Irena Barukčić | University of Zagreb (original) (raw)
Papers by Irena Barukčić
Whey originates from cheese or casein production and can be defined as a yellowish-greenish liqui... more Whey originates from cheese or casein production and can be defined as a yellowish-greenish liquid that remains after casein coagulation by enzymes and/or acids [1]. Milk production and processing is increasing continuously, with cheese making being the most abundant dairy product. Consequently, there are growing amounts of the produced whey [2]. Depending on the type of casein coagulation, whey can be acid or sweet. On average whey contains approximately 93% of water and 6-7% solids. Besides the differences in acidity, the proportions of certain constituents such as calcium or the present whey protein fractions are also distinct. Nevertheless, lactose is the main constituent of the whey dry matter (70%) and recovers almost entirely from the used milk. Whey proteins, minerals, milk fat and minor components like water soluble vitamins are present in moderate to low amounts [1,3].
Zbog brojnih fizioloskih i funkcionalnih svojstava proteina sirutke te nedostatka metoda industri... more Zbog brojnih fizioloskih i funkcionalnih svojstava proteina sirutke te nedostatka metoda industrijskih razmjera za frakcioniranje istih, cilj ovoga r
Kakvoća meda znatno utječe na njegovu uporabu i važnost u prehrani. Kod utvrđivanja kakvoće meda ... more Kakvoća meda znatno utječe na njegovu uporabu i važnost u prehrani. Kod utvrđivanja kakvoće meda potrebno je odrediti njegova fizikano-kemijska svojstva. Ona ovise o brojnim čimbenicima kao što su botaničko i geografsko porijeklo, klimatski uvjeti, način prerade, uvjeti i duljina skladištenja. U ovom radu su određeni maseni udjeli hidroksimetilfurfurala (HMF-a) i prolina na 132 uzorka i 16 različitih vrsta meda sa područja Hrvatske i Slovenije. Pri tom su dobiveni sljedeći rezutati: maseni udio HMF-a kretao se između 1,54 i 104,48 mg/kg , dok je maseni udio prolina bio u rasponu od 51,74 do 850,28 mg/kg. Razlike među uzorcima unutar iste vrste meda bile su znatne, a medovi različitog botaničkog porijekla su također pokazali razlike. 39 ispitanih uzoraka ne zadovoljava zahtjev Pravilnika o kakvoći meda i drugih pčelinjih proizvoda za dozvoljeni maseni udio HMF-a, a 23 ispitana uzorka ne zadovoljavaju dodatni kriterij IHC-a za dozvoljeni udio prolina.Honey quality has a geat influence...
Mljekarstvo, 2015
Pregledni rad-Review UDK: 637.13 Utjecaj ultrazvuka visokog intenziteta na fermentaciju mlijeka b... more Pregledni rad-Review UDK: 637.13 Utjecaj ultrazvuka visokog intenziteta na fermentaciju mlijeka bifidobakterijama Uvod Probiotik se definira kao: "jedna ili više kultura živih stanica mikroorganizama koje primijenjene u ljudi ili životinja djeluju korisno na domaćina poboljšavajući svojstva autohtone mikroflore probavnog sustava domaćina" (Š uško vi ć, 1996). Znanstveni temelji izučavanja i razvoja probiotičkih bakterija polaze od spoznaje da je crijevna mikroflora uključena u zaštitu "domaćina" (čovjeka ili životinje) od naseljavanja probavnog sustava neautohtonim mikroorganizmima. Zbog mnogih pogodnosti za ljudsko zdravlje svrstane su u funkcionalnu hranu. Probiotičke bakterije se najčešće nalaze u fermentiranim mliječnim proizvodima. Razmnožavanje probiotičkih bakterija tijekom fermentacije, kao i preživljavanje stanica tijekom skladištenja proiz
Científic@ - Multidisciplinary Journal, 2018
The functional foods present many health benefits besides their nutritional values pertinent to t... more The functional foods present many health benefits besides their nutritional values pertinent to their chemical composition. They can play an important role on reducing the risk of chronic-degenerative diseases, like cancer, diabetes and others. The prebiotics are non-digestive fibers by the human body, but they increase the intestinal bacterial flora. Among these prebiotics are the fructooligosaccharides. This research aims to evaluate the physical-chemical, microbiological and sensory properties of fructooligosaccharides enriched yogurt. Sensory analysis was performed with 50 non-trained panelists using a structured nine point Hedonic scale for acceptance and buying intention. Microbiological (thermo-tolerant coliforms and salmonella sp/25g) and physical-chemical analyses (pH, titratable acidity expressed as, lactic acid concentration, and soluble solids as °Brix) were carried out in triplicate. All results were submitted to ANOVA and Tukey Test at 5 % of significance to verify the...
