棒詰水産食品に5I－Ribonucleotidesの利用

橋田 度・ 毛利 威祐・ 志 賀 岩雄

Application of5l－Ribonucleotides to Canned Sea－Foods＊

WATARU HASHIDA，TAI（ENORIMouRI and IwAO SHIGA

SU］ⅦMARY

Effectof5′－ribonucleotides onenhanclngtaSteOfcannedsea－foodswasinvestigatcd． Short－neCked clam（thnm4）is semidecusata），OySter（OstrcG gbs），red crab（Acanihodes armatus），and whale meat were experimental1y packedwith smallamounts of5′－ ribonucleotidesinlacquered tincans andprocessedaccordingtocommercialprocedures・ Thepaired－preference test and rankingtest werc employedfor evaluatingsensory qualitiesofthecanncdfoodsstored for6months at roomtemperature．Itwasfound that tasteisenhancedat the followinglevels：0．040r O．08％of Ribotide（1：1－miⅩture Of5′－Ⅰ入1P・Naニand5′一GMP・Na＝）forshort－neCked clam，0．040r O．08％of Ribotide for redcrab meat，0．1％of5’－TMP・Nae，0．1％of5′－GMP・Na2，Or O．2％of Ribotide for COrnedbeef－StYlewhalemeat． Tomeasurestabilitiesofadded5′－ribonucleotidesduring heat processlng and storage，amOuntS Of residua15J－ribonucleotides were determined with5′－nuCleotidase，The added nucleotidcswere found to be fairly stable．Canned redcrabmeat showed a retcntion of77to88％ofaddedm］CIcotidcsduringstoragefor 28days，and canlled short－neCked clam a retention of52to61％during storage for 189days．

INTRODUCTION

TlleLlavor－enl1anCingeffectsof5′一nuCleotjdes，eSPeCia11y5′－IMP and5′一GMP，have been established．Theirapplication as foodseasoningsis extensivelyreported（Shima－ ZOnO，1964．1965；Kuninaka etaZ．，1964；Oharaetal．，1964；Hashida，1964；Sawyer，1966）． Results oncanned vegetables have beenpublished（Hashida eial．，1966）．The present paperdescribes the application of5′－nuCleotides to canned sea－foods． Studies have bcen made on the distribution of5′－nuCleotidesin sea－foods（Saito， 1960．1961；Jones，1960：Fujita etal。1960：Kobayashi，1966；Arai，1966；Tomiyama et

＊Reprinted froTn FooDTECIINOLOGY，Volume22，Numbcrll，November1968，Pages：1436

－182－ αム，1966；Spinellig≠αんて1966）． Shimazono（1964）summarized the resultsondistibutionpattenlSOfnucleotidesand dividedthesea－foodsinto two categories，1MP－type and AMP－type．Usually，5′一1MP has bee11repOrted to be the majorcomponent of nucleotidesin負sh muscle and whale meatwhichare designated asIMP－tyPe．In aquaticinvertebrates such as shellBsh Cuttle丘shandprawnbelonging to theAMP－type，COnSiderable amount of5′－AMP has been found but no measurable amount of5／－IMP． Addition of5′－1入IP to materials，in which5’－IMPis notinherentlycontained，might CauSe mOdificationof the orlglnaltaste．In the casesofshort－neCkedclam，OySterand red crab，eXtremely carefulinvestigations willbe needed to determine whether the 刊avorcausedby the use of5’－Ⅰ丸IPisacceptable．Onthe other hand，When5′－nIPis inherentlycontainedinmaterials，5′－1MPwillbe more readily acceptablein order to COmpeTISateitsloss duringprocesslI－gOrtO enhance the originalnavor．From these Viewpoints，theadditioT10f5′－1MPtowhalemcatisconsideredtobe promising． The presentinvestingationwasundertaken to study theeffectof5′一IMP・Naヱand／ Or5’－GMP・Na3aPplied to fourkinds ofcannedsea－foods producedin relativcl）－1arge VOlumesinJapan．The nucleotides effectivelyenhanccd tastc ofcannedshort－neCked Clam，rCdcrabandcorlledwhale meat，and were fairly stablein thc coursc of heat PrOCCSSlngandlong・term StOrage．

