Biochemical and physical changes of grass carp (Ctenopharyngodon idella )?llets stored at à3and 0°C
Dasong Liu a ,Li Liang a ,Wenshui Xia a ,Joe M.Regenstein b ,Peng Zhou a ,?
a State Key Laboratory of Food Science and Technology,School of Food Science and Technology,Jiangnan University,Jiangsu Province,Wuxi 214122,China b
Department of Food Science,Cornell University,Ithaca,NY 14853-7201,USA
a r t i c l e i n f o Article history:
Received 2November 2012
Received in revised form 2February 2013Accepted 11February 2013
Available online 19February 2013Keywords:Grass carp Fillets
Superchilling Ice storage
Differential scanning calorimetry Light microscopy
a b s t r a c t
The objective of this study was to investigate the effect of superchilling at à3°C compared with ice stor-age at 0°C on the biochemical and physical properties of grass carp ?llets.Fillets stored at à3°C showed signi?cant changes in whiteness,drip loss and textural hardness,while changes in pH,total volatile basic nitrogen and TCA-soluble peptides were slowed down.Partial denaturation of myosin as demonstrated by differential scanning calorimetry differed between ?llets stored at à3and 0°C in that the transition peak showed a left shoulder at à3°C and sharpened at 0°C.Detachments between muscle cells and for-mation of cracks within cells were accelerated during storage at à3°C,and from 10days on,clear spaces between and within cells were observed with the concurrent appearance of white spots on the surface of ?llets,suggesting the formation of both extra-and intracellular large ice crystals.
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1.Introduction
Freshness is an essential factor that determines the quality,consumer acceptability and ultimately commercial value of ?sh and ?shery products.It is also a complex and often ill-de?ned char-acter that can be evaluated by different methods:sensory analyses based on appearance,color,?avor,odor,juiciness,and texture;chemical methods involving proteolysis,lipid hydrolysis and oxidation,and degradation of adenosine triphosphate (ATP);microbial parameters such as total viable counts and biogenic amines;and physical measurements including light and electron microscopy (Delbarre-Ladrat,Chéret,Taylor,&Verrez-Bagnis,2006).Compared with terrestrial animal,?sh deteriorates more rapidly during post-mortem storage due to a series of biochemical,physicochemical and microbial mechanisms,which vary consider-ably depending on species,biological status at the time of catch,slaughter methods,and storage temperatures and times.The most important factor affecting freshness and shelf life that can be con-trolled by the processor is temperature.Therefore,to meet the increasing demand for high ?esh quality in the market,?sh should be kept at low-temperature immediately after capture or death.It is commonly recognized that ?sh after death goes through the following stages:pre-rigor,rigor mortis and resolution of rigor mortis,while autolysis and microbial spoilage occur throughout these stages.The lower the temperature of cold storage is,the longer the period that the ?sh stays in pre-rigor stage,thus extend-ing the shelf life of the product.Ice has traditionally been used for the preservation of aquatic food products,and it can keep the prod-ucts moist and glossy.Superchilling has emerged as a promising method to prolong shelf life,and it is positioned between refriger-ation and freezing,where a product is partly frozen by lowering the temperature 1–2°C below its freezing point.In this way,a cold reservoir is built into the product and it might not require addi-tional chilling by addition of external ice during distribution,thus reducing the overall transport weight and costs (Duun &Rustad,2008).Superchilling is potentially more attractive compared with freezing,since less water is frozen,resulting in a lower degree of freeze denaturation of the proteins and less mechanical damages to the tissue structures.However,the ice fraction curve is fairly steep in the superchilling temperature range,and how to keep the temperature steady to avoid recrystallization has appeared as a practical challenge especially when it comes to commercial use of the technique,since recrystallization may contribute to the for-mation of larger ice crystals and also the changes in the location and orientation of the ice crystals,and hence causes structural damages (Duun &Rustad,2007).
The effect of superchilling on the quality of ?sh ?esh is still quite controversial,and most of the studies on superchilling focused on sensory analysis and microbial spoilage,while a few explored bio-chemical and physical properties such as protein denaturation and structural changes (Digre et al.,2011;Duun &Rustad,2008).
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Corresponding author.Tel./fax:+8651085912123.
E-mail address:zhoupeng@https://www.doczj.com/doc/d07656002.html, (P.Zhou).
For farmed Atlantic cod,the advantages of superchilling atà2.0°C over regular ice storage included a lower microbiological activity and better maintenance of freshness,while an earlier development of cloudy eyes was observed for superchilled cod(Digre et al., 2011).For vacuum packed Atlantic salmon superchilled atà1.4 andà3.6°C,the storage time was doubled compared with ice stor-age and the drip loss only slightly increased;while the textural hardness was signi?cantly higher for the?llets stored atà3.6°C, and the extractability of salt soluble proteins decreased for the?l-lets stored atà1.4°C suggesting a higher degree of freeze denatur-ation atà1.4°C(Duun&Rustad,2008).For Atlantic salmon pre-rigor?llets subjected to superchilling atà1.5°C,the drip loss was higher,and the myo?ber–myo?ber detachments and the myo?ber breakages were accelerated compared with ice storage;however, no difference in textural breaking force was observed between superchilled and iced?llets1week later(Bahuaud et al.,2008).
In China,grass carp is one of the‘‘four major cultured?sh spe-cies’’along with black carp,bighead carp and silver carp,and the production of cultured grass carp in China is estimated to be 4,220,000tons and ranked second among domestic cultured fresh-water?sh production in2010(Fishery Bureau of the Ministry of Agriculture of China,2011).Traditionally,grass carp has been sold as a whole?sh;however,with the rapid development of the domestic cold chain and the changes in consumption patterns, the sales of grass carp?llets are growing.Thus it is very important to?nd an effective way to maintain the postmortem quality of?sh ?llets.The objective of this study was to compare the effect of superchilling(à3°C)and ice storage(0°C)on the biochemical and physical properties of grass carp?llets.
2.Materials and methods
2.1.Chemicals
All chemicals used were of analytical grade.Sodium dodecyl sulphate,acrylamide,bisacrylamide and b-mercaptoethanol were purchased from Sangon Biotech Co.,Ltd.(Shanghai,China);tyro-sine was purchased from Sigma–Aldrich Co.(St.Louis,MO,USA); molecular weight(MW)markers(manufacturer’s speci?ed MW: rabbit phosphorylase,98kDa;rabbit actin,45kDa;bovine car-bonic anhydrase,31kDa;trypsin inhibitor,20kDa;hen egg white lysozyme,14kDa)were obtained from PimeGene Bio-Tech Co.,Ltd. (Shanghai,China).
2.2.Fish samples
One lot of live farmed grass carps(3.50±0.25kg,n=30)were obtained in the spring from a local retail market in Wuxi,Jiangsu Province,China.They were transported to the laboratory in water within30min.Upon arrival,the?sh were stunned by a sharp blow to the head with a wooden stick.Immediately after death,they were manually?lleted;the skin,all visible fat and red muscle were removed with a?lleting knife.The dorsal half of the?sh?llets were washed with sterile iced water,and drained and cut into blocks of approximately4?3?2cm3.All the?sh blocks were randomly mixed and packed in polyethylene bags with four blocks in each bag,and then separated to two groups.Immediately,the two groups were placed as one layer in heat-insulated white Styro-foam boxes,?lled with an ice-water mixture(0.0±0.1°C)and an ice-brine mixture(à3.0±0.3°C),respectively.The ice-brine mix-ture contained about20%(w/w)ice,and was prepared using a 4.8%(w/w)NaCl solution,corresponding to a freezing point of à2.8°C(Hilderbrand,1999).A core temperature of0.2±0.1°C was established for?sh blocks stored in ice-water mixture,while the corresponding value for?sh blocks stored in ice-brine mixture wasà2.8±0.2°C.All the procedures were done in a walk-in chill room at a temperature around4°C.During the experimental period,the ice-water mixture and the ice-brine mixture would be renewed everyday to maintain the preset temperature.
2.3.pH determination
The pH of grass carp?llets was measured according to the method of Benjakul,Seymour,Morrissey,and An(1997)with slight modi?cations.A10g sample of muscle was homogenized with 100ml of cold distilled water using a T18Basic Ultra-Turrax homogenizer(IKA Werke GmbH&Co.KG,Staufen,Germany)at a speed of13,500rpm for1min,and the pH of the resulting homogenate was determined using a SevenEasy pH meter (Mettler-Toledo GmbH,Schwerzenbach,Switzerland).
2.4.Determination of TVB-N
TVB-N values were estimated according to the current Chinese hygienic standard method for typical freshwater species(GB/T 5009.44-2003).A13.5g sample of muscle was homogenized with 40ml of cold distilled water,and the resulting suspension was cen-trifuged at10,000g for5min at4°C using a Heraeus Multifuge X1R centrifuge(Thermo Electron LED GmbH,Osterode,Germany).A 25ml of the supernatant was distilled after the addition of25ml of10g/l MgO using a KDN-103F Kjeldahl Apparatus(Shanghai Qianjian Instrument Co.,Ltd.,Shanghai,China).The distillate was collected in a?ask containing20ml of25g/l boric acid with methyl red-bromocresol green mixed indicator.Then,the boric acid solution was titrated with a0.01M sulfuric acid solution, and the TVB-N value was expressed as mg nitrogen/100g muscle.
