Thermo-alkaline Treatment as a Practical Degradation Strategy To Reduce Indospicine Contamination in Camel Meat

Abstract

Ingestion of indospicine-contaminated camel and horse meat has caused fatal liver injury to dogs in Australia, and it is currently not known if such contaminated meat may pose a human health risk upon dietary exposure. To date, indospicine-related research has tended to focus on analytical aspects, with little information on post-harvest management of indospicine-contaminated meat. In this study, indospicine degradation was investigated in both aqueous solution and also contaminated meat, under a range of conditions. Aqueous solutions of indospicine and indospicine-contaminated camel meat were microwaved (180 °C) or autoclaved (121 °C) with the addition of food-grade additives [0.05% (v/v) acetic acid or 0.05% (w/v) sodium bicarbonate] for 0, 15, 30, and 60 min. An aqueous sodium bicarbonate solution demonstrated the greatest efficacy in degrading indospicine, with complete degradation after 15 min of heating in a microwave or autoclave; concomitant formation of indospicine degradation products, namely, 2-aminopimelamic and 2-aminopimelic acids, was observed. Similar treatment of indospicine-contaminated camel meat with aqueous sodium bicarbonate resulted in 50% degradation after 15 min of heating in an autoclave and 100% degradation after 15 min of heating in a microwave. The results suggest that thermo-alkaline aqueous treatment has potential as a pragmatic post-harvest handling technique in reducing indospicine levels in indospicine-contaminated meat.

Toxin Degradation by Rumen Microorganisms: A Review

“…Indospicine hydrolysis directly to 2-aminopimelic acid was also reported with concentrated hydrochloric acid (6 N HCl, 120 °C, 20 h) [ 124 ]. Indospicine was also found to be stable under mild acidic aqueous conditions in vitro and it was hypothesised that the mild acidic conditions in the stomach would not be able to hydrolyse indospicine [ 137 ].…”

Old World camels in a modern world – a balancing act between conservation and genetic improvement

“…A wide range of variation was observed for most of the variables between the four dromedary types, with a clear differentiation of Majaheem from the other three dromedary types (Maghateer, Hamrah and Safrah). The effect of thermo-alkaline treatment in reducing hepatotoxin contamination in camel meat has been demonstrated (Tan et al 2016). Whereas myostatin gene structure, polymorphism and expression in dromedaries have been characterised (Favia et al 2019), no (genome-wide) association study has been performed for growth or meat performance.…”

Release of Indospicine from Contaminated Camel Meat following Cooking and Simulated Gastrointestinal Digestion: Implications for Human Consumption

“…Our results suggest that the human digestive system does not have the capacity to degrade indospicine. Tan et al [ 38 ] have recently reported that microwaving indospicine-contaminated camel meat under mild alkaline conditions (0.05% sodium bicarbonate, pH 8.8, 15 min) achieved 100% degradation of indospicine, with products identified as 2-aminopimelamic acid (major) and 2-aminopimelic acid (minor) ( Figure 5 ). Such processing treatments may have ready applicability in the pet food industry given the recorded sensitivity of dogs to indospicine-contaminated meat, but are perhaps not appropriate in the processing of food for human consumption.…”

“…Such processing treatments may have ready applicability in the pet food industry given the recorded sensitivity of dogs to indospicine-contaminated meat, but are perhaps not appropriate in the processing of food for human consumption. Additionally, the metabolic fate and toxicity of indospicine hydrolysis products remains unknown and requires further investigation [ 38 ].…”