Assessment of microwave roasting-induced changes in composition and signature flavor compounds of black pepper (Pepper nigrum L.)

Abstract

The present study highlighted the impact of microwave roasting (300 W-600 W for 5–15 min) on the flavor profile and proximate composition of black pepper (BP). The proximate composition of BP was marginally modulated upon roasting. The varying FTIR spectrum profiles of control and roasted BP demonstrated thermal-oxidative changes upon roasting. GC–MS-HS analysis detected 50 volatile compounds in unroasted and roasted BP, among which terpenes were the dominant contributors. The principal component analysis (PCA) and Hierarchical cluster analysis (HCA) better visualize the variance in flavor profile and indicated that the low roasting conditions (300 W-5 and 10 min, 450 W-5 min) were contributing green, herbal flavor note, medium roasting conditions (300 W-15 min, 450 W-10,15 min, and 600 W-5 min) were indicated transitional phase contributing pepper, spicy note and high roasting conditions (600 W-10,15 min) indicated state of overheating with significant reduction in moisture and fat. These findings will provide novel insights into microwave implications for improving quality attributes during roasting.