his study aimed to investigate the effect of dietary selenium (Se) supplementation of Friesian cows on the aromatic properties of dairy products. Thirty-two Friesian cows, balanced for parity, milk production and days in milk, were randomly assigned to 2 groups. The trial lasted 63 days in which the control group (CG) was fed with a conventional feeding strategy, while the experi- mental group (SeG) received daily selenomethionine (SeMet) supplementation. During the experimental period, the milk yield was monitored and samples of milk and related Caciocavallo cheese were collected and analysed in order to obtain information on chemical-nutritional composition. To evaluate the effect of ripening on the aromatic profile, the analysis was performed on cheese samples collected after 7 (T7) and 120 (T120) days after the cheese-making. The volatile compounds composition resulted positively affected by dietary Se intake, with a significant increase in concentration of carboxylic acids, esters and lactones (p<.05), reflecting the predominance of the lipolytic processes respect to the proteolytic events. The general increase of carboxylic acids in ripened cheese could be explained by the extent of starter cell autolysis, with the consequent release of peptidases and espe- cially lipases that accelerate the lipolytic events. Among the most represented carboxylic acids must be indicated butanoic and ANIMAL PRODUCTS hexanoic acids; such compounds are considered to be mainly involved in the determination of cheese flavour, giving origin to cheesy, rancid and sweaty odours. The increased production of such compounds could be probably explained by an increase of lipolysis of the triglycerides by microbial and endogenous milk enzymes, resulting in an augmented release of free fatty acids (FFAs). With regard to the esters, such compounds are charac- terised by a low odour threshold and are generally associated with the sweet, fruity, and floral notes of surface-ripened cheese fla- vour. Lactones, instead, are generally produced by a one-step transesterification reaction of hydroxylated FFAs which represent the main precursors. Such findings could contribute to the pro- duction of cheeses with interesting organoleptic properties, although further sensorial evaluations should be performed to deeply investigate these changes and confirm the consumer acceptability.
Dietary selenium supplementation of Friesian cows modifies the aromatic profile of dairy products
Andrea Ianni;Marco Iannaccone;Lisa Grotta;Denise Innosa;Giuseppe Martino
2019-01-01
Abstract
his study aimed to investigate the effect of dietary selenium (Se) supplementation of Friesian cows on the aromatic properties of dairy products. Thirty-two Friesian cows, balanced for parity, milk production and days in milk, were randomly assigned to 2 groups. The trial lasted 63 days in which the control group (CG) was fed with a conventional feeding strategy, while the experi- mental group (SeG) received daily selenomethionine (SeMet) supplementation. During the experimental period, the milk yield was monitored and samples of milk and related Caciocavallo cheese were collected and analysed in order to obtain information on chemical-nutritional composition. To evaluate the effect of ripening on the aromatic profile, the analysis was performed on cheese samples collected after 7 (T7) and 120 (T120) days after the cheese-making. The volatile compounds composition resulted positively affected by dietary Se intake, with a significant increase in concentration of carboxylic acids, esters and lactones (p<.05), reflecting the predominance of the lipolytic processes respect to the proteolytic events. The general increase of carboxylic acids in ripened cheese could be explained by the extent of starter cell autolysis, with the consequent release of peptidases and espe- cially lipases that accelerate the lipolytic events. Among the most represented carboxylic acids must be indicated butanoic and ANIMAL PRODUCTS hexanoic acids; such compounds are considered to be mainly involved in the determination of cheese flavour, giving origin to cheesy, rancid and sweaty odours. The increased production of such compounds could be probably explained by an increase of lipolysis of the triglycerides by microbial and endogenous milk enzymes, resulting in an augmented release of free fatty acids (FFAs). With regard to the esters, such compounds are charac- terised by a low odour threshold and are generally associated with the sweet, fruity, and floral notes of surface-ripened cheese fla- vour. Lactones, instead, are generally produced by a one-step transesterification reaction of hydroxylated FFAs which represent the main precursors. Such findings could contribute to the pro- duction of cheeses with interesting organoleptic properties, although further sensorial evaluations should be performed to deeply investigate these changes and confirm the consumer acceptability.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