MATERIALS ANI）］旺ETHOI）S

Sodium salts of5′一Ⅰ丸・IP，5′－GMP and“Ribotide”（regjstcred trade name forl：1－ mixture of5′－IMP・Na已 and5′－GMP・Na2 aS naVOr Cnhancer from Takeda Chemical rndustries）and 5’－nuCleotidase used for analyzing5′－nuCleotides were supplied by Takeda ChemicalIndustries、Ltd，，Osaka．Japan． Canning・Fourkindsofca11nedsea・foodswereprocessedbycommercialpractices asfollows：boiled short・neCked clam，Yanagawa Plant，Hayashikane－Sangyo Co，；red CrabTKurayoshiPlant，TottoriCanningCo・；boiledoyster，HeadPlant，AohataCanning Co．；andcornedbeef－Style whalemeat，SenouePlant，TeihokuShokuryoCo． Ribotide，5′－IMP・Na2，5′－G丸／IP・NaヱOr mOnOSOdium glutamate（MSG）was added Separately orincombinationat the prescribcdconcentrationsforthetotalcontents．and thecanswcre sterilized conventionally．The cans were stored for6months at room temperature，and were openedatscheduled time for the sensory test and the deter一 minatiol10f remaining5′－nuCleotides． Sensorytest・Bothor either the paired－Prefcrence test and／or the ranking test WereCOnductedforevaluatingthequality of canned foods according to the methods usedonvegetablespreviously described（Hashida etcl．，1966）． Assay of5’－ribonucleotide．Thecanned foodswereseparatedintothesolidsand liquid．andextractedwith coldperchloric acid．Individua15′－nuCleotidein the extract WaSdeterminedby meansofa DowexlX8columnaccordi一一gtOaprOCedureproposed

－183－ byBergkvistctal，（1954）andmodi負edby Nakajima etal．（1961a）． Thetotalamountof5′－ntlCleotidesremalnlngin thesolidsorliquidofthe canned foodswasdeterminedenzymatically by the method of Nakajima et al．（1963），Which hadbeenpreviously examinedforitsapplicationtotheanalysisofthemarineproducts： Tengrams of boiled short－neCked clam were homogenizedwith cold perchloric acid andcentrifuged．The supernatantliquidwasneutralizedtopH7．O with5ルKOH． Theprecipitatewasremoved，andthe supernatant WaS made up to200mlwith distilled water．Portions（5，10，20，25 and50 ml）of the prepared extract were treatedwithactivecarbonandwasas5iayedwith5′－nuCleotidase．AsshowninTable l，therewasnoconsistentdriftinthecontentof5J－nuCleotidc among the amounts of theextractcorrespondingto O．5，1．0，1．25and2，5gofclammeat． InTable2areshown resultsofrecoveryexperimentsinwhich O．21to C．62jLmOl ofRibotidewasaddedto O．5gof red crab meat orl．Og of short－neCked clam meat and assayed with5′－nuCleotidase．The recovery of5′－nuCleotides from short－neCked Clam was more than92％，and that from red crab was between91to g5％．This method wasthus proved to be adequate for the present purpose．Itisdesirableto make acorrection by using the recoveries obtainedfrom test runs at the same assay periods．

TablelConstancyofassay for thetotalamount of5′一nuCleotideat ascending levels of clam meat．

Table2 Recovery ofRibotide addcd tD Short・neCked clam and red crab．

－184－ RESULTS ANDI）ISCUSSION

NucleotidesitlCanned foods．Distribuiton of5′－nuCleotidesin raw materials and theirbehaviorsduringprocessing．whichwereconsidered to greatlyin且uence the efr fectivenessoftheforeignnucleotides，Wereinvestigatedpriortothestudiesontheappli－ Cation of theaavor－enhancers． Distribuiion d5′－nuChoiidcb2mateTiaLs．The amounts ofindividualnucleotidesin perchloricacid extractsoftheraw materialsareshow11in Table3．

