Effect of hydrogenation of palm oil products spiked with octachlorodibenzo-p-dioxin on dioxin congener profiles and toxic equivalent levels

Wilma Taverne-Veldhuizen,Rik Herbes,Ron Hoogenboom,Vincenzo Fogliano,Pieternel Luning,Guillaume Ten Dam

doi:10.1016/j.foodcont.2021.108546

Abstract

Between 1999 and 2020, there were twelve rapid alerts on dioxins in palm fatty acid distillate (PFAD) products, six of which were associated with hydrogenated palm fatty acid distillates (HPFADs). In palm oil refineries for food and feed, refined palm oil and PFADs can be processed into hydrogenated palm oil and HPFADs. This study investigated the effect of hydrogenation of palm oil products which contain OCDD and impact on the profiles of dioxins in palm oil products and on the toxic equivalent (TEQ) level. Palm oil and PFADs were spiked with octachlorodibenzo-p-dioxin (OCDD) and hydrogenated at different pressures, temperatures, and catalyst conditions. Initially, the concentrations of the lower-chlorinated dioxin congeners, some with a higher toxic equivalency factor, increased. Consequently, the TEQ levels increased and exceeded the regulatory limit. However, further hydrogenation extended the dechlorination of dioxins resulting in decreased TEQ levels. Optimisation of the hydrogenation process is required to reduce the risk of exceeding the limits on dioxins. • Hydrogenation of palm oil products affected the toxicity of dioxin congeners. • Octachlorodibenzo-p-dioxin (OCDD) dechlorinated during hydrogenation. • OCDD dechlorination initially formed congeners with higher toxicity. • Further hydrogenation reduced dioxin concentration and toxic equivalence level.

Highlights

Control of chemical hazards is vital in the food and feed industry to ensure safe products
An incident with much lower levels occurred in Ger many in 2011, where fatty acids intended for deinking, were used for feed production (Abraham et al, 2011). This incident affected consumer trust and resulted in specific dioxin testing re quirements for products derived from vegetable oils and blended fats (EC, 2012a, 2015), such as palm fatty acid distillates (PFADs), and hy drogenated palm fatty acid distillates (HPFADs)
Twelve notifications were related to exceeding the dioxin toxic equiva lent (TEQ) level in PFAD products, and at least six of these were asso ciated with hydrogenated palm fatty acid distillates (HPFADs)

Summary

Introduction

Control of chemical hazards is vital in the food and feed industry to ensure safe products. Dioxins have been involved in several food and feed safety issues, and have been reported regularly to the European (EU) Rapid Alert System for Food and Feed (RASFF) in the last few decades An incident with much lower levels occurred in Ger many in 2011, where fatty acids intended for deinking, were used for feed production (Abraham et al, 2011). This incident affected consumer trust and resulted in specific dioxin testing re quirements for products derived from vegetable oils and blended fats (EC, 2012a, 2015), such as palm fatty acid distillates (PFADs), and hy drogenated palm fatty acid distillates (HPFADs). The highest level in PFADs reported in the RASFF database was 2.3 ng WHO-TEQ/kg (RASFF, 2020), which justified the research on the mechanism of the chemical processes

Objectives

Methods

Results