2.5.Sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE)
SDS–PAGE was done using a4%stacking gel and a10%resolving gel made in the lab according to the method of Laemmli(1970) with a Mini-PROTEAN Tetra Cell system(Bio-Rad Laboratories, Inc.,Hercules,CA,USA),and the protein extraction was done according to the method of Benjakul et al.(1997)with slight mod-i?cations.A1.25g sample of muscle was homogenized with25ml of5%(w/v)SDS.The resulting homogenate was incubated at85°C for1h in a HWS26water bath(Shanghai Yiheng Instrument Co., Ltd.,Shanghai,China),followed by centrifugation at10,000g for 5min.A1ml of the supernatant was mixed with1ml of sample buffer(0.5M Tris–HCl,pH6.8,containing4%(w/v)SDS,5%(v/v) b-mercaptoethanol and20%(v/v)glycerol),and then a6l l of the sample was loaded in each well.After electrophoresis,the gels were stained with0.1%(w/v)Coomassie Brilliant Blue R-250in 50%(v/v)methanol and6.8%(v/v)glacial acetic acid for6h and then destained using7.5%(v/v)glacial acetic acid and5%(v/v) methanol for about9h with a change of solution every3h.
2.6.Measurement of TCA-soluble peptides
The TCA-soluble peptides of grass carp?llets were measured according to the method of Sriket,Benjakul,Visessanguan,Hara, and Yoshida(2012)with slight modi?cations.A3g sample of mus-cle was homogenized with27ml of cold5%(w/v)TCA,and the resulting homogenate was kept in ice for30min and then centri-fuged at10,000g for5min at4°C.The TCA-soluble peptides in the supernatant were measured according to the method of Lowry, Rosebrough,Farr,and Randall(1951)and expressed as l mol tyro-sine/g muscle.
106 D.Liu et al./Food Chemistry140(2013)105–114
2.7.Differential scanning calorimetry(DSC)
DSC studies were done using the Q2000Series differential scan-ning calorimeter(TA Instruments,Inc.,New Castle,DE,USA).The instrument was calibrated for temperature and enthalpy using in-dium,and the scans were done while the samples were under the ultra-high purity nitrogen(Wuxi Taihu Gas Factory,Wuxi,China) purge of50ml/min.Muscles(7.0–9.0mg)were accurately weighted into aluminium pans and hermetically sealed,and an empty sealed pan was used as the reference.Two different DSC scans were performed separately:one scan was run to determine the freezing point of fresh grass carp?llets,and the other one to measure the protein denaturation of grass carp?llets during stor-age.The freezing point scan was done according to the method of Agustini et al.,(2001)with modi?cations.Samples were cooled rapidly toà40°C and then heated fromà40to10°C at a heating rate of0.5°C/min.The freezing point is estimated from the DSC thermograms as the intercept between the baseline and the tan-gent at the in?ection point of the left part of the endothermic melt-ing peak.In the protein denaturation scans,samples were heated from10to95°C at a heating rate of10°C/min.
2.8.Light microscopy
Grass carp?llets were cut into small blocks(10?10?3mm3), and?xed in3%glutaraldehyde in0.1M sodium phosphate buffer (pH7.4)at4°C for24h.After being washed with the same buffer, the samples were dehydrated at4°C with a graded series of etha-nol solutions(30–100%,v/v),followed by substitution with xylene. Then the samples were embedded in paraf?n wax,and the orienta-tion of the muscle?ber in the embedded samples was adjusted so as to achieve both cross and longitudinal sections(4l m)using a RM2235microtome(Leica Microsystems CMS GmbH,Wetzlar, Germany).Consecutively,the sections
transferred onto glass slides,air-dried,
stained with haematoxylin and eosin,and
tographed using a DM2000light
CMS GmbH).
2.9.Determination of whiteness
The color of grass carp?llets was
chroma meter(Konica Minolta Sensing,
analysis was done in CIE L?a?b?color
lated using the following equation(
ksuban,2003):
Whiteness?100à?e100àL?T2ta?2tb?
2.10.Determination of drip loss
Drip loss of grass carp?llets was
method of Duun and Rustad(2008)
The?llets were removed and the liquid
lected and weighed.Drip loss was
100g muscle.
2.11.Texture analysis
The hardness of grass carp?llets was
plus Texture Analyzer(Stable Micro
Grass carp?llets were cut into small
and kept on ice prior to texture analysis.
pressed using a?at-ended aluminium
diameter)at a constant test speed of1deformation.The compression force was perpendicular to the mus-cle?ber orientation.The maximum force during compression was recorded as the hardness.
2.12.Statistical analysis
A completely randomized design was used in this study.For all parameters,the determinations were done in duplicate,except for whiteness and hardness,where the analyses were carried out with 6and4determinations,respectively.Statistical analysis was done using SAS version8.0(1999,SAS Institute,Inc.,Cary,NC,USA). Analysis of variance(ANOVA)using the General Linear Model pro-cedure and the difference between means using the Duncan test were determined at an a level of0.05.To evaluate the correlations among the analysed parameters,Pearson’s correlation coef?cients (r)were calculated.
3.Results and discussion
3.1.Freezing point
From the DSC melting thermograms(data not shown),the freezing point of fresh grass carp?llets was estimated to be à1.1°C.The freezing point of food is a crucial factor for the deter-mination of many physical and thermal properties such as the amount of frozen water,freezing time and water activity,and it is lower than that of pure water due to the presence of proteins, salts,sugars,acids and other organic compounds.Most foodstuffs have a freezing point betweenà0.5andà2.8°C(Duun&Rustad, 2007).
3.2.Changes in pH and TVB-N values
Fig.1.Changes in pH and TVB-N values of grass carp?llets stored atà3and0°C. The vertical bars represent the standard deviations(n=2).
D.Liu et al./Food Chemistry140(2013)105–114107
acid by anaerobic glycolysis and
phate by the degradation of ATP,
ter stages of storage might be
basic compounds,such as
from autolytic and microbial
2006).Múgica,Barros-Velázquez,
ported that the pH of both
rays increased during10days of
mer batch was signi?cantly
suggesting that superchilling
microbial spoilage which may
components,such as ammonia
drat et al.,2006).The time
depending on species,seasons,
stress,and both the rate and the
important.The pH value is
evaluate?sh spoilage,and
indicate a?rst grade quality,
0.2units are referred to as an
than0.2units suggesting
eco-Aguilar,Díaz-Rojas,&
TVB-N is widely used as an
mainly composed of ammonia,
trimethylamine,resulting from
tein and non-protein
and nucleotide catabolites.The
carp?llets during storage are
phase of10and3days with no
was observed for?sh?llets
tively.Subsequently,the TVB-N
à3°C increased slightly;while a
?sh?llets stored at0°C(P<
pH during the later stages of
ported that superchilling atà1.5
TVB-N in comparison with ice
Chinese hygienic standard for
2733-2005),the limit level of
20mg/100g muscle.For grass
TVB-N value was far below the limit level during the whole storage period,while the TVB-N value of grass carp?llets stored at0°C
nearly reached the limit level at the end of storage.
3.3.Proteolytic degradation
The proteolytic degradation of grass carp?llets during storage was evaluated by changes in electrophoretic patterns and TCA-sol-uble peptide contents.As shown in Fig.2A,numerous bands were obtained with those corresponding to myosin heavy chain and ac-tin being the most intense in terms of optical density.Generally,no signi?cant changes in the electrophoretic pro?les were observed for grass carp?llets stored atà3and0°C,namely,neither the fad-ing of the original bands nor the appearance of new bands was ob-served with the SDS–PAGE(data not shown for the?llets stored at à3°C during the?rst15days).However,this does not necessarily indicate that no enzymatic proteolysis occurred during storage, due to the possible fact that the amount or the size of the protein fragments might be too small to be detected owning to the sensi-tivity and resolution limits of the present electrophoretic analysis.
To further characterize the degradation of?sh proteins,the changes in TCA-soluble peptides of grass carp?llets during storage were determined(Fig.2B).The initial level(as tyrosine equiva-lents)might indicate the endogenous oligopeptides in?sh?llets as well as the degradation products generated during post-harvest handling(Benjakul et al.,1997).The increase in the contents of TCA-soluble peptides during storage might indicate the activity of endogenous and microbial proteases.In general,only a slight increase in TCA-soluble peptide contents was observed for?sh?l-lets stored atà3°C,while a higher rate of increase was observed for?sh?llets stored at0°C(P<0.05),suggesting the continuous occurrence of proteolysis during storage.Similarly,for headed and eviscerated lizard?sh stored in ice,no marked changes in the electrophoretic pro?les were observed,while the TCA-soluble pep-tide contents increased signi?cantly(Benjakul et al.,2003).In com-parison,for hybrid cat?sh?llets stored at4°C,the TCA-soluble peptide content increased more rapidly from an initial value of 0.49–0.60to7.29l mol tyrosine/g muscle at day15,corresponding to a marked decrease in the band intensity of the myosin heavy chain during storage as seen using SDS–PAGE,which further suggested that the myosin heavy chain was more susceptible to hydrolysis than other proteins such as actin,tropomyosin and troponin(Chomnawang,Nantachai,Yongsawatdigul,Thawornch-insombut,&Tungkawachara,2007).Similar results were also re-ported for Paci?c whiting muscle during8days of ice storage (Benjakul et al.,1997).
Autolytic proteolysis through the action of endogenous enzymes may contribute to the deterioration of?sh?esh.The differences in?sh species and the temperatures of their normal habitat may contribute to the differences in postmortem degrada-tion of various muscle proteins(Delbarre-Ladrat et al.,2006).For shrimp subjected to ice storage,postmortem degradation of mus-cle proteins occurred in Arctic species and gave rise to fragments as potential freshness markers,suggesting the presence of active Fig.2.Changes in electrophoretic patterns(A)and TCA-soluble peptide contents (B)of grass carp?llets stored atà3and0°C.Std,protein standard;0–21d,days of storage;MHC,myosin heavy chain.The vertical bars represent the standard deviations(n=2).
108
muscle protease;however,for tropical species,proteolytic degra-dation seemed to be prevented by the severe difference between the natural living temperature and the storage temperature(Mar-tinez,Friis,&Careche,2001).
