| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 455.93 KB | Adobe PDF |
Advisor(s)
Abstract(s)
The impacts of ultraviolet-C radiation, blanching
by heat, and combination of heat/ultrasounds (thermosonication)
were studied for Listeria innocua (inoculated) in red bell
peppers, total mesophiles in strawberries and total coliforms
in watercress, in the temperature range 50–65 °C. Quality
attributes such as colour and firmness were studied for all
products, and total anthocyanins content was additionally
determined for strawberries. Results showed that ultraviolet-
C radiation was the least effective treatment in terms of
microbial load reduction and was equivalent to a simple
water washing. Log reductions were 1.05±0.52 for L.
innocua, 0.53±0.25 for total coliforms and 0.26±0.18 for
total mesophiles. This treatment had the lowest impact on the
quality parameters analysed. Thermosonication treatment
was similar to heat blanching for all microorganism/product
tested, excepted for total coliforms in watercress at 65 °C, in
which thermosonication had a higher effect (p<0.05). Heat
blanching at 65 °C allowed 7.43±0.12 log-cycles reduction,
while loads were diminished by 8.24±0.13 log-cycles if
thermosonication at the same temperature was applied.
Thermosonication also allowed better quality retention, when
compared to heat blanching at the same temperatures. The
impact of thermosonication on microbial load reductions was
statistically significant and thermosonicated samples retained
quality attributes better than heat blanched ones at the same
temperatures (p<0.05). Hence, it can be concluded that
thermosonication is a promising process and may be a
favourable alternative to the conventional thermal treatments.
Description
Keywords
Ultraviolet-C radiation Thermosonication Blanching Microbial load reduction Quality Fruits and vegetables
Pedagogical Context
Citation
ALEXANDRE, Elisabete M. C....[et al] - Study on thermosonication and ultraviolet radiation processes as an alternative to blanching for some fruits and vegetables. Food and Bioprocess Technology. ISSN 1935-5130. Vol. 4 n.º 6 (2011), p. 1012-1019