Mogućnost primene okare kao sekundarne sirovine u proizvodnji hraniva za ribe

Poslednjih godina istraživanju soje poklanja se velika pažnja zbog povoljnih zdravstvenih efekata. Mnoge studije su utvrdile u zrnu soje prisustvo komponenti poput proteina, dijetalnih vlakana, masnih kiselina, izoflavona i drugih fitohemikalija, koje povoljno deluju na organizam. Sirova okara, poznata i kao "sojina pulpa", je nusprodukt u priozvodnji sojinog mleka. To je belo-žućkasta materija koja se sastoji od nerastvorljivih delova semena soje (uglavnom semenjače) koji ostaju na filteru pri filtriranju usitnjenog kuvanog zrna soje pri proizvodnji sojinog mleka (Jimenez-Escrig et al., 2008). Cilj ovog rada je bio da se proceni uticaj metoda polupogonskog postrojenja koje koristi hidrotermičku obradu sojinog zrna u proizvodnji sojinog mleka (HTC obrada; visoka temperatura i povišen pritisak/kratko vreme) na sadržaj i aktivnost hranljivih komponenti okare, pripremane od šest različitih genotipova soje, kao i da se proceni mogućnost korišćenja okare u pripremi hrane za ribe. Može se pretpostaviti da će primenjeni HTC postupak, koji je sličan procesu ekstrudiranja, koji se najčešće koriste u proizvodnji hrane za ribe (visoka temperatura/kratako vreme), dati okaru povoljnih svojstava, pogodna za ishranu riba. Pored toga, obzirom da je optimalna pH vrednost vode za uzgoj riba od 7.0 do 8.0 (Zhanga et al., 2011), različita od izoelektrične tačke (Ip) glavnih proteina okare može se pretpostaviti da se proteini okare neće taložiti u mulju, već će ostati da plutaju u vodi. Glavne komponente okare dobijene primenjenim HTC postupkom su ugljeni hidrati (51.25-59.25%) i proteini (31.81-40.36%). Mateos-Aparicio et al. (2010b) ističu veoma povoljnu antioksidativnu aktivnost okare, koju uglavnom pripisuju polisharidima semenjače sojinog zrna, pre svega pektinima, iako ističu da se ne može isključiti ni doprinos belančevina. Ovakva istraživanja ukazuju na mogućnost delovanja okare kao komponete u ishrani riba u smislu odbrane od antioksidativnog stresa. Visok sadržaj proteina, čini okaru potencijalno dobrim izvorom biljnih proteina, niske cene, za ishranu ljudi i životinja. Visok sadržaj i vrlo dobre funkcionalne karakteristike proteina okare (Mateos-Aparicio et al., 2010a), ukazuju na to da mogu biti pogodni kao dopuna hrane za ribu u smislu vezivnog medijuma za druge aktivne i hranljive komponente u proizvodu, pri čemu doprinose nutritivnoj vrednosti hraniva. Štaviše, odnos esencijalnih amino kiselina u ukupnom aminokiselinskom sastavu proteina okare je sličan kao u sojinom mleku i tofuu (Vang i Cavins, 1989). Glavni proteini okare su bazni, 7S globulin (Bg7S; 24.61-28.37%) i glicinin (11S globulin; 28.49-33.11%). Poznato je da je Bg7S glikoprotein bogat cisteinom (Omi et al., 1996) što povećava nutritivnu vrednost proizvoda. Proteini soje nisu nutritivno idealni proteini, obzirom da ispoljavaju neželjeni efekat na metabolizam nakon konzumiranja sirove sojine sačme, što se pripisuje prisustvu tripsin inhibitora (TI) i lektina. Tripsin inhibitorska aktivnost ispitivanih uzoraka je veoma mala (4.82-7.99%) što ukazuje da okara ne bi ispoljavala antinutritivni efekat na organizam, tim pre što se veruje da postizanje zadovoljavajućeg nivoa TIA dovoljno smanjuje aktivnost lektina, obzirom da su inhibitori termički stabilniji nego lektini (Friedman i Brendon, 2001)

Effect of limited hydrolysis on traditional soy protein concentrate

The influence of limited proteolysis of soy protein concentrate on protein extractability, the composition of the extractable proteins, their emulsifying properties and some nutritional properties were investigated. Traditional concentrate (alcohol leached concentrate) was hydrolyzed using trypsin and pepsin as hydrolytic agents. Significant differences in extractable protein composition between traditional concentrate and their hydrolysates were observed by polyacrylamide gel electrophoresis (PAGE) and by SDS-PAGE. All hydrolysates showed better extractability than the original protein concentrate, whereas significantly better emulsifying properties were noticed at modified concentrates obtained by trypsin induced hydrolysis. These improved properties are the result of two simultaneous processes, dissociation and degradation of insoluble alcohol-induced protein aggregates. Enzyme induced hydrolysis had no influence on trypsin-inibitor activity, and significantly reduced phytic acid content