3.4.Changes in DSC thermal pro?les
Fig.3shows the DSC thermal pro?les of grass carp?llets during storage.As the muscle is a fairly complex system containing various types of proteins and protein domains,the endothermic peaks are mechanisms during the heating process,such as the breakdown of hydrogen bonds and hydrophobic interactions.Therefore,the changes in thermal pro?les may suggest the alterations in protein conformation from a native form to a denatured or partially denatured state.For grass carp?llets stored atà3°C for1day,a shoulder appeared just before the main myosin peak,and this shoulder became more and more prominent as the storage time progressed,suggesting a partial denaturation of myosin by super-chilling(Fig.3A).Similarly,a pronounced shoulder just before the main myosin peak was observed for sea bass muscle subjected to either pressured-shift freezing or pressured-assisted thawing (Tironi et al.,2007a).However,for minced sea salmon stored at 1°C for7days,an apparent shoulder appeared just behind the main myosin peak,suggesting a different modi?cation in the myo-sin structure(Tironi,Tomás,&A?ón,2007b).Additionally,the appearance of a shoulder right before the main myosin peak was also reported for horse mackerel mince subjected to air?oatation washing and was tentatively attributed to the easier unfolding of the myosin rod portion at lower temperatures after a breakdown of the sarcolemma during washing(Lin,Chen,&Chen,2005).How-ever,when stored at0°C,the myosin peak became sharper and sharper,suggesting a different partial denaturation of myosin (Fig.3B).Therefore,it was suggested that the myosin of grass carp ?llets showed different thermal stability patterns during storage at temperature below or above the freezing point.
It was also worth noting that the peak corresponding to sarcoplasmic proteins remained almost unchanged for grass carp ?llets storedà3°C,while the sarcoplasmic protein peak gradually disappeared for grass carp?llets stored at0°C,suggesting that the conformational stability of sarcoplasmic proteins was better main-tained during storage atà3°C(Fig.3).In addition,the DSC thermal pro?les in Fig.3showed that the actin peak remained almost unal-tered for?sh?llets stored atà3and0°C,indicating that actin was more resistant to denaturation than myosin during storage.Similar results were also reported for goat?sh muscle subjected to ice stor-age(Yarnpakdee,Benjakul,Visessanguan,&Kijroongrojana,2009).
Denaturation and degradation of?sh proteins are closely asso-ciated with the quality deterioration of?sh?esh as well as the loss of the functional properties that relied on the integrity of muscle proteins,especially the myo?brillar proteins.Benjakul et al. (2003)reported that the gel-forming ability of lizard?sh surimi decreased during storage in ice,owning to the denaturation and proteolysis of muscle proteins.Duun and Rustad(2007)reported that compared with the cod?llets stored on ice,the liquid loss determined by low-speed centrifugation was higher and the extractability of salt soluble proteins was lower in those samples superchilled atà2.2°C,due to the denaturation of muscle proteins caused by the superchilling.
3.5.Light microscopy observations
Fig.4shows the representative light microscopy observations on cross and longitudinal sections of grass carp?llets during stor-age.For fresh grass carp?llets,almost all of the muscle cells showed a well-preserved typical polygonal shape and were tightly attached to one another(Fig.4and0d).Before the10th day,the muscle cells of?sh?llets stored atà3°C showed a gradual loss of integrity as characterized by the formation of detachments be-tween muscle cells and cracks inside the cells,while only a few small detachments between muscle cells and cracks inside the cells were occasionally observed for?sh?llets stored at0°C.From 10days on,the muscle cells were more seriously damaged and de-formed,as re?ected by the gradual formation of clear spaces be-tween muscle cells and inside muscle cells for?sh?llets stored atà3°C,and the more extensive and conspicuous occurrence of detachments between muscle cells and cracks within the cells for
Fig.3.DSC thermal pro?les of grass carp?llets stored atà3°C(A)and0°C(B).0–
21d,days of storage.
D.Liu et al./Food Chemistry140(2013)105–114109
those stored at0°C.In addition,observations on longitudinal sec-tions even showed myo?ber breakages for?sh?llets stored at à3°C for21days.
The pre-rigor?llets of Atlantic salmon superchilled atà1.5°C also showed the appearance of clear spaces both between and within muscle cells and the accelerated myo?ber breakages,result-ing from the formation of both extra-and intracellular ice crystals (Bahuaud et al.,2008).The formation of ice crystal involves two following steps:?rstly,nuclei forms,and then grows to a speci?c size.However,recrystallization typically occurs during storage, resulting in a decreased surface-to-volume ratio for ice crystals, since it is energetically more favorable.The resulting changes in the size and location of the ice crystals can cause irreversible mechanical damages to both extra-and intracellular structures. Moreover,muscle structure weakening could also be induced by the local proteolytic activity on both the costameres and
the
pericellular connective tissues.Enzymatic degradation of key structural proteins such as dystrophin and desmin in cytoskeleton and costameres,which maintain the structural integrity of myo?-bers,may contribute to the postmortem disorganization of?sh muscle.Two main groups of enzymes,calpains and cathepsins, may work in a complementary way and in synergy at different stages of structural protein degradation process;while the exact role played by each enzyme especially in vivo needs further identi-?cation(Delbarre-Ladrat et al.,2006).As demonstrated in sea bream stored on ice,muscle degradation occurred rapidly with the breakdown of cytoskeleton and costameres,a connection between the sarcomeres and sarcolemma,thus contributing to the detachment of myo?bers from both the sarcolemma and the endomysium(Ayala et al.,2010).For sea bass stored at4°C,the degradation of dystrophin,which was located in the costameres, was also simultaneously accompanied by the myo?ber detach-ments from the sarcolemma(Papa et al.,1997).Chub mackerel also showed pronounced detachments between muscle cells after24h of storage at5°C,due to a rapid weakening of pericellular connec-tive tissues(Ando et al.,2001).For sardine?llets stored at5°C,the weakening of pericellular connective tissues was caused by disinte-gration of thin collagen?brils due to the degradation of type V col-lagen(Sato et al.,1997).Moreover,for cod?llets stored in ice,the degradation of the matrix proteoglycans and glycoproteins could also contribute to the weakening of pericellular connective tissues (Ofstad,Olsen,Taylor,&Hannesson,2006).Therefore,following the weakening of both extra-and intracellular structures by the above-mentioned mechanisms,the physical strength associated with shrinkage of muscle tissues during?xation and dehydration may contribute to the formation of detachments between muscle cells,cracks within muscle cells,myo?ber breakages,and clear spaces both between and within muscle cells(Ando et al.,2001).
On the basis of the above-mentioned mechanisms,it was suggested that the mechanical damages caused by superchilling in the present study may directly contribute to the accelerated formation of detachments between muscle cells and cracks within muscle cells during the initial stages of storage,and also the forma-tion of clear spaces both between and within muscle cells and myo?ber breakages during the later stages of storage.However, for grass carp?llets subjected to ice storage,the development of detachments between muscle cells and cracks within muscle cells seemed to be a consequence of enzymatic proteolysis,as indicated by the changes in the TCA-soluble peptide contents(Fig.2B).
3.6.Changes in visual appearance and whiteness
Fig.5shows the changes in visual appearance and whiteness of grass carp?llets during storage.The macroscopic appearance is an important factor that determines the perceived freshness and hence the market value of?sh?llets.The fresh grass carp?llets had a translucent appearance(Fig.5A and0d).Before the10th day,the?sh?llets stored atà3°C gradually lost the translucency and developed an opaque white color macroscopically.After 10days of storage,white spots were observed on the surface of the?sh?llets stored atà3°C and became more and more intense as the storage time proceeded.Coincidently,the appearance of white spots on the surface of?sh?llets paralleled the formation of clear spaces both between and within muscle cells(Fig.4)which might result from the formation of both extra-and intracellular large ice crystals(Bahuaud et al.,2008).Moreover,the white spots were not observed for?sh?llets subjected to ice storage(Fig.5A), under which no ice crystals were formed in the?sh?llets(Fig.4). Therefore,it was suggested that the formation of large ice crystals may be related to the appearance of these white spots.Duun and Rustad(2007)also reported the formation of similar white spots on the surface of cod?llets after about1week of storage at à2.2°C,suggesting the diffusional effects of drip channels from the interior to the exterior of?sh muscle,which were formed when the cell membrane was detached from the cell body while the cell membrane and cellular matrix still remained attached.The grass carp?llets stored at0°C lost some of the translucency and gradu-ally developed an opaque white color macroscopically as the stor-age time progressed.
The development of opaque white color for grass carp?llets during storage was quanti?ed as changes in whiteness(Fig.5B). For?sh?llets stored atà3°C,a sharp increase in whiteness was observed after1day of storage,followed by a gradual increase in whiteness until the end of storage(P<0.05).Over the whole stor-age period,the whiteness of?sh?llets stored at0°C also increased gradually,but was signi?cantly lower than that of?llets stored at à3°C at individual time-point(P<0.05).The?esh color is associated with heme-based pigments and tissue structure which will affect light scattering and re?ection(Chéret,Chapleau,Del-barre-Ladrat,Verrez-Bagnis,&Lamballerie,2005).No signi?cant changes in redness and yellowness were observed for?sh?llets stored at bothà3and0°C(data not shown),possibly due to the fact that only the main white muscle of grass carp?llets was inves-tigated in the present study.Therefore,the initial faster increase in whiteness for grass carp?llets stored atà3°C might be attributed to the changes in light scattering and re?ection which might result from the accelerated damages of tissue structure caused by super-chilling(Fig.4).Moreover,the formation of white spots on the sur-face of?sh?llets stored atà3°C might also contribute to the higher whiteness during the later stages of storage.Duun&Rustad (2008)reported a higher L?value for vacuum packed Atlantic sal-mon?llets stored atà3.6°C compared with those stored at à1.4°C,due to the formation of more intense white spots on the surface of?llets during the later stages of storage atà3.6°C.
