Volume 52(1):7-15, 2008Acta Biologica Szegediensis

http://www.sci.u-szeged.hu/ABS

ARTICLE

Horticulture Department, Faculty of Agriculture, Kafrelsheikh University, Kafr El-Sheikh, Egypt, and Department of Vegetable and Mushroom Growing, Faculty of Horticulture, Corvinus University, Budapest, Hungary

Improvement of postharvest keeping quality of white pepper fruits (Capsicum annuum, L.) by hydrogen peroxide treatment under storage conditionsYousry A. Bayoumi

ABSTRACT Sweet pepper is one of the most important vegetable crops in the world, it has excellent nutritive value but it is susceptible to relatively fast quality changes after harvest time. The objective of the present research was to evaluate the effect of dipping pepper fruits in hydrogen peroxide solutions on postharvest keeping quality during storage time. Whole pep-per fruits were soaked for 30 min in a solutions of hydrogen peroxide (0, 1, 5 and 15 mM) then, air dried and stored at room temperature (20ºC) for 2 weeks and in fridge (10ºC) for 4 weeks. Hydrogen peroxide treatments significantly reduced weight loss, rot rate index and nitrate content of fruits specially with 15 mM hydrogen peroxide as compared with control treatement (0 mM hydrogen peroxide). Moreover, hydrogen peroxide treatments significantly increased general appearance, ascorbic acid content and the activity of the antioxidant enzymes such as ascorbate peroxidase and dehydroascorbate reductase. For dry matter and TSS%, there are no significant differences among treatments. Therefore, the use of hydrogen peroxide in posthar-vest treatments have a good potential strategy to improve the postharvest quality, extend shelf life period and maintained some nutritional quality as well as inhibited decay development of white peppers which natural infected under storage conditions.Acta Biol Szeged 52(1):7-15 (2008)

KEY WORDS

pepper fruitshydrogen peroxidepostharvest quality

Materials and Methods

Figure 1. General appearance in zero time (before storage) and affter storage time (10 and 20 days) as influenced by hydrogen peroxide treat-ments under both room temperature (20 oC) and fridge (10 oC) conditions. Means designed by the same letter are not significantly difference at the 5% level according to Duncan’s test.

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Figure 2. Effect of hydrogen peroxide treatments on the general appearance and delaying senescence of pepper fruits. A- Fruits after 1 week stored at 20°C, B- Fruits after 2 weeks stored at 20°C, C- Fruits after 2 weeks stored at 10°C and D- Fruits after 4 weeks stored at 10°C.

Initial and stored quality measurements

Statistical analysis

Results and Discussion

Effect of hydrogen peroxide treatments

General appearance

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Figure 3. Weight loss of pepper fruits as influenced by hydrogen peroxide treatments during storage time at both room temperature (20°C, every 2 days) and fridge (10°C, every 4 days). Means designed by the same letter (at the same storage time) are not significantly difference at the 5% level according to Duncan’s test.

Weight loss %

The rot rate index

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Figure 4. The role of hydrogen peroxide in reducing rot rate index of pepper fruits during storage time under both 20°C (room temperature) and 10°C (fridge) conditions. Means designed by the same letter (at the same storage time) are not significantly difference at the 5% level according to Duncan’s test.

Enzyme activities

Figure 5. Activities of both ascorbate peroxidase and dehydroascorbate reductase in pepper fruits during postharvest storage time (at the 10th day) as influenced by H2O2 treatments at 20 °C (room temperature) condition. Means designed by the same letter are not significantly differ-ence at the 5% level according to Duncan’s test.

Figure 6. Changes of ascorbic acid content in pepper fruits during postharvest storage time at both room temperature (20°C) and fridge (10°C) conditions as influenced by H2O2 treatments. Means designed by the same letter (at the same storage time) are not significantly difference at the 5% level according to Duncan’s test.

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Ascorbic acid content

Figure 7. Effect of H2O2 treatments on dry matter and TSS (%) of pepper fruits during storage time under room temperature (20°C) and fridge (10°C) conditions. Means designed by the same letter (at the same storage time) are not significantly difference at the 5% level according to Duncan’s test.

Figure 8. Effect of H2O2 treatments on nitrate content of pepper fruits during storage time under room temperature (20°C) and fridge (10°C) conditions. Means designed by the same letter (at the same storage time) are not significantly difference at the 5% level according to Duncan’s test.

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Dry matter and TSS (%)

Nitrate content (ppm)

Conclusion

Acknowledgements

References

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