Table3 The amounts of nucleotidesin maLcrials．

Concentrationin pmol／g Sea・r∝ds 5′－C呵5′一AMPl5′一UMPl 5l－IMPi5′－GMPIADPIATP

Short－neCked clam

（陀〝βr～ゆ由∫g郡元kcz持αね）

Red crab

（月α∽〟肋免官〃〃欺ガ肌） Oyster （05行gαg鹿ざ）

1＋indicates a trace amount．

Asa result，5′－AMPand5′－UMP werc fotmd to de the major components of5′－ nucleotidesin short－neCked clam，redcrabandoyster．Trace of5′－CMPwasdctected insomecases，but5′－GMP and5′－m1Pwerenegligible． Ithasbeenfoundby Nakajimactcl．（1961b）thatapproximately2mg／gof5′－1MP is containedin whale meat． αanges d nuchotide during canllingprocess．Short－neCked clam was she11ed after blanchir］ginboiledwaterfor7min．Strippedmeatwasrinsedanddippedovernight inamplewater．Clam meatwaspackedin65．4×101．1mm cans，eaCh can contaiTling 210gofsolidandlOOgof4％NaCIsolution・210gofpreparedrneatwasequivalent to 194gofrawmeat・Samplesfromeachstagewereextractedwithcoldperchloricacid andassayedwith5′－nuCleotidaseforthetotalamountof5l－nuCleotides．Theincrease inthe totalamount of5′一nuCleotides was observed during heat－prOCeSSlng Of clam meat（Table4）． A chromatographicalstudyi－1dicatedthattheincreasein the totalamount of5′－ nucleotidescouldbeintel－pretedastheincrcaseofAMP（apoorflavor－enhancer）formed bythedegradationofATPduringheat－prOCeSSing・ Red crabmeatwas alsocanlledinlacquered74．1×39．2mm cans，andaftersteri1i－ zationtlleCanSWerC Openedandthetotalamountof5′－nuCleotideswasmeasured・1t wasfoundthatthetotalamountof5′－nuCleotidesincreased during heat－prOCeSSing of crabmeatsimi1arly tothecaseofshorトneckedclam・

－185－ Table4 Chal－geOf the tota15，－nuCleotidein canning processofshort－neCkedclaTn．

Canned foods with added Ribotide and5′一nuCleotides．Canned shori－neCked chlm． Stripped and prepared clam meat was packedin65．4×101．1mm cans．each can con－ taining230g of solid and80g of seasonlllg SOlutionwith Ribotide of the following COnCentrations： No．1，COntrOl，nO Ribotide added No．2，Ribotide added at O．02％of toLalcontent No．3，Ribotide added at O，04％of totalconten・t No．4，Ribotibe added at O．08％of totalcontent The cans were opened12，99，and189days after steri1ization．The contents of Canned clams were separatedinto the solids and theliquid，and tlle taSte and the determination ofremainingRibotidc were carried out． AsshowninTable5，insamplesstol’edfor120r99days，thesolidsenrichcdwith

Table5 Effect of addition of Ribotide on canned short－neCked clam （a paired－preference test）．

・・・Indicates no signほcance aL5％level． ＊Signほcant．at5％level． さ睾Signi丘cant atl％1evel．

ー186－ 0．08％RibotidetastedbetterthantheRibotide－freesolidsatal％1evelofsigni丘cance． Butthe effectof O．020r O．04％Ribotideonthe solids was notclearevenata5％1evel ofsigniBcance．InsamplesstoredforlB9days，thesolidswithO・02％，0・04％orO・C8％ Ribotide tasted better thanthe Ribotide－free atthe5％1evelofsigniAcance． Therankingtotalsgiven by a panelon the solids of cans receiving3different levelsofRibotideareshowninTable6．Ttcanbeseenthat alargenumberofthe tasterspreferredSample4（C．08％Ribotide）asthebestandSample3（0・04％Ribotide） asthe 2nd，Whenthesewereexaminedafterthestorageof990r189days・However， norematkable differencebetween3samples wasrecognizedafter12－day storage・ Table7showstheremainingRibotidelevelpercan，after12and189daysofstorage， determinedas5′－nuCleotidebyenzymaticmethod・In the samples held for12days， 5′－nuCleotidelevelsinliquidwerehigherthanthoscinsolids．AsRibotidewasadded

