Fermentation is a metabolic process that belongs to anaerobic glucose metabolism characterized by cellular catabolism. Specifically, from a biochemical point of view, it is nothing but an alternative metabolic pathway to normal cellular respiration exploited by prokaryotic and eukaryotic cells for the purpose of obtaining energy to be used for cell multiplication and growth. Chemically, however, it is set of oxidation-reduction reactions. It takes place in the absence of oxygen (which is the e-acceptor of respiration), and the molecules involved in electron transfer are the coenzyme NAD+ (nicotinamide adenine dinucleotide), which is always reduced to NADH (acquires e-), which acts as an electron transporter; (there must be continuous NAD+ /NADH recycling) Energy (ATP) is produced by substrate-level phosphorylation reactions; energy yields are low, ranging from a minimum of 1 ATP to a maximum of 4 ATP. From pyruvic acid, various end products can be obtained that distinguish the various bacterial fermentations. Through such knowledge, it is possible to understand how food industries use the technological aspects of the fermentation process to their advantage in order to preserve food safely by increasing its shelf-life and giving products particular organoleptic characteristics.
La Fermentazione è un processo metabolico che appartiene al metabolismo anaerobio del glucosio caratterizzato dal catabolismo cellulare. Nello specifico, dal punto di vista biochimico, altro non è che una via metabolica alternativa alla normale respirazione cellulare sfruttata da cellule procariote ed eucariote, con lo scopo di ottenere energia da sfruttare per la moltiplicazione e l’accrescimento della cellula. Chimicamente, invece, è insieme di reazioni di ossidoriduzione. Avviene in assenza di ossigeno (che è l’accettore di e- della respirazione) e le molecole protagoniste del trasferimento di elettroni sono il coenzima NAD+ (nicotinammide adenina dinucleotide) che è sempre ridotto a NADH (acquista e-) che funge da trasportatore di elettroni; (deve esserci un continuo riciclo NAD + /NADH) L’energia (ATP) è prodotta con reazioni di fosforilazione a livello di substrato; le rese energetiche sono basse e vanno da un minimo di 1 ATP a un massimo di 4 ATP. A partire dall’acido piruvico è possibile ottenere vari prodotti finali che distinguono le varie fermentazioni batteriche. Attraverso tali conoscenze, è possibile comprendere come le industrie alimentari sfruttano gli aspetti tecnologici del processo di fermentazione a proprio vantaggio per conservare gli alimenti in maniera sicura aumentandone la shelf-life ed attribuendo ai prodotti particolari caratteristiche organolettiche.
Alimenti fermentati: aspetti tecnologici e sensoriali.
BALLARIN, ALESSANDRO
2022/2023
Abstract
Fermentation is a metabolic process that belongs to anaerobic glucose metabolism characterized by cellular catabolism. Specifically, from a biochemical point of view, it is nothing but an alternative metabolic pathway to normal cellular respiration exploited by prokaryotic and eukaryotic cells for the purpose of obtaining energy to be used for cell multiplication and growth. Chemically, however, it is set of oxidation-reduction reactions. It takes place in the absence of oxygen (which is the e-acceptor of respiration), and the molecules involved in electron transfer are the coenzyme NAD+ (nicotinamide adenine dinucleotide), which is always reduced to NADH (acquires e-), which acts as an electron transporter; (there must be continuous NAD+ /NADH recycling) Energy (ATP) is produced by substrate-level phosphorylation reactions; energy yields are low, ranging from a minimum of 1 ATP to a maximum of 4 ATP. From pyruvic acid, various end products can be obtained that distinguish the various bacterial fermentations. Through such knowledge, it is possible to understand how food industries use the technological aspects of the fermentation process to their advantage in order to preserve food safely by increasing its shelf-life and giving products particular organoleptic characteristics.File | Dimensione | Formato | |
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https://hdl.handle.net/20.500.12608/59165