Produçăo de enzimas amilolíticas fúngicas a-amilase e amiloglucosidase por fermentaçăo no estado sólido /

Orientador: Carlos Ricardo SoccolCo-orientadoras: Adenise Woiciechowsk e Luciana P. S. VandenbergheDissertaçăo (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduaçăo em Tecnologia de Alimentos. Defesa: Curitiba, 2005Inclui bibliografia e anexo

Brine Solution with Hydrocolloids Used to Enhance the Properties of Sterilized Meat

Pozadina istraživanja. Obrada u tlačnoj posudi, tzv. retorti, jedna je od najčešćih metoda toplinske inaktivacije koja se koristi u proizvodnji gotove hrane. Iako je ova tehnologija vrlo rasprostranjena, njezina se primjena može modernizirati pomoću novih sastojaka, kao što su gume. Svrha je ovoga rada bila ispitati utjecaj dodatka hidrokoloida, i to kolagena, izolata proteina soje, karagenana i modificiranog škroba te različitih masenih udjela soli na mesne proizvode obrađene u tlačnoj posudi. Eksperimentalni pristup. Prvo su ispitane otopine različitih masenih udjela soli s dodatkom hidrokoloida za određivanje učinka soljenja. Zatim su tijekom skladištenja radi odabira najboljeg postupka obrade ispitani sljedeći parametri: oksidacija lipida, sinereza i aktivitet vode. Naposljetku su ispitana senzorska i teksturna svojstva proizvoda radi utvrđivanja učinka dodanih hidrokoloida. Rezultati i zaključci. Primjenom većih masenih udjela soli uz dodatak hidrokoloida dobiveni su bolji rezultati prinosa, kala kuhanja i sposobnosti zadržavanja vode. Fizikalno-kemijska svojstva kolagena razlikovala su se od ostalih ispitanih hidrokoloida. Vrijednosti sinereze ostale su slične neovisno o postupku obrade. Također nisu opažene razlike niti u vrijednostima aktiviteta vode. Međutim, nakon sterilizacije, vakumiranja i dodatka hidrokoloida smanjila se oksidacija svih uzoraka. Naposljetku, ispitivanja senzorskih i teksturnih svojstava te smične sile potvrdila su da su proizvodi s dodatkom kolagena bili čvršći i tvrđi od kontrolnog uzorka, koji je zbog toga dobio bolje ocjene. Usprkos tome, panelisti nisu opazili prisutnost kolagena u uzorcima. Novina i znanstveni doprinos. Obradom mesa u tlačnoj posudi u kombinaciji s dodatkom hidrokoloida salamuri poboljšana su njegova fizikalno-kemijska i senzorska svojstva.Research background. Retort processing is one of the most widely used methods of thermal inactivation that provides convenient, ready-to-eat foods. Although this technology remains widespread, it can be revamped through processing of novel ingredients such as gums. This article aims to investigate the effect of the hydrocolloids collagen, soy protein isolate, carrageenan and modified starch with different salt mass fractions on the retorted meat products. Experimental approach. Firstly, solutions of the added hydrocolloids of different salt mass fractions in order to stimulate the salting-in effect were studied. Lipid oxidation, syneresis and water activity were analysed during shelf life to find the best overall treatments. Lastly, sensory and texture analyses were then performed to assess the impact of the added hydrocolloids. Results and conclusions. Yield, cooking loss and water-holding capacity had better results when higher salt mass fractions with hydrocolloids were used. The physicochemical results distinguished collagen from the other tested hydrocolloids. Syneresis remained in similar ranges regardless of the treatment. No difference was observed in water activity either. However, sterilization, vacuum sealing and the addition of a hydrocolloid contributed to low oxidation levels in all treatments. Lastly, sensory, texture and shear force analyses confirmed that the products with collagen were harder and firmer than the control samples, which explains the preference of control samples by the panellists. Nevertheless, assessors did not perceive the presence of collagen. Novelty and scientific contribution. Physicochemical and sensory characteristics of the retorted meat can be considerably improved when brine and hydrocolloids are combined with the retort technology

