Pulsed Ultraviolet Light

Pulsed ultraviolet light (PUV), a non-thermal food processing technology, is reported to be able to inactivate enzymes and reduce allergen levels from peanut extracts. The objective of this study was to determine if PUV would reduce the allergen levels and allergenic potency of soy extracts. Soy extracts were treated with PUV at various times (2, 4 and 6 min), centrifuged, and analyzed by SDS-PAGE and an indirect ELISA for IgE binding or allergenic potency. Results showed that PUV treatment led to an increase in sample temperature/weight loss but a decrease in the levels of soy allergens (i.e., glycinin and ?-conglycinin) as shown in SDS-PAGE. Allergens were reduced probably through aggregation which increased with treatment time. IgE binding was reduced as well in the following order: 20%, 44% and 50% reductions in absorbance values at 2, 4, 6 min, respectively (the latter two were not significantly different (p < 0.05%) from each other). It was concluded that PUV was capable of reducing the allergenic potency of soy extracts, and that the optimal PUV treatment time was 4 min. Clinical data is still needed before PUV can find an application in the development of less allergenic soybean beverages and products.

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Inactivation ofStaphylococcus aureusandEscherichia coliO157:H7 on fresh kashar cheese with pulsed ultraviolet light

Food Science and Technology International ◽

10.1177/1082013219860925 ◽

2019 ◽

Vol 25 (8) ◽

pp. 680-691 ◽

Cited By ~ 6

Author(s):

Nene M Keklik ◽

Adil Elik ◽

Uğur Salgin ◽

Ali Demirci ◽

Gamze Koçer

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Moisture Content ◽

Ultraviolet Light ◽

Escherichia Coli O157 ◽

Visual Evaluation ◽

Quartz Window ◽

E Coli ◽

Pulsed Ultraviolet Light ◽

Hard Cheese

Pulsed ultraviolet light is a potential postprocessing decontamination method which is able to reduce pathogens on solid food surfaces. Cheese surfaces may become easily contaminated with pathogens due to improper handling or contact with unhygienic surfaces during or after processing. In this study, the effects of pulsed ultraviolet light on Staphylococcus aureus and Escherichia coli O157:H7 on fresh kashar cheese were investigated. Pulsed ultraviolet light was applied to kashar cheese for different times (5, 15, 30, 45, 60 s) at 5, 8, and 13 cm from the quartz window in a pulsed ultraviolet light system. Based on the inactivation level, time, and visual evaluation, the most favorable treatment was determined as the 45 s–13 cm treatment (∼44 J/cm2). This treatment yielded about 1.62 and 3.02 log10reductions (cfu/cm2) for S. aureus and E. coli O157:H7, respectively, while did not alter (p>0.05) the pH, lipid oxidation, and moisture content of kashar cheese, except the color parameters. When 0.5 cm thick kashar cheese was treated with pulsed ultraviolet light at a distance of 5 cm from the quartz window, the highest energy transmittance was found to be about 9.16%. These findings demonstrate that pulsed ultraviolet light has the potential for postprocessing decontamination of semi-hard cheese surfaces.

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