Almonds are extremely nutrient-dense nuts. They provide generous amounts of calories, fats, complex carbohydrates, protein, vitamins, minerals and fiber. They are consumed as raw nuts or as ingredients of derived products. However, almonds can be susceptible to aflatoxins contamination, extremely harmful for the human health even at low concentrations. We evaluated the evolution of aflatoxins during processing of almonds into traditional Italian products, such as pastries, nougat and syrup. The mass balance approach was used to determine levels and distribution of aflatoxins in each fraction collected during processing steps. Experiments were conducted on almonds inoculated with a toxigenic strain of Aspergillus flavus. A robust and horizontal HPLC-FLD method was optimized and used for aflatoxins determination in all the matrices considered in this study. The two tested blanching processes (steaming and boiling in water) did not reduce aflatoxins levels in peeled almonds. Standard roasting conditions produced up to 50% reduction of aflatoxins. Higher aflatoxin reduction (82%) was observed by roasting at 150°C for 120 min, but almonds lost their organoleptic characteristics. The preparation and cooking of nougat produced a consistent reduction of 54-70% of aflatoxins due to the caramelisation of sugar on almond surface. Almond pastries were prepared by mixing almond paste, eggs and sugar and cooked at 140°C for 30 min, 160°C for 20 min or 180°C for 15 min. Aflatoxins were substantially stable during cooking of pastries. Almond syrup was prepared from ground peeled almond that was infused in water for 5 hours. After infusion spent almonds were discarded and the infuse was sugared and boiled until it reaches the consistency of a syrup. About 18-25% of total aflatoxins passed in the final syrup. The whole process of almond syrup preparation produced a marked increase of total aflatoxins. This increase was probably due to the activation of endogenous almond enzymes that release free aflatoxins from modified aflatoxins during the water infusion of ground peeled almonds.
Making traditional italian almond sweets: effects on aflatoxins levels and distribution in final and waste products
Gambacorta Lucia;Piemontese Luca;Perrone Giancarlo;Solfrizzo Michele
2015
Abstract
Almonds are extremely nutrient-dense nuts. They provide generous amounts of calories, fats, complex carbohydrates, protein, vitamins, minerals and fiber. They are consumed as raw nuts or as ingredients of derived products. However, almonds can be susceptible to aflatoxins contamination, extremely harmful for the human health even at low concentrations. We evaluated the evolution of aflatoxins during processing of almonds into traditional Italian products, such as pastries, nougat and syrup. The mass balance approach was used to determine levels and distribution of aflatoxins in each fraction collected during processing steps. Experiments were conducted on almonds inoculated with a toxigenic strain of Aspergillus flavus. A robust and horizontal HPLC-FLD method was optimized and used for aflatoxins determination in all the matrices considered in this study. The two tested blanching processes (steaming and boiling in water) did not reduce aflatoxins levels in peeled almonds. Standard roasting conditions produced up to 50% reduction of aflatoxins. Higher aflatoxin reduction (82%) was observed by roasting at 150°C for 120 min, but almonds lost their organoleptic characteristics. The preparation and cooking of nougat produced a consistent reduction of 54-70% of aflatoxins due to the caramelisation of sugar on almond surface. Almond pastries were prepared by mixing almond paste, eggs and sugar and cooked at 140°C for 30 min, 160°C for 20 min or 180°C for 15 min. Aflatoxins were substantially stable during cooking of pastries. Almond syrup was prepared from ground peeled almond that was infused in water for 5 hours. After infusion spent almonds were discarded and the infuse was sugared and boiled until it reaches the consistency of a syrup. About 18-25% of total aflatoxins passed in the final syrup. The whole process of almond syrup preparation produced a marked increase of total aflatoxins. This increase was probably due to the activation of endogenous almond enzymes that release free aflatoxins from modified aflatoxins during the water infusion of ground peeled almonds.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