Table6 Ranking totalsof canned short－neCked clam．

．は 一一t．－

…Tndicates no signi丘canceat5％1evel・ ＊寧Signi丘cantatl％lcvel・

Table7 Retention of5′一nuCleotidein canned short－neCked c】am．

Total COntentS per Can 5／－nuCleotide 5／－nuCleoti（∃e

（g） （〟mOl／100g） （〟mOl／Can）

After12－days storage 7 l－▲A●7 0 9 3 6 8 9 9 0 64 45 63 47 64 亜 l l l－ ｝1 i i1 1 No．1control， SOlid l〇 7 9 A一 〇 9 1 3 3 added no Ribotide liq11id No．3added solid 1 1 1 2 O．04％Ritntide liquid No．4added solid O．08％Ribotide liquid After189－days storage 5 46 6・4一7 0 0 76 73 96 QU3 5 47 38 21－2 l3 ｝1 5ハロ i只） ｝ L⊃ 0 2 1 1 1 1 1 1－ 1 1 No．1control， SOlid 7 【⊃ 7 7 12 19 27 誠 added no Ribotide liq11id No．2added solid O．02％Ribotide liquid －－ i l 1 2 No．3added solid O．04％Ribotide liquid No．4added solid O．08％Ritx）tide liquid

ー187－ intotheseasonlngliquid，thedifferencesofthelcvelsmayindicateinsu疏cieTltpenetration OfRibotide fromliquidinto solids． Insamdesof189days ofstorage，CertaindecreaseinRibotidecontentwasobserved in theliquid，aCCOmpanying theincreasein the solids．Thus，itis assumed that Ribotideaddedto theseasonlngliquid only slowly penetratesinto the clam meatin thedurationofthestorageperiod． Even without Ribotide being added，a fairlylarge amount Of5′－nuCleotide was detectedbecauseoftheendogenous5′－AMPa】1d5′一UMPinthe material（cf．Table3）． ThestabilityofaddedRibotideinSamples2，3．and4dしIring189daysof storage WaS Calculated as follows： TheamountofRibotide remainlngWaS eStimated by colnparing the5′－nuCleotide COlltentOfSamples2，3．and4withthatofSamplel（Ribotidenotaddcd），reSpeCtively． Sample2－Samplel＝195－127＝ 68jLrnoI Sample3－Samplel＝277－127＝150JLmoI SalTlple4－Samplel＝387－127＝260JLmOI AstheamountofRibotideadded（0．02，0．04，and O．08％）correspondsto124jLmol inSample2，248jLmolinSample3，and496JLmolinSample4，theretentionofadded Ribotideafter189daysofstorage are： （68／124）×100＝55％inSample2 （150／248）×100＝61％inSample3 （260／496）×100＝52％inSample4 The remainlngrateSOfRibotideaLter12・day storage wcre65％in Sample3and 51％inSample4． From the resultsobtainedonthesensory tests for canned clams，itis concluded thattheadditionsof O．08％andO．04％of Rjbotide are high1y efEective on enhancing the且avor，Whereas，0．02％Ribotideisless efEective． Cannedboihdqysie7・・Toeachoflacquered65・4×81・3mmcans contairling200g of OySterand50g ofbrine（4％saltsolution）were addedasfollows：nO nuCleotide（con－ trol），0．04％5’－IMP（No．1），0．04％5′－GMP（No．2），0．04％Ribotide（No．3），andO．08％ Ribotide（No．4）． Thesteri1izedcanswerestoredatroomtemperature．Theyweretested after45． 96．98，210and236daysofstorage．Thecontentsweredividedintosolidsandliquid， andthesensorytestwascarriedoutonthesolids，andremalnlngnuCleotidesin both SOlids andliquid were determined． Taste of the samples to which O．04％of5′－n4PorO．04％of5′－GMPhadbeenadded WaS COmParedwith the controlby means of the paired－preference test．More than 60％oftasterspreferredoysterswithadded5′－IMPor5′GMPafter45to210days of StOrage，though，theevaluations，Whenassessedbythexニmethod，WerenOtSignificant at the5％1evel． Therankingtestwas conducted by emp】oying15tasters on3kinds of samples StOred for45days towhich，reSpeCtively，nil（control），0．04％and O．08％Ribotide had

