Name: preparation of high-quality fermented fish product
Uploaded: 2019-08-23T15:00:00
Description: Watch this Scientific Journal Video about Preparation of High-Quality Fermented Fish Product at JoVE.com

Denne forskning blev finansielt støttet af den øremærkede fond for Jiangsu Natural Science Fund (BK20170185), projekt fra Jiangsu Fisheries administrator (Y2017-30), National Natural Science Foundation i Kina (NFSC31801575), Kina Agri kulturer Research System (CARS-45-26), national førsteklasses disciplin program for Food Science and Technology (JUFSTR20180201), og Yi Tong-Jiangsu postdoc program.

1. forberedelse af prøver
<ol><li>Tø frosset stør kød under Rind vand under 20 °C. Derefter, ren, hud ud og skær fisken i tern (2 cm × 2 cm × 1,5 cm). Bemærk: råmaterialet kan være fersk eller frosset stør kød.</li>
	<li>Bland fiske terninger med 6-12% (w/v) saltopløsning med en hastighed på 1:1 (fiske terning masse til opløsning volumen), ved 10 °C for 1-3 h.</li>
	<li>Sæt de marinerede fiske kuber på en rustfri stålplade og tørre fiske kuber ved 40-60 °C i ca. 6-10 h ved varm luft eller tør ...

