Efecto de diferentes pre-tratamientos sobre la cinética de secado y las propiedades fisicoquímicas de la harina obtenida a partir de residuos de brócoli (Brassica oleracea var. italica Plenck)

Abstract

This research evaluated the effect of different thermal pretreatments – boiling in water, steaming, and microwave heating – on the drying kinetics and physicochemical properties of flour produced from broccoli residues (Brassica oleracea var. italica Plenck). The study aimed to promote the integral utilization of vegetable by-products to reduce agroindustrial waste and support food sustainability. Broccoli residues underwent various pretreatments and were then dehydrated through convective drying. Drying kinetics were assessed by constructing moisture loss curves and estimating key parameters such as critical moisture content, effective moisture diffusivity (Deff), and moisture loss rates. Additionally, the physicochemical properties of the flours were analyzed, including moisture content, water activity (aw), pH, Brix degrees, and titratable acidity.The results showed that pretreatments significantly affect both drying efficiency and final product quality. Water boiling achieved the highest initial drying rate, while steaming led to the lowest water activity and greatest microbial stability. Microwave treatment, although faster in moisture removal, showed reduced performance during the diffusion-dominated drying phase. The resulting flours presented significant differences in acidity and °Brix, with the steam treatment producing the most balanced outcomes, so this study provides scientific insights for the development of functional ingredients derived from vegetable waste, reinforcing circular economy practices in the Ecuadorian food industry.