TOTAL ANTIOXIDANT ACTIVITY IN LEAVES OF FOUR AUTOCHTHONOUS OLIVE CULTIVARS

Listovi masline (Olea europea L.) imaju veliki potencijal kao prirodni antioksidansi. Brojna istraživanja dokazala su antioksidativno, antimikrobno i antivirusno djelovanje ekstrakta lista masline. Cilj ovog istraživanja bio je ispitati razlike u koncentraciji askorbinske kiseline i ukupnih fenola te ukupne antioksidativne aktivnosti u listovima ĉetiri autohtona kultivara maslina (Oblica, Duţica, Lastovka i Rošinjola) te utvrditi postojanje korelacija između tih parametara. Koncentracija askorbinske kiseline, fenolnih spojeva te ukupna antioksidativna aktivnost ekstrakta listova ĉetiri kultivara maslina određeni su spektofotometrijski. Ukupna antioksidativna aktivnost u listovima maslina bila je u pozitivnoj korelaciji s koncentracijom fenolnih spojeva i koncentracijom askorbinske kiseline. Dobiveni rezultati pokazuju da je ekstrakt lista kultivara Oblica pokazuje najveći potencijal kao prirodni dodatak prehrani budući da je imao najveću antioksidativnu aktivnost i najveću koncentraciju ukupnih fenola koji iznimno povoljno djeluju na zdravlje ljudi i ţivotinja.The olive leaves (Olea europaea L.) have great potential as natural antioxidants. Numerous studies have demonstrated the antioxidant, antimicrobial and antiviral activities of olive leaf extract. The aim of this study was to investigate differences in the content of ascorbic acid, total phenols and total antioxidant activities of four autochthonous cultivars of olive leaves (Oblica, Duzica, Lastovka and Rosinjola) and to establish correlations between these parameters. The content of ascorbic acid, total phenols and total antioxidant activity in leaf extract of four olive cultivars were determined spectrophotometrically. The total antioxidant activity of olive leaves significantly positively correlated with the content of total phenols. The results obtained show that the extract of cultivar Oblica had the best quality of the four tested olive cultivars due to the highest antioxidant activity and the highest content of total phenols. The results obtained pointed out that the leaf extract of cultivar Oblica show the greatest potential as a natural dietary supplement since it had the highest antioxidant activity and the highest content of total phenols that are extremely beneficial for the human and animal health

TOTAL ANTIOXIDANT ACTIVITY IN LEAVES OF FOUR AUTOCHTHONOUS OLIVE CULTIVARS

Listovi masline (Olea europea L.) imaju veliki potencijal kao prirodni antioksidansi. Brojna istraživanja dokazala su antioksidativno, antimikrobno i antivirusno djelovanje ekstrakta lista masline. Cilj ovog istraživanja bio je ispitati razlike u koncentraciji askorbinske kiseline i ukupnih fenola te ukupne antioksidativne aktivnosti u listovima ĉetiri autohtona kultivara maslina (Oblica, Duţica, Lastovka i Rošinjola) te utvrditi postojanje korelacija između tih parametara. Koncentracija askorbinske kiseline, fenolnih spojeva te ukupna antioksidativna aktivnost ekstrakta listova ĉetiri kultivara maslina određeni su spektofotometrijski. Ukupna antioksidativna aktivnost u listovima maslina bila je u pozitivnoj korelaciji s koncentracijom fenolnih spojeva i koncentracijom askorbinske kiseline. Dobiveni rezultati pokazuju da je ekstrakt lista kultivara Oblica pokazuje najveći potencijal kao prirodni dodatak prehrani budući da je imao najveću antioksidativnu aktivnost i najveću koncentraciju ukupnih fenola koji iznimno povoljno djeluju na zdravlje ljudi i ţivotinja.The olive leaves (Olea europaea L.) have great potential as natural antioxidants. Numerous studies have demonstrated the antioxidant, antimicrobial and antiviral activities of olive leaf extract. The aim of this study was to investigate differences in the content of ascorbic acid, total phenols and total antioxidant activities of four autochthonous cultivars of olive leaves (Oblica, Duzica, Lastovka and Rosinjola) and to establish correlations between these parameters. The content of ascorbic acid, total phenols and total antioxidant activity in leaf extract of four olive cultivars were determined spectrophotometrically. The total antioxidant activity of olive leaves significantly positively correlated with the content of total phenols. The results obtained show that the extract of cultivar Oblica had the best quality of the four tested olive cultivars due to the highest antioxidant activity and the highest content of total phenols. The results obtained pointed out that the leaf extract of cultivar Oblica show the greatest potential as a natural dietary supplement since it had the highest antioxidant activity and the highest content of total phenols that are extremely beneficial for the human and animal health

UTJECAJ EKOLOŠKI PRIHVATLJIVIH TRETMANA NA ANTIOKSIDACIJSKU AKTIVNOST U PLODOVIMA JAGODA TIJEKOM SKLADIŠTENJA

Proper postharvest storage is an effective way to maintain the quality and nutritional values of fruits. The aim of this study was to determine how environmentally friendly postharvest treatments with salicylic acid solution, colloidal silver solution and ozone, affect the antioxidant activity of strawberry fruits (Fragaria x ananassa Duch. cv. Albion) during 7 days of storage at 4°C. The content of ascorbic acid, total phenols and antioxidant activity of strawberry fruits were determined spec-trophotometrically. After 7 days of storage in strawberry fruits treated with all three treatments separately, the contents of ascorbic acid were higher than in the control fruits, supporting the usefulness of these treatments for preserving fruit quality and nutritional value during storage. The treatment with salicylic acid solution showed the most beneficial effect during storage causing a significant increase in the content of ascorbic acid, phenols and antioxidant activity at the end of the storage period.Pravilno skladištenje voća učinkovit je način za održavanje kvalitete i nutritivne vrijednosti plodova nakon berbe. Cilj ovog istraživanja bio je utvrditi kako ekološki prihvatljivi tretmani (otopina salicilne kiseline, otopina koloidnoga srebra i ozon) utječu na ukupnu antioksidacijsku aktivnost u plodovima jagoda (Fragaria x ananassa Duch.) sorte Albion tijekom 7 dana skladištenja pri 4°C. Koncentracije askorbinske kiseline, ukupnih fenola i ukupna antioksidacijska aktivnost u plodovima jagoda određeni su spektrofotometrijski. Svi primijenjeni tretmani prouzročili su povećanje koncentracije askorbinske kiseline u plodovima jagoda, što potvrđuje povoljno djelovanje navedenih tretmana na očuvanje kvalitete i nutritivne vrijednosti plodova. Tretman otopinom salicilne kiseline bio je najučinkovitiji, jer je prouzročio značajno povećanje koncentracije fenola, askorbinske kiseline i ukupne antioksidacijske aktivnosti na kraju perioda skladištenja

UTJECAJ EKOLOŠKI PRIHVATLJIVIH TRETMANA NA ANTIOKSIDACIJSKU AKTIVNOST U PLODOVIMA JAGODA TIJEKOM SKLADIŠTENJA

Proper postharvest storage is an effective way to maintain the quality and nutritional values of fruits. The aim of this study was to determine how environmentally