Hot-Air-Assisted Infrared Drying for Marinated Anchovy: Effects of Spice Blends on Drying Characteristics and Quality

Abstract

This study examined the drying characteristics and quality of raw and marinated anchovy using a hot-air-assisted pilot-scale infrared (IR) dryer. Anchovy was marinated with various Indian spice blends and dried for 3 h under controlled conditions. Four marinade formulations were tested: M1 (0.5% salt, 0.25% red chili powder, 0.25% turmeric powder), M2 (1% salt, 0.25% red chili powder, 0.25% turmeric powder), M3 (1% salt, 0.5% red chili powder, 0.5% turmeric powder), and M4 (0.5% salt, 0.5% red chili powder, 0.5% turmeric powder), along with a control. Both marination and drying time significantly affected the final moisture content (p ≤ 0.001). The highest drying rate was observed for M3 (1.442 g/g dry matter/h) and the lowest for raw anchovy (1.389 g/g dry matter/h). Tukey's analysis revealed significant differences in drying rates between M3 and other marinated samples, as well as between raw and certain marinated samples, highlighting the effect of marination on drying efficiency. The diffusion approach model worked best with M3 anchovy. Effective moisture diffusivity values ranged from 7.003 × 10⁻⁹ to 8.913 × 10⁻⁹ m²/s, with a highest value reported for M3. The results signify the opportunities to improve the hot-air-assisted infrared (IR-HA) drying process and potentially reduce drying time and certainly energy usage. The findings emphasize that spice blends influence both drying characteristics and sensory attributes, offering valuable insights for refining marination strategies to enhance flavor, consistency, and product quality. Marinating before drying is recommended as a method to add the value to anchovy. The economic analysis revealed that the payback period for the IR-HA dryer when used to dry marinated anchovy is 0.88 years.