Proteomic and quality analysis of uv-c and thermal treated cut chokanan mango (mangifera indica l.) and josephine pineapple (ananas comosus l. merr.) / Dominic Soloman George
The increasing demand for high quality fruit products, fresh-cut and the likes that meet safety standards has spurred the development of treatments such as ultraviolet-C (UVC) light and thermal treatment. In this study, fresh cut Chokanan mangoes and Josephine pineapples were subjected to UV-C tr...
| Main Author: | |
|---|---|
| Format: | Thesis |
| Published: |
2016
|
| Subjects: | |
| Online Access: | http://studentsrepo.um.edu.my/6324/ http://studentsrepo.um.edu.my/6324/4/dominic.pdf |
| Summary: | The increasing demand for high quality fruit products, fresh-cut and the likes that meet
safety standards has spurred the development of treatments such as ultraviolet-C (UVC)
light and thermal treatment. In this study, fresh cut Chokanan mangoes and
Josephine pineapples were subjected to UV-C treatment (for 15, 30 and 60 minutes at
25 ± 1 °C) and thermal treatment (at 70 ± 1 °C for 5, 10 and 20 minutes). The proteomic
changes in the fruits following UV-C and thermal treatments as well as the effects of the
treatments on the quality characteristics (physicochemical, nutritional, microbial,
sensorial and shelf-life) were evaluated and compared with untreated fruits (control).
UV-C and thermal treatments resulted in significant changes in the expression of
several proteins that are known to play important roles in various metabolic processes.
Spots that were differentially expressed following UV-C and thermal treatment were
identified through LCMS-MS and classified according to functional groups. They were,
in the order, stress and defence, energy and metabolism, cell structure and finally
ripening and senescence. Several allergenic proteins were found to be reduced in
expression following UV-C and thermal treatment which could prove to be invaluable
in reducing allergic reactions in patients.
As for the quality attributes, no significant changes were observed in pH, total soluble
solids and titratable acidity after UV-C and thermal treatment. UV-C treated fruits
showed significant improvement in selected quality parameters, which included a
significant enhancement in polyphenols (up to 7%), DPPH scavenging activity (up to 4
%) and total antioxidant capacity (up to 17%) when compared to the control. Thermal
treatment on the other hand resulted in a decrease in these quality parameters. In
iii
addition, significant reduction in microbial load was observed in both UV-C and
thermally treated fruits with UV-C achieving higher microbial inactivation. Both UV-C
and thermal treatment successfully extended shelf-life of fresh cut fruits to a maximum
of 15 days.
Sensory attributes (appearance, aroma, texture, and taste) were evaluated by 90
panellists using a hedonic scale, and results showed that UV-C treated fruit samples
were preferred more than thermally treated fruit samples. The sensory evaluation
verified that UV-C treatment for 30 minutes was the most promising treatment
compared to the other treatments. |
|---|