2.1.3. Ammoniation

Ammonia (NH3) is a gas stored in water solution or pressurized bottles. It is used to detoxify mycotoxins in different food matrices. Most studies have focused on aflatoxins [37]. Many studies supported the use of ammonia to detoxify aflatoxins in foods and feeds and proposed it as an effective, economic alternative [55,56]. High reduction rates of aflatoxins have resulted in ammoniation reaching 96 and 99% [54].

Ammonia is more effective against aflatoxins G1 and G2 than aflatoxins B1 and B2. This is confirmed by a study that demonstrated that the degradation rate was 95% for aflatoxin G1, 93% for aflatoxin G2, 85% for aflatoxin B1, and 83% for aflatoxin B2 in artificially contaminated maize crops [56].

The highest efficiency of ammoniation in aflatoxin detoxification is achieved by the use of 0.5 to 2.0% ammonia at moisture levels between 12 and 16% and under pressure (45–55 psi) at high temperatures reaching 80–100 ◦C for 20 to 60 min where the recovery of the ammonia is conducted by evaporation at the end of the process [54,64].

The degradation of deoxynivalenol (DON) in contaminated wheat kernels was confirmed, and the achieved degradation rates were 75% or higher. The initial concentrations of DON in the kernels were up to 2000 μg/kg and vapor ammonia was implemented at a high temperature reaching 90 ◦C for 2 h. The toxicity of the ammoniation products is lower than DON [37].

Aflatoxins-contaminated corn is detoxified by the use of aqua-ammonia (liquid) or anhydrous ammonia (gas). The treatment with aqua-ammonia imposes the drying of the crops before storage. Ammoniation could affect the organoleptic characteristics of the treated corn by causing grain darkness as a result of the caramelization of sugar (altrose) caused by the increase in the temperature during treatment [55].
