Mogućnost primjene bakterije Lactobacillus reuteri, izolirane iz kiselog tijesta, kao dodatka starter-kulturi, radi poboljšanja kakvoće kruha

Retardation of microbial spoilage of bread can be achieved by the use of spontaneous sourdough with an antimicrobial activity. This study was undertaken to identify lactic acid bacteria naturally occurring in spontaneous sourdough and use them for quality improvement and prolonging shelf life of rye, wheat and rye with wheat bread. Identification of isolates from spontaneous sourdough by pyrosequencing assay showed that Lactobacillus reuteri were dominant lactic acid bacteria. The isolates showed a wide range of antimicrobial activity and displayed a synergistic activity against other lactobacilli, some lactococci and foodborne yeasts. The best application of spontaneous sourdough was noticed in the rye bread with the lowest crumb fi rmness of the fi nal product, although the sensory results of wheat and rye with wheat bread did not statistically diff er from control bread. L. reuteri showed a high preserving capacity against fungi during storage. This may be due to bacteriocins and various fatty acids secreted into the growth medium that were identified by agar well diffusion assay and gas chromatography. L. reuteri showing high antimicrobial activity have the potential to be used as a starter additive that could improve safety and/or shelf life of bread.Usporavanje mikrobnog kvarenja kruha može se postići uporabom kiselog tijesta koje ima antimikrobni učinak. U ovom su radu identificirane bakterije mliječno-kiselog vrenja prirodno prisutne u kiselom tijestu, te su upotrijebljene za poboljšanje kakvoće i produljenje trajnosti raženog, bijelog i miješanog raženog kruha. Pirosekvenciranjem su identificirani izolati iz kiselog tijesta, te je utvrđeno da među mliječno-kiselim bakterijama prevladava bakterija Lactobacillus reuteri. Izolati su imali antimikrobni učinak na razne uzročnike kvarenja i sinergistički učinak na druge vrste bakterija Lactobacillus i Lactococcus, te na kvasce. Najbolji je učinak dodatka izolata iz kiselog tijesta postignut u raženom kruhu, koji je imao najmanju tvrdoću mrvica, no senzorska se svojstva bijelog i miješanog raženog kruha, u usporedbi s kontrolnim uzorkom, nisu bitno promijenila. Bakterija L. reuteri učinkovito je spriječila pojavu plijesni na kruhu tijekom skladištenja, vjerojatno zato što je u podlogu za rast lučila bakteriocine, koji su identificirani pomoću metode difuzije u jažicama agara, te razne masne kiseline, određene plinskom kromatografijom. Zaključeno je da L. reuteri ima izražen antimikrobni učinak, pa se može upotrijebiti kao dodatak starter-kulturi radi sprečavanja kvarenja i/ili produljenja trajnosti kruha

Potential of Lactobacillus reuteri from Spontaneous Sourdough as a Starter Additive for Improving Quality Parameters of Bread

Retardation of microbial spoilage of bread can be achieved by the use of spontaneous sourdough with an antimicrobial activity. This study was undertaken to identify lactic acid bacteria naturally occurring in spontaneous sourdough and use them for quality improvement and prolonging shelf life of rye, wheat and rye with wheat bread. Identification of isolates from spontaneous sourdough by pyrosequencing assay showed that Lactobacillus reuteri were dominant lactic acid bacteria. The isolates showed a wide range of antimicrobial activity and displayed a synergistic activity against other lactobacilli, some lactococci and foodborne yeasts. The best application of spontaneous sourdough was noticed in the rye bread with the lowest crumb fi rmness of the fi nal product, although the sensory results of wheat and rye with wheat bread did not statistically diff er from control bread. L. reuteri showed a high preserving capacity against fungi during storage. This may be due to bacteriocins and various fatty acids secreted into the growth medium that were identified by agar well diffusion assay and gas chromatography. L. reuteri showing high antimicrobial activity have the potential to be used as a starter additive that could improve safety and/or shelf life of bread

ß-galactosidase from Penicillium canescens. Properties and immobilization

ß-galactosidase from Penicillium canescens was immobilized on chitosan, sepharose-4B, foamable polyurethane and some other carriers. The highest yield of immobilization (up to 98 %) was obtained by using chitosan as a carrier. The optimum pH and temperature were not significantly altered by immobilization. High stability of immobilized ß-galactosidase during storage was demonstrated. Efficient lactose saccharification (over 90 %) in whey was achieved by using immobilized ß-galactosidase. (C) Central European Science Journals. All rights reserved