3.7.Changes in drip loss
Drip loss is not only unappealing to consumers in that it might affect juiciness,?avor,appearance and texture,but also of great economic importance as?sh is sold by weight(Huff-Lonergan& Lonergan,2005).Moreover,the drip loss also entails the loss of water soluble nutritional compounds such as minerals,providing a nutritious medium for bacteria.The changes in drip loss of grass carp?llets during storage are shown in Fig.6A.A rapid increase in drip loss was observed for?sh?llets stored atà3°C for3days and also for those stored at0°C for1day(P<0.05).During the subse-quent period of storage,the drip loss continued to increase gradu-ally for?sh?llets stored at bothà3and0°C.However,the drip loss was signi?cantly higher for?sh?llets stored atà3°C com-pared with those stored at0°C at each time-point(P<0.05).Drip loss refers to the most loosely bound water in muscle,and it is mainly associated with the structure of muscle and muscle cells, denaturation and degradation of proteins,and the rigor state of muscle(Huff-Lonergan and Lonergan,2005).Since the majority of water is held within the myo?bril,the partial denaturation of myosin(Fig.3A)and the accelerated damages of tissue structures (Fig.4)caused by superchilling may work in synergy to result in the higher drip loss for?sh?llets stored atà3°C compared with those stored at0°C.
3.8.Changes in hardness
The texture of?sh?esh is a valued indicator of freshness and is also an important attribute that affects the mechanical processing of?llets for the?sh industry.The changes in the texture of grass carp?llets measured instrumentally as hardness are shown in Fig.6B.For?sh?llets stored at bothà3and0°C,the hardness decreased sharply within the?rst3days(P<0.05),and then
D.Liu et al./Food Chemistry140(2013)105–114111
remained almost unchanged up to 6days of storage (P >0.05).Dur-ing the initial 6days,the hardness of ?sh ?llets stored at 0°C was signi?cantly higher compared with those stored at à3°C (P <0.05).However,from 10days on,no further signi?cant decreases were observed for ?sh ?llets stored at both à3and 0°C (P >0.05).The rapid deterioration of texture for ?sh ?esh may be related to vari-ous intrinsic and extrinsic factors,such as loss of water from the muscle and destruction of muscle tissues (Delbarre-Ladrat et al.,2006;Huff-Lonergan &Lonergan,2005).A negative linear correla-tion between hardness and drip loss was observed for ?sh ?llets stored at both à3°C (r =à0.95)and 0°C (r =à0.96),respectively.Moreover,the initial faster decrease in hardness for grass carp ?l-lets stored at à3°C may also be attributed to the accelerated dam-ages of tissue structures caused by superchilling (Fig.4).However,during the later stages of storage,with the further deterioration of tissue structures (Fig.4),the hardness did not decrease
further
and whiteness (B)of grass carp ?llets stored at à3and 0°C.The pictures were taken using a Cannon IXUS represent the standard deviations (n =6).
(Fig.6B).Ando et al.(2001)suggested that a threshold may be ob-tained when the tissue structures deteriorated to a certain degree, thereafter,no further changes in texture could be measured instrumentally.
4.Conclusions
Within the21days of storage,both advantages and disadvan-tages were observed for grass carp?llets subjected to superchilling atà3°C in comparison with ice storage at0°C.The microbial spoilage and proteolytic degradation were largely delayed in?sh ?llets stored atà3°C compared with those stored at0°C. However,the accelerated damages of tissue structures caused by superchilling atà3°C promoted the deterioration of visual appearance,water holding capacity and texture.Moreover,partial denaturation of myosin differed between?llets stored atà3and 0°C.Superchilling of grass carp?llets is still a potentially promising technique,however,the degree of superchilling has to be optimized to minimize the tissue structure damages and protein denaturation as well as the concurrent quality deterioration. Acknowledgements
This research was partly supported by the National Natural Sci-ence Foundation of China(30901123),the111project(B07029) and special funds of the Modern Agricultural Industry Technology System(CARS-46-22).
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草鱼的养殖管理技术大全 1.环境与池塘消毒草鱼最容易生病，养殖无公害草鱼应有专门的养殖基地，并形成一定的规模，基地周围无污染源。养殖基地应具备水源充足，水质良好，符合《无公害食品淡水养殖用水水质标准》，进排水畅通，鱼塘之间互不相通，交通运鱼方便，饲料资源丰富，生态环境条件良好。 2.优质鱼种的放养要想养好草鱼，必须选用健康活泼的优质鱼种，自繁自育的鱼种的亲本应来源于有资质的国家认定的原料场，苗种经无公害培育而成，质量符合相关标准，具备品种优良性状，条件具备的最好自繁自育为好，如从外地引进鱼种须经检疫合格方能引入。鱼种放入前须经消毒处理，可选用二氧化氯每5－10分钟20 －40毫克／升、食盐每5－20分钟用1％－3％、每15－30分钟用8毫克／升，高锰酸钾每15－30分钟10－20毫克／升等药物浸泡消毒。放养比例按80∶20放养模式投放鱼种，即主养草鱼占80％，配养鱼(鲢、鳙、鲤、鲫等)占20％。 3.科学投饵草鱼在自然水域主要取食水草，在池塘无公害养殖中，适宜采用配合科学配比的颗粒饲料，减少残饵对水质的污染，充分提高饵料利用率。生产草鱼颗粒饲料，应加入一定量的草鱼粉，既可降低饵料成本，又能满足草鱼对纤维素等特殊营养的需求，促进草鱼生长。搭配投喂的水旱草、应柔嫩、新鲜、适口。饼粕类及其他类饵料，要无霉变、无污染、无毒性，并经粉碎、浸泡、煮熟等方式处理后，制成草鱼便于取食、易于消化的饵料。投喂饵料要坚持定时、定位、定质、定量的投饵原则，还要通过观察天气、水体情况及鱼的吃食量确定合理的投喂量。