Mikrofiltracija i ultrafiltracija otvaraju nove mogućnosti iskorištavanja sirutke u prehrambene s... more Mikrofiltracija i ultrafiltracija otvaraju nove mogućnosti iskorištavanja sirutke u prehrambene svrhe. Njihovom primjenom osigurava se mikrobiološka kvaliteta i očuvanje hranjive vrijednosti proizvoda, a glavni nedostatak je pojava začepljivanja membrana. Stoga je svrha ove disertacije optimirati proces mikrofiltracije sirutke kao alternativnog postupka pasterizaciji uz očuvanje nativnih proteina sirutke te ispitati njezin utjecaj kao predtretmana sa ciljem povećanja djelotvornosti ultrafiltracije. Filtracije su provedene pri različitim procesnim temperaturama (20ºC, 40ºC, 50ºC) korištenjem keramičkih membrana različitih graničnih vrijednosti zadržavanja (0,1 μm, 0,5 μm , 0,8 μm, 20 kDa). Izuzetim uzorcima određivana je mikrobiološka kvaliteta te fizikalno kemijska svojstva. Mikrofiltracija primjenom membrana promjera pora 0,5 μm i 0,8 μm pokazala je dobar učinak na očuvanje prehrambene vrijednosti sirutke. Stupanj redukcije prisutnih mikroorganizama opada razmjerno veličini promjera pora primijenjenih membrana. Bez obzira na procesnu temperaturu, membrana od 0,5 μm se pokazala optimalnom u smislu očuvanja hranjive vrijednosti i redukcije pristunih mirkoorganizama. Prema svim praćenim parametrima, ultrafiltracija pri 20°C se pokazala najpovoljnijim režimom za obradu svježe sirutke. Predtretman mikrofiltracijom primjenom membrana promjera pora 0,8 μm nije povećao djelotvornost procesa ultrafiltracije, bez obzira na procesnu temperaturu. Predtretman mikrofiltracijom primjenom membrana promjera pora 0,5 μm povećao je djelotvornost procesa ultrafiltracije, što se očituje prvenstveno u povećanju fluksa permeata i smanjenu formiranih otpora prema začepljivanju. Navedene promjene intenzivinije su pri procesnoj temperaturi od 20ºC.Microfiltration and ultrafiltration enable new opportunities of whey utilization in human nutrition. The implementation of these processes ensures appropriate microbiological quality and the preservation of the nutritional value of the product. The main disadvantage is the phenomenon of membrane fouling. The aim of this dissertation was to optimize the process of whey microfiltration in order to ensure aduequate micorbiological quality, to preserve the native whey proteins and to be tesetd as a pretreatment for enhancement of the ultrafiltration process. The filtrations were performed at different process temperatures (20ºC, 40ºC, 50ºC) by using ceramic membranes with different cut-offs (0,1 μm, 0,5 μm , 0,8 μm, 20 kDa). All samples of whey were analized for microbiological quality, physical and chemical properties. Microfiltration by ceramic membranes with mean pore diameter of 0,5 μm and 0,8 μm allowed preservation of the native wehy proteins. Microbial reduction rates decreased proportionally with the mean pore diameter of the used membranes. Regardless the process temperature, the membrane with mean pore diameter of 0,5 μm appeared to be optimal for purposes of preserving the nutritional value and achieveing proper micribiological quality of whey. According to all measured parameters, ultrafiltration process at 20ºC appeared to be the most appropriate for whey processing. Microfiltration of whey by ceramic membrane with the mean pore diameter of 0,8 μm didn´t significantly affect the efficiency of the ultrafiltration, regardless the process temperature. Microfiltration of whey by ceramic membranes with the mean pore diameter of 0,5 μm affected the efficiency of whey ultrafiltration by siginificantly increasing the permeate flux and reducing the fouling resistance. The described effects are more intensive at the process temperature of 20ºC
Hrvatski časopis za prehrambenu tehnologiju, biotehnologiju i nutricionizam
Jestivi se filmovi i premazi sve više koriste u proizvodnji sireva zbog zahtjeva potrošača za pri... more Jestivi se filmovi i premazi sve više koriste u proizvodnji sireva zbog zahtjeva potrošača za prirodnim i ekološki prihvatljivim pakovinama. U radu je prikazano što su jestivi filmovi i prevlake, od kojih se materijala mogu proizvoditi i koje prednosti nude pri proizvodnji sira. Materijali koji pokazuju veliki potencijal za moguću komercijalnu proizvodnju u budućnosti su galaktomanani, kitozan, škrob, alginati i proteini sirutke. Jestivi filmovi i prevlake od navedenih materijala mogu produljiti rok trajanja sira te poboljšati kvalitetu sira, a pružaju i mogućnost ugradnje antimikrobnih sredstava koja djeluju kao dodatna zaštita protiv mikroorganizama uzročnika kvarenja sira.