－188－ Table8 RetentioT10f5′－nuCleotideincanned boiled oyster．

5′－nuCleotide 5／一nuCleotide （〟mOl／100g） （〟mOl／Can）

After98－days storage 1 詔92認92認92 1－ 1 58犯58犯 1 1 詔92鎚921 14650881488飢83233872 1－2 5892 58921 2 1 ワ】 2 乱用297196297206289㍑3762502 4449鋸1481188108 1 ｝1 1｝ 2 ヽ－・・rノ 1 2 1 2 i l 描137291197286201加192 No．O control， SOlid 3 9 4 3 6 9 added no nucleotide liquid 封0．1added solid O．04％5′－mヰP liquid

No．2addd solid 5 3 4 4 6 6 （U 9 ▲ソ】 O．04％5′－G丸IP liquid No．3added solid O．04％Ribotide liquid No．4added solid O．08％Ribotide liquid After236－days storage 1－ 1 1 1 、－ゝ－J i ｝ i No．O controI， S8iid 3 63 added no nucleotide liquid No．1added solid O．04％5′－Ⅰ九rIP liquid No，2added solid O．04％5′－G丸工P liquid No．3added solid O．04％Ribotide liquid beenaddedbeforepacking．Therankingtotalswere：35for the control，31for the sampleswith O．04％Ribotideadded，and24forthosewithO．08％Ribotide．Evaluation of these data，also agreed with the paired preference testindicating no significant difference at the5％level． TheamountOfRibotide，designated as the totalamount of5′－nuCleotide present， percanisshowninTable8．Insamples held for98and236days，5J－nuCleotideievels intheliquidwerehigherthanthoseinthesolidsofcorrespondingsamples，indicating thepenetrationof5’一nuCleotideinto oystermeatislimitedduringthestorageperiods． TheratesofrernalnlngRibotide，Calculatedasdescribed previously，are： after98days of storage， 61，65，63and64％inSamplesl，2，3and4，reSpeCtively， after236daysofstorage． 61，60，and58％inSamplesl．2and3，reSpeCtively． Cbnnedrcdcrab．Red crab meatprepared under conventionalmethod was packed inlacquered74．1X39．2mmcans，eaChcancontaininglO5gofsolids，2gofNaCland the負avorenhancingsubstances．Themarks ofsamples were： No．1，COntrOl，nO Ribotide added No．2，Ribotide added at O．04％oftotalcontent No．3，Ribotide added at O．08％oftotalcontent No．4，Ribotide and丸ISGaddedatO．04and O．1％，reSpeCtively．

－189－ Table9 Effect oE Ribotideadded oncannedredcrab（a paired・preferencetest）．

No Ribotide vs．0．04％Ribotide 13 77 26 65 No Ribotide vs．0．08％Ribotide 16 94 14 88 28 72 No Ribotide vs．0．04％Ritx）tide plus O．1％MSG

O 1 17 100 100 75

…Indicates no signiRcance at5％level． ＊Signiacant at5％】evel． ＊＊Signincant atl％1eve】． ＊＊寧Signほcant at o．1％1evel．

Asshownin Table9，the resultsofthc paired－Preference testindicate that most tasterspreferredSamples2．3，and4toSamplel． TheeffectofRibotidewas clear atthel％orO．1％1evelofsignificanceinSarnples3and4duringa period of half a year．Significance reachedhigherlevelswiththe additionofO．08％ofRibotide．One－ tenthpercentMSGwasfoundtobesynergisticauyeffectivewhenusedtogethereven With thelowerlevelof Ribotide（0．04％）． Threesamplesofcannedcrabmeatreceiving O．04％Ribotide，0．08％Ribotideand O・04％RibotideplusO・1％MSGwererankedin theorderofpreference by the panel． AsshowninTablelO，Samples with O▲08％Ribotide andO．04％Ribotide plus O．1％ MSGwerepreferredathigh1evels ofsignほcance tothesampleswith O．04％Ribotide． TheamountofremainingRibotidewasdeterminedasabovedescribed（Tablell）． Acertainamountof5／－nuCleotidewasdetectedinthecontroIs，indicatingthat5′－AMP and5′－UMPareoriginallycontainedinthematerial．TheratesofRibotideremaining