4.合理投喂渔药渔药是用于预防和治疗水产动植物病虫害的物质，如果使用不当，极易在鱼体内残留，造成鱼的质量不合格，因此要目前最好的壮阳药慎重使用。渔药一般包括杀菌剂、灭虫剂、水质改良剂等，目前一些传统渔药已被禁用，如氯霉素、呋喃唑酮、五氯酚钠、孔雀石绿、磺胺噻唑、泰乐菌素、喹乙醇、磺胺脒、杀虫脒等32种渔药，不能在水产养殖中使用，在选用渔药时应特别注意。在农业部颁布的行业标准中列出了宜用渔药26种，如二溴海因、优氯净、漂白粉、氯化钙、强氯精，并规定了用途及用法，休药期和注意事项，在使用时可参考。 一是多投喂鲜嫩草料。鲜嫩草料营养丰富、纤维素少、易被消化，草鱼摄食鲜嫩草料，长得快、少生病，能降低养殖成本，提高经济效益。草料的种类，应是平行脉的长叶青嫩草，不宜投喂网状脉的团叶草料。以投喂种的黑麦草、苏丹草等牧草和采集的野生长叶嫩草为好。平时，要对草鱼吃草情况进行观察，草鱼喜食的草类应多投喂，反之应不喂或尽量少喂。 二是减少水生水草的投喂。据水产养殖专家介绍，草鱼吃15公斤陆生水草就可以长1公斤肉，而吃60～80公斤水生水草才能长1公斤肉。因此，在陆生水草来源不足的情况下，可少喂或不喂水生水草。 三是按鱼类口径大小不同投喂的草料。草鱼在幼鱼阶段口径小，不能投喂粗大、坚硬的草料，宜投喂莎莎草、小浮萍等草料，或将鲜嫩的长叶草铡碎后投喂。以后，随着鱼龄增大，口径逐渐增大，便可过渡到投喂鲜嫩草料。 四是投喂方法要得当。对草鱼喂草，每天要定时、足量、均匀投喂，力求将草料撒开，让鱼吃饱、吃好、吃匀，以提高养殖效果。要
竭诚为您提供优质文档/双击可除 草鱼养殖可行性报告 篇一：＊＊＊＊鱼塘养殖建设项目可行性报告 高青鱼塘养殖建设项目 可行性研究报告 一、项目概况 项目名称：高青鱼塘养殖建设项目 项目建设单位：****养鱼场 项目建设地点：淄博市******** 建设性质:新建 项目负责人：张** 二、项目建设的必要性 该项目建设有利于高青县低洼盐碱地资源保护利用，按照统 一勘察、分区规划的原则，因地制宜地划分功能区域布局，使低洼盐碱地资源得到保护和合理开发利用，形成优势特色产业带，实现区域化布局、专业化生产、产业化经营的良好态势，优化资源配置，使资源保护和开发利用实现双赢。
渔业是我县的农业优势特色产业之一，水产品也是我县的“拳头”产品之一，在市场经济的锤炼下，渔业在大农业中的特色产业地位得到不断的巩固和强化。水产品是我县“产得下、卖得出、受欢迎、叫得响”的农产品。项目建设有利于高青县水域与低洼盐碱地资源保护和利用，对做大做强渔业特色产业、促进农业产业结构调整有重要意义。 渔业是与生态环境密切相关的农业产业，它既能利用生态环 境，又可以改造、优化生态环境。平罗县地处西北内陆，生态环境脆弱，发展生态渔业对于改善生态环境、提高植被覆盖率、改良盐渍化土壤、促进社会经济可持续发展更具现实意义。近年来，我县利用低洼盐碱地“以渔改碱”、湖泊湿地“以渔养水”生态渔业模式取得了初步成效。利用低洼盐碱荒地，发展“以渔改碱”生态养殖，形成种养良性循环的生态农业生产系统，有效遏制了土壤盐渍化。利用湖泊湿地，按照比例科学投放草食性、滤食性、吃食性鱼类，发展“以渔养水”生态养殖，在发展渔业生产的同时，可降低水域富营养化程度，可有效地保护水域生态环境。 渔业是推动人类农业文明进步的重要产业。渔业在繁荣区域经济，促进农业增效，增加农民收入中的作用越来越突出。从农民收入看，多年来全县从渔农民人均纯收入高出农民人均收入1倍以上，一些养殖大户要高出几倍，成为农村
第六章由病毒引起的疾病 第一节概述 一、病毒： ①只具备一种核酸，即RNA or DNA ； ②个体微小（比细菌小）,一般30~300nm； ③病毒的增殖-----靠复制繁殖； ④不能用培养基培养，只能在活细胞中生长增殖，并 只有一种细胞-----敏感细胞。 ~（Virus）是一类体积微小、能通过滤菌器,含一种类型核酸（RNA or DNA ），只能在活细胞内生长增殖的非细胞形态的微生物。 一般用纳米（nm）测量其大小，电镜放大观察。 病毒颗粒—--主要由核酸和蛋白质组成。核酸在中心部分，形成病毒核心，外面包围的蛋白质称为衣壳，------核酸与衣壳组成核衣壳。 最简单的病毒是裸露的核衣壳；有些病毒的核衣壳外面还有一层囊膜。 对水产动物造成的危害很大，不少是口岸检疫对象。由于病毒寄生在寄主的细胞内，---目前主要是预防！ 二、病毒的鉴定： 1、用5-氟脱氧尿苷鉴别出核酸是DNA 还是RNA . * 如出血病病毒--- RNA病毒群. ——取病料（灶）-----用敏感细胞培养 ---加入5-氟脱氧尿苷---此物质对有DNA抑制作用，---这样即可鉴定： 如果是DNA ，则细胞就会死亡； 若是RNA ，则细胞照常生长。 2、测定病毒的大小。 ——用Seize（塞氏）漏斗测定病毒粒子的大小，放一过滤膜（50，100，220，300，450），如通过100~220nm 的过滤菌器. *---只能测病毒粒子大小的范围。 **---还可作病毒切片估计和扫描计算。 3、耐乙醚试验： ——有的病毒核酸外有脂质外壳（Evenlope） *乙醚--处理病毒的悬浮液--感染细胞--具保护作用--生长！否则---死亡！ 4、耐pH 3 试验： ——病毒在pH3 溶液中处理5~30分钟------接入细胞培养器---细胞死亡；或细胞生长。 5、耐热试验： ——例如---出血病病毒---耐热：60℃保持1小时后，仍能使10%的鱼死亡！ *——悬浮液—恒温保持---感染Cell --- 结果：草鱼出血病毒耐热试验—— 41℃处理18h---100%死亡；55℃处理3h---100%死亡；60℃处理1h---1%死亡。 ***水产动物病毒病——传染性疾病！ 三、水产动物病毒的种类 ——自从Wolf（1959）分离到第一株鱼类病毒以来，迄今报道的鱼病毒已超过70种。已知水生动物病毒分类属于18个科（表1），在绝大多数动物病毒科中都有分布。 DNA 病毒---7科；RNA 病毒---11科。 *疱疹病毒属、出血病病毒等---耐热， 特征：正二十面体（肾脏超薄切片—电子显微镜观察）第二节病毒的研究概况 80年代以来，我国水产业迅速发展，并且在农业产值中所占的比重逐年上升，已成为我国大农业的四大支柱产业之一。 〖粮食、肉类、水产（98年产量3800万t）和禽蛋〗但令人遗憾的是水生动物疾病---尤其是因病毒引起的爆发性流行病明显增多，危害极为严重! ——目前，水产动物病毒病已受到人们广泛的关注，以研讨水生动物病毒病为主题、由国际著名专家 倡导并组织的------ “国际低等脊椎动物病毒学术会议”—就每4年召开一次，现在已经召开过4~5次（1989，1998）。 水生动物普遍存在病毒病、细菌病和寄生虫病等。 其中病毒病具有潜伏期长短不一、症状复杂多变、传染性强、导致死亡率高的特点，并且病原个体小，浸染动物后在宿主细胞内复制。因而抗菌素对病毒的作用小或无；而化学药物在杀灭病毒前，又可能使宿主动物受损或致死。 可见病毒是危害非常严重的一类病原。 一、鱼类病毒病 1、重要病毒的种类及形态特征（见表2） 始于70年代后期对草鱼出血病病原的分离研究。 近十年来，又发现和分离到新的鱼类病毒。 2、草鱼出血病与呼肠孤病毒 是草鱼种苗阶段危害性大、流行普遍的疾病，也是我国最早发现和研究得最多的鱼类病毒病。-----近年对其分子生物学、干扰素等有较多研究报道……。 除草鱼呼肠孤病毒（Grass carp reovirus，GCRV）外，草鱼还有其它病毒分离株（或不同病毒）。如： 1
无公害生态草鱼的养殖技术 1xx 准备 池塘应选择在水源充足,水质良好,无污染的地点,并配备专用的进水及排水渠道生态环境良好。面积以10?20亩为宜，水深能够达到2m左右。另外，池塘应该按每亩 0.4kw 配备增氧机,一个池塘配自动投饵机1 台。鱼种放养前10?15天,用 7kg/亩?10kg/亩漂白粉清塘消毒，或用75kg/亩生石灰兑水趁热全池泼洒。清池后3?5 天,注水入池达 0.8m?1m,注水时用xx 0.6mm筛网过滤,1天后施放绿肥400kg/亩，或施放腐熟的有机肥250kg,5~ 7 天后即可放养鱼种。塘周围种植一定面积的青饲料。 2 鱼种的放养 2.1 鱼种选择与消毒 选择规格整齐,体质健壮,体表光滑完整,无畸形,无病伤的苗种放养。自繁鱼 种应具备优良性状,经无公害培育而成。如从外地引进鱼种须经检疫合格方能引入。放养前应该严格消毒苗种,全部鱼种均用4%食盐水浸浴消毒10min?15min, 以预防各种细菌性疾病和水霉病。短途运输的苗种可直接浸泡消毒,而经长途运 输的苗种最好经过一段时间的吊养后再浸泡消毒。 2.2 放养时间 一般在11 月至春节前后放,因为深秋、冬季水温较低,鱼体亦不易患病,开春水温回升即开始投饵,鱼体很快得到恢复,增强了抗病力,提早生长发育。 2.3 放养密度 按8 : 20放养模式投放鱼种，即草鱼占80%适当混养鲤、鳙、鲢、鲫等鱼作 搭配鱼,搭配鱼占20%。这样遗留在水中的饲料和草鱼排出的废物,可以培养浮游
生物,作为鲢、鳙的饲料,净化水质。另外可配养少量青虾等优质品种,以充分利用水域空间及残饵,提高养殖效益。 2.4 免疫接种 鱼种放养时注射灭活疫苗，可降低出血病和三病”的发生，提高成活率15%~ 20%,减少生产中使用鱼药量及残饵,提高养殖效益。 2.4 免疫接种 鱼种放养时注射灭活疫苗,可降低出血病和“三病”的发生,提高成活率15%~ 20%,减少生产中使用鱼药量及药残量。已患病草鱼不宜进行注射免疫。注射器、针头以及稀释器皿须用75％的酒精消毒或用开水煮沸消毒。 3 养殖管理 3.1 饲料投喂 草鱼在池塘无公害养殖中提倡安全环保的颗粒或膨化配合饲料。配方为： 豆粕18%,菜粕28%,棉粕8%,麦芽根8%,次粉28%,米糠6%,磷脂粉 1.2%,食盐 0.6%,豆油1%,氯化胆碱 0.2%,磷酸二氢钙1%。鱼的摄食能力与水温高低密切相关。从3月底开始, 投喂次数由一天1~2 次增加到3~ 4 次,坚持少量多餐,每餐只喂八成饱。如遇闷热、寒流、大暴雨等天气可酌情减量,每日投喂 2 次。随着春夏各种水草的增多, 每天可以增加一次草料的投喂。平时注意在饲料中适量添加维生素等,避免草鱼患肝胆综合症等疾病而造成大量死亡。 3.2 水质管理 80 : 20的生态养鱼模式，管理工作主要是保持良好、稳定的水质，重点防缺氧泛塘。养殖草鱼的水质指标为： pH 值7~