Fermentation
Background: Fermented dairy products are known for their many positive effects on human health an... more Background: Fermented dairy products are known for their many positive effects on human health and are consumed worldwide. The supplementation of food with plant extracts as sources of valuable nutritional compounds has recently gained a lot of attention. Milk and fermented products are deficient in bioactive components such as phenolic compounds and iron. Moringa oleifera leaf extract is rich in vitamins, minerals (iron), polyphenols, flavonoids, tannins and proteins. Its addition to milk before fermentation might represent an excellent way to enrich fermented milk products. Methods: Yoghurts enriched with moringa extract (ME) (1, 3 and 4-%, v/v) were produced and compared to a control yoghurt without ME. In all samples, acidity, microbiological parameters, syneresis and water holding capacity, rheology parameters, total colour difference, mineral content, total phenols and antioxidant capacity (FRAP method) and sensory properties were determined. Results: The addition of ME to mil...
Zbornik sažetaka 42. Hrvatskog simpozija mljekarskih stručnjaka s međunarodnim sudjelovanjem, 2016
British Food Journal, 2021
PurposeIn the past two decades the popularity of artisan cheese emerged. The present study aimed ... more PurposeIn the past two decades the popularity of artisan cheese emerged. The present study aimed to investigate similarities and differences in beliefs towards artisan cheeses among participants from Serbia, Croatia and Spain and to determine consumer profiles. Better understanding of their behaviours and beliefs could serve as the basis for the development of appropriate production and marketing strategies and for further popularisation of artisan cheeses.Design/methodology/approachThe data on demographic structure, behaviours and beliefs of 947 participants in total were obtained via a questionnaire collected online. In order to identify consumer profiles and to define their specific beliefs, a cross-country cluster analysis has been conducted. Four clusters were identified: “highly educated men”, “highly educated women”, “millennials” and “educated senior women”. Mann–Whitney U test was used to identify statistically significant differences between countries and clusters.Findings...
Journal of Dairy Research, 2019
The experiments reported in this research paper examine the potential of digestion using acidic e... more The experiments reported in this research paper examine the potential of digestion using acidic enzymes Protease A and Protease M to selectively hydrolyse α-lactalbumin (α-La) whilst leaving β-lactoglobulin (β-Lg) relatively intact. Both enzymes were compared with pepsin hydrolysis since its selectivity to different whey proteins is known. Analysis of the hydrolysis environment showed that the pH and temperature play a significant role in determining the best conditions for achievement of hydrolysis, irrespective of which enzyme was used. Whey protein isolate (WPI) was hydrolysed using pepsin, Acid Protease A and Protease M by randomized hydrolysis conditions. Reversed-phase high performance liquid chromatography was used to analyse residual proteins. Regarding enzyme selectivity under various milieu conditions, all three enzymes showed similarities in the reaction progress and their potential for β-Lg isolation.
Fermentation
Various factors affect rennet coagulation and consequently cheese yield, but the subject of resea... more Various factors affect rennet coagulation and consequently cheese yield, but the subject of research has been mainly the cow milk. For the purpose of goat cheese production optimization, this paper investigated the influence of enzyme concentration (0.01–0.054 g/L), pH (6.5–6.1) and temperature (27–35 °C) on rennet coagulation of goat milk. Coagulation time (RCT), aggregation rate (AR), and gel firmness (G’60 and GF), were measured by oscillatory rheometry. The decrease in rennet concentration extended RCT. At lower rennet concentrations, a lower AR was recorded, which ranged from 0.02 Pa/s to 0.05 Pa/s. The decrease in pH from 6.5 to 6.1 caused a two times shorter RCT, and a two times faster AR. There was no effect of pH on the firmness of the rennet gel. The increase in coagulation temperature from 27 °C to 35 °C reduced the RCT of pasteurized milk from 12.6 min to 8.6 min, and caused a linear increase in the AR, but did not significantly affect the firmness of the gel. The presen...