TablelO Ranking totalsofcanned redcrab．

叫Signほeant atl％】evel．

ー190－ Tablell Retention of5J－nuCleotidein canned red crab．

Additives Total COntent 5′－nuCleotide 5l－nuCleotide

（g／Can） （〟1nOl／g） （〟mOl／can）

0 0 0 0 l l 一－－一〇 「∂ 1 5 Lつ 〔－6 0－、リ 4 1 1 ．4－ 0 （U O O 04 随 04 1 2 1

6 6 ▲‖U 2 O O O O 1 1 1r〇 1 5 5 5 0 0 0 0 7・．4 0 4 1 2 1

4 00 4 （U O O

〓J O ●」J 9 O （U （U O l l0 l0【〇 l0 ∧U ■つ 5 5 7 A一 9．4一 l l l

0 40 00（U 4

in cans stored for28days wcre calculatedin the similar manner descrjbedinthecase of short・neCked clam： Sample2－Samplel＝ 74JLmoI Sample3－Samplel＝138JLmoI Sample4－Samplel＝ 65jLmOI As the amounts of Ribotide added were84．168，84／lmOlin Samples2，3，and4． respectivcly，the percentages ofRibotideremainingwere月gured tobe88，82and77％， respectively． The percentagcs of Ribotide remainingafter78days of storage were83．74and 7g％inSamples2．3and4，reSpeCtively． As mentionedabove（Table3），red crab meatdoesnotcontaininherentmeasurable amounts of5′－nノ1P and5′・GMP． AdditionofRibotidetothecrabmeat，however，SeemS tobereadilyacceptable judgingfrom theresultsfromsensorytests．Thus，theappro－ priatequantityofRibotide，i．e．，0．04％，addedsimultaneouslywithMSG，SeemSreaSOnable from the viewpoint not only of forti丘ed taste but also of over－alldesirable aavor． Stability ofRibotide addedtocannedredcrabisrelatively high． annedwhQLb meat（cornedbcqf一頭頭）．Whale meat was packedin99．1×120．9mm CanSinthe simi1armannerto corned beef：WhalemeattrimmlngWaSmiⅩedwellwith Shortening，gelatiTl，egg White，fatand otheringredients andMSGand／or5′－nuCleotides Of the amounts prescribed below： No．0，0．5％MSG，nO5′－nuCleotide No．1，0．2％MSG，nO5′－nuCleotide No．2，0．2％丸4SG，0．1％5′－miP

－191－ No．3，0．2％MSG，C．1％5′－GMP No．4，0．2％MSG，0．1％Ribotide No．5，0．2％MSG，0．2％Ribotide Thecanswerestoredat room temperature and opcned aboutl．3and6months afterprocessing．Thecontentwasmincedarldmixed uniformly・The taste of the mincedsampleswasevaluatedbythepaired・prefercncetestandrankingtest． AsseeniTITable12，thepaired－preferencetestshowsthatmorethan59％oftasters preferred Samples2and3to Samplelstoredforhalf a year・The effect of5′－ nucleotideswasdetectedatthe5％1evelofsignificanceamong samples stored for29 0r97days．

Table12 Effect of5，－nuCleotideadded on ca71ned whale meat （a paired－Preference test）．

‾ ・ ・・三三 い ・・ ． 三・ No Nucleotide（No．1）vs．O．1％5′－IMP（No．2） 67 ＊ 59 59 NoNucleotide（No．1）vs．0．1％5，rGMP（No．3） 69 ＊ 69 ♯ 62

…Indicates no sigTli五cance at5％1evel． ＊Signiacant at5％level．

The ranking totals on fourof the6samples after31days ofstorage were35，48． 38and29forSamplesO．1，4，and5，reSpeCtively．Theonlysmalldifferencebetween SamplesO and4may beinterpreted as showing that the eたect of O．5％of MSGis Simi1arto O．2％MSGplus O．1％Ribotide． Inanotherseriesofsensorytests．the navorsof themincedmeatdiluted負vetimes withlVaterinto soup were compared．By the paired－Preference test，the effect of addition of5l－IMP or5′－GMP was recognizedin higherlevelof signiBcance on the dilutedsoupthanonthemincedmeat．Table13showsthe ranking totals glVen by thepanelon thesoupsamplcs．Itcanbeseenthatalargenumberoftasterspreferred SamplesOand5toSamplelopenedafter31，100and200daysofstorage．Theeffect OfaddedRibotide was obvious atthel％1evelofsigTli丘cance． Theamountof5J－nuCleotideremalnlngafter30daysofstorageisshowninTable 14．Theremainingratesof5′．nucleotidesafter30，97and200days of storage were 67to72％，60to72％，and52to71％，reSPCCtively． Fromthe resultsobtainedfromthesensorytestsforcannedwhalemeats，itisclear 盲h争tthe且avoris enhancedwiththeadditionof O．1％of5′－1MP，5′－GMP or Ribotide．