Oat β-glucan in milk products: impact on human health

The aim of this study was to determine the impact of the bioactive ingredient – oat β-glucan – on the quality characteristics of the fermented milk products (kefir, yogurt and fermented milk beverages) made on buttermilk-skimmed milk mixture base and establish the influence of the consumption of one of them on the health characteristics of volunteers. The enrichment of fermented milk products with 0.6 % oat β-glucan had no impact on the fermentation time, enhanced the apparent viscosity and changed sensory properties. The experiments of medical nutrition of volunteers showed a significant decrease of total (p<0.05) and low density lipoprotein (p<0.05) cholesterol, increase in high density lipoprotein cholesterol (p<0.01) in their blood after a 21-day period of consumption of fermented product with β-glucan. According to these findings, consumption of fermented milk beverage prepared on the buttermilk-skimmed milk base and enriched with oat β-glucan had a beneficial effect on human health

Effect of NSP degrading enzymes and prebiotics on quality and texture profile of laying hen’s eggs

The trial was conducted to investigate the supplementation of NSP degrading enzymes, prebiotics and its combination on the laying hens’ performance and quality of eggs. Lohman Brown laying hens aged 38 weeks were assigned to 4 dietary treatments for 8 weeks. The dietary treatments were: 1) control (C), 2) compound feed supplemented with enzymes (endo-1,4-β-xylanase 22000 VU/g, endo-1,3(4)-β-glucanase 30000 VU/g and endo-1,4 -β-glucanase (cellulase) 6400 DNS units/g of feed) (E), 3) compound feed with prebiotics (mannanoligosaccharides (MOS) 1.0 kg/t of feed) (P), 4) compound feed with NSP degrading enzymes (endo-1,4-β-xylanase 22000 VU/g, endo-1,3(4)-β-glucanase 30000 VU/g, endo-1,4 -β-glucanase (cellulase) 6400 DNS units/g of feed) and prebiotics (MOS 1.0 kg/t of feed) (EP). All laying hens were kept under the same conditions. Egg’s quality was determined using automatic egg quality analyzer and thickness of eggshell was evaluated with electronic micrometer. The texture characteristics were determined with the universal texture analyzer Instron 3343. Instrumental colour measurements of eggs were performed using a spectrophotometer Konica Minolta. Egg weight of E group was increased by 6%, but feed conversion ratio to produce 1 kg of eggs was decreased by 11%, compared to C group (P<0.05). Enzymes and MOS did not significantly effect egg quality parameters, but in E group shell weight increased by 9% (P<0.05). In addition of enzymes, the hens had produced eggs with higher albumen L* scores (P<0.05). Diet supplementation with enzymes had no significant effects on the yolk colour. In E group of laying hens, the egg mass and egg shell thickness were improved. The addition of enzymes and MOS mixture had highest positive effect on egg quality parameters, but had no statistically significant influence of egg’s texture and colour. Introduction Egg shell quality and egg internal quality are of major importance t

An Inulin-Enriched Soy Drink and Its Lowering Effect on Oxidized Low Density Lipoproteins in Healthy Volunteers

Due to selection of appropriate ingredients and parameters, a microbiologically-safe drink enriched with soy protein isolate (SPI) and prebiotic dietary fiber inulin with high scores of acceptability was produced. The results of medical nutrition survey showed that on the 21 day of using drink the level of oxidized low density lipoproteins (LDL) significantly decreased while the other biochemical parameters of blood of healthy patients as compared to the control tests remained unchanged. As well there was no apparent impact on the intestinal microflora balance of recipients established

Development of a functional whey beverage, containing calcium, vitamin D, and prebiotic dietary fiber, and its influence on human health

This study describes the development of a beverage made from curd whey with addition of functional ingredients and its influence on human healt

An inulin-enriched soy drink and its lowering effect on oxidized low density lipoproteins in healthy volunteers

Due to selection of appropriate ingredients and parameters, a microbiologically-safe drink enriched with soy protein isolate (SPI) and prebiotic dietary fiber inulin with high scores of acceptability was produced. The results of medical nutrition survey showed that on the 21 day of using drink the level of oxidized low density lipoproteins (LDL) significantly decreased while the other biochemical parameters of blood of healthy patients as compared to the control tests remained unchanged. As well there was no apparent impact on the intestinal microflora balance of recipients established