Whey originates from cheese or casein production and can be defined as a yellowish-greenish liqui... more Whey originates from cheese or casein production and can be defined as a yellowish-greenish liquid that remains after casein coagulation by enzymes and/or acids [1]. Milk production and processing is increasing continuously, with cheese making being the most abundant dairy product. Consequently, there are growing amounts of the produced whey [2]. Depending on the type of casein coagulation, whey can be acid or sweet. On average whey contains approximately 93% of water and 6-7% solids. Besides the differences in acidity, the proportions of certain constituents such as calcium or the present whey protein fractions are also distinct. Nevertheless, lactose is the main constituent of the whey dry matter (70%) and recovers almost entirely from the used milk. Whey proteins, minerals, milk fat and minor components like water soluble vitamins are present in moderate to low amounts [1,3].
Zbog brojnih fizioloskih i funkcionalnih svojstava proteina sirutke te nedostatka metoda industri... more Zbog brojnih fizioloskih i funkcionalnih svojstava proteina sirutke te nedostatka metoda industrijskih razmjera za frakcioniranje istih, cilj ovoga r
Kakvoća meda znatno utječe na njegovu uporabu i važnost u prehrani. Kod utvrđivanja kakvoće meda ... more Kakvoća meda znatno utječe na njegovu uporabu i važnost u prehrani. Kod utvrđivanja kakvoće meda potrebno je odrediti njegova fizikano-kemijska svojstva. Ona ovise o brojnim čimbenicima kao što su botaničko i geografsko porijeklo, klimatski uvjeti, način prerade, uvjeti i duljina skladištenja. U ovom radu su određeni maseni udjeli hidroksimetilfurfurala (HMF-a) i prolina na 132 uzorka i 16 različitih vrsta meda sa područja Hrvatske i Slovenije. Pri tom su dobiveni sljedeći rezutati: maseni udio HMF-a kretao se između 1,54 i 104,48 mg/kg , dok je maseni udio prolina bio u rasponu od 51,74 do 850,28 mg/kg. Razlike među uzorcima unutar iste vrste meda bile su znatne, a medovi različitog botaničkog porijekla su također pokazali razlike. 39 ispitanih uzoraka ne zadovoljava zahtjev Pravilnika o kakvoći meda i drugih pčelinjih proizvoda za dozvoljeni maseni udio HMF-a, a 23 ispitana uzorka ne zadovoljavaju dodatni kriterij IHC-a za dozvoljeni udio prolina.Honey quality has a geat influence...
Mljekarstvo, 2015
Pregledni rad-Review UDK: 637.13 Utjecaj ultrazvuka visokog intenziteta na fermentaciju mlijeka b... more Pregledni rad-Review UDK: 637.13 Utjecaj ultrazvuka visokog intenziteta na fermentaciju mlijeka bifidobakterijama Uvod Probiotik se definira kao: "jedna ili više kultura živih stanica mikroorganizama koje primijenjene u ljudi ili životinja djeluju korisno na domaćina poboljšavajući svojstva autohtone mikroflore probavnog sustava domaćina" (Š uško vi ć, 1996). Znanstveni temelji izučavanja i razvoja probiotičkih bakterija polaze od spoznaje da je crijevna mikroflora uključena u zaštitu "domaćina" (čovjeka ili životinje) od naseljavanja probavnog sustava neautohtonim mikroorganizmima. Zbog mnogih pogodnosti za ljudsko zdravlje svrstane su u funkcionalnu hranu. Probiotičke bakterije se najčešće nalaze u fermentiranim mliječnim proizvodima. Razmnožavanje probiotičkih bakterija tijekom fermentacije, kao i preživljavanje stanica tijekom skladištenja proiz
Científic@ - Multidisciplinary Journal, 2018
The functional foods present many health benefits besides their nutritional values pertinent to t... more The functional foods present many health benefits besides their nutritional values pertinent to their chemical composition. They can play an important role on reducing the risk of chronic-degenerative diseases, like cancer, diabetes and others. The prebiotics are non-digestive fibers by the human body, but they increase the intestinal bacterial flora. Among these prebiotics are the fructooligosaccharides. This research aims to evaluate the physical-chemical, microbiological and sensory properties of fructooligosaccharides enriched yogurt. Sensory analysis was performed with 50 non-trained panelists using a structured nine point Hedonic scale for acceptance and buying intention. Microbiological (thermo-tolerant coliforms and salmonella sp/25g) and physical-chemical analyses (pH, titratable acidity expressed as, lactic acid concentration, and soluble solids as °Brix) were carried out in triplicate. All results were submitted to ANOVA and Tukey Test at 5 % of significance to verify the...