－192－ Table13 Ranking totalsof canned whale meat．

Whale meat was dil11ted丘ve timesinto soup and tasted． さ＊SigTli丘cant atl％1evel．

Table14 Retention of5′－nuCleotidein canned whale meat．

5′－nuCleotide jLmOl／g Recovery Additives ATlalysed valuelRecoveredvaluelAddedamount （％）

0 0．5％hISG no5／－れuCleotide

1 O．2鬼∵MSG no5′一nuCleotide

2 O．2％11SG O．1％5′－mfP

3 O．2％入」ISG O．1％5′－GMP

4 O．2％丸iSG O．1％Ribotide

5 O．2％MSG O．2％Ribotide

Ithas been shown that5′－GMPis containedin only smallamountsin whale meat・ Nevertheless，the nucleotidewas foundtobe effectivein enhancingthe tastethesarne as5l－IMP whichis contained abundantlyin meat．AIso，it was adjudged that thc additionofO．2％MSGandO．2％Ribotideyieldsabetterresultas cornpared with the addition of O．5％MSG alone． Generally．theeffectof5′－nuCleotidcwasfeltmorestrcnglyinthesoupthaninthe minced meat． Stabilityof5′一7MP，5′一GMP or Ribotide was rather highin canned whale meat： about70％ofthe nucletideaddedwas found tostandsterilization andstorage．

要

5′－イノシン酸（5′一m4P），5′－グァニル敢（5′－GMP）よりなる所謂核酸系調味料がひろく食品加 エに応用されている．缶詰野菜類に添加して効果のあることほ既に前朝（本誌帯8号167貢（1968））

－193－ に報告した． 本報では水産食品として，あさり，かき，ずわいがに，コンビーフ風鯨肉の缶詰に核酸系詭味料 を添加した場合の旨味増強効果と調味料の成分5′－ヌクレオチドの安定性について報告する．製造 後6カ月問室温に貯蔵した場合の缶詰食品の風味を2点揉択試験と順位法による官能検査で評価し た．添加した5′－ヌクレオチドの安定性ほ5′－ヌクレオチダーゼを用いる辞乗法によって測定した． 核酸系調味料は次の缶詰食品で顕著な効果を示した．即ちあさりに0．04あるいは0．08％のリボタ イド（5′－Ⅰ丸IPと5′－G14Pの等畳混合物），ずわいがにに0．04あるいは0．08％のリボタイド，コン ビーフ風鯨肉に0．1％の5′－Ⅰ丸IP，0．1％の5′－GMPあるいは0．2％のリボタイドを添加した場合．

明らかに旨味を増強した． 添加されたヌクレオチドは缶詰の加熱殺鼠 その後の貯蔵期間を通じてかなり安定であり，ずわ いがに缶詰では28日後に77－88％，あさり缶詰では189日後に52～61％の残存率を示した．

ABBREVIATIONS USED

AL／rP，adenosine monophosphate；ADP，adenosine diphosphate；ATP，adenosine triphosphate：IMP．inosine monophosphate；GMP，guanOSinemonophosphate；C入坪， Cytidinemonophosphate；UMP，uridinemonophosphate．

