Work

Comparative evaluation of drying techniques on quality attributes, phytochemicals, and antioxidant capacity of Coffea arabica var. typica pulp

Year: 2025

Type: article

Abstract: This study investigated the effects of different drying methods, including freeze drying (FD), sun drying (SD), hot air drying at 60 °C and 70 °C (HA60, HA70), and vacuum drying at 60 °C and 70 °C (VC60, VC70), on the microbiological safety, physicochemical properties, bioactive compounds, antioxidant capacity, and 5-hydroxymethylfurfural (HMF) content of dried coffee pulp. FD preserved the highest levels of chlorogenic acid, caffeine, proanthocyanidins, total phenolic content (557 mg GAE/100 g DW), total flavonoid content (203 mg CE/100 g DW), and antioxidant activity (DPPH, FRAP, and ORAC assays), while also maintaining superior color quality and undetectable HMF levels. However, FD-samples exhibited microbial counts within acceptable limits, whereas all thermal drying methods effectively eliminated detectable microorganisms. HA at 70 °C led to the greatest degradation of bioactive compounds and highest HMF formation (42 mg/kg DW). Vacuum drying, particularly at 70 °C, emerged as a promising alternative, providing a balance between microbial safety, retention of phytochemicals, antioxidant activity, and lower HMF accumulation. These findings suggested that VC70 as a practical and efficient method for producing microbiologically safe, bioactive-rich coffee pulp powder suitable for functional food applications.

Source: Journal of Agriculture and Food Research

DOI: 10.1016/j.jafr.2025.102274