Value-added processing of blackcurrants:use of membrane technologies for clarification and concentration of blackcurrant juice and extraction of anthocyanins from blackcurrant marc

التفاصيل البيبلوغرافية
العنوان:	Value-added processing of blackcurrants:use of membrane technologies for clarification and concentration of blackcurrant juice and extraction of anthocyanins from blackcurrant marc
بيانات النشر:	Oulun yliopisto 2018-11-09
تفاصيل مُضافة:	Keiski, R. (Riitta Liisa) Pongrácz, E. (Eva) Pap, N. (Nora)
نوع الوثيقة:	Electronic Resource
مستخلص:	Blackcurrants (Ribes nigrum L.) are widely consumed due to their favourable taste and health-promoting effects. The berries and extracts from different parts of the plant show anticarcinogenic, antioxidative and anti-inflammatory properties, and are effective in reducing the risk of cardiovascular disease and in promoting brain health. These health-promoting benefits are due to high concentrations of valuable compounds such as anthocyanins and flavonols in blackcurrants. However, these compounds are sensitive to heat and processing and some are lost when the berries are processed into products such as jams, purees and juices. Industrial processing of juices is a multistep process that typically includes enzyme treatment, pressing, pasteurisation, clarification and usually also thermal concentration. Alternative minimal processing technologies are required to preserve the health-promoting compounds in products by avoiding the use of high temperatures and extensive clarification. Integrated membrane technology, i.e. combined ultrafiltration and reverse osmosis, was used in this thesis for the production of blackcurrant juice concentrate. Pre-treatment methods, such as enzymatic treatment, ultrafiltration, enzymatic treatment combined with ultrafiltration and centrifugation to increase the filtration efficiency in reverse osmosis were evaluated. Processing was modelled to define the resistances, using the resistance-in-series model. The preservation and concentration of anthocyanins and flavonols were analysed. The results indicated that the main resistance in the reverse osmosis process was polarisation resistance, while membrane resistance was lower and fouling resistance was one order of magnitude lower than the other resistances. The filtration efficiency results showed that the highest flux was achieved by ultrafiltered blackcurrant juice, but that the resulting juices were substantially lower in anthocyanins and flavonols, which were retained on the ultr Tiivistelmä Mustaherukoita käytetään paljon niiden hyvän maun ja terveyttä edistävien vaikutusten ansiosta. Marjoilla ja marjakasvin eri osien uutteilla on osoitettu olevan antikarsinogeenisia, antioksidatiivisia ja tulehduksia estäviä ominaisuuksia ja ne ovat tehokkaita pienentämään sydän- ja verisuonisairauksia. Ne edistävät myös aivojen terveyttä. Marjojen arvokkailla yhdisteillä kuten antosyanideillä ja flavonoleilla on terveyttä edistäviä vaikutuksia. Mustaherukassa on runsaasti näitä yhdisteitä. Hillojen, soseiden ja mehujen prosessoinnissa menetetään näitä hyödyllisiä yhdisteistä, koska ne ovat herkkiä lämmölle ja prosessoinnin vaikutuksille. Mehujen prosessoinnissa käytetään entsyymikäsittelyjä, puristusta, pastörointia, selkeytystä ja usein myös lämpökonsentrointia. Tuotteiden terveyttä edistävien yhdisteiden säilyttämiseksi tarvitaan uudenlaisia hellävaraisia prosessointitekniikoita ilman korkeita lämpötiloja ja voimakasta selkeyttämistä. Tässä työssä tutkittiin yhdistettyjen kalvotekniikoiden kuten ultrasuodatuksen ja käänteisosmoosin käyttöä mustaherukkatiivistemehun prosessoinnissa. Esikäsittelymenetelmiä, mm. entsyymikäsittelyä, ultrasuodatusta, entsyymikäsittelyn ja ultrasuodatuksen yhdistelmää sekä sentrifugointia, arvioitiin käänteisosmoosin suodatustehokkuuden parantamisessa. Suodatusvastuksen määrittämiseksi prosessi mallinnettiin käyttäen sarja -vastus mallia. Antosyanidien ja flavonolien säilyminen ja konsentroituminen prosesseissa määritettiin. Tulokset osoittivat, että suurin vastus käänteisosmoosissa aiheutui polarisaatiovastuksesta, kun taas kalvon vastus oli pienempi. Mallinnus osoitti myös, että likaantumisen aiheuttama vastus oli yhtä magnitudia alhaisempi kuin muut vastukset. Suodatusteho osoitti, että suurin virtaus saavutettiin ultrasuodatetulla mustaherukkamehulla. Ultrasuodatetussa mehussa oli kuitenkin huomattavasti vähemmän antosyaniineja ja flavonoleja, mikä johtui näiden yhdisteiden tarttumisesta ultrasuodatuskalvoon. Näin ollen
مصطلحات الفهرس:	anthocyanins, blackcurrant, conventional extraction, flavonols, microwave-assisted extraction, reverse osmosis, ultrafiltration, value-added processing, antosyanidit, flavonolit, käänteisosmoosi, lisäarvon tuotto mustaherukkaprosessissa, mikroaaltoavusteinen uutto, tavanomainen uutto, ultrasuodatus, info:eu-repo/semantics/doctoralThesis, info:eu-repo/semantics/publishedVersion
URL:	http://urn.fi/urn:isbn:9789526220840 info:eu-repo/semantics/altIdentifier/pissn/0355-3213 info:eu-repo/semantics/altIdentifier/eissn/1796-2226
الإتاحة:	Open access content. Open access content info:eu-repo/semantics/openAccess © University of Oulu, 2018
ملاحظة:	application/pdf English
أرقام أخرى:	OUX oai:oulu.fi:isbn978-952-62-2084-0 urn:isbn:9789526220840 1061273984
المصدر المساهم:	UNIV OF OULU From OAIster®, provided by the OCLC Cooperative.
رقم الأكسشن:	edsoai.on1061273984
قاعدة البيانات:	OAIster

الوصف
الوصف غير متاح.