<ol>
	<li>Riebroy, S., Benjakul, S., Visessanguan, W., Tanaka, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Changes+during+fermentation+and+properties+of+som-fug+produced+from+different+marine+fish.">Changes during fermentation and properties of som-fug produced from different marine fish.</a> Journal of Food Processing and Preservation. 31 (6), 751-770 (2007).</li><li>Xu, Y., Xia, W., Yang, F., Jinmoon, K., Nie, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+fermentation+temperature+on+the+microbial+and+physicochemical+properties+of+silver+carp+sausages+inoculated+with+Pediococcus+pentosaceus.">Effect of fermentation temperature on the microbial and physicochemical properties of silver carp sausages inoculated with Pediococcus pentosaceus.</a> Food Chemistry. 118 (3), 512-518 (2010).</li><li>Cano-Garcia, L., Flores, M., Belloch, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+characterization+and+aromatic+potential+of+Debaryomyces+hansenii+strains+isolated+from+naturally+fermented+sausages.">Molecular characterization and aromatic potential of Debaryomyces hansenii strains isolated from naturally fermented sausages.</a> Food Research International. 52 (1), 42-49 (2013).</li><li>Chen, Q., Liu, Q., Sun, Q., Kong, B., Xiong, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flavour+formation+from+hydrolysis+of+pork+sarcoplasmic+protein+extract+by+a+unique+LAB+culture+isolated+from+Harbin+dry+sausage.">Flavour formation from hydrolysis of pork sarcoplasmic protein extract by a unique LAB culture isolated from Harbin dry sausage.</a> Meat Science. 100, 110-117 (2015).</li><li>Saithong, P., Panthavee, W., Boonyaratanakornkit, M., Sikkhamondhol, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+a+starter+culture+of+lactic+acid+bacteria+in+plaa-som,+a+Thai+fermented+fish.">Use of a starter culture of lactic acid bacteria in plaa-som, a Thai fermented fish.</a> Journal of Bioscience &amp; Bioengineering. 110 (5), 553-557 (2010).</li><li>Zeng, X., Xia, W., Jiang, Q., Guan, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biochemical+and+Sensory+Characteristics+of+Whole+Carp+Inoculated+With+Autochthonous+Starter+Cultures.">Biochemical and Sensory Characteristics of Whole Carp Inoculated With Autochthonous Starter Cultures.</a> Journal of Aquatic Food Product Technology. 24 (1), 52-67 (2015).</li><li>Casaburi, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biochemical+and+sensory+characteristics+of+traditional+fermented+sausages+of+Vallo+di+Diano+(Southern+Italy)+as+affected+by+the+use+of+starter+cultures.">Biochemical and sensory characteristics of traditional fermented sausages of Vallo di Diano (Southern Italy) as affected by the use of starter cultures.</a> Meat Science. 76 (2), 295-307 (2007).</li><li>Gao, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+autochthonous+starter+cultures+on+the+volatile+flavour+compounds+of+Chinese+traditional+fermented+fish+(Suan+yu).">Effect of autochthonous starter cultures on the volatile flavour compounds of Chinese traditional fermented fish (Suan yu).</a> International Journal of Food Science and Technology. 51 (7), 1630-1637 (2016).</li><li>Zeng, X. F., Xia, W. S., Jiang, Q. X., Xu, Y. S., Fan, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contribution+of+Mixed+Starter+Cultures+to+Flavor+Profile+of+Suanyu+-+A+Traditional+Chinese+Low-Salt+Fermented+Whole+Fish.">Contribution of Mixed Starter Cultures to Flavor Profile of Suanyu - A Traditional Chinese Low-Salt Fermented Whole Fish.</a> Journal of Food Processing and Preservation. 41 (5), 15 (2017).</li><li>Anihouvi, V. B., Sakyi-Dawson, E., Ayernor, G. S., Hounhouigan, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microbiological+changes+in+naturally+fermented+cassava+fish+(Pseudotolithus+sp.)+for+lanhouin+production.">Microbiological changes in naturally fermented cassava fish (Pseudotolithus sp.) for lanhouin production.</a> International Journal of Food Microbiology. 116 (2), 287-291 (2007).</li><li>Corral, S., Salvador, A., Flores, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Salt+reduction+in+slow+fermented+sausages+affects+the+generation+of+aroma+active+compounds.">Salt reduction in slow fermented sausages affects the generation of aroma active compounds.</a> Meat Science. 93 (3), 776-785 (2013).</li><li>Wang, W., Xia, W., Pei, G., Xu, Y., Jiang, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proteolysis+during+fermentation+of+Suanyu+as+a+traditional+fermented+fish+product+of+China.">Proteolysis during fermentation of Suanyu as a traditional fermented fish product of China.</a> International Journal of Food Properties. 20 (90), 29-38 (2017).</li><li>Coventry, M. J., Hickey, M. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+spices+and+manganese+on+meat+starter+culture+activity.">The effect of spices and manganese on meat starter culture activity.</a> Meat Science. 33 (3), 391-399 (1993).</li><li>Zhu, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+study+on+quality+characteristics+of+pickled+and+fermented+sturgeon+(Acipenser+sinensis)+meat+in+retort+cooking.">Comparative study on quality characteristics of pickled and fermented sturgeon (Acipenser sinensis) meat in retort cooking.</a> International Journal of Food Science &amp; Technology. , (2019).</li><li>Mendonca, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamics+of+the+yeast+flora+in+artisanal+country+style+and+industrial;dry+cured+sausage+(yeast+in+fermented+sausage).">Dynamics of the yeast flora in artisanal country style and industrial;dry cured sausage (yeast in fermented sausage).</a> Food Control. 29 (1), 143-148 (2013).</li><li>Zeng, X. F., Xia, W. S., Jiang, Q. X., Yang, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+autochthonous+starter+cultures+on+microbiological+and+physico-chemical+characteristics+of+Suan+yu,+a+traditional+Chinese+low+salt+fermented+fish.">Effect of autochthonous starter cultures on microbiological and physico-chemical characteristics of Suan yu, a traditional Chinese low salt fermented fish.</a> Food Control. 33 (2), 344-351 (2013).</li><li>Gao, P., Jiang, Q., Xu, Y., Xia, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Esterase+activities+of+autochthonous+starter+cultures+to+increase+volatile+flavor+compounds+in+Chinese+traditional+fermented+fish+(Suan+yu).">Esterase activities of autochthonous starter cultures to increase volatile flavor compounds in Chinese traditional fermented fish (Suan yu).</a> International Journal of Food Properties. 20 (1), 663-672 (2017).</li><li>Wahyuni, S., Holilah, , Asranudin, , Noviyanti, <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Estimation+of+shelf+life+of+wikau+maombo+brownies+cake+using+Accelerated+Shelf+Life+Testing+(ASLT)+method+with+Arrhenius+model.">Estimation of shelf life of wikau maombo brownies cake using Accelerated Shelf Life Testing (ASLT) method with Arrhenius model.</a> IOP Conference Series Earth and Environmental Science. 122 (1), 12-22 (2018).</li><li>Zeng, X. F., Xia, W. S., Jiang, Q. X., Yang, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+and+microbial+properties+of+Chinese+traditional+low-salt+fermented+whole+fish+product+Suan+yu.">Chemical and microbial properties of Chinese traditional low-salt fermented whole fish product Suan yu.</a> Food Control. 30 (2), 590-595 (2013).</li><li>Yu, D., Jiang, Q., Xu, Y., Xia, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+shelf+life+extension+of+refrigerated+grass+carp+(Ctenopharyngodon+idellus)+fillets+by+chitosan+coating+combined+with+glycerol+monolaurate.">The shelf life extension of refrigerated grass carp (Ctenopharyngodon idellus) fillets by chitosan coating combined with glycerol monolaurate.</a> International Journal of Biological Macromolecules. 101, 448-454 (2017).</li><li>Czerner, M., Tomas, M. C., Yeannes, M. 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I denne undersøgelse er der en ny teknik til fremstilling af fermenteret fiskeprodukt af høj kvalitet med vin aroma og test for sensoriske egenskaber. De vigtigste processer i denne teknik er marinering, tørring, gæring og sterilisering. I marinering proces, saltkoncentrationen, temperaturen og den tid, alle påvirker de stoflige egenskaber af fiskene. Hårdhed og chewiness af produktet øges gradvist med stigningen i saltkoncentrationen (0-12%, w/v) og forlængelsen af marinerende tid (0-2.5 h); men stigningen efter...

