Utjecaj oplodnje na kemijski sastav grožđa sorte ‘Grk’ (Vitis vinifera L.) | The influence of fertilization on chemical composition of 'Grk bijeli' grapes (Vitis vinifera L.)

Croatian. Grk bijeli sorta je vinove loze usko vezana za mjesto Lumbarda na otoku Korčuli. Jedna je od rijetkih sorata koja posjeduje funkcionalno ženski tip cvijeta. Zbog nepravilnosti u građi cvijeta te često sterilnog polena dolazi do lošije oplodnje. U grozdu se formiraju velike, sjemene bobe te male besjemene bobe – „pasoline”. Uslijed lošije oplodnje dolazi do većeg udjela pasolina u grozdu te nižeg priroda. Pretpostavlja se kako oplođene i neoplođene bobe imaju različita kemijska svojstva te se samim time izravno povezuje razina oplodnje i kvaliteta vina Grk. U ovom istraživanju utvrđen je kemijski sastav sjemenih boba i pasolina. Od polifenolnih spojeva pasoline su sadržavale značajno više koncentracije gotovo svih flavonoidnih spojeva, kumarinske kiseline, ferulinske kiseline te resveratrola. S druge strane, sjemene bobe bile su bogatije kaftarinskom, fertarinskom te kafeinskom kiselinom. Značajnih razlika u osnovnim pokazateljima kakvoće mošta nije bilo.

English. Grk bijeli is grapevine variety closely related to the place Lumbarda on the island of Korčula. It is one of the rare grape varieties with functionally female type of flower. Fertilization is often poor due to irregularities in the flower structure and sterile pollen. Two types of berries are developed in the cluster, large, seeded berries and small, seedless berries – 'pasoline'. Due to the poor fertilization, a greater share of the cluster is seedless berries, which consequently leads to lower yields. It is believed that these two types of berries have different chemical properties which directly connects fertilization rate with the Grk wine quality. This research determined the chemical content of seeded and seedless berries. Seedless berries had higher concentrations of almost all flavonoid compounds, coumaric acid, ferulic acid and resveratrol. On the other hand, seeded berries had a higher caftaric, fertaric and caffeic acid content. Also, there were not significant differences in basic quality indicators.