Validation of UV coiled tube reactor for fresh juices

Koutchma, Tatiana; Parisi, Brian; Patazca, Eduardo

doi:10.1139/s06-058

Cited by 90 publications

(47 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Turbulent flow of liquid foods in continuous flow UV reactors increased inactivation of microorganisms in fresh juices, liquid egg whites and milk (Koutchma et al, 2007;Franz et al, 2009;Matak, 2004). Reynolds number (Re) is a measure of turbulence of liquid in a coiled tube reactor.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

UV-C treatment of soymilk in coiled tube UV reactors for inactivation of Escherichia coli W1485 and Bacillus cereus endospores

Bandla

Choudhary

Watson

et al. 2012

LWT - Food Science and Technology

View full text Add to dashboard Cite

Coiled tube UV reactors were used to investigate the influence of tube diameter (1.6 mm ID, and 3.2 mm ID) and Reynolds number (Re) to inactivate Escherichia coli W1485 and Bacillus cereus spores in raw soymilk (RSM). Four levels of Re (343, 686, 1029 and 1372) were tested in RSM inoculated separately with each bacterium and treated in the UV reactors at a constant residence time of 11.3 s with UV-C dose of 11.187 mJ/cm 2 at 253.7 nm. Inactivation efficiency of both microorganisms increased with Re. Maximum reductions of 5.6 log10 CFU/ml of E. coli and 3.29 log10 CFU/ml of B. cereus spores were achieved in the 1.6 mm ID UV reactor. Inactivation efficiency was higher in the 1.6 mm ID UV reactor than the 3.2 mm ID UV reactor for both the organisms. Effect of UV-C light on lipid oxidation of untreated RSM, measured as malondialdehyde and other reactive substances (MORS) content, was much higher (95 nmol/ml) than the UV-treated (58 nmol/ml) and thermally pasteurized (55 nmol/ml) RSM during the storage period of 7 days. The UV-C treatment can be effectively used for reducing E. coli cells and B. cereus spores in soymilk without compromising its quality.

show abstract

Section: Introductionmentioning

confidence: 99%

“…This occurs when the ratio (D/Dc) in equation (2) is within 0.03 < D/Dc < 0.1 (Dean, 1927). Dean flow causes superior mixing conditions, leading to better exposure of liquid food to UV-C in a UV reactor (Koutchma et al, 2007;Franz et al, 2009). Matak (2004) reported off-flavor in UV-C treated milk.…”

Section: Introductionmentioning

confidence: 99%

UV-C treatment of soymilk in coiled tube UV reactors for inactivation of Escherichia coli W1485 and Bacillus cereus endospores

Bandla

Choudhary

Watson

et al. 2012

LWT - Food Science and Technology

View full text Add to dashboard Cite

show abstract

“…In the last years, the application of UV radiation has been focused in the treatment of raw apple cider or fruit juices. Different works have been conducted to analyze the effect of UV on E. coli (Koutchma et al 2007 in orange juice; Guerrero-Beltrán and BarbosaCánovas 2006 in apple juice; Oteiza et al 2005 in orange juice; Basaran et al 2004 in apple cider; Koutchma et al 2004 in apple juice; Wright et al 2000 in apple cider;and Worobo 1999 in apple cider).…”

Section: Introductionmentioning

confidence: 99%

Ultraviolet Treatment of Orange Juice to Inactivate E. coli O157:H7 as Affected by Native Microflora

Oteiza

Giannuzzi

Zaritzky

2009

Food Bioprocess Technol

View full text Add to dashboard Cite

The effect of yeast concentration on ultraviolet (UV) inactivation of five strains of Escherichia coli O157: H7 from different sources, inoculated both individually and simultaneously in orange juice, was analyzed and mathematically modeled. The presence of yeast cells in orange juice decreases the performance of UV radiation on E. coli inactivation. UV absorption coefficients in the juice increased with increasing yeast concentration, and higher UV doses were necessary to inactivate bacterial strains. UV intensities of I=3.00±0.3 mW/cm 2 and exposure times (t) between 0 and 10 min were applied; radiation doses (energy, E=I×t) ranging between 0 and 2 J/cm 2 were measured using a UV digital radiometer. All the tested individual strains showed higher resistance to the treatment when UV radiation was applied at 4°C in comparison to 20°C. UV inactivation of E. coli O157:H7 individual strain was satisfactory fitted with a first order kinetic model. A linear relationship was found between UV absorptivities and D values (radiation doses required to decrease microbial population by 90%) for each strain. The dose required to reach 5-log reduction for the most unfavorable conditions that is the most UV resistant strain, and maximum background yeast concentration was 2.19 J/cm 2 at 4°C (corresponding to 11 min of UV treatment) and 2.09 J/cm 2 at 20°C (corresponding to 10.55 min of UV treatment). When a cocktail of strains was inoculated in orange juice, the logistic equation was the best model that fits the experimental results due to the deviation from the log-linear kinetics. The UV resistance between strain cocktail and single strain were mathematically compared. Slopes of the decline curves for strain cocktail at high UV doses were lower than the slopes of the log-linear equation calculated for the individual strains, even for the most resistant one. Therefore, microbial inactivation tests using a cocktail of strains are particularly important to determine the performance of the UV inactivation treatment.

show abstract

“…Thus, several strategies have been proposed to optimize the effect of UV radiation. On one hand, new UV reactors have been designed to ensure turbulent flow patterns so that all portions of a liquid food are exposed to UV light (24). On the other hand, UV light can be combined with other novel processing techniques or milder conventional preservation methods in a so-called "hurdle" approach to guarantee acceptable inactivation of pathogenic microorganisms (49).…”

mentioning

confidence: 99%

Inactivation of Salmonella enterica by UV-C Light Alone and in Combination with Mild Temperatures

Gayán

Serrano

Raso

et al. 2012

Appl Environ Microbiol

View full text Add to dashboard Cite

The aim of this investigation was to study the efficacy of the combined processes of UV light and mild temperatures for the inactivation of Salmonella enterica subsp. enterica and to explore the mechanism of inactivation. The doses to inactivate the 99.99% (4D) of the initial population ranged from 18.03 (Salmonella enterica serovar Typhimurium STCC 878) to 12.75 J ml ؊1 (Salmonella enterica serovar Enteritidis ATCC 13076). The pH and water activity of the treatment medium did not change the UV tolerance, but it decreased exponentially by increasing the absorption coefficient. An inactivating synergistic effect was observed by applying simultaneous UV light and heat treatment (UV-H). A less synergistic effect was observed by applying UV light first and heat subsequently. UV did not damage cell envelopes, but the number of injured cells was higher after a UV-H treatment than after heating. The synergistic effect observed by combining simultaneous UV and heat treatment opens the possibility to design combined treatments for pasteurization of liquid food with high UV absorptivity, such as fruit juices.

show abstract

Validation of UV coiled tube reactor for fresh juices

Cited by 90 publications

References 8 publications

UV-C treatment of soymilk in coiled tube UV reactors for inactivation of Escherichia coli W1485 and Bacillus cereus endospores

UV-C treatment of soymilk in coiled tube UV reactors for inactivation of Escherichia coli W1485 and Bacillus cereus endospores

Ultraviolet Treatment of Orange Juice to Inactivate E. coli O157:H7 as Affected by Native Microflora

Inactivation of Salmonella enterica by UV-C Light Alone and in Combination with Mild Temperatures

Contact Info

Product

Resources

About