Ultra high pressure treatment of orange juice: a kinetic study on inactivation of pectin methyl esterase

Basak, Somnath; Ramaswamy, Hosahalli S.

doi:10.1016/s0963-9969(96)00068-3

Cited by 159 publications

(136 citation statements)

References 14 publications

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“…Ası´en los frutos tratados por 60 MPa durante 10 o 20 min la firmeza fue mayor entre los dı´as 5 y 11 que en los otros frutos tratados aunque menor que en el testigo; esto puede deberse a que a presio´n mayor pudieron inactivarse parcialmente las enzimas como la pectimetilesterasa (Hendricks et al, 1998). Se ha reportado que las APH modifican la actividad de la pectinmetilesterasa (Basak & Ramaswamy, 1996).…”

Section: Firmezaunclassified

Efecto de las altas presiones hidrostáticas en la fisiología postcosecha del mango ‘Ataulfo’

Álvarez-Virrueta¹,

García-López²,

Montalvo‐González³

et al. 2012

CyTA - Journal of Food

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Section: Firmezaunclassified

Efecto de las altas presiones hidrostáticas en la fisiología postcosecha del mango ‘Ataulfo’

Álvarez-Virrueta¹,

García-López²,

Montalvo‐González³

et al. 2012

CyTA - Journal of Food

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“…Thermal pasteurisation of orange juice can cause degradation of the product's quality (non-enzymatic browning and off-flavours production), while the fresh juice flavour (Basak & Ramaswamy, 1996) may be impaired and its vitamin content decreased. In recent years consumers have increasingly sought ready-to-use 'fresh-like' products, which are usually refrigerated.…”

Section: Introductionmentioning

confidence: 99%

Inactivation of Escherichia coli in orange juice using ozone

Patil¹,

Bourke²,

Frias³

et al. 2009

Innovative Food Science & Emerging Technologies

112

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This research investigated the efficacy of gaseous ozone for the inactivation of Escherichia coli ATCC 25922 and NCTC 12900 strains in orange juice. Orange juice inoculated with E. coli (10 6 CFU mL -1 ) as a challenge microorganism was treated with ozone at 75-78µg mL -1 for different time periods (0-18 min). The efficacy of ozone for inactivation of both strains of E. coli was evaluated as a function of different juice types: model orange juice, fresh unfiltered juice, juice without pulp, and juice filtered through 500m or 1mm sieves. Fast inactivation rates for total reduction of E. coli were achieved in model orange juice (60 seconds) and in juice with low pulp content (6 min). However, in unfiltered juice inactivation was achieved after 15-18 min. This indicated that juice organic matter interferes with antibacterial activity of gaseous ozone. The effect of prior acid (pH 5.0) exposure of E. coli strains on the inactivation efficacy of ozone treatment was also investigated. There was a strain effect observed, where prior acid exposure resulted in higher inactivation times in some cases by comparison with the control cells.However, the overarching influence on inactivation efficacy of ozone was related to the pulp content. Generally, the applied gaseous ozone treatment of orange juice resulted in a population reduction of 5 log cycles.Key words: Escherichia coli, ozone, non-thermal inactivation, acid exposure, orange juice, microbial kinetics Industrial relevance: To facilitate the preservation of unstable nutrients many juice processors have investigated alternatives to thermal pasteurisation, including unpasteurised short shelf life juices with high retail value. This trend has continued within the European Union. However within the US recent regulations by the FDA have 3 required processors to achieve a 5-log reduction in the numbers of the most resistant pathogens in their finished products. Pathogenic E. coli may survive in acid environments such as fruit juices for long periods. This study demonstrates that the use of ozone as a non-thermal technology is effective for inactivation of E. coli and acid exposed E. coli in orange juice. Information on the design of the ozone treatment for inactivation of E. coli which results into safe juice products is also among the main outputs of this work. Ozone auto-decomposition makes this technology safe for fruit juice processing.4

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“…Thermal inactivation of some enzymes including keratinase, tomato peroxidase, pectin methylesterase and lipase follows simple first-order kinetic model (Basak and Ramaswamy, 1996;Ercan and Soysal, 2011;Silveira et al, 2010;Tomizuka et al, 1966). Considering complex structure of proteins, however, it is easily presumed that inactivation of enzymes does not always obey simple first-order kinetic model.…”

Section: Methodsmentioning

confidence: 99%

Reduced Thermal Inactivation of Trypsin and Marugoto E by High-pressure Treatment

Kim

2012

FSTR

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.5 and 2.5 mg/mL concentrations, respectively. At all heating temperatures and time of heat-treatment, the residual activities of trypsin and Marugoto E solutions that were heat-treated at high pressure were significantly higher than those of the same solutions that were heat-treated at ambient pressure. First-order reaction rate constants for thermal inactivation of the enzymes at high pressure were significantly smaller than those at ambient pressure, which led to considerable decreases in activation energies of the enzyme reactions.Keywords: reduction, thermal inactivation, proteases, high-pressure treatment *To whom correspondence should be addressed. E-mail: k9130sen@hanmail.net IntroductionIt has been reported that enzyme inactivation takes place owing to many factors that include extreme temperature and pH, oxidation, exposure to surfactants, detergents, denaturing agents, heavy metals, thiol reagents and mechanical force, radiation, freezing and thawing, and dehydration (Volkin and Klibanov, 1990). From these factors, inactivation by thermal treatment is perhaps the most frequently encountered and most thoroughly studied cause of enzyme inactivation in laboratory and industry (Kim, 1992). From biotechnological point of view, enzyme processes at high temperature often provide considerable merits such as increased solubility and reaction rate, and reduced microbial contamination and solution viscosity, which is evidenced by the fact that most industrial enzyme processes are conducted at elevated temperatures (Lei and Stahl, 2001;Novo, 2001;Zhu et al., 2010). In this context, the maintenance of thermal stability of enzymes seems to be very important to conduct enzymebased food processes that comprise hydrolysis, synthesis and biotransformation.One important issue in enzyme technology that gains recent attention is the enzyme reaction at high pressure. It has been shown that stability and activity of several enzymes are increased at specific conditions, and catalytic behavior is modified by changing rate-limiting step or modulating enzyme selectivity (Balny, 2006;Heremans and Smeller, 1998;Vila Real et al., 2007). When the stability of subtilisin and lysozyme were studied at medium hydrostatic high pressure up to 200 MPa, neither subtilisin nor lysozyme showed measurable changes in tertiary or secondary structure or sign of aggregation, which indicated that they retained catalytic activity at this harsh condition (Webb et al., 2000). When the apparent rate constant and maximum rate of hydrolysis for a dipeptide, Fua-Gly-LeuNH 2 , were measured using vimelysin, a neutral protease from Vibrio sp. T1800, in a variable pressure-temperature gradient, it was found that pressureactivation ratio was about sevenfold high and the pressureactivation below 200 MPa was chiefly caused by the change in k cat parameter (Ikeuchi et al., 2000). In contrast, calpains (calcium-activated neutral proteases) from sea bass (Dicentrarchus labrax L.) lost catalytic activity by the high-pressure treatment from 100 MPa, with accompanyi...

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Ultra high pressure treatment of orange juice: a kinetic study on inactivation of pectin methyl esterase

Cited by 159 publications

References 14 publications

Efecto de las altas presiones hidrostáticas en la fisiología postcosecha del mango ‘Ataulfo’

Efecto de las altas presiones hidrostáticas en la fisiología postcosecha del mango ‘Ataulfo’

Inactivation of Escherichia coli in orange juice using ozone

Reduced Thermal Inactivation of Trypsin and Marugoto E by High-pressure Treatment

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