Trattamenti termici: valutazione delle degradazioni termossidative di oli da frittura e determinazione di composti aromatici in matrici alimentari complesse
Thermal treatment: evaluation of thermoxidative degradation in frying oils and determination of aromatic compounds in complex food matrices
Creators: name: Natale, Daniela <1982>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2012
Subjects: AGR/15 Scienze e tecnologie alimentari

description: Lo studio condotto durante il Dottorato di Ricerca è stato focalizzato sulla valutazione e sul monitoraggio delle diverse degradazioni termossidative in oli da frittura. Per raggiungere tale obiettivo si è ritenuto opportuno procedere mediante uno screening dei principali oli presenti sul mercato italiano e successiva messa a punto di due miscele di oli vegetali che sono state sottoposte a due piani sperimentali di frittura controllata e standardizzata in laboratorio, seguiti da due piani di frittura eseguiti in due differenti situazioni reali quali mensa e ristorante. Ognuna delle due miscele è stata messa a confronto con due oli di riferimento. 
A tal fine è stata identificato il profilo in acidi grassi, la stabilità ossidativa ed idrolitica, il punto di fumo, i composti polari, il contenuto in tocoferoli totali, ed i composti volatili sia sugli oli crudi che sottoposti ai diversi processi di frittura. 
Lo studio condotto ha permesso di identificare una delle miscele ideate come valida alternativa all’impiego dell’olio di palma ampiamente utilizzato nelle fritture degli alimenti, oltre a fornire delle indicazioni più precise sulla tipologia e sull’entità delle modificazioni che avvengono in frittura, a seconda delle condizioni impiegate.
description: The study conducted during the PhD research was focused on the assessment of various thermoxidative degradations in frying oils. To achieve this objective, it was considered appropriate to firs proceed with a screening of the major frying oils present in the Italian market, followed by the development of two frying blends, which were subjected to two different experimental frying plans at lab-scale, under controlled and standardized conditions. The same frying blends were also utilized under two different catering frying situations (cafeteria and restaurant). Each frying blend was compared with two reference frying oils (palm olein and extra virgin olive oil).
To evaluate the frying performance of each frying oil and blend, different analytical determinations were carried out; such analysis were performed before, during and at the end of the frying process. The study led to the identification of one of the mixtures here developed as a valid alternative to palm oil, which is widely used for food frying at catering level; in addition, this research allowed a better definition of the modifications (type and entity) that occur during food frying, according to the conditions used. The determination of polar compounds generated during frying were analyzed by both the official method and a high-performance size-exclusion chromatographic method (HPSEC). In the last part of the PhD period, the stability and usage of a special marinade, made of grape seed phenolic extracts encapsulated in liposomal systems, was tested on beef patties. The objective was to evaluate the ability of phenol-enriched liposomes to inhibit the formation of heterocyclic aromatic compounds generated by pan-frying.