Effect of MW-assisted roasting on nutritional and chemical properties of hazelnuts

Fatih Kalkan,Sai Kranthi Vanga,Yvan Gariepy,Vijaya Raghavan

doi:10.3402/fnr.v59.28916

Abstract

In order to enhance the flavor, texture, color, and appearance of hazelnuts, they are roasted during postharvest processing. In this study, raw hazelnuts (Corylus avellana L.) were roasted using microwave (MW) and MW-assisted hot air methods under various roasting conditions. The hazelnuts roasted were then examined to determine the percent DPPH radical scavenging activity, antioxidant capacity, total phenolic content, resistant starch, non-resistant starch, total starch, and protein concentration. The roasting experiments were done using a completely randomized factorial arrangement of two roasting types by three roasting times (9, 15, and 21 min) by three roasting temperatures (70, 90, and 110°C) using three replications within each experiment. These roasting methods were found to yield significant differences in antioxidant capacity, total phenolic content, resistant starch, non-resistant starch, and protein concentration between MW and MW-assisted hot air roasting processes, while no difference was found in percent DPPH radical scavenging activity and total starch. The results obtained may be of great importance to the food research community and industrial hazelnut roasting technologies.

Highlights

In order to enhance the flavor, texture, color, and appearance of hazelnuts, they are roasted during postharvest processing
Effect of MW and MW-assisted hot air roasting process on percent DPPH radical scavenging activity and antioxidant capacity In order to evaluate the ability of antioxidants to the scavenge free radicals, the percent DPPH radical scavenging assay is extensively used
A study supporting our results reported that the level of resistant starch of chickpeas and beans decreased with application of a thermal treatment by MW [25]

Summary

Introduction

In order to enhance the flavor, texture, color, and appearance of hazelnuts, they are roasted during postharvest processing. The roasting experiments were done using a completely randomized factorial arrangement of two roasting types by three roasting times (9, 15, and 21 min) by three roasting temperatures (70, 90, and 1108C) using three replications within each experiment These roasting methods were found to yield significant differences in antioxidant capacity, total phenolic content, resistant starch, non-resistant starch, and protein concentration between MW and MW-assisted hot air roasting processes, while no difference was found in percent DPPH radical scavenging activity and total starch. Texture, and color during the roasting process are primarily related to drying and non-enzymatic browning of the hazelnuts (5Á7). Kim et al reported that brown color, antioxidant activity, and flavor in agricultural products increases due to the Maillard reaction during the roasting process [9]. Creativecommons.org/licenses/by/4.0/), allowing third parties to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material for any purpose, even commercially, provided the original work is properly cited and states its license

Methods

Results

Conclusion