Comparative study of intermediate-wave and catalytic infrared drying on the kinetics and physicochemical properties of pineapple rings

Abstract

This comprehensive study examined the effects of two infrared drying modes: intermediate-wave infrared drying (IWD) and catalytic infrared drying (CID), on drying kinetics and various quality parameters of pineapple rings at 60–80 °C. Hot-air drying (HAD) was the control drying operation. CID showed the highest drying rates and coefficients of moisture diffusivity (3.05 × 10−8 m2/s to 5.12 × 10−8 m2/s), resulting in drying times (1.88–3.15 h) that were about half that of HAD (3.57–7.25 h) and 10–34% less than that of IWD (2.08–4.75 h). Compared to IWD, CID exhibited minor color changes and a stronger flavor profile and enzyme inactivation potential. However, it resulted in a hardened product surface, thus reducing the rehydration ability. Overall, CID exhibited higher bioactive retention rates, especially at 60 °C (56–87%), followed by IWD at 70 °C (50–80%) and 80 °C (35–90%). Based on the results of this study, CID produces superior quality dried pineapples in a significantly shorter drying time, which is of potential industrial interest.