Behavior of Aflatoxin M1 in dairy wastes subjected to different technological treatments: Ricotta cheese production, ultrafiltration and spray-drying

Although considered by-products of cheese production, milk whey, deproteinized whey and valuable components extracted from them, have several commercial uses as nutritional supplements and processing aids. In order to verify the safety of these products, destiny of AFM1 contaminating whey and deproteinized whey subjected to different technological treatments was investigated. During Ricotta cheese production the main part of AFM1, on average 94%, was lost in the liquid portion, while only 6% remained in the curd. Whey and deproteinized whey remaining from Ricotta cheese production were then subjected to ultrafiltration and spray-drying. In the first case, ultrafiltration coupled with diafiltration allowed to remove more than 90% of toxin without losing proteins. Spray-drying was efficient in reducing AFM1 contamination, too: in whey, toxin recovery was around 60%, aligned with powder recovery, while in deproteinized whey AFM1 recovery was around 39%, by far lower than powder recovery, confirming a loss. ► Destiny of AFM1 in naturally contaminated whey and deproteinized whey subjected to different technological treatments was studied. ► Only 6% of toxin remained associated to Ricotta cheese while 94% was lost in the liquid portion. ► During a simple ultrafiltration step at least 60–80% of toxin was lost in permeate. ► Spray-drying reduced contamination levels in powders despite great losses of material.