Nuværende kommercielle marinerede fisk produkt i Kina har problemet med tung salt smag, utilstrækkelig vin aroma, dårlig elasticitet og bleg farve, hvilket mindsker accepten til forbrugerne. Derfor, en ny teknik til en høj kvalitet fiskekød produkt med vin aroma skal skabes og optimeres.
I de seneste år, anvendelse af moderne fermenterings teknikker i kød og fisk har tiltrukket sig opmærksomhed fra flere og flere forskere1,2,3,4. Ved inokulering af start kulturer til kød og fisk er fødevaresikkerheden blevet forbedret, forarbejdningstiden er blevet forkortet; og produktets sensoriske egenskaber er blevet ændret. Saithong et al.5 isolerede Lactobacillus bakterier (Lab) fra naturlige plaa-som og brugte dette laboratorium som en starterkultur, som inducerede høj surhedsgrad og undertrykte patogene bakterier. Zeng et al.6 rapporterede, at inokulation med de autoktone starter kulturer reduceret fermenterings tiden og forbedrede de sensoriske egenskaber af prøver. Casaburi et al.7 hævdede, at brugen af mikrobielle starter kulturer påvirke udviklingen af aroma i gæret kød. I disse starter kulturer kunne S. cerevisiae producere vin aroma ved alkoholisk gæring og kunne også give produktet andre forbedrede organoleptiske kvaliteter. Derfor er s. cerevisiae en egnet starterkultur for vin-aroma produkter8,9,10 og vin-aroma fisk produkt kunne laves af S. cerevisiae.
I processen med at fremstille vin-aroma fiskeprodukt, tekstur af kød og fisk kan blive påvirket af saltindhold, vandindhold, pH, proteindenaturering, etc. Derfor kan marinating, tørring, gæring og sterilisering alle påvirke tekstur egenskaber. Dannelsen af smag og smag er kompliceret og er hovedsageligt påvirket af marinering og gæring, fordi det er meget relateret til hydrolyse af kulhydrater, proteiner og lipider, og mild lipid oxidation11,12. Det kunne også blive påvirket af tilsætning af krydderier13. For udvikling af farve, Maillard reaktion opstår, som er involveret i processen med gæring og sterilisering10.
Denne artikel kan yde teknisk støtte til industrialisering af gæret fiskeprodukt med vin aroma, som er af stor betydning for udviklingen af fiskeforarbejdnings industrien. Denne teknik kan forbedre smagen af produktet ved øget proteolyse (flere frie aminosyrer og TCA-opløselige peptider), ændre smag hovedsagelig af alkoholer (ethanol, 1-octen-3-OL, 2-methyl-1-propanol og 3-methyl-1-butanol), estere (ethylacetat) og aldehyder (nonanal, 3-methylbutanal og benzaldehyd), øge mundfornemmelse ved højere hårdhed, fjedren, klæbrighed og chewiness, og give mere attraktiv Russet farve ved og en lys overflade14. Det giver også forbrugerne bekvemmelighed, fordi produktet kan opbevares ved stuetemperatur. Som beskrevet i andre tidligere undersøgelser15,16,17, har gæring med S. cerevisiae også vist sig at forbedre organoleptiske kvaliteter i andre kød-eller fiskeprodukter betydeligt.
Det er værd at bemærke, at den indførte protokol også kan anvendes i andre arter af fisk, såsom græs karper, sølv karper, sort karpe, af karper, torsk, laks osv. For at fiskevarer af høj kvalitet bør der anvendes fisk uden forarbejdning, såsom frisk fisk, fisk i is eller frosne fisk oplagret i mindre end 1 år. Udover, da mild lipid oxidation kunne forbedre smag mens omfattende lipid oxidation bringer ubehagelig smag, fisk med mindre fedt foretrækkes eller skummetfisk anbefales.

