Influence of innovative technologies on rheological and thermophysical properties of whey proteins and guar gum model systems

Autor: Greta Krešić, Anet Režek Jambrak, Vesna Lelas, Zoran Herceg
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Zdroj: Mljekarstvo : časopis za unaprjeđenje proizvodnje i prerade mlijeka
Volume 61
Issue 1
ISSN: 1846-4025
0026-704X
Popis: The aim of this study was to examine the effect of high-power ultrasound (US) and highpressure processing (HP) on model systems composed of whey protein concentrate (WPC) and whey protein isolate (WPI) with or without guar gum addition. This kind of systems can be found in food production industry so the aim was to use novel food processing technologies to be utilized as a method for products development. Aqueous suspensions (10 g kg-1) of powdered whey proteins were treated with either ultrasound or high pressure. The treatment conditions were as follows: US: frequency of 30 kHz, for 5 and 10 min; HP: pressure intensity 300-600 MPa, for 5 and 10 min. Rheological and thermophysical properties were analyzed after guar gum addition (0.5 g kg-1). Ultrasound treatment showed a significant influence on all examined properties through protein denaturation caused by cavitation and microstreaming effects. High pressure caused significant increase in viscosity and consistency coefficients of model systems with and without guar addition. Significant decrease of initial freezing and initial thawing temperature was observed in all samples. With this research the direct influence of ultrasound and high-pressure treatment on the rheological and thermophysical properties of whey protein isolate and concentrate model systems with or without guar gum was demonstrated.
Svrha ovog istraživanja je ispitati utjecaj ultrazvuka visoke snage (US) i procesiranja visokim tlakom (HP) na modelne sustave sastavljene od koncentrata proteina sirutke (WPC) i izolata proteina sirutke (WPI) sa ili bez dodatka guar gume. Ovi sustavi mogu se naći u prehrambenoj industriji, tako da je cilj ovog rada koristiti nove tehnike procesiranja kao metodu koja se može koristiti u razvoju novih proizvoda. Vodene suspenzije (10 g kg-1) proteina sirutke su tretirane s ultrazvukom ili visokim hidrostatskim tlakom. Uvjeti tretiranja su bili sljedeći: US: frekvencija od 30 kHz, kroz 5 i 10 min.; HP: intenzitet tlaka 300-600 MPa, kroz 5 and 10 min. Reološka i termofizička svojstva analizirana su nakon dodatka guar gume (0,5 g kg-1). Ultrazvučnim tretmanom pokazan je značajan utjecaj na sva ispitivana svojstva kroz denaturaciju proteina sirutke uzrokovanu putem kavitacije i učinaka mikrostrujanja. Tretman visokim hidrostatskim tlakom uzrokovao je značajno povećanje viskoznosti i koeficijenta konzistencije modelnih sustava sa ili bez dodatka guar gume. Također, zamijećeno je značajno smanjenje početne temperature smrzavanja i odmrzavanja kod svih uzoraka. S ovim istraživanjem pokazan je direktan utjecaj tretmana ultrazvukom i visokim hidrostatskim tlakom na reološka i termofizikalna svojstva modelnih sustava izolata i koncentrata proteina sirutke sa ili bez dodatka guar gume.
Databáze: OpenAIRE
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