ICSXX.XXX BXX DB 湖南省地方标准 DB/T XXX (200x) 草鱼出血病检疫技术规范 Technical code of quarantine for hemorrhage disease of grass carp 2006-XX-XX发布2006-XX-XX实施湖南省质量技术监督局发布
目次 前言 (Ⅲ) 1 范围 (1) 2规范性引用文件 (1) 3 检样质量要求 (1) 4 检疫方法 (1) 4.1 群体检疫 (1) 4.1.1 免疫核实 (1) 4.1.2 现场检查 (1) 4.2 流行病学调查 (1) 4.3 解剖检查 (1) 4.4 病理学检查 (2) 4.5 病原电镜检查 (2) 4.6 免疫学检验 (2) 4.6.1 斑点酶联免疫吸附试验(Dot-ELISA) (2) 4.6.2 葡萄球菌A蛋白协同凝集试验（SPA-COA） (2) 4.7 逆转录聚合酶链式反应（RT-PCR）检测 (2) 5 非草鱼出血病的判定 (2) 6 无害化处理 (2) 附录A（规范性附录）流行病学调查 (3) 附录B（规范性附录）斑点酶联免疫吸附试验(Dot-ELISA) (4) 附录C（规范性附录）葡萄球菌A蛋白协同凝集试验（SPA-COA） (5) 附录D（规范性附录）逆转录聚合酶链式反应（RT-PCR）检测 (6) 参考文献 (8)
前言 本标准为强制性标准。 本标准附录A、B、C、D为规范性附录。 本标准由湖南省畜牧水产局提出并归口。 本标准起草单位：湖南省水生动物防疫检疫站,湖南农业大学动物科技学院本标准主要起草人：肖光明，江为民，肖克宇，黄兴国。
草鱼养殖综合管理方案 九月份按二十节气可分为白露和秋分：每年9月7日或8日，节气特点天气渐凉，昼夜之间温差达10度或更多；秋分的节气特点昼短夜长，昼夜温差进一步加大，幅度变大，冷空气开始入侵，慢慢步入深秋，温度适宜。 草鱼养殖过程在九月份白露节气时，会出现“白露瘟”。“白露瘟”一般指白露前后发生鱼病的统称,“白露瘟”来势凶，病害种类多, 往往造成养殖水产养殖对象死亡的重大损失，应做好“白露瘟”预 防工作，“白露瘟”的产生多方面因素综合的。 首先，在此节气下，昼夜温差大，一般昼夜温差大于5度以上时，会引起鱼体的应激反应，同时也破坏水体养殖环境，使水质恶化或变化剧烈，引起一系列不良反应，最后导致鱼病害的产生。 第二，白露节气下，白天温度较高，草鱼的投喂量也大，在此高温条件下，高负荷的投喂水平下，会导致的鱼的肝肠等消化系统负担大，会出现肝胆综合症，肠炎等问题，故造成鱼体质下降，若不良环境或气候条件，会出现病害甚至大面积的死鱼现象； 第三，此节气下，病原微生物易大量繁殖，同时昼夜温差大，破坏水体养殖环境，使水质恶化，导致缺氧、氨氮，亚盐上升，这时水质的变化也会为病原微生物大量繁殖提供了适宜条件。因此要做好消毒的同时也做好抗应激和保持水体环境的稳定； 第四，九月份是草鱼养殖中后期，经过高强度投喂后，水体中氨氮、亚硝酸盐、有机物碎屑等比较高，水体生态环境较脆弱，遇到天气变化时，易打破此平衡，使养殖环境的水质或底质恶化。故在此阶段应做好水质和底质的维护。 综合所述，在白露节气，我们应做好水质维护，保持水环境稳定，另外也要增强鱼体质，改善肝肝，提高消化吸引能力，同时由于应激较大也要做好抗应激的处理。
草鱼的功效与作用 草鱼的功效和作用 1.草鱼含有丰富的不饱和脂肪酸，对血液循环有利，是心血管病人的良好食物; 2.草鱼含有丰富的硒元素，经常食用有抗衰老、养颜的功效，而且对肿瘤也有一定的防治作用; 3.对于身体瘦弱、食欲不振的人来说，草鱼肉嫩而不腻，可以开胃、滋补。 草鱼的营养价值 1.富含蛋白质，具有维持钾钠平衡;消除水肿。调低血压，有利于生长发育。 2.富含磷，具有构成骨骼和牙齿，促进成长及身体组织器官的修复，供给能量与活力，参与酸碱平衡的调节。 3.富含铜，铜是人体健康不可缺少的微量营养素，对于血液、中枢神经和免疫系统，头发、皮肤和骨骼组织以及脑子和肝、心等内脏的发育和功能有重要影响。 4.草鱼含有丰富的不饱和脂肪酸，对血液循环有利，是心血管病人的良好食物。 草鱼的食用方法 1.烹调时不用放味精就很鲜美; 2.鱼胆有毒不能吃;
3.草鱼要新鲜，煮时火候不能太大，以免把鱼肉煮散; 4.切鱼方法：鱼肉质细，纤维短，极易破碎，切鱼时应将鱼皮朝下，刀口斜入，最好顺着鱼刺，切起来更干净利落;鱼的表皮有一层黏液非常滑，所以切起来不太容易，若在切鱼时，将手放在盐水中浸泡一会儿，切起来就不会打滑了。 草鱼的基本介绍 草鱼属鲤形目鲤科雅罗鱼亚科草鱼属。草鱼的俗称有：鲩、油鲩、草鲩、白鲩、草鱼、草根(东北)、混子、黑青鱼等。英文名：grasscarp。栖息于平原地区的江河湖泊，一般喜居于水的中下层和近岸多水草区域。性活泼，游泳迅速，常成群觅食。为典型的草食性鱼类。在干流或湖泊的深水处越冬。生殖季节亲鱼有溯游习性。已移殖到亚、欧、美、非各洲的许多国家。因其生长迅速，饲料来源广，是中国淡水养殖的四大家鱼之一。 草鱼体略呈圆筒形，头部稍平扁，尾部侧扁;口呈弧形，无须;上颌略长于下颌;体呈浅茶黄色，背部青灰，腹部灰白，胸、腹鳍略带灰黄，其他各鳍浅灰色(见图)。为中国东部广西至黑龙江等平原地区的特有鱼类。栖息于平原地区的江河湖泊，一般喜居于水的中下层和近岸多水草区域。性活泼，游泳迅速，常成群觅食。为典型的草食性鱼类。在干流或湖泊的深水处越冬。生殖季节亲鱼有溯游习性。已移殖到亚、欧、美、非各洲的许多国家。因其生长迅速，饲料来源广，是中国淡水养殖的四大家鱼之一。中国重要淡水经济鱼类中最负盛名者当推草鱼、青鱼、鲢鱼、鳙鱼等世界著名的“四大家鱼”，虽均为我国特有鱼类，而草鱼以其独特的食性和觅食手段而被当做拓荒者而移植至世界各地。其体较长，
农家肥的合理使用 1.人粪尿。人粪尿的养分含量高、腐熟快、肥效显著,有“细肥”之称。注意事项:1人粪尿在施用前必须要经过彻底腐熟,经过无害化处理后才可使用。o忌氛植物如马铃薯、甜菜、烟草等不易多用,干早、排水不畅的盐碱地限量施用。?禁止人粪尿与草木灰、碳酸氢按等碱性物质混合混用。?不要将人粪晒制粪干,避免氮损失。 2.猪类尿。猪粪质地比较细,成分复杂,含有较多的氨化微生物,容易分解,而且形成的腐殖质较多。猪粪是性质柔和而有后劲的有机肥料。注意事项:1氮素易分解,含磷较高,而且有机磷宜易被土壤固定,钾素大多为水溶性钾,易被作物吸收。o在微生物的作用下含磷的化合物极易转化为磷酸盐;蛋白质、尿素、氨基酸、尿酸等要转化为按盐和硝酸盐,极易分解和流失。?积存时要加铺垫物,常用土或草炭,土肥比以3:1为佳。?提倡圈内垫圈和圈外堆制相结合,勤起勤垫,有利于粪肥养分腐熟。?禁止将草木灰倒人圈内,以免引起氮素的挥发流失。 3.牛粪。牛粪质地致密,成分与猪粪相似,粪中含水量高,通气性差,分解缓慢,发酵温度低,肥效迟缓,故习称牛粪为“冷性肥料”。未经腐熟的牛粪肥效较低。注意事项:1牛粪宜加人秸秆、青草、泥炭或土等垫圈物,吸收尿液,加人马粪、羊粪等热性粪肥有利于促进牛粪腐熟。o制堆肥时加入钙、镁、磷肥,以保氮增磷,提高肥料质量。同时要在堆肥外层抹泥7厘米左右。?腐熟好的牛粪宜作基肥,整地起垅时施人。必须腐熟后施用,确保养分转化和消灭病菌与虫卵。?不宜与碱性肥料混合使用,如氨水、碳酸氢钱等。 4.鸡粪。鸡粪养分含量高,全氮1.03,全钾0.72%,是牛粪的4.1倍。注意事项:1在堆肥过程中,鸡粪易发热,氮素易挥发,因而鸡粪应干燥存放,施用前再沤制,并加人适量的钙、镁、磷肥料,起保氮的作用。o适用于各种土壤,因其分解快宜作追肥,也可与其它肥料混合使用做基肥。鸡粪能明显提高作物品质。?鸡粪养分含量高,尿酸多,施用肥量每公顷不宜超过30吨,否则会引起烧苗。
水煮鱼 材料： 草鱼1只（鲶鱼、黑鱼等都行约1斤半）、黄豆芽200克、干辣椒（剪成段）100克、花椒20克、郫县豆瓣（剁碎）2汤匙（30ml）、酱油1汤匙（15ml）、姜片10克、蒜末15克、淀粉2汤匙（30ml）、蛋清1只、料酒2茶匙（10ml）、盐适量、鸡精少量、糖1茶匙（5克）、胡椒粉少量、清汤 五香油材料：八角2块、花椒5克、干辣椒10克、山奈1块、桂皮1块、香叶2片、油500ml 做法： 1、先处理鱼。将杀好的鱼洗净，剁去鱼鳍，切下鱼头； 2、紧贴鱼骨将鱼身的肉片下； 3、将片下的鱼肉鱼皮朝下，斜片成厚约0.5厘米的鱼片，鱼排剁成长约5厘米的块，鱼头剖成两半； 4，将鱼片和鱼排鱼头分别用1茶匙料酒、2茶匙淀粉和1/2个蛋清和适量的盐抓匀，腌制15分钟； 5、开始做五香油，这个油会使水煮鱼特别香，可以多做一些，平时拌菜用。锅中放入油，将八角、花椒、干辣椒、山奈、桂皮、香叶放入，用小火加热，直到把香料炸成棕黄色，捞出香料不要，油待用； 6、锅中烧热水，放入适量盐，放入豆芽煮熟，捞出铺在一个深盆的底部待用； 7、炒锅烧热，放入3汤匙的五香油，放入剁碎的郫县豆瓣炒香。加入10克干辣椒段、10克花椒、蒜末、姜片炒香； 8、加入鱼头和鱼排炒匀。加入酱油、料酒、糖、胡椒粉一起炒； 9、加入清汤（或者开水），没过鱼肉； 10、烧沸以后，将腌制好的鱼片一片片地放入，用筷子拨散，待鱼片煮变色以后关火。将鱼片和汤汁一起倒入铺好豆芽的深盆中； 11、锅洗净，将剩余的五香油倒入（油的量以能覆盖鱼片为准，可以根据容器的大小决定油的多少），烧至5成热，放入剩余的干辣椒段和花椒，用小火将辣椒和花椒的香味炸出来，注意不要炸糊了，辣椒的颜色稍变就关火； 12、将热油浇在鱼片上即可。