Analysis of inducers of xylanase and cellulase activities production by Ganoderma applanatum LPB MR-56

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Primjena lančane reakcije polimerazom za određivanje genetski modificiranog zrnja soje sorte Roundup ReadyTM u smjesi s drugim sortama

Strong increase in the production of genetically modified organisms (GMOs) observed over the years has led to a consolidation of transgenic seed industries worldwide. The dichotomy between the evaluated risk and the perceived risk of transgenic use has defined their level of acceptability among different global societies. GMOs have been widely applied to agricultural commodities, among them the Roundup Ready™ (RR™) soybean line GTS 40-3-2 has become the most prevalent transgenic crop in the world. This variety was developed to confer plant tolerance against glyphosate-based agricultural herbicide Roundup Ready™. Issues related to detection and traceability of GMOs have gained worldwide interest due to their increasing global diffusion and the related socioeconomic and health implications. Also, due to the widespread use of GMOs in food production, labelling regulations have been established in some countries to protect the right of consumers and producers. Besides regulatory demand, consumer concern issues have resulted in the development of several methods of detecting and quantifying foods derived from genetically engineered crops and their raw materials. Polymerase chain reaction (PCR) has been proven to be the method of choice to detect the presence or absence of the introduced genes of GMOs at DNA level. The present paper aims to verify whether the PCR technique can detect RR™ soybean seeds among conventional ones to further certification as non-GM soybean seeds and grains. This analysis could be accomplished through the development of new methodology called \u27intentional contamination\u27 of soybean conventional seeds or grains with the respective RR™ soybeans. The results show that the PCR method can be applied with high sensitivity in order to certify conventional soybean seeds and grains.Povećana je proizvodnja genetski modificiranog organizama uzrokovala konsolidaciju industrije transgenog sjemena diljem svijeta. Dihotomija između procijenjenog i opaženog rizika uporabe transgenog sjemena odredila je razinu njegove prihvatljivosti u različitim društvenim zajednicama. Genetski se modificirani organizmi već uvelike primjenjuju u poljoprivredi, a Roundup ReadyTM (RRTM) linija soje GTS 40-3-2 prevladavajući je transgeni usjev u svijetu. Ova je sorta razvijena da bi stekla otpornost na glifosatni herbicid Roundup ReadyTM. Određivanje i sljedivost genetski modificiranih organizama (GMO) vrlo je važno jer se GMO sve više koristi, a njegova primjena ima socioekonomske i zdravstvene posljedice. Također se zbog raširene uporabe GMO u proizvodnji hrane u nekim zemljama uvela obveza označavanja proizvoda radi zaštite prava proizvođača i potrošača. Osim zahtjeva za regulativom, potrošači traže i nadzor nad GMO, pa je razvijeno nekoliko metoda za detekciju i kvantificiranje hrane koja potječe iz transgenih usjeva i sirovina. Lančana reakcija polimerazom (PCR) najbolja je metoda za detekciju introduciranih gena GMO na razini DNK. Stoga je u radu istraženo može li PCR metoda odrediti zrna RRTM soje među konvencionalnim zrnjem, te može li se primijeniti za certifikaciju sjemena koje nije genetski modificirano. Postupak se sastoji od namjerne kontaminacije konvencionalnog sjemena zrnjem RRTM soje i određivanja GMO zrnja PCR metodom. Utvrđeno je da se ova metoda s visokom sigurnošću može primijeniti pri certifikaciji konvencionalnog sjemena

Proizvodnja fitaze fermentacijom pulpe citrusa i drugih ostataka agroindustrije s pomoću izolata gljiva

