Species authentication in meat products sold in Kilosa District in Tanzania using HRM-enhanced DNA barcoding

Abstract

Species substitution in meat products is a common form of food fraud that raises ethical, religious, dietary, and conservation issues. Measures to monitor meat substitution are being implemented in many parts of the world. However, information on similar efforts in Tanzania is scarce. This study aimed to assess species authenticity in kebabs sold in the Kilosa District. During 4 months (November 2023 to March 2024), 100 processed kebabs were purchased from fast food outlets across 3 wards: Dumila (n = 49), Kimamba (n = 24), and Mikumi (n = 27). Species authentication was conducted using High-resolution melting analysis and DNA barcoding, targeting two mitochondrial markers: cytochrome oxidase 1 (COI) and 16 S rRNA. Out of 100 kebabs, 64 were misidentified. Notably, goat-based kebabs were the most substituted, with 36 out of 43 (83.7%) containing different species: cattle (30), chicken (2), impala (1), and warthog (3). Out of 40 cattle kebabs, 18 (45%) consisted of meat from different species: chicken (7), goat (8), 2 impala (2), and 1 warthog (1). Chicken kebabs had only 7 undeclared cattle species, and all 3 samples sold as mutton kebabs were substituted with cattle (2) and goat (1). The findings indicate a high prevalence of species substitution in meat products within the Kilosa District. Undeclared wildlife species might represent illegal bushmeat harvests in the conserved ecosystems. Extensive meat inspections and educational interventions are recommended to ensure the integrity of the meat market, consumer trust, and the conservation of wildlife.