20.500.12556/RUL-102717 Odstranjevanje trpkosti plodov kakija (Diospyros kaki Thunb.) Removing of astringency in persimmon fruit (Diospyros kaki Thunb.) Kaki (Diospyros kaki Thunb.) je dober vir primarnih in sekundarnih metabolitov, katerih vsebnosti se med zorenjem spreminjajo. Med sekundarnimi metaboliti je potrebno izpostaviti fenole, med katere uvrščamo tudi tanine. V tehnološki zrelosti vsebuje kaki veliko taninov, ki so lahko v topni ali netopni obliki. Sorte, pri katerih v tehnološki zrelosti prevladujejo topni tanini, so po okusu trpke in neužitne. Zato je pri teh sortah nujno potrebno medenje oz. odstranjevanje trpkosti. V desetletju iskanja optimalnih načinov odstranitve trpkosti so bile preizkušene oz. uporabljene številne tehnike odstranjevanja trpkosti. Tretiranje z veliko koncentracijo CO2, etanolom, veliko koncentracijo N2, s toplo vodo, zamrzovanje plodov in tretiranje z etilenom so tehnike, ki so najbolj uporabne za odstranitev trpkosti. Tretiranje z veliko koncentracijo CO2 se je izmed vseh tehnik izkazalo za najbolj učinkovito. Učinkovitost tehnike je zagotovljena s sprožitvijo anaerobnega dihanja in posledično povečane produkcije acetaldehida, ki reagira s topnimi tanini. Topni tanini se pri tem polimerizirajo v netopne tanine, ki pa niso več organoleptično aktivni. V primerjavi z ostalimi uporabljenimi tehnikami, tretiranje z veliko koncentracijo CO2 v najkrajšem času zmanjša vsebnost topnih taninov pod mejno vrednost senzoričnega zaznavanja trpkosti (0,1 g/100 g sveže mase) in hkrati ohrani najboljšo kakovost plodov. Persimmon (Diospyros kaki Thunb.) is a good source of primary and secondary metabolites, which contents change during fruit ripening. It is necessary to specifically mention phenols among secondary metabolites, among which we also place tannins. At technological maturity, persimmon contains a lot of tannins, which can exist in soluble or insoluble form. Cultivars, which during technological maturity contain more soluble tannins, are astringent and inedible. For this reason it is necessary to remove astringency from the fruit. In a decade of finding optimal ways of removing astringency from the fruit there have been tested and used multiple techniques, among which we place: treating with high concentration of CO2, ethanol, high concentration of N2, treating with warm water, freezing the fruit, and treating with ethylene. These techniques count as the most useful for removing astringency. Treating with high concentration of CO2 has proven to be the most effective of all mentioned techniques. Effectiveness of the technique is guaranteed with activation of anaerobic respiration and consequent rises of acetaldehyde production, which reacts with soluble tannins. These polymerize into insoluble tannins during this process, which are no longer organoleptically active. In comparison with other mentioned techniques, treating with high concentration of CO2 in the shortest period of time, lessens the content of soluble tannins below lower limit of sensory perception (0.1 g/100 g of fresh weight) and at the same time preserves the highest quality of the fruit. sadjarstvo kaki Diospyros kaki trpkost fruit growing persimmon Diospyros kaki astringency true false false [K. Sočič] Slovenski jezik Angleški jezik Diplomsko delo/naloga 2018-09-07 07:46:07 2018-09-07 07:46:09 2022-08-15 03:43:31 0000-00-00 00:00:00 2018 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 634.45(043.2) 154928 9024889 3752.pdf 3752.pdf 1 66A6CCF454D6938BA69F2957292B22CC 752dc627d8f2093de0577ed8729ccdb2e89c9b320d55646a4a441dd24b8d7054 99e5c3ac-a1b5-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=113072 Biotehniška fakulteta 0 0 0