<table>
	<tbody>
		<tr>
			<td>2,4,6-trimethylpyridine</td>
			<td>Tokyo Chemical Industry Co., Ltd.</td>
			<td>Purity 98%</td>
			<td></td>
		</tr>
		<tr>
			<td>Colorimeter</td>
			<td>Hunterlab</td>
			<td>UltraScan Pro1166</td>
			<td></td>
		</tr>
		<tr>
			<td>DB-WAX column</td>
			<td>Agilent</td>
			<td>30 m &#215; 0.25 mm &#215; 0.25&#956;m</td>
			<td></td>
		</tr>
		<tr>
			<td>Digital pH meter</td>
			<td>Mettler toledo Instrument (Shanghai) Co., Ltd.</td>
			<td>DELTA-320</td>
			<td></td>
		</tr>
		<tr>
			<td>Drying oven</td>
			<td>Shanghai Yiheng Scientific Instrument Co., Ltd.</td>
			<td>DHG-9070A</td>
			<td></td>
		</tr>
		<tr>
			<td>Frozen sturgeon</td>
			<td>Huada Marine Industry Group Co., Ltd</td>
			<td>-</td>
			<td></td>
		</tr>
		<tr>
			<td>Gas chromatograph-mass spectrometer</td>
			<td>Thermo Fisher Scientific</td>
			<td>TSQ Quantum XLS</td>
			<td></td>
		</tr>
		<tr>
			<td>Humidities incubator</td>
			<td>Shanghai Yiheng Scientific Instrument Co., Ltd.</td>
			<td>LHS-250HC-II</td>
			<td></td>
		</tr>
		<tr>
			<td>Saccharomyces cerevisiae</td>
			<td>Angel Yeast Co., Ltd</td>
			<td>-</td>
			<td></td>
		</tr>
		<tr>
			<td>Spices</td>
			<td>Auchan Supermarket</td>
			<td>-</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterilization pot</td>
			<td>Longqiang Machinery Technology Co., Ltd.</td>
			<td>RHS-03-700</td>
			<td></td>
		</tr>
		<tr>
			<td>Supelco</td>
			<td>Sigma</td>
			<td>65&#956;m, PDMS/DVB</td>
			<td></td>
		</tr>
		<tr>
			<td>Texture analyzer</td>
			<td>Stable Micro Systems, Ltd.</td>
			<td>TA-XT2i</td>
			<td></td>
		</tr>
		<tr>
			<td>Vacuum package machine</td>
			<td>Quanzhou Yiminxin Electromechanical Co., Ltd.</td>
			<td>YMX-958-10L</td>
			<td></td>
		</tr>
	</tbody>
</table>

preparation of high-quality fermented fish product

Denne protokol indeholder en metode til tilberedning af industrielt gæret fiskeprodukt med et kødprodukt af stør (Aquilaria sinensis). Procedurerne var: 1) forbehandling af opdrættet stør, herunder afpudsning, udtagning af organer, flåning, rengøring og opskæring; (2) marinering fiske terninger i 6-12% (w/v) saltopløsning (1:1, fisk kube masse til opløsning volumen); 3) tørring af fiske terninger til et vandindhold på 50-60% med varm luft (40-60 °C) eller ved vakuum (4) fermentering med inokulerende fiske terninger med 0,4-1,6% (w/w) S. cerevisiae i smags opløsning til fiske terninger og fermentering ved 25-35 °c for 6-10 h; (5) forsegling af fiske terninger i vakuumpakker med marinerende og gærings opløsninger; (6) sterilisering ved 115-121 °C i 10-20 min. Den stør kød produkt udarbejdet af denne metode har lækker smag, som er Mellow og tyk, har forskellige typer og store mængder af flygtige smag forbindelser såsom alkoholer og estere, som kunne maskere muggen og ubehagelig lugt fra fisk, har moderat salt indhold, men gode tekstur egenskaber såsom høj springiness, klæbrighed og chewiness, og har lyse Russet farve og attraktivt udseende. Denne nye teknik kunne også anvendes i behandlingen af andre fisk til at give praktisk fisk snack fødevarer, som kunne opbevares ved stuetemperatur. Det er hensigtsmæssigt for både hav-og ferskvandsfisk.

Den passende saltkoncentration, marinerende tid og temperatur gør produktets tekstkvalitet bedre. De bedste marinerende betingelser var som følger: saltkoncentrationen af 8% i marinerende opløsning; marinerende tid på 2 h; og marinerende temperatur på 10 °C. Se figur 1.
I tørringsprocessen kan det endelige fugtindhold og tørrings temperaturen påvirke tekstur og sensorisk kvalitet. De bedste tørre forhold var som følger: vandindholdet i de tørrede fiske...

Watch this Scientific Journal Video about Preparation of High-Quality Fermented Fish Product at JoVE.com

Preparation of High-Quality Fermented Fish Product

Målet med protokollen er at tilvejebringe en industrialiseret fiske fermenterings teknik baseret på inokulering af Saccharomyces cerevisiae.

Tilberedning af fermenteret fiskeprodukt af høj kvalitet

This protocol provides a method for preparation of industrialized fermented fish product with sturgeon (Aquilaria sinensis) meat product. The procedures ...