冷藏过程中草鱼肌肉组织学特性的研究 王建辉1，靳娜1，刘冬敏1,2，刘永乐1，陈奇1，王发祥1，李向红1，俞健1 （1.长沙理工大学，湖南省水生资源食品加工工程技术研究中心，湖南长沙 410114） （2.湖南科技学院生命科学与化学工程系，湖南永州 425199） 摘要：采用透射电镜、气相色谱-质谱法以及SDS-P AGE技术，研究了2~4 ℃冷藏过程中草鱼肌肉微观组织学特性及典型脂肪酸、蛋白质的变化情况。研究结果表明，新鲜草鱼肌纤维膜下积累有大量脂滴，且多有排出迹象，腹部肌肉肌原纤维间线粒体周围存在大量粒径约0.25~0.50 μm的脂滴，而背部肌肉肌原纤维间无脂滴存在；2~4 ℃冷藏过程中，草鱼肌肉肌丝发生不同程度断裂，肌细胞结构逐渐模糊，严重时，肌原纤维大面积酶解自溶或呈现水样变化，出现空泡状细胞和变性细胞碎片，肌浆网、线粒体严重水肿，胞内脂滴逐渐向肌纤维膜处迁移，并逐步降解。与此同时，随着冷藏时间的延长，草鱼肌肉MUFA和PUFA及其相应的主要脂肪酸逐渐降解，SF A及其相应的主要脂肪酸的相对含量逐渐上升；肌原纤维蛋白和肌浆蛋白逐渐降解，肌球蛋白重链和肌动蛋白的显著降解导致草鱼肌肉肌丝逐步发生断裂、肌纤维结构模糊，最终导致鱼肉品质的劣化。 关键词：草鱼；冷藏；微观结构；脂肪酸；肌原纤维蛋白；降解； 文章篇号：1673-9078(2014)10-19-23 DOI: 10.13982/j.mfst.1673-9078.2014.10.004 Histological Characteristics of Grass Carp Muscle during Cold Storage W ANG Jian-hui1, JIN Na1, LIU Dong-min1, 2, LIU Y ong-le1, CHEN Qi1, W ANG Fa-xiang1, LI Xiang-hong1, YU Jian1 (1.Hunan Provincial Engineering Research Center for Food Processing of Aquatic Biotic Resources, Changsha University of Science and Technology, Changsha 410114, China) (2.Department of Biology and chemistry, Hunan University of Science and Engineering, Y ongzhou 425100, China) Abstract: The histological features and changes in lipid and protein characteristics of grass carp muscle during cold storage at 2 ℃~4 ℃were investigated using transmission electron microscopy, gas chromatography-mass spectrophotometry, and sodium dodecyl sulfate- polyacrylamide gel electrophoresis. The results showed that there was a large number of lipid droplets accumulated below the sarcolemma of fresh grass carp muscle and most of these droplets showed signs of discharging. Additionally, there were numerouslipid droplets with diameter of 0.25~0.5 μm around the mitochondria, observed between myofibrils in the abdominal muscle of the fish. However, no lipid droplets were found between the myofibrils in the muscle of the back region. During cold storage at 2 ℃~4 ℃, varying degrees of rupture were observed in the myofilaments of grass carp muscle, and the cell structure gradually disintegrated. In severe cases, autolysis or watery transformation appeared in a large area of myofibrils; vacuole-like cells and degenerated cell debris were noted; severe edema accumulated in sarcoplasmic reticulum and mitochondrias; intracellular lipid droplets gradually migrated toward the sarcolemma, where they slowly degraded. Meanwhile, with increasing cold storage time, monounsaturated fatty acids, polyunsaturated fatty acids, and their main corresponding fatty acids degraded gradually, while saturated fatty acids and their main corresponding fatty acids increased. Furthermore, myofibrillar content and sarcoplasmic proteins gradually degraded. The significant degradation of myosin heavy chains and actin led to a gradual rupture of myofilament in the muscle and visual blurring of cell structures, which eventually led to deterioration of fish meat quality. Key words: grass carp; cold preservation; microstructure; fatty acid; myofibrillar proteins; degradation 收稿日期：2014-03-12 基金项目：国家自然科学基金青年科学基金项目(31301564，31201427)；湖南省科技重大专项(2010FJ1007)；“十二五”国家科技支撑计划项目课题 (2012BAD31B08)；湖南省“十二五”重点学科建设项目 作者简介：王建辉(1980-)，男，博士，副教授，研究方向为淡水生物资源开发与功能性食品 通讯作者：刘永乐(1962-)，男，博士，教授，研究方向为食品生物技术与农副产品加工 19
草鱼成鱼的年度生产养殖计划 池塘基本情况： 广西大学水产教学科研基地，有鱼塘9口，总面积约17.5亩，无补充水源，靠积集雨水补充，平均水深1.6m左右。 一、确定生产目标： 草鱼栖息于平原地区的江河湖泊，一般喜居于水的中下层和近岸多水草区域。性活泼，游泳迅速，常成群觅食。为典型的草食性鱼类。在干流或湖泊的深水处越冬。生殖季节亲鱼有溯游习性。已移殖到亚、欧、美、非各洲的许多国家。因其生长迅速，饲料来源广，是中国淡水养殖的四大家鱼之一 二、养殖技术 1、养殖条件及放养前准备工作 保持水深常年在1.5m左右，塘中淤泥不超过15cm，因基地无补充水源，而且池塘的水无流动性，故配备1.5KW的叶轮式增氧机9台 池塘在放鱼种前10~15天，用150公斤／亩生石灰化成浆全池均匀泼洒，进行干法清塘消毒。第3天加注水至池水深1.5m左右，由于基地的鱼塘旁边有许多“大草”，故可直接利用其来增加有机肥，清塘10天左右待生石灰毒性完全消失后放入鱼种。 2、鱼种放养 放养时间选在4月，一般清塘10天后开始放苗，放养时间在晴天的上午最佳。从市场上购买规格为约17CM的草鱼鱼种，放养密度
约为600尾∕亩，所放鱼种应要求规格整齐、色泽鲜艳、体表光滑、无病无伤、体质健壮。入池钱需要用5%盐水浸洗10分钟。待草鱼鱼种在池塘内养殖20天左右后，每亩套养100g规格的鲢鱼100尾、鳙鱼80尾和三两左右的甲鱼30只。 3、饵料投喂 鱼种刚下塘时，池塘中浮游动物较多，开始几天不用投料，在苗种入池3天后采用人工投饵驯化，驯化时配以固定的投饵信号，进行定点、定时投饲训练。经耐心驯化5~7天后即可正常投喂。喂养草鱼用的饲料含粗蛋白质约28%的颗粒饵料，颗粒直径大小以适合鱼类摄食为准。50g的鱼种喂长度4mm~5mm的颗粒饲料，成鱼养殖过程中，根据个体大小可选择粒径4mm~6mm，长度6mm~8mm饲料投喂。投喂饲料不宜过多，混合着投喂些鲜嫩人工种植草料，因为鲜嫩草料营养丰富、纤维素少，容易消化，能够使草鱼长得快、少生病，同时还可以减少投喂量。以黑麦草、苏丹草等草料为主。 根据养殖期的水温、气温、水质、天气和鱼的摄食情况灵活增减投饵量，具体投喂量以黄颡鱼吃完而不剩为宜。 投喂时应坚持“四定”“四看”原则。即（定质、定量、定食、定位）和（看天气、看水质、看鱼情、看水温）。水温低的月份，一天喂2次，上午投一次草料，下午喂一次精料；7-9月旺食季节，一天喂3次，一次草料，二次精料，第三次可在傍晚进行。 饲料投喂具体如下表：
草鱼人工免疫防疫技术 草鱼人工免疫防疫技术防治草鱼病毒性出血病、细菌性烂鳃病、肠炎病、赤皮病： 一、疫苗的选择与保存 1．疫苗选择：购买疫苗时,要挑选正规厂家生产的疫苗，并仔细查看疫苗名称、批准文号、生产批号、出厂日期、保存期、使用方法、保管容器、运输方法等.同时,还要逐瓶检查疫苗瓶有无破损、瓶盖是否松动、疫苗瓶内容物的性状是否有异常，疫苗瓶内容物颜色与标签上的说明是否一致等等. 2．疫苗保存：草鱼疫苗购进后应及时放入冰箱中保存.疫苗保存时必须注意以下事项：疫苗保存温度0—4℃；保存时间6个月以内；保存过程中,玻璃瓶装的疫苗要经常翻动,防止冻破（裂）玻璃瓶。 二、注射前的准备工作 1．清塘消毒:注射疫苗的前１０天左右，要对养殖池塘进行彻底消毒杀菌,杀死鱼体及池水病原菌。 2．注射时间和地点选择：每年立冬之后，气温在10℃左右的日子，是草鱼人工免疫的最佳时间。草鱼人工免疫以晴天注射免疫效果为最好,阴雨天次之，
冰冻期间和其它季节较差。草鱼人工免疫的注射地点应选择在户外、避风、向阳的养殖水体岸边。
3．注射器械准备和消毒:注射器械主要包括兽用连续金属注射器若干支（容量2毫升为宜）、6-7号兽用针头、3—5号兽用排气针或医用一次性输液器、医用一次性注射器、酒精、消毒棉签、生理盐水，以及疫苗瓶挂杆、疫苗瓶挂篓、塑料盆、抄网、矮凳、鱼桶、遮阳网（膜）、下水裤、雨衣、手套等.6-7号兽用针头、3-5号兽用排气针等注射用器具需用水煮沸消毒后待用。 4．注射人员调配和分工:一般情况下,一个熟练注射操作员一个工作日可以完成5000尾左右的草鱼种的注射免疫。因此，若要在1个工作日内完成5万尾以上草鱼种的注射免疫,需要配备1名疫苗保管、配制和调试员，10名熟练注射操作员,2名鱼种配送员，1名免疫后鱼种消毒员，共计14人。每2名注射操作员为一组，共用一个疫苗瓶挂杆、一个暂养鱼种盆、一个消毒盆。 5．免疫鱼种的筛选和暂养：挑选无病无伤，规格一致的苗种进行人工注射免疫.病鱼和体质差的鱼种不宜注射疫苗，且不宜放入已注射了疫苗的鱼群中混养，需另行处理.