Primarna proteoliza bijelog sira u salamuri proizvedenog od sirovog kravljeg mlijeka praćena visokomolarnim SDS-PAGE elektroforetskim sistemom

The aim of this work was to investigate primary proteolysis of white brined cow cheese prepared from raw milk by SDS-electrophoretic method based on high-molarity Tris buffer system and to correlate with the results of other commonly used parameters. Proteolytic changes of white brined cow cheese were monitored by three parameters: total protein, water soluble proteins and degree of proteolysis. Changes of major casein fractions were followed by SDS-electrophoretic system in reducing conditions. The total protein content and moisture content of white brined cow cheese were significantly affected by ripening. Ripening in brine increased water soluble proteins and degree of proteolysis. Major caseins were differently resistant to proteolysis; αs-CN was more susceptible than β-CN. The αs-CN content was highly and negatively correlated with time of ripening and water soluble proteins whereas no significant correlation (p<0.05) between β-CN content and these parameters was found. Also, a strong significant correlation (p<0.05) between the amount of low molecular weight products and time of ripening, water soluble proteins and αs-CN content was observed. SDS-PAGE method used in this study could be useful for monitoring the white cow cheese proteolysis.Cilj ovog rada bio je istražiti proces primarne proteolize bijelog sira u salamuri pripremljenog od sirovog kravljeg mlijeka metodom SDS-poliakrilamidne gel elektroforeze zasnovane na primjeni visoko molarnog sistema Tris pufera i korelirati s rezultatima uobičajeno korištenih parametara. Proteolitičke promjene bijelog sira u salamuri praćene su pomoću tri parametra: ukupnih proteina, proteina topljivih u vodi i stupnja proteolize. Promjena glavnih kazeinskih frakcija praćena je SDS-elektroforetskom metodom u reducirajućim uvjetima. Zrenje je značajno utjecalo na sadržaj ukupnih proteina i sadržaj vlage u kravljem bijelom siru. Ovaj proces povećao je sadržaj proteina topljivih u vodi i stupanj proteolize. Glavne kazeinske frakcije bile su različito otporne na proteolizu. αs-CN je bio mnogo osjetljiviji na djelovanje proteolitičkih enzima u odnosu na β-CN. Količina αs-CN u jakoj je negativnoj korelaciji sa trajanjem zrenja i proteinima topljivim u vodi, dok nije utvrđena značajna korelacija između sadržaja β-CN i ovih parametara. Također, značajna korelacija utvrđena je između količine produkata male molekulske mase i trajanja zrenja, sadržaja αs-CN i proteina topljivih u vodi. SDS-elektroforetska metoda korištena u ovim istraživanjima može biti korisna za praćenje proteolitičkih promjena tijekom zrenja kravljeg bijelog sira u salamuri

Profile and Functional Properties of Seed Proteins from Six Pea (Pisum sativum) Genotypes

Extractability, extractable protein compositions, technological-functional properties of pea (Pisum sativum) proteins from six genotypes grown in Serbia were investigated. Also, the relationship between these characteristics was presented. Investigated genotypes showed significant differences in storage protein content, composition and extractability. The ratio of vicilin: legumin concentrations, as well as the ratio of vicilin + convicilin: Legumin concentrations were positively correlated with extractability. Our data suggest that the higher level of vicilin and/or a lower level of legumin have a positive influence on protein extractability. The emulsion activity index (EAI) was strongly and positively correlated with the solubility, while no significant correlation was found between emulsion stability (ESI) and solubility, nor between foaming properties and solubility. No association was evident between ESI and EAI. A moderate positive correlation between emulsion stability and foam capacity was observed. Proteins from the investigated genotypes expressed significantly different emulsifying properties and foam capacity at different pH values, whereas low foam stability was detected. It appears that genotype has considerable influence on content, composition and technological-functional properties of pea bean proteins. This fact can be very useful for food scientists in efforts to improve the quality of peas and pea protein products

