Celiac disease is an autoimmune disease triggered, in genetically-disposed individuals, by the ingestion of prolamins, a protein complex present in different cereals, such as wheat, rye, and barley. Some studies suggest that the oxidative stress is one of the mechanisms responsible for the gluten toxicity. The gluten-free diet is the only universally accepted treatment for celiac disease; although the dietetic offer for celiac subjects has improved significantly in quality and quantity, an improvement in the nutritional, sensorial and functional quality of gluten-free products is still necessary. Antioxidant and anti-inflammatory properties of the diet are important for all consumers, but are particularly critical for celiac patients who show intestinal inflammation even when the gluten-free diet is followed. Pigmented corns are naturally gluten free cereals mainly cultivated in South America and not widespread through Europe. They are rich in anthocyanins, active molecules with known antioxidant and antiradical activities; for the content in these active molecules, pigmented corns could be included among ingredients of new gluten-free products. To evaluate this possibility, different corn samples were included in this study: one purple corn (used for animal feeding), three yellow varieties (suitable for human consumption) and three pigmented varieties obtained by the crossbreeding between the purple and the yellow varieties. The crossbreeding process was performed in order to obtain pigmented varieties suitable for human diet and for the cultivation in temperate climate areas. The first tier of the research plan consisted of the chemical characterization of cereal samples and the parallel evaluation of their antioxidant activity, applying both spectrophotometric and chromatographic (HPTLC, LC-MS e HPLC-DAD) techniques. The pigmented varieties were compared to both parental varieties (yellow and purple corns) for their phenolic profile in terms of free (phenolic acids and anthocyanins) and bound (phenolic acids) phenolic compounds. A good correlation between total polyphenol content and the antioxidant activity of samples was observed. After the chemical characterization, the human gastro-intestinal digestion was mimicked by an in vitro model, in order to monitor the stability of anthocyanins at intestinal level. Finally, different cellular tests (cell agglutination test and the measure of transepithelial electrical resistance) were performed, confirming the safety of these new pigmented varieties for the celiac subjects. The methods developed in this study are important tools to characterize corn samples and to investigate about the role of polyphenols in the modulation of chronic inflammatory conditions in celiac subjects. The results obtained in this project could contribute to inclusion of pigmented varieties among new functional naturally gluten-free ingredients. The novel products, obtained with the new varieties rich in polyphenols, could have a role in enhancing the quality of life in patients with celiac disease in term of both intestinal health and sensorial aspects.
La celiachia è una malattia autoimmune scatenata, in soggetti geneticamente predisposti, dall’ingestione di prolammine contenute in alcuni cereali quali frumento, orzo e segale. Recenti studi hanno messo in luce come tale condizione sia accompagnata da un quadro generale di stress ossidativo che, in alcuni casi, permane anche dopo il trattamento dietetico. In questo contesto risulta dunque importante identificare nuovi ingredienti senza glutine che possano contribuire a un miglioramento delle condizioni di salute dei soggetti affetti da celiachia. I mais pigmentati, diffusi principalmente in Sud America e ancora poco utilizzati in Europa, potrebbero rappresentare degli ingredienti senza glutine innovativi in quanto sono ricchi in antociani, molecole ad elevata attività antiossidante, e sono naturalmente privi di glutine. In questo progetto sono stati inclusi differenti campioni di mais: un campione di mais viola (ad uso animale), tre varietà di mais giallo (ad uso umano) e tre varietà pigmentate, ciascuna ottenuta dall’incrocio di una varietà gialla con il mais viola. Il processo di incrocio è stato condotto al fine di ottenere varietà pigmentate ad uso umano adatte ad essere coltivate in climi temperati. Nella prima fase del lavoro differenti metodi spettrofotometrici e cromatografici (HPTLC, LC-MS e HPLC-DAD) sono stati sviluppati ed applicati al fine di caratterizzare le diverse varietà di mais incluse nello studio e valutarne parallelamente la relativa capacità antiossidante. Le varietà pigmentate, confrontate con i rispettivi mais parentali (mais viola e mais gialli), hanno mostrato un interessante profilo fenolico sia in termine di componente solubile (antociani e acidi fenolici), sia insolubile (acidi fenolici). Il contenuto di polifenoli è risultato proporzionale all’attività antiossidante valutata con le differenti metodiche spettrofotometriche e cromatografiche. Nella seconda fase del lavoro è stata applicata una digestione in vitro al fine di monitorare la stabilità delle antocianine nel tratto gastrointestinale. Infine, differenti test cellulari (test di agglutinazione e valutazione della resistenza elettrica trans-epiteliale) hanno permesso di confermare la sicurezza d’uso delle nuove varietà pigmentate per i soggetti affetti da celiachia. I risultati derivanti da questo progetto potrebbero contribuire all’inclusione delle varietà pigmentate tra i nuovi ingredienti funzionali naturalmente privi di glutine. I prodotti alimentari, ottenuti con le nuove varietà ricche di polifenoli, potrebbero avere un ruolo nel migliorare la qualità della vita dei pazienti con malattia celiaca in termini sia di salute intestinale che di aspetti sensoriali.
