| Abstract | Za proizvodnju soka korišteni su plodovi mandarina ubrani u dolini Neretve, u dva termina berbe. Plodovi su predtretirani pektolitiĉkim enzimom te se variralo vrijeme (30, 60 min), temperatura (20, 50°C) i koncentracija enzima (50, 150ppm) te ultrazvukom gdje se variralo vrijeme (5, 1 min) te amplitude (60, 120μ), paralelno je rađena i kontrola. Nakon predtretmana sirovine, sok je dobiven prešanjem na pak preši. Iskorištenje sirovine tijekom proizvodnje soka bilo je od 59,1% do 88,3%. Predtretman ultrazvukom je pokazao bolje iskorištenje. Nadalje u sokovima se određivala suha tvar, pH vrijednost, količina ukupnih karotenoida i fenola te njihova antioksidacijska aktivnost i vitamin C. Nije dokazan utjecaj berbe i predtretmana na fizikalna svojstva soka. U ispitivanim sokovima količine karotenoida kretale su se od 0,00328 mg g-1 do 0,1116 mg g-1. Veće količine karotenoida imali su sokovi druge berbe uz predtretman enzimom dok su uzorci predtretiranim ultrazvukom imali manje količine istih. Količine fenola kretale su se od 3,333 mg g-1 do 15,000 mg g-1, te antioksidacijska aktivnost od 1,671 μg/100g do 286,76 μg/100g . nije utvrđena pravilnost u promjeni udjela fenola i antioksidacijske aktivnosti s obzirom na termin berbe i predtretman. Količine vitamina C kretale su se od 11,4 mg/100mL do 22,61 mg/100mL bez značajnog utjecaja termina i predtretmana. |
| Abstract (english) | For the production of juice, mandarins harvested in the Neretva valley, at two times of harvest were used. Fruit wase pre-treated with pectolytic enzyme where time (30, 60 min), temperature (20, 50 ° C) and concentrations of the enzyme (50, 150ppm) varied and ultrasound where time (5, 1 min) and intensity of amplitude (60, 120μ) varied. Control was conducted in parallel. After pre-treatment of raw material, juice was obtained by pressing the pack press. Yield of raw materials during the production of juice was from 59.1% to 88.3%. Pre-treatment with ultrasound showed a better yield. In addition dry matter, pH value, amount of total carotenoids and phenols and their antioxidant activity and vitamin C was determined. There was no impact of harvest and pre-treatment on physical properties of the juice. In tested juices amounts of carotenoids ranged from 0.328 to 1.116 mg/100g. Larger amounts of carotenoids had juice from second harvest pre-treatmed with enzyme, while samples predtreated with ultrasound had lower amounts of the same. Amounts of phenols ranged from 33.33 to 150.00 mg/100g, and antioxidant activity from 1.671 to 286.76 μg/100g. Regularity in the change of phenols and antioxidant activity with respect to harvest date and pre-treatment wasn’t established. Amounts of vitamin C ranged from 11.4 to 22.61 mg/100mL and no significant effect of the term and pre-treatment was established. |
