Digestomika alergena kikirikija i karakterizacija fragmenata otpornih na proteolizu
Digestomics of peanut allergens and characterization of digestion resistant fragments
Doktorand
Prodić, IvanaMentor
Ćirković Veličković, TanjaČlanovi komisije
Smiljanić, KatarinaStanić-Vučinić, Dragana
Radosavljević, Jelena
Apostolović, Danijela
Metapodaci
Prikaz svih podataka o disertacijiSažetak
INFOGEST metoda predstavlja standardizovani protokol za in vitro simulaciju
digestije kompletne hrane, zasnovanom na fiziološki relevantnim uslovima. Predmet
rada ove disertacije je ispitivanje digestibilnosti alergena kikirikija iz celog zrna
primenom INFOGEST metode, kao i karakterizacija njihovih fragmenata otpornih na
proteolizu.
Za odstranjivanje lipida primenjena je metoda taloženja proteina, koja se pokazala kao
superiornija u odnosu ekstrakciju lipida organskim rastvaračem, usled manjeg
kvalitativnog i kvantitativnog gubitka proteina.
U ovoj tezi je pokazano da termički tretmani kikirikija, pored matriksa hrane, dodatno
otežavaju oslobađanje proteina iz zrna, što čini glavne alergene kikirikija Ara h 1, Ara h
2 Ara h 3 i Ara h 6 nedostupnijim za pepsinsku hidrolizu. Oslobađanje proteina
kikirikija, kao i digestibilnost, u gastričnoj fazi se pokazala znatno izraženijom, u
odnosu na intestinalnu fazu, s tim da je digestija kod pečenog kikirikija otežana u
odnosu na sirovi. Nakon ...oralno-gastrične digestije celog zrna sirovog kikirikija, glavni
alergeni kikirikija u velikoj meri ostaju intaktni, a njihovi peptidi otporni na digestiju
zadržavaju alergeni kapacitet. Pokazano je da većina Ara h 2 i Ara h 6 alergena ostaje
rezistentna na digestiju. Ara h 1 i Ara h 3 kaskadno podležu pepsinolizi, do fragmenata
koji i dalje zadržavaju IgE vezujući potencijal. Mali peptidi koji potiču od Ara h 2
alergena, su se pokazali kao najpotentniji inhibitori vezivanja IgE iz seruma pacijenata
alergičnih na kikiriki, u odnosu na male Ara h 1 i Ara h 3 peptide.
U ovoj disertaciji je pokazana izuzetno važna uloga efekata matriksa hrane, kao i njene
termičke obrade, na digestiju proteina hrane, koji mogu povećati stabilnost alergena
hrane tokom digestije, i time omogućiti zadržavanje potencijala aktivacije alergijske
reakcije nakon oralno-gastrične faze digestije.
INFOGEST method is standardized protocol for in vitro simulation of complete food
digestion, based on physiologicaly relevant conditions. The objective of this
dissertation was to investigate digestibility of peanut allergens from whole peanut
kernel by INFOGEST method, as well as to characterize their fragments resistant to
proteolysis.
For delipidation, protein precipitation approach was applied, showing to be superior in
comparison to delipidation by organic solevent, due to lower qualitative and
quantitative protein loss.
In this thesis it was shown that peanut thermal processing, in addition to effect of food
matix, further complicates the extractability and digestibility of proteins from the grain,
making peanut allergens Ara h 1, 2, 3 and 6, less accessible for pepsin hydrolysis.
Extractability and digestibility of peanut proteins in the gastric phase have shown to be
significantly more pronounced, in comparison to intestinal phase, and roasted peanut
digestion was impaired comp...ared to the raw. It was shown that after oral and gastric
digestion of whole raw peanut grains peanut allergens largely remain intact, and their
digestion resistant peptides retain allergenic capacity. The most Ara h 2 and Ara h 6
allergens have been shown to remain resistant to digestion. Ara h 1 and Ara h 3
undergo pepsinolysis with cascade pattern to consequently smaller peptide fragments
with retained IgE binding capacity. Small peptides from Ara h 2 allergens were the
most potent inhibitors of IgE binding from sera of peanut allergic patients, compared to
small peptides from Ara h 1 and Ara h 3.
This thesis points to the great importance of the effects of food matrix, as well as food
thermal processing, on protein digestibility, which can create additional stability of
food allergens during digestion, and thus enable retaining of their potential for the
sensitization or triggering of allergic reactions.
Fakultet:
Универзитет у Београду, Хемијски факултетDatum odbrane:
04-12-2019Projekti:
- Molekularne osobine i modifikacije nekih respiratornih i nutritivnih alergena (RS-172024)
- FoodEnTwin-Twinning of research activities for the frontier research in the fields of food, nutrition and environmental omics (EU-810752)