Denne procedure giver en høj kvalitet af fermenteret fiskeprodukt med vinaroma og kan anvendes i industriens produktion. Denne teknik giver fiskeproduktet et attraktivt udseende, unik smag, lækker smag og gode teksturegenskaber. Og dette produkt kan opbevares ved stuetemperatur i mindst et år.For at begynde denne procedure, tø, ren, og hud frosset stør kød som skitseret i tekstprotokollen. Skær fisken i tern. Dernæst blandes fisketernerne med seks til 12% saltopløsning i et forhold på en-til-en ved 10 grader Celsius i en til tre timer.Derefter sætte marinerede fisk terninger på en rustfri stål rist plade og tørre dem med varm luft ved en temperatur mellem 40 og 60 grader Celsius i seks til 10 timer. For at forberede krydderi væske, bland krydderier, herunder 1,2 enheder af forårsløg, en enhed af ingefær, 0,6 enheder af stjerne anis, 0,6 enheder af fennikel, 0,3 enheder af grøn te, og 0,3 enheder af peber med 40 enheder vand. Kog i en halv time, og indsamle filtrat.For at forberede smag løsning, bland krydderier flydende, gul vin, hvidvin, sukkerrør sukker, mononatriumglamamate, og eddike i massefraktioner vist her. Efter dette, bland de tørrede fisk terninger med smag løsning, podning 0,4 til 1,6% saccharomyces cerevisiae i et forhold på en-til-en. Forsegle blandingen i en beholder, og gære ved en temperatur mellem 25 og 35 grader Celsius, i seks til 10 timer.De gærede fisketerninger skal sættes i en vakuumpakke med marinerings- og fermenteringsopløsninger, og vakuumpakken forsegles med en vakuumstyrke på 0,085 megapascal, en forseglingstid på 3,6 sekunder og en køletid på 5,5 sekunder. Derefter steriliseres de pakkede fisketerninger ved hjælp af en sterilisationstemperatur mellem 115 og 121 grader Celsius i 10 til 20 minutter. I denne undersøgelse fremstilles fermenterede fiskeprodukt af høj kvalitet.Ved hjælp af en passende saltkoncentration, marineringstid og temperatur gør produkternes lydkvalitet bedre. De bedste marinering betingelser er syntes at være en saltkoncentration på 8%Og marinering løsning, en marinering tid på to timer. Og en marinering temperatur på 10 grader Celsius.I tørringsprocessen kan det endelige fugtindhold og tørretemperatur påvirke tekstur- og sensorkvaliteten. De bedste tørreforhold er syntes at være et fugtindhold af de tørrede fisketerninger på 55% og tørring temperatur på 50 grader Celsius. I fermenteringsprocessen, tilsætning af saccharomyces cerevisiae, temperaturen, og den tid alle effekt smag, smag, farve og tekstur egenskaber af fisk.Den succesfulde fermenterede fisk har high scores for smag, smag, farve og tekstur, hvilket resulterer i harmonisk smag, fermentativ duft, vinagtig, russet farve, lys overflade, karamel og al dente tekstur. Den mislykkede fisk produkt har den lave score for smag, smag, farve og tekstur resulterer den dårlige smag, bitterhed, surhed, fishiness, bleg farve, ru overflade, grov mundfornemmelse, og forværret tekstur. Den passende sterilisering og intensitet ser ud til at være 4,5 minutter.Og en passende sterilisation temperatur syntes at være 121 grader Celsius. Lagerovervejelserne beregnes og bestemmes derefter som beskrevet i tekstprotokollen. Og forudsigelsen for holdbarheden er 264 dage ved 25 grader Celsius eller 205 dage ved 35 grader Celsius.Når du udfører denne procedure, er det vigtigt at bemærke, at både gæring og sterilisation trin er afgørende for succes af denne teknik. Efter at have lært denne procedure, kan det bruges til gæring af andre fiskearter. I fremtiden kan gæring med andre stammer undersøges.Såsom lactobacillus, staphylococcus, osv. regioner, skal du sørge for at tage forholdsregler, når sterilisering af fiskeprodukter, da ekstremt høj temperatur kan forårsage skade.

preparation-of-high-quality-fermented-fish-product

Research

JoVE Journal

Biochemistry

Preparation of Homogeneous MALDI Samples for Quantitative Applications

This protocol demonstrates a simple sample preparation to reduce spatial heterogeneity in ion signals during matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The heterogeneity of ion signals is a severe problem in MALDI, which results in poor data reproducibility and makes MALDI unsuitable for quantitative analysis. By regulating sample plate temperature during sample preparation, thermal-induced hydrodynamic flows inside droplets of sample solution are able to reduce the heterogeneity problem. A room-temperature sample preparation chamber equipped with a temperature-regulated copper base block that holds MALDI sample plates facilitates precise control of the sample drying condition. After drying of sample droplets, the temperature of sample plates is returned to room temperature and removed from the chamber for subsequent mass spectrometric analysis. The areas of samples are examined with MALDI-imaging mass spectrometry to obtain the spatial distribution of all components in the sample. In comparison with the conventional dried-droplet method that prepares samples under ambient conditions without temperature control, the samples prepared with the method demonstrated herein show significantly better spatial distribution and signal intensity. According to observations using carbohydrate and peptide samples, decreasing substrate temperature while maintaining the surroundings at ambient temperature during the drying process can effectively reduce the heterogeneity of ion signals. This method is generally applicable to various combinations of samples and matrices.