Biologically active components of soybeans and soy protein products: A review

Soybeans provide a source of low-cost protein with good nutritional and physico-chemical properties. Recently, soybean has received much attention because of its potential role in preventing and treating several diseases including cancer and other human chronic diseases. Health benefits of soy diet are attributed to the minor soybean constituents (calledphytochemicals). Soybean contains a variety of phytochemicals with demonstrated anticancer activity, including bioactive proteins andpolypeptides (trypsin inhibitors and the most recently discoveredpeptide lunasin), isofl avones, phytic acid, phytosterols and saponins. The present review provides an overview of recent knowledge about biologically active components of soybean.Soja predstavlja dobar izvor nutritivno visokovrednih proteina pogodnih fizičko-hemijskih osobina. Danas se soji poklanja velika pažnja kao potencijalno značajnom izvoru komponenti koje mogu imati ulogu u prevenciji i lečenju nekih hroničnih i teških bolesti, kao što su bolesti srca i različiti oblici kancera. Pozitivni efekti ishrane sojom pripisuju se manje zastupljenim biološki aktivnim komponentama sojinog semena. Ove supstance u literaturi se često nazivaju i "fitohemikalijama". Soja sadrži ceo spektar biološki aktivnih supstanci koje ispoljavaju antikancerogena svojstva poput bioaktivnih proteina i polipeptida (inhibitori proteaza, lektin i najnovije detektovani polipeptid - lunasin), fitinska kiselina, izoflavoni, fitosteroli i saponini. Ovaj rad daje pregled današnjih saznanja o biološki aktivnim komponentama zrna soje i proteinskih proizvoda od soje

The effect of autoclaving on soluble protein composition and trypsin inhibitor activity of cracked soybeans

The effects of autoclaving conditions (heating for 5, 10 and 15 minutes at 0.5 bars over pressure) and oil-extracting temperatures (40°C, 60°C) on protein content, composition, and inhibitor activity of cracked soybeans were investigated. The results obtained indicated that oil-extracting method and heat treatment had significant influence on soluble protein content and composition. Raw soybean samples defatted at lower temperature had better solubility (535.42±2.10 mg/g) than those obtained by the Soxhlet procedure (345.53±2.80). The same results were obtained for nitrogen solubility index. Autoclaving combined with two oil-extraction methods decreased protein solubility to 180.32±1.50 -245.41±1.41 mg/g, while the dominant component of heat treated flours was 11S fraction. High content of glycinin fraction (44.59-41.10%) implies the possible use of treated samples in food industry. Residual activity of treated samples was 43.40-84.26%. Kunitz inhibitor (KTI) was responsible for residual inhibitor activity.Ispitivan je uticaj termičke obrade lomljenog zrna u autoklavu pri nadpritisku od 0.5 bara i temperaturi od 96°C u toku 5, 10 i 15 minuta, kao i efekat ekstrakcije ulja pri temperaturama od 40 i 60°C na sadržaj i sastav rastvorljivih proteina i tripsin inhbitorsku aktivnost. Dobijeni rezultati ukazuju da ovi tretmani imaju značajan uticaj na sadržaj i sastav rastvorljivih proteina. Netretirani uzorci odmašćeni pri nižim temperaturama karakterišu se većim sadržajem rastvorljivih proteina od uzoraka odmašćenih pri 60°C. Tretman u autoklavu kombinovan sa dva različita postupka ekstrakcije ulja redukuje sadržaj proteina rastvorljivih u puferu pH 8.0 do 180.32±1.50 -245.41±1.41 mg/g. Rezervni proteini soje ispoljili su različitu stabilnost tokom obrade. Najosetljivijim su se pokazale komponente 7S frakcije. Rezidualna inhibitorska aktivnost tretiranih uzoraka je 43.40-84.26%, pri čemu je KTI okarakterisan kao nosilac te aktivnosti

Distribution of β-amylase and lipoxygenase in soy protein products obtained during tofu production

Soybean is considered an important source of human food and animal feed. Okara and tofu whey are the main by-products of soymilk and tofu production. The distribution of enzymes beta-amylase and lipoxygenase (Lox) from six soybean genotypes in protein extracts of okara and tofu as well as in soymilk and tofu whey was assessed. SDS-electrophoretic results showed that production process significantly affected high molecular mass protein fractions of soybean by-products. Low amounts of Lox in soymilk were registered, while in okara protein extracts and tofu whey this enzyme was present in trace. In tofu protein extracts, Lox was registered in higher quantity that might be the result of the aggregation process during formation of the tofu gel. Content of beta-amylase in all soy protein products was high and similar to the content in soybean genotype. Content of beta-amylase in okara depended on respective soybean genotype

Full Paper Effect of Limited Hydrolysis on Traditional Soy Protein Concentrate

Abstract: The influence of limited proteolysis of soy protein concentrate on protein extractability, the composition of the extractable proteins, their emulsifying properties and some nutritional properties were investigated. Traditional concentrate (alcohol leached concentrate) was hydrolyzed using trypsin and pepsin as hydrolytic agents. Significant differences in extractable protein composition between traditional concentrate and their hydrolysates were observed by polyacrylamide gel electrophoresis (PAGE) and by SDS-PAGE. All hydrolysates showed better extractability than the original protein concentrate, whereas significantly better emulsifying properties were noticed at modified concentrates obtained by trypsin induced hydrolysis. These improved properties are the result of two simultaneous processes, dissociation and degradation of insoluble alcohol-induced protein aggregates. Enzyme induced hydrolysis had no influence on trypsin-inibitor activity, and significantly reduced phytic acid content