| Abstract | Cilj ovog rada bilo je ispitivanje utjecaja dodavanja različitih ekstrakata na ukupan sadržaj fenola, antocijana, antioksidativnu aktivnosti i postotak polimerne boje soka kupine tijekom 52 dana skladištenja pri 4°C. Sadržaj antocijana u kontrolnom uzorku (sok kupine bez dodatka ekstrakta) bio je 149,91 mg/L. Uzorci u koje su dodani ekstrakti lista masline, kore bora PE 5:1 i PE 95%, zelenog čaja, crnog vina PE 30% i PE 4:1 i bioflavonoda su imali viši udio antocijana (od 152,42 do 161,19 mg/L) u usporedbi s kontrolnim uzorkom. Uzorci s dodanim ekstraktima su imali puno veći ukupni udio fenola i antioksidativnu aktivnost u usporedbi s kontrolnim uzorkom, što je bilo i za očekivat pošto su ekstrakti bogati fenolima. Tijekom skladištenja smanjenje sadržaja fenola, antocijana i antioksidativne aktivnosti pojavilo se u većem ili manjem opsegu, ovisno o tipu dodanog ekstrakta. Sadržaj antocijana u kontrolnom uzorku je bio 119,95 mg/L. Uzorci s dodatkom bioflavonoida, lista masline, kore bora PE 5:1 i crnog vina PE 4:1 su imali niži (od 103,44 do 118,84 mg/L), dok su ostali uzorci imali viši (od 131,99 do 135, 57mg/L) udio antocijana u usporedbi s kontrolnim uzorkom. Nakon skladištenja, smanjenje sadržaja antocijana je bilo popraćeno povećanjem postotka polimerne boje, izuzev uzoraka u koje je dodan ekstrakt zelenog čaja. Zagrijavanjem uzoraka pratio se utjecaj dodanih ekstrakata na termičku degradaciju antocijana. Povećanjem temperature opažen je pad sadržaj antocijana, a najveći sadržaj imali su uzorci s dodatkom lista masline (75,77 mg/L) i zelenog čaja (75,52 mg/L). |
| Abstract (english) | The aim of this study was investigation of influence of different extracts addition on total phenols, anthocyanin content ,antioxidant activity and percent of polymeric colour of blackberry juice during storage of 52 days at 4 °C. Anthocyanin content of control sample (blackberry juice without extracts addition) was 149.91 mg/L. Samples with addition of extracts (olive leaf, pine bark PE 5:1 and PE 95 %, green tea, red wine PE 30 % and PE 4:1 and bioflavonoids had higher anthocyanin content (from 152.42 to 161.19 mg/L) in comparison to control sample.Samples with addition of extracts had much higher total phenol content and antioxidant activity than control sample, what was expected since extracts are rich in phenols. During storage decrease of phenols, anthocyanins and antioxidant activity occurred in higher or lesser extent, depending on extract type addition. After storage, decrease of anthocyanins was followed with increase of percent of polymeric colour, with exception of samples with addition of green tea. Samples were also heated at different temperatures and influence of different teparatures on anthocyanin content was aslo monitored. Anthocyanin content was lower on higher temperatures. Increase of temperature coused decrease of anthocyanin content. Samples with adition of olive leaf (75.77 mg/L) and green tea (75.52 mg/L) had higher anthocyanin content. |
