# Enhancing Quality and Processing Efficiency of Germinated Buckwheat Tea Through Hot Air-Assisted Radio Frequency Roasting

## TL;DR

This study shows that using hot air-assisted radio frequency roasting improves the quality and efficiency of making germinated buckwheat tea.

## Contribution

The novel use of hot air-assisted radio frequency roasting for germinated buckwheat tea processing is introduced.

## Key findings

- HARF roasting reduced moisture content from 40% to 5% in 20-22 minutes.
- HARF roasting saved 1/5 time and 1/11~1/18 energy compared to traditional methods.
- HARF-roasted tea had superior aroma, taste, and overall acceptability.

## Abstract

Buckwheat germination can increase bioactive compounds; however, it also increases moisture content, which then requires drying and roasting. This study focused on applying hot air-assisted radio frequency (HARF) roasting to germinated buckwheat (GB) tea to improve the tea quality and processing efficiency. Seeds were soaked in reverse osmosis water for 6 h, followed by germination at 25 °C for 24 h. HARF roasting (100 °C, 10 kW, 16 cm gap) rapidly heated one bucket (2 kg) and two buckets (2 + 2 kg) of GB to 140 °C in only 22 and 20 min, respectively, to reduce the moisture content from 40% to 5%. HARF roasting could save about 1/5 time and 1/11~1/18 energy compared with a cyclonic oven at 140 °C for 100 min roasting to 120 °C. GC-IMS and sensory evaluation indicated a superior aroma, taste, and higher overall acceptability for HARF-roasted GB tea. These results demonstrate that GB using HARF roasting enhances the functional, sensory, and industrial value of buckwheat tea.