversion to ferric ion.

0

24

6

8

1012

14

16

Control HC LC HC+LC

Per

oxid

e va

lue

(meq

/kg) 0 day 15 days

Fig. 2. Peroxide values of grass carp gels stored at 4 �C for 0 and 15 days.Gels added with 1% 300 kDa chitosan (HC), 1% 10 kDa chitosan (LC),1% mixture of HC and LC chitosans (HC + LC) or without chitosan(control).

L. Mao, T. Wu / Journal of Food Engineering 82 (2007) 128–134 133

Furthermore, amino groups in chitosan may participate inthe chelation of metal ions (Peng, Wang, & Tang, 1998;Xue, Yu, Hirat, Terao, & Lin, 1998). The varying antioxi-dant effect of chitosan may be attributed to the differenceof molecular weight which determine the chelation of metalions. In their charged state, the cationic amino groups ofchitosan impart intramolecular electric repulsive forces,which increase the hydrodynamic volume by extendedchain conformation (Anthonsen, Varum, & Smidsrod,1993). Perhaps this phenomenon may be responsible forlesser chelation by high molecular weight chitosan. Furda(1990) has reported that the degree of polymerization ofthe glucosamine unit is a major factor determining the vis-cosity of chitosan. Thus the degree of deacetylation isanother factor that may be involved in chelaton ability ofchitosan.

4. Conclusions

Chitosan could improve thermal gelling properties andprevent lipid oxidation of kamaboko gels from grass carp.Addition of chitosan improves gel color and texture withhigh whiteness and lightness, low yellowness, and highhardness and chewiness. When 1% chitosan is added,expressible water was significantly reduced. Chitosan oflow molecular weight is more effective in preventing lipidoxidation than that of high molecular weight. Additionof 300 kDa chitosan or 10 kDa chitosan, at a level of0.5–1%, would be considered as a promising approach inthe preparation of grass carp gels for improving textureand stabilizing color and lipid to prolong shelf life. Thepresent study should provide a possible application ofchitosan as a food additive to surimi food systems.

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