A protocol for reducing spatial heterogeneities of ion signals in MALDI mass spectrometry by regulating substrate temperature during sample drying processes is demonstrated.

Udarbejdelse af Homogene MALDI Prøver til Kvantitative applikationer

This protocol demonstrates a simple sample preparation to reduce spatial heterogeneity in ion signals during matrix-assisted laser desorption/ionization ...

A Filtration-based Method of Preparing High-quality Nuclei from Cross-linked Skeletal Muscle for Chromatin Immunoprecipitation

Chromatin immunoprecipitation (ChIP) is a powerful method to determine protein binding to chromatin DNA. Fiber-rich skeletal muscle, however, has been a challenge for ChIP due to technical difficulty in isolation of high-quality nuclei with minimal contamination of myofibrils. Previous protocols have attempted to purify nuclei before cross-linking, which incurs the risk of altered DNA-protein interaction during the prolonged nuclei preparation process. In the current protocol, we first cross-linked the skeletal muscle tissue collected from mice, and the tissues were minced and sonicated. Since we found that ultracentrifugation was not able to separate nuclei from myofibrils using cross-linked muscle tissue, we devised a sequential filtration procedure to obtain high-quality nuclei devoid of significant myofibril contamination. We subsequently prepared chromatin by using an ultrasonicator, and ChIP assays with anti-BMAL1 antibody revealed robust circadian binding pattern of BMAL1 to target gene promoters. This filtration protocol constitutes an easily applicable method to isolate high-quality nuclei from cross-linked skeletal muscle tissue, allowing consistent sample processing for circadian and other time-sensitive studies. In combination with next-generation sequencing (NGS), our method can be deployed for various mechanistic and genomic studies focusing on skeletal muscle function.

We present a filtration-based protocol to isolate high-quality nuclei from cross-linked mouse skeletal muscle wherein we removed the need for ultracentrifugation, making it easily applicable. We show that chromatin prepared from the nuclei is suitable for chromatin immunoprecipitation and likely chromatin immunoprecipitation sequencing studies.

En filtreringsbaseret metode til fremstilling af højkvalitetsnuclei fra tværbundet skeletsmuskel til chromatinimmunpræcipitation

Chromatin immunoprecipitation (ChIP) is a powerful method to determine protein binding to chromatin DNA. Fiber-rich skeletal muscle, however, has been a ...

Biosynthesis of a Flavonol from a Flavanone by Establishing a One-pot Bienzymatic Cascade

Flavonols are a major subclass of flavonoids with a variety of biological and pharmacological activities. Here, we provide a method for the in vitro enzymatic synthesis of a flavonol. In this method, Atf3h and Atfls1, two key genes in the biosynthetic pathway of the flavonols, are cloned and overexpressed in Escherichia coli. The recombinant enzymes are purified via an affinity column and then a bienzymatic cascade is established in a specific synthetic buffer. Two flavonols are synthesized in this system as examples and determined by TLC and HPLC/LC/MS analyses. The method displays obvious advantages in the derivation of flavonols over other approaches. It is time- and labor-saving and highly cost-effective. The reaction is easy to be accurately controlled and thus scaled up for mass production. The target product can be purified easily due to the simple components in the system. However, this system is usually restricted to the production of a flavonol from a flavanone.

The derivation of a flavonol is crucial for its application in healthcare and the food industry. Here, we provide a detailed protocol for the biosynthesis of a flavonol from a flavanone and discuss the crucial steps and its advantages over other approaches.

Biosyntese af en flavonol fra en Flavanone ved at etablere en en-pot Bienzymatisk kaskade

Flavonols are a major subclass of flavonoids with a variety of biological and pharmacological activities. Here, we provide a method for the in vitro ...

