The Effect of Traditional and Non-Thermal Treatments on the Bioactive Compounds and Sugars Content of Red Bell Pepper.

Katarzyna Rybak,Oleksii Parniakov,Artur Wiktor,Dorota Witrowa-Rajchert,Małgorzata Nowacka

doi:10.3390/molecules25184287

Katarzyna Rybak, Oleksii Parniakov + Show 3 more

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https://doi.org/10.3390/molecules25184287

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Abstract

The aim of the study was an investigation of the effect of traditional and non-thermal treatment on the bioactive compounds of red bell pepper. As a thermal process, blanching in water and in steam was studied, while for non-thermal the sonication, pulsed electric field treatment and their combination were used in this experiment. The red bell peppers were evaluated based on quality attributes such as: total carotenoids content; polyphenols; vitamin C; antioxidant activity and sugars content. Vitamin C and sugar content were analyzed using liquid chromatography and other measurements were determined based on the spectrophotometric method. Results showed that the blanching in water or in steam reduced bioactive compounds concentration; whereas non-thermal treatments as pulsed electric field (PEF) applied separately or in combination with ultrasound (US + PEF) let to obtain similar or slightly lower content of bioactive compounds in comparison to untreated peppers. When sonication (US) and combined treatment as PEF + US were applied; in most cases reduction of bioactive compounds concentration occurred. This effect was probably related to the effect of relatively long (30 min) ultrasound treatment. The application of appropriate parameters of non-thermal processing is crucial for the high quality of processed material.

Highlights

Red bell pepper (Capsicum annuum L.) is characterized by intensive red color, strong and/or sweet flavor, crispy texture and thin wax layer [1,2]
Samples blanched in steam demonstrated total carotenoid content of 702 mg/100 g dry matter (d.m.) whereas the material treated by hot water exhibited even lower carotenoid content which was equal to 636 mg/100 g d.m
When the non-thermal, unconventional methods as sonication (US) and pulsed electric field treatment (PEF) and their combinations were used, comparable or lower contents of bioactive compounds were obtained in comparison to fresh pepper

Summary

Introduction

Red bell pepper (Capsicum annuum L.) is characterized by intensive red color, strong and/or sweet flavor, crispy texture and thin wax layer [1,2]. This well-known vegetable is valued by consumers for its high content of bioactive substances such as carotenoids, flavonoids, polyphenols, vitamins. The shelf-life of pepper even in cold room storage is quite short. In this regard, various methods of processing of the bell pepper such as blanching, freezing [7], pickling [4,8], osmotic dehydration [9,10]

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