Phytases have important applications in human and animal nutrition because they hydrolyze the phytate present in legumes, cereal grains and oil seeds. This results in an increased availability of minerals, trace elements and amino acids as well as phosphate. Fifty potential phytase-producing fungal strains were isolated from a fertile soil obtained from the northern part of Paraná State in Brazil and other alternative sources using a selective media. Thereafter phytase production was evaluated in solid-state fermentation using different residues from the agroindustry supplemented with a nitrogen source at 60 % of moisture after 96 hours at 30 °C. The highest phytase activity (51.53 units per gram of dry substrate, U/g) was achieved with citric pulp and the soil isolate FS3 in solid-state fermentation. Furthermore, treatment of the substrates prior to fermentation in order to reduce microbial contamination was shown to affect phytase production during solid-state fermentation. Heat treatment resulted in an increase of the concentration of inorganic phosphate, a well known repressor of microbial phytase production, and therefore in a reduction of phytase production. UV exposure of the substrate was shown to reduce microbial contamination without affecting phytase production.Fitaze imaju važnu ulogu u prehrani ljudi i životinja jer hidroliziraju fitate leguminoza, zrnja žitarica i sjemenki uljarica, pa tako povećavaju pristupačnost minerala, elemenata u tragovima, aminokiselina i fosfata. Iz plodnog tla sjevernog dijela brazilske države Paraná, a i iz drugih izvora, na selektivnim podlogama izolirano je 50 sojeva gljiva koje mogu proizvesti fitaze. Nakon toga je proizvodnja fitaze ispitana uzgojem na čvrstoj podlozi od raznih ostataka agroindustrije, uz dodatak izvora dušika, pri 60 %-tnoj vlažnosti i 30 °C tijekom 96 sati. Najveća aktivnost fitaze (51,53 U/g suhe tvari) dobivena je uzgojem izolata FS3 iz tla na pulpi citrusa. Obrada supstrata prije procesa, radi smanjenja onečišćenja mikroorganizmima, utjecala je na proizvodnju fitaze. Toplinskom obradom povećala se koncentracija anorganskog fosfata, koji suzbija mikrobiološku proizvodnju fitaze. Izloženost supstrata UV-zrakama smanjuje onečišćenje mikroorganizmima, a pritom ne utječe na proizvodnju fitaze

Mogućnosti primjene probiotika

Probiotics, live cells with different beneficiary characteristics, have been extensivelly studied and explored commercially in many different products in the world. Their benefits to human and animal health have been proven in hundreds of scientific research. Lactobacillus and Bifidobacterium are the main probiotic groups; however, there are reports on the probiotic potential of Pediococcus, Lactococcus, Bacillus and yeasts. Some of the identified probiotic strains exhibit powerful anti-inflammatory, antiallergic and other important properties. Apart from that, the consumption of dairy and non-dairy products stimulates the immunity in different ways. Various food matrices have been used with probiotics, which are briefly documented. In this review, the history of probiotics, their application in the health and food areas and new trends in probiotic products and processes are presented.Probiotici su žive stanice koje imaju različite pozitivne osobine, pa se intenzivno proučavaju i komercijalno primjenjuju u mnogim proizvodima diljem svijeta. U više stotina znanstvenih istraživanja dokazan je njihov pozitivan učinak na zdravlje ljudi i životinja. Glavne su skupine probiotika bakterije vrste Lactobacillus i Bifidobacterium, ali spominju se i probiotička svojstva bakterija vrsta Pediococcus, Lactococcus i Bacillus, te nekih kvasaca. Neki od identificiranih probiotičkih sojeva imaju izraženi protuupalni i antialergijski učinak, pa se konzumiranjem probiotičkih mliječnih i nemliječnih proizvoda povećava imunitet. U radu su ukratko spomenute razne namirnice što se koriste u kombinaciji s probioticima. Također je dan povijesni pregled razvoja probiotika, navedene su mogućnosti njihove primjene u prehrambenoj industriji, a i u zdravstvu, te prikazani novi pravci proizvodnje probiotičkih proizvoda