Valorized pineapple waste by conventional and energy-saving ohmic extraction: potentially toxic elements and mycotoxin contamination

Abstract

Pineapple peel is a food waste with environmental concerns. It can be valorized by extracting its bioactive compound through conventional and emerging technologies such as ohmic heating. However, mycotoxins and heavy metals contaminations could be concerns of such a valorization process. This study assessed the effects of conventional and ohmic heating on selected aflatoxins and metal ions in pineapple peel extract using high- performance liquid chromatography (HPLC) and inductively coupled plasma mass spectrometry (ICP-MS). Also, energy consumption and environmental impacts of the ohmic process were analyzed. According to the results, the ohmic-based valorization system reduced energy consumption and greenhouse gas emissions by more than 83%, contributing to net-zero and sustainable development goals (SDGs). Aflatoxins B1, B2, G1, and G2 were below the detection limit (B1, G1: 0.2µg/kg; B2, G2: 0.1µg/kg). However, ohmic extracts contained higher concentrations of Cr, Pb, Ni, and Fe because of electrochemical reactions and electrode corrosion. Despite the capability of ohmic valorization systems, inspecting food waste and valorized products for hazardous chemicals and investing in durable electrodes (e.g., titanium) are among the considerations for ohmic systems’ industrial implementation.