Obtaining High-Quality Transcriptome Data from Cereal Seeds by a Modified Method for Gene Expression Profiling

The characterization of gene expression is dependent on RNA quality. In germinating, developing and mature cereal seeds, the extraction of high-quality RNA is often hindered by high starch and sugar content. These compounds can reduce both the yield and the quality of the extracted total RNA. The deterioration in quantity and quality of total RNA can subsequently have a significant impact on the downstream transcriptomic analyses, which may not accurately reflect the spatial and/or temporal variation in the gene expression profile of the samples being tested. In this protocol, we describe an optimized method for extraction of total RNA with sufficient quantity and quality to be used for whole transcriptome analysis of cereal grains. The described method is suitable for several downstream applications used for transcriptomic profiling of developing, germinating, and mature cereal seeds. The method of transcriptome profiling using a microarray platform is shown. This method is specifically designed for gene expression profiling of cereals with described genome sequences. The detailed procedure from microarray handling to final quality control is described. This includes cDNA synthesis, cRNA labelling, microarray hybridization, slide scanning, feature extraction, and data quality validation. The data generated by this method can be used to characterize the transcriptome of cereals during germination, in various stages of grain development, or at different biotic or abiotic stress conditions. The results presented here exemplify high-quality transcriptome data amenable for downstream bioinformatics analyses, such as the determination of differentially expressed genes (DEGs), characterisation of gene regulatory networks, and conducting transcriptome-wide association study (TWAS).

A method for transcriptome profiling of cereals is presented. The microarray-based gene expression profiling starts with the isolation of high-quality total RNA from cereal grains and continues with the generation of cDNA. After cRNA labelling and microarray hybridization, recommendations are given for signal detection and quality control.

Opnåelse af udskriftsdata af høj kvalitet fra kornfrø ved en modificeret metode til genekspressionsprofilering

The characterization of gene expression is dependent on RNA quality. In germinating, developing and mature cereal seeds, the extraction of high-quality ...

Single Cell Analysis Of Transcriptionally Active Alleles By Single Molecule FISH

Gene transcription is an essential process in cell biology, and allows cells to interpret and respond to internal and external cues. Traditional bulk population methods (Northern blot, PCR, and RNAseq) that measure mRNA levels lack the ability to provide information on cell-to-cell variation in responses. Precise single cell and allelic visualization and quantification is possible via single molecule RNA fluorescence in situ hybridization (smFISH). RNA-FISH is performed by hybridizing target RNAs with labeled oligonucleotide probes. These can be imaged in medium/high throughput modalities, and, through image analysis pipelines, provide quantitative data on both mature and nascent RNAs, all at the single cell level. The fixation, permeabilization, hybridization and imaging steps have been optimized in the lab over many years using the model system described herein, which results in successful and robust single cell analysis of smFISH labeling. The main goal with sample preparation and processing is to produce high quality images characterized by a high signal-to-noise ratio to reduce false positives and provide data that are more accurate. Here, we present a protocol describing the pipeline from sample preparation to data analysis in conjunction with suggestions and optimization steps to tailor to specific samples.&#160;

Single molecule RNA fluorescence in situ hybridization (smFISH) is a method to accurately quantify levels and localization of specific RNAs at the single cell level. Here, we report our validated lab protocols for wet-bench processing, imaging and image analysis for single cell quantification of specific RNAs.

Enkeltcelleanalyse af transskriptionsaktive alleler efter enkeltmolekyle FISH

Gene transcription is an essential process in cell biology, and allows cells to interpret and respond to internal and external cues. Traditional bulk ...

Nano-Differential Scanning Fluorimetry for Screening in Fragment-based Lead Discovery

Thermal shift assays (TSAs) examine how the melting temperature (Tm) of a target protein changes in response to changes in its environment (e.g., buffer composition). The utility of TSA, and specifically of nano-Differential Scanning Fluorimetry (nano-DSF), has been established over the years, both for finding conditions that help stabilize a specific protein and for looking at ligand binding by monitoring changes in the apparent Tm. This paper presents an efficient screening of the Diamond-SGC-iNEXT Poised (DSi-Poised) fragment library (768 compounds) by the use of nano-DSF, monitoring Tm to identify potential fragment binding. The prerequisites regarding protein quality and concentration for performing nano-DSF experiments are briefly outlined followed by a step-by-step protocol that uses a nano-liter robotic dispenser commonly used in structural biology laboratories for preparing the required samples in 96-well plates. The protocol describes how the reagent mixtures are transferred to the capillaries needed for nano-DSF measurements. In addition, this paper provides protocols to measure thermal denaturation (monitoring intrinsic tryptophan fluorescence) and aggregation (monitoring light back-scattering) and the subsequent steps for data transfer and analysis. Finally, screening experiments with three different protein targets are discussed to illustrate the use of this procedure in the context of lead discovery campaigns. The overall principle of the method described can be easily transferred to other fragment libraries or adapted to other instruments.

Monitoring changes in the melting temperature of a target protein (i.e., thermal shift assay, TSA) is an efficient method for screening fragment libraries of a few hundred compounds. We present a TSA protocol implementing robotics-assisted nano-Differential Scanning Fluorimetry (nano-DSF) for monitoring intrinsic tryptophan fluorescence and light back-scattering for fragment screening.