RE万一EREドCES

Arai，K・1966．Nucleotidesin the musc！es of marincinvertebrates．Bull．ノ如c71．．S？C．Sti． ∫払ん汀お∫．32，174． Bergkvist，R・andDeutch，A・1954．Ionexchangechromatographyofnucleotidespolyphosphates． Aぐね．（乃の乱＆の7d8，1877． Fujita，T．andHashimoto．Y．1960．lnosinicacid contentof foodstuffsIII．MariTle Products． 劫花畑α机5bc．＆f．鞄如rおざ．26，907． Hashida，Wr1964．Chemicalseasoninges．ノ如anFbodSbie71Ce3（12）一33． Hashida，W・，Mouri．T・and Shiga．Ⅰ．1966．Application of5′・ribonucleotides to canned Vegetables・FbodTbch710L20（7），95． Jones，NR・1960．TheseparationanddeterminaLior）Offreepurines．pyrimidinesandnucleoside incdmuscte，7ⅥgA，J♂如f鮎，111． Kobayashi，K・1966．Theacid－SOlublenucleotidesof丘shmuscle．Bu耽ノ如an．Sbc．．Sti．Ebheries． 32，166． Kuninaka，A・・Kibi，M・andSakaguchi，K・1964．Historyanddevelopmentofnavornucleotides． 乃d乃c加姶エ18（3），29． Nakajima．N・，Ichikawa，K。Kamada．M．andFu5jta．E．1961a．Food chemicalstudies on5′・ ribonucleotides．Ⅰ．On the5′－nuCleotidesin foods．L Determinationofthe5′－ribonucleo＿ tidesinvariousstocksbyion exchange chromatograph．）．Agr．Cたem．Sbc．ノ如Gn．35， 797． Nakajima，N・，Ichikawa，K．，Kamada，M．andFujita，E．1961b．Foodchemicalstudies on5′．

－194－ ribonucleotides．ⅠⅠ．On the5，・ribonucleotidesin Foods．（2）5，－Ribonucleotidesin負shes， Shell鮎hes and meats．］．Agr．Chem．Sbc．］＊GTl．35，803． Naka5ima，N．．Ichikawa，K．，YoshiTnura，I．．Kuriyama，C．，Kamda，M．and Fujita，E．1963． Food chemicalstudies on5′－ritnnucleotides．ill．Enzymatic determination of5′・ribo－ nucleotidesinfood．］．Agr．C7zelTl．蝕．舟97l．37，558． Ohara，M．and Komata，Y．1964．Chemicalseasonings．hE，a71FbodSt如ce3（12）．15． Saito，T．1960．Taste of伝shes，鮎hery productsandinosinicacid．KaBt2ku（Chemislヮ），］＊an 15，101． Saito，T．1961．Adenosine triphosphate andthe related compoundsin the musclesofaquatic animals．β〟丑畑〃乱5bc．＆f．撤カ♂rね∫．27，461． Sawyer，F．M．1g66．Interaction ofAavor mcdifyingeffectsof monosodiumglutamate and5′－ ribonucleotidesin processed foods．Paper preSented at rneeting of Amcrica11Chemical SocりSept．15． Shimazono．H．1964．Distribution of5′－riboTluCleotidesin foods andtheirapplicationtofoods． ノ匂α77セぐ触○エ18（3）．36， Shimazono，H，1965．A new Bavor enhaIICer，the5′－ribonucIcotides．Fbod肋nqfbctELTC40 （11），53． Spinelli，J．and Kemp．B．］．1966．Rapid measurement ofinosine monophosphate arld total adenosine nucleotidesin丘shtissue．L Agr．hod C71em．14，176． Tomiyama，T．，Kobayashi．K．，Kitahara，K．．Shirasaki，E．and Ohba，N．1966．A studyonthe Changein nucleotides and freshness Dfcarpmuscleduringthechillstoragc．Bu孔佃an． 助c．甜．ダ払血♂rね∫．32，262． Ms．rec’d8／23／67；reVised6／17／68；a∝ePted7／2／68．

Appreciationis expressed to Prof．Dr．S．Teramoto，Osaka University．andMr．U．Inamoto， ex－preSidentofToyo FoodInstitute，for th巳irencouragementsin this work．Theauthors thank Hayashikane－Sangyo Co．，TottoriCanning Co．，Aohata Canning Co．，and Teihoku Shokuryo Co．for the courtesyin experimentalcanning．This work was supprted by Takeda ChemicalTndnstries，Japan．The authorsare gratefulto Dr．H．Shimazono，Mr．Y． Sumita，Mr．S．Hori，Mr．H．Sugibayashiand othersofTakeda Chemicallndustriesfortheir advice andinterest．The authors acknowledge the technicalassistance of MissJ．Terada and】uiss K．Hata．

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