Effects of red pepper powder colour–pungency characteristics on kimchi fermentation and sensory quality: A proof-of-concept half-dose assessment

Abstract

Red pepper powder is an essential kimchi ingredient that strongly influences colour, pungency, and sensory quality while representing an important raw-material cost in industrial production. Here, we evaluated the effects of red pepper powders with contrasting American Spice Trade Association (ASTA) colour values and capsaicinoid content on kimchi fermentation, colour expression, pungency perception, and sensory quality, together with a proof-of-concept assessment of a half-dose formulation. Representative treatments were selected from 15 red pepper powders based on their positions within the ASTA–capsaicinoid distribution. Storage time accounted for a larger proportion of variance than treatment for most fermentation-related physicochemical, metabolite, and culture-based microbial variables, whereas clear treatment-dependent differences were observed for instrumental colour and trained-panel sensory responses. The a*/b* ratio was positively associated with perceived redness, and total capsaicinoid content was strongly associated with perceived pungency. Taste liking peaked within an intermediate pungency range rather than at the highest capsaicinoid level. Under the tested formulation conditions, kimchi containing Dabok at 17.5 g/kg maintained overall liking comparable to several full-dose treatments containing 35 g/kg red pepper powder. These findings provide formulation-specific proof-of-concept evidence for reducing Dabok input while retaining sensory quality when adequate colour expression and moderate pungency are maintained.