Mikrofiltracija i ultrafiltracija otvaraju nove mogućnosti iskorištavanja sirutke u prehrambene s... more Mikrofiltracija i ultrafiltracija otvaraju nove mogućnosti iskorištavanja sirutke u prehrambene svrhe. Njihovom primjenom osigurava se mikrobiološka kvaliteta i očuvanje hranjive vrijednosti proizvoda, a glavni nedostatak je pojava začepljivanja membrana. Stoga je svrha ove disertacije optimirati proces mikrofiltracije sirutke kao alternativnog postupka pasterizaciji uz očuvanje nativnih proteina sirutke te ispitati njezin utjecaj kao predtretmana sa ciljem povećanja djelotvornosti ultrafiltracije. Filtracije su provedene pri različitim procesnim temperaturama (20ºC, 40ºC, 50ºC) korištenjem keramičkih membrana različitih graničnih vrijednosti zadržavanja (0,1 μm, 0,5 μm , 0,8 μm, 20 kDa). Izuzetim uzorcima određivana je mikrobiološka kvaliteta te fizikalno kemijska svojstva. Mikrofiltracija primjenom membrana promjera pora 0,5 μm i 0,8 μm pokazala je dobar učinak na očuvanje prehrambene vrijednosti sirutke. Stupanj redukcije prisutnih mikroorganizama opada razmjerno veličini promjera pora primijenjenih membrana. Bez obzira na procesnu temperaturu, membrana od 0,5 μm se pokazala optimalnom u smislu očuvanja hranjive vrijednosti i redukcije pristunih mirkoorganizama. Prema svim praćenim parametrima, ultrafiltracija pri 20°C se pokazala najpovoljnijim režimom za obradu svježe sirutke. Predtretman mikrofiltracijom primjenom membrana promjera pora 0,8 μm nije povećao djelotvornost procesa ultrafiltracije, bez obzira na procesnu temperaturu. Predtretman mikrofiltracijom primjenom membrana promjera pora 0,5 μm povećao je djelotvornost procesa ultrafiltracije, što se očituje prvenstveno u povećanju fluksa permeata i smanjenu formiranih otpora prema začepljivanju. Navedene promjene intenzivinije su pri procesnoj temperaturi od 20ºC.Microfiltration and ultrafiltration enable new opportunities of whey utilization in human nutrition. The implementation of these processes ensures appropriate microbiological quality and the preservation of the nutritional value of the product. The main disadvantage is the phenomenon of membrane fouling. The aim of this dissertation was to optimize the process of whey microfiltration in order to ensure aduequate micorbiological quality, to preserve the native whey proteins and to be tesetd as a pretreatment for enhancement of the ultrafiltration process. The filtrations were performed at different process temperatures (20ºC, 40ºC, 50ºC) by using ceramic membranes with different cut-offs (0,1 μm, 0,5 μm , 0,8 μm, 20 kDa). All samples of whey were analized for microbiological quality, physical and chemical properties. Microfiltration by ceramic membranes with mean pore diameter of 0,5 μm and 0,8 μm allowed preservation of the native wehy proteins. Microbial reduction rates decreased proportionally with the mean pore diameter of the used membranes. Regardless the process temperature, the membrane with mean pore diameter of 0,5 μm appeared to be optimal for purposes of preserving the nutritional value and achieveing proper micribiological quality of whey. According to all measured parameters, ultrafiltration process at 20ºC appeared to be the most appropriate for whey processing. Microfiltration of whey by ceramic membrane with the mean pore diameter of 0,8 μm didn´t significantly affect the efficiency of the ultrafiltration, regardless the process temperature. Microfiltration of whey by ceramic membranes with the mean pore diameter of 0,5 μm affected the efficiency of whey ultrafiltration by siginificantly increasing the permeate flux and reducing the fouling resistance. The described effects are more intensive at the process temperature of 20ºC
Hrvatski časopis za prehrambenu tehnologiju, biotehnologiju i nutricionizam
Jestivi se filmovi i premazi sve više koriste u proizvodnji sireva zbog zahtjeva potrošača za pri... more Jestivi se filmovi i premazi sve više koriste u proizvodnji sireva zbog zahtjeva potrošača za prirodnim i ekološki prihvatljivim pakovinama. U radu je prikazano što su jestivi filmovi i prevlake, od kojih se materijala mogu proizvoditi i koje prednosti nude pri proizvodnji sira. Materijali koji pokazuju veliki potencijal za moguću komercijalnu proizvodnju u budućnosti su galaktomanani, kitozan, škrob, alginati i proteini sirutke. Jestivi filmovi i prevlake od navedenih materijala mogu produljiti rok trajanja sira te poboljšati kvalitetu sira, a pružaju i mogućnost ugradnje antimikrobnih sredstava koja djeluju kao dodatna zaštita protiv mikroorganizama uzročnika kvarenja sira.