VARIETÀ PIGMENTATE DI ZEA MAYS L.: CARATTERIZZAZIONE DEL PROFILO FENOLICO E POTENZIALITÀ DI IMPIEGO NELLA DIETA SENZA GLUTINE / F. Colombo ; tutor: P. Restani ; coordinatore: L. Pinotti. DIPARTIMENTO DI SCIENZE FARMACOLOGICHE E BIOMOLECOLARI, 2020 Jan 27. 32. ciclo, Anno Accademico 2019. [10.13130/colombo-francesca_phd2020-01-27].
VARIETÀ PIGMENTATE DI ZEA MAYS L.: CARATTERIZZAZIONE DEL PROFILO FENOLICO E POTENZIALITÀ DI IMPIEGO NELLA DIETA SENZA GLUTINE
F. Colombo
2020
Abstract
Celiac disease is an autoimmune disease triggered, in genetically-disposed individuals, by the ingestion of prolamins, a protein complex present in different cereals, such as wheat, rye, and barley. Some studies suggest that the oxidative stress is one of the mechanisms responsible for the gluten toxicity. The gluten-free diet is the only universally accepted treatment for celiac disease; although the dietetic offer for celiac subjects has improved significantly in quality and quantity, an improvement in the nutritional, sensorial and functional quality of gluten-free products is still necessary. Antioxidant and anti-inflammatory properties of the diet are important for all consumers, but are particularly critical for celiac patients who show intestinal inflammation even when the gluten-free diet is followed. Pigmented corns are naturally gluten free cereals mainly cultivated in South America and not widespread through Europe. They are rich in anthocyanins, active molecules with known antioxidant and antiradical activities; for the content in these active molecules, pigmented corns could be included among ingredients of new gluten-free products. To evaluate this possibility, different corn samples were included in this study: one purple corn (used for animal feeding), three yellow varieties (suitable for human consumption) and three pigmented varieties obtained by the crossbreeding between the purple and the yellow varieties. The crossbreeding process was performed in order to obtain pigmented varieties suitable for human diet and for the cultivation in temperate climate areas. The first tier of the research plan consisted of the chemical characterization of cereal samples and the parallel evaluation of their antioxidant activity, applying both spectrophotometric and chromatographic (HPTLC, LC-MS e HPLC-DAD) techniques. The pigmented varieties were compared to both parental varieties (yellow and purple corns) for their phenolic profile in terms of free (phenolic acids and anthocyanins) and bound (phenolic acids) phenolic compounds. A good correlation between total polyphenol content and the antioxidant activity of samples was observed. After the chemical characterization, the human gastro-intestinal digestion was mimicked by an in vitro model, in order to monitor the stability of anthocyanins at intestinal level. Finally, different cellular tests (cell agglutination test and the measure of transepithelial electrical resistance) were performed, confirming the safety of these new pigmented varieties for the celiac subjects. The methods developed in this study are important tools to characterize corn samples and to investigate about the role of polyphenols in the modulation of chronic inflammatory conditions in celiac subjects. The results obtained in this project could contribute to inclusion of pigmented varieties among new functional naturally gluten-free ingredients. The novel products, obtained with the new varieties rich in polyphenols, could have a role in enhancing the quality of life in patients with celiac disease in term of both intestinal health and sensorial aspects.File | Dimensione | Formato | |
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