Heat treatment improves the sensory properties of the ultrafiltration by‐product of honeybush (Cyclopia genistoides) extract

BACKGROUND Ultrafiltration of green honeybush (Cyclopia genistoides) extract results in a by‐product (retentate). Application of further separation processes for recovery of polyphenols would entail creation of additional waste. Repurposing the retentate as a food flavour ingredient provides an alternative valorization approach. RESULTS The retentate, suspended in water (270 g L−1), was heat‐treated at 80 °C for 2, 4, 8 and 16 h, and at 90 °C for 2, 4, 6 and 8 h to change its sensory profile. The heat‐treated retentate, diluted to beverage strength (2.15 g L−1), had prominent ‘grape/Muscat‐like’ and ‘marmalade/citrus’ aroma and flavour notes. Overall, heating for ≤ 4 h increased the intensities of positive flavour and aroma notes, while reducing those of ‘green/grass’, ‘hay’ and bitterness, whereafter further heating only had a slight effect on the aroma profile at 80 °C (P