Fermentation
Background: Fermented dairy products are known for their many positive effects on human health an... more Background: Fermented dairy products are known for their many positive effects on human health and are consumed worldwide. The supplementation of food with plant extracts as sources of valuable nutritional compounds has recently gained a lot of attention. Milk and fermented products are deficient in bioactive components such as phenolic compounds and iron. Moringa oleifera leaf extract is rich in vitamins, minerals (iron), polyphenols, flavonoids, tannins and proteins. Its addition to milk before fermentation might represent an excellent way to enrich fermented milk products. Methods: Yoghurts enriched with moringa extract (ME) (1, 3 and 4-%, v/v) were produced and compared to a control yoghurt without ME. In all samples, acidity, microbiological parameters, syneresis and water holding capacity, rheology parameters, total colour difference, mineral content, total phenols and antioxidant capacity (FRAP method) and sensory properties were determined. Results: The addition of ME to mil...
Zbornik sažetaka 42. Hrvatskog simpozija mljekarskih stručnjaka s međunarodnim sudjelovanjem, 2016
British Food Journal, 2021
PurposeIn the past two decades the popularity of artisan cheese emerged. The present study aimed ... more PurposeIn the past two decades the popularity of artisan cheese emerged. The present study aimed to investigate similarities and differences in beliefs towards artisan cheeses among participants from Serbia, Croatia and Spain and to determine consumer profiles. Better understanding of their behaviours and beliefs could serve as the basis for the development of appropriate production and marketing strategies and for further popularisation of artisan cheeses.Design/methodology/approachThe data on demographic structure, behaviours and beliefs of 947 participants in total were obtained via a questionnaire collected online. In order to identify consumer profiles and to define their specific beliefs, a cross-country cluster analysis has been conducted. Four clusters were identified: “highly educated men”, “highly educated women”, “millennials” and “educated senior women”. Mann–Whitney U test was used to identify statistically significant differences between countries and clusters.Findings...
Journal of Dairy Research, 2019
The experiments reported in this research paper examine the potential of digestion using acidic e... more The experiments reported in this research paper examine the potential of digestion using acidic enzymes Protease A and Protease M to selectively hydrolyse α-lactalbumin (α-La) whilst leaving β-lactoglobulin (β-Lg) relatively intact. Both enzymes were compared with pepsin hydrolysis since its selectivity to different whey proteins is known. Analysis of the hydrolysis environment showed that the pH and temperature play a significant role in determining the best conditions for achievement of hydrolysis, irrespective of which enzyme was used. Whey protein isolate (WPI) was hydrolysed using pepsin, Acid Protease A and Protease M by randomized hydrolysis conditions. Reversed-phase high performance liquid chromatography was used to analyse residual proteins. Regarding enzyme selectivity under various milieu conditions, all three enzymes showed similarities in the reaction progress and their potential for β-Lg isolation.
Fermentation
Various factors affect rennet coagulation and consequently cheese yield, but the subject of resea... more Various factors affect rennet coagulation and consequently cheese yield, but the subject of research has been mainly the cow milk. For the purpose of goat cheese production optimization, this paper investigated the influence of enzyme concentration (0.01–0.054 g/L), pH (6.5–6.1) and temperature (27–35 °C) on rennet coagulation of goat milk. Coagulation time (RCT), aggregation rate (AR), and gel firmness (G’60 and GF), were measured by oscillatory rheometry. The decrease in rennet concentration extended RCT. At lower rennet concentrations, a lower AR was recorded, which ranged from 0.02 Pa/s to 0.05 Pa/s. The decrease in pH from 6.5 to 6.1 caused a two times shorter RCT, and a two times faster AR. There was no effect of pH on the firmness of the rennet gel. The increase in coagulation temperature from 27 °C to 35 °C reduced the RCT of pasteurized milk from 12.6 min to 8.6 min, and caused a linear increase in the AR, but did not significantly affect the firmness of the gel. The presen...
Cheeses around the world - Types, production, properties and cultural and nutritional relevance , 2019