Acid–thermal responses and co-gel performance of konjac flours from Amorphophallus bulbifer and Amorphophallus rivieri in κ-carrageenan systems

Flour source altered acid–thermal response of konjac sols. • Amorphophallus bulbifer flour showed higher sol transmittance and slower modulus decay. • Water distribution differed among the tested κ-carrageenan co-gel formulations. • Flour-dependent differences were expressed differently in sol and κ-carrageenan co-gel systems. Commercial refined konjac flours contain glucomannan as their dominant polysaccharide, but their functional performance requires evaluation across processing conditions and gel formulations. Here, flours from Amorphophallus bulbifer (ABF) and Amorphophallus rivieri (ARF) were compared using compositional analysis, swelling behaviour, rheology, optical measurements, low-field NMR, and κ-carrageenan co-gel systems. Relative to ARF, ABF showed lower swelling viscosity, higher sol transmittance, and later modulus maxima during prolonged holding. Under combined acid–thermal stress, ABF retained low-shear viscosity more effectively than ARF, indicating distinct response modes rather than uniformly weaker behaviour. ABF-based co-gels showed higher transmittance across matched formulations. Water distribution and mechanical properties varied among the tested flour–formulation combinations. Flour-dependent differences were expressed differently across the sol and co-gel systems. These findings support evaluating commercial flours through processing response and formulation-specific gel properties. Download: Download high-res image (221KB) Download: Download full-size image