草鱼养殖技术 养殖过程中，根据草鱼疾病发生规律，通过生态健康饲养、品种合理搭配和水质生态修复来防控鱼病的发生而无需使用渔药和喷洒农药。回形池种青养鱼模式是湖北省草鱼养殖的典型模式之一。本文以湖北洪湖红仙喜水产专业合作社的草鱼生态健康养殖模式为例，介绍种青养鱼养殖模式、节能减排效果以及经济效益和生态效益，以期为广大养殖户提供参考借鉴和将其进一步推广应用。 一、回形池种青养鱼模式介绍 1、回形池建设
回形池种青养草鱼生态健康养殖模式的养殖池塘为回形池，规格一般为40～60亩，沟渠宽度为15～20米，水深3.5米，中部浅滩水深2米，底泥厚度0.2～0.3米。每个池塘需配备增氧设备2套以上(一般为叶轮式增氧机或喷灌式洒水增氧设备)。 2、回形池种青养草鱼生态健康养殖技术 每年10月底干塘起捕，清塘消毒处理后于春节前后在回形池四周深水区按65%、12%、13%、3%、5%、2%的比例放养草鱼、花鲢、白鲢、青鱼、鲫鱼、黄颡鱼苗种。来年3月份在回形池中间平滩和池埂种植黑麦草或小米草，4月底、5月初青草长成，鱼池加水至部分淹没青草以便草鱼自由上滩吃草，6月份在池埂种植苏丹草，通过反复割长，可基本满足每年3-10月份草鱼青饲料需求。草鱼饵料投喂以青饲料为主，辅以投喂颗粒饲料(0.3～0.5吨/亩)。黑麦草、小米草和苏丹草种植过程中无需喷施农药，只需施少量有机磷肥。草鱼养殖过程中，加强日常管理，做好巡塘工作，并根据草鱼发病规律切实落实鱼病防治工作。 二、节能减排效果
种植青草 每年3月，在回形池平滩和池埂上种植黑麦草或小米草，然后逐步加水至水深15厘米左右，使平滩上青草部分淹没在水中，草鱼便可自由上平滩吃草。 这样不仅可以让草鱼吃到鲜嫩可口的青草，还可以有效地节省收割和投喂青草的人力。从6月份开始，在池埂上种植苏丹草，通过施底肥加快苏丹草的生长，在苏丹草长出3个节秆，便可开始收割投喂草鱼。黑麦草和小米草在生长过程中只需少量施有机磷肥而无需喷施农药，而苏丹草生长过程中只需少量喷洒高效低毒药物防治主要病害蚜虫即可。在草鱼精养模式下，一般每亩药物开支年均为212元，而回形池种青养草鱼模式下，每亩药物开支年均为110元。黑麦草、小米草和苏丹草生长过程中不施或少施农药和化肥，既节省了农药和化肥成本，又几乎不会造成环境污染。 一年内，一般黑麦草可以重复割长3次，小米草割长2次。每亩每茬青饲料可收割0.9万千克左右，每亩年产青饲料可达4.5万千克(黑麦
电子鼻结合GC-MS 分析草鱼脱腥前后风味变化 崔方超1，李婷婷2，杨?兵1，刘?滢1，励建荣1,*，李洪军3，李敏镇4 （1.渤海大学化学化工与食品安全学院，辽宁省食品安全重点实验室，辽宁 锦州 121013；2.大连民族学院生命科学学院，辽宁 大连 116600；3.西南大学食品科学学院，重庆 400715； 4.鞍山嘉鲜农业发展有限公司，辽宁 鞍山 114100） 摘?要：采用柠檬酸、碳酸氢钠、酵母3 种脱腥剂对草鱼鱼肉进行脱腥处理，通过电子鼻和顶空固相微萃取-气相色谱-质谱联用技术对未经处理的鱼肉与不同脱腥剂处理的鱼肉的挥发性成分进行分析和鉴定。结果表明，电子鼻能够较好区分未经脱腥处理及不同脱腥剂处理的鱼肉样品的风味。主成分分析显示各个样品间差异明显，电子鼻区分度良好。采用气相色谱-质谱法在脱腥前、柠檬酸处理、碳酸氢钠处理和酵母处理的鱼肉样品中分别检测出35、20、21 种和29 种挥发性物质。经3 种脱腥剂处理的鱼肉样品的挥发性成分均呈现减少趋势，其中柠檬酸处理鱼肉中挥发性成分的数量和峰面积减少最为显著，其次为碳酸氢钠及酵母。这一结果与电子鼻分析结果相一致。关键词：电子鼻；气相色谱-质谱法；顶空固相微萃取；草鱼；脱腥 Flavor Compounds of Fresh and Deodorized Grass Carps as Determined by Electronic Nose Combined with GC-MS CUI Fang-chao 1, LI Ting-ting 2, YANG Bing 1, LIU Ying 1, LI Jian-rong 1,*, LI Hong-jun 3, LI Min-zhen 4 (1. Food Safety Key Laboratory of Liaoning Province, College of Chemistry, Chemical Engineering and Food Safety, Bohai University, Jinzhou 121013, China; 2. College of Life Science, Dalian Nationalities University, Dalian 116600, China; 3. College of Food Science, Southwest University, Chongqing 400715, China; 4. Anshan Jiaxian Agricultural Development Co. Ltd., Anshan 114100, China) Abstract: Grass?carp?muscles?were?deodorized?by?using?citric?acid,?yeast?or?NaHCO 3.?The?volatile?compounds?in?undeodorized?and?deodorized?fish?meats?were?identified?by?electronic?nose?and?head-space?solid-phase?microextraction?coupled?with?gas?chromatography?and?mass?spectrometry?(HS-SPME-GC-MS).?The?results?revealed?that?electronic?nose?could?discriminate?among?undeodorized?and?deodorized?fish?meats?by?flavor?characteristics.?Principal?component?analysis?(PCA)?showed?that?the?apparent?difference?among?undeodorized?and?deodorized?samples?could?be?well?discriminated?by?electronic?nose.?Meanwhile,?GC-MS?analysis?showed?that?35,?20,?21,?and?29?volatile?compounds?were?identified?in?fresh?meat?and?samples?deodorized?with?citric?acid,?NaHCO 3?and?yeast,?respectively.?Moreover,?the?deodorized?samples?were?less?rich?in?volatile?compounds,?and?citric?acid?resulted?in?the?most?significant?reduction?in?the?number?of?volatile?compounds?and?peak?area,?followed?in?decreasing?order?by?NaHCO 3?and?yeast.?The?GC-MS?results?were?consistent?with?those?from?electronic?nose.? Key words: electronic?nose;?gas?chromatography-mass?spectrometry?(GC-MS);?headspace?solid?phase?micro-extraction?(HS-SPME);?grass?carp;?deodorization? 中图分类号：TS254.9 文献标志码：A 文章编号：1002-6630（2014）20-0126-05 doi:10.7506/spkx1002-6630-201420025 收稿日期：2014-02-26 基金项目：国家自然科学基金青年科学基金项目（31301572）；“十二五”国家科技支撑计划项目（2012BAD29B06）； 辽宁省食品安全重点实验室开放课题项目（LNSAKF2011008） 作者简介：崔方超（1989—），男，硕士研究生，主要从事水产品贮藏加工与质量安全控制研究。E-mail ：cfc1031@https://www.doczj.com/doc/d07656002.html, *通信作者：励建荣（1964—），男，教授，博士，主要从事水产品和果蔬贮藏加工及质量安全研究。E-mail ：lijr6491@https://www.doczj.com/doc/d07656002.html, 我国淡水资源丰富，淡水鱼产量居世界首位。但长期以来，我国的淡水鱼加工技术滞后于其他产业的发展，主要原因有加工技术落后，深加工比例低等；此外淡水鱼特殊的土腥味也是制约其发展的一个重要原因[1]。青、草、鲢、鳙“四大家鱼”在我国水产养殖业中占有 非常重要的地位。草鱼鱼肉中有丰富的蛋白质，含水量高，自身带有较多的微生物和酶，容易腐败变质，而且鱼肉的腥味较重[2]。腥味物质的形成受很多因素的影响，主要是由于生存水体中含有大量的鱼腥藻、颤藻等蓝绿藻或放射菌，这些藻菌等微生物生长产生的各种次生代