Nano-differentialscanning fluormetri til screening i fragmentbaseret lead discovery

Thermal shift assays (TSAs) examine how the melting temperature (Tm) of a target protein changes in response to changes in its environment (e.g., buffer ...

Preparation of High-Temperature Sample Grids for Cryo-EM

The sample grids for cryo-electron microscopy (cryo-EM) experiments are usually prepared at a temperature optimal for the storage of biological samples, mostly at 4 &#176;C and occasionally at room temperature. Recently, we discovered that the protein structure solved at low temperature may not be functionally relevant, particularly for proteins from thermophilic archaea. A procedure was developed to prepare protein samples at higher temperatures (up to 70 &#176;C) for cryo-EM analysis. We showed that the structures from samples prepared at higher temperatures are functionally relevant and temperature dependent. Here we describe a detailed protocol for preparing sample grids at high temperature, using 55 &#176;C as an example. The experiment made use of a vitrification apparatus modified using an additional centrifuge tube, and samples were incubated at 55 &#176;C. The detailed procedures were fine-tuned to minimize vapor condensation and obtain a thin layer of ice on the grid. Examples of successful and unsuccessful experiments are provided.

This paper provides a detailed protocol for preparing sample grids at temperatures as high as 70 &#176;C, prior to plunge freezing for cryo-EM experiments.

Forberedelse af højtemperaturprøvegitre til Cryo-EM

The sample grids for cryo-electron microscopy (cryo-EM) experiments are usually prepared at a temperature optimal for the storage of biological samples, ...

The Extraction of Liver Glycogen Molecules for Glycogen Structure Determination

Liver glycogen is a hyperbranched glucose polymer that is involved in the maintenance of blood sugar levels in animals. The properties of glycogen are influenced by its structure. Hence, a suitable extraction method that isolates representative samples of glycogen is crucial to the study of this macromolecule. Compared to other extraction methods, a method that employs a sucrose density gradient centrifugation step can minimize molecular damage. Based on this method, a recent publication describes how the density of the sucrose solution used during centrifugation was varied (30%, 50%, 72.5%) to find the most suitable concentration to extract glycogen particles of a wide variety of sizes, limiting the loss of smaller particles. A 10 min boiling step was introduced to test its ability to denature glycogen degrading enzymes, thus preserving glycogen. The lowest sucrose concentration (30%) and the addition of the boiling step were shown to extract the most representative samples of glycogen.

An optimal sucrose concentration was determined for the extraction of liver glycogen using sucrose density gradient centrifugation. The addition of a 10 min boiling step to inhibit glycogen-degrading enzymes proved beneficial.

Ekstraktionen af leverglykogenmolekyler til bestemmelse af glykogenstruktur

Liver glycogen is a hyperbranched glucose polymer that is involved in the maintenance of blood sugar levels in animals. The properties of glycogen are ...

Preparation of siRNA Mixture for Mitochondrial DNA Synthesis

To begin, prepare a 140 nano molar mix of small interfering RNA or siRNA by diluting the siRNA in optimum medium. Add the five microliters of the diluted mix to the wells of a black 384 well cell culture microplate. Prepare the appropriate amount of RNAiMAX transfection reagent solution in optimum medium and add 10 microliters to each well of the 384 well plate with a reagent dispenser.

Fremstilling af siRNA-blanding til mitokondriel DNA-syntese

Forberedelse af elektronmikroskopigitre til in situ cellulær kryotomografi

Sample Preparation for In Situ Cryotomography of Mammalian Cells

In situ cellular cryotomography is a powerful technique for studying complex objects in their native frozen-hydrated cellular context, making it highly relevant to cellular biology and virology. The potential of combining cryotomography with other microscopy modalities makes it a perfect technique for integrative and correlative imaging. However, sample preparation for in situ cellular tomography is not straightforward, as cells do not readily attach and stretch over the electron microscopy grid. Additionally, the grids themselves are fragile and can break if handled too forcefully, resulting in the loss of imageable areas. The geometry of tissue culture dishes can also pose a challenge when manipulating the grids with tweezers. Here, we describe the tips and tricks to overcome these (and other) challenges and prepare good-quality samples for in situ cellular cryotomography and correlative imaging of adherent mammalian cells. With continued advances in cryomicroscopy technology, this technique holds enormous promise for advancing our understanding of complex biological systems.

Forfatter Spotlight: Optimering af gitterforberedelse til forbedret kryoelektrontomografi 

This method provides an accessible and flexible protocol for the preparation of electron microscopy (EM) grids for in situ cellular cryotomography and correlative light and electron microscopy (CLEM).

Prøveforberedelse til in situ kryotomografi af pattedyrceller

In situ cellular cryotomography is a powerful technique for studying complex objects in their native frozen-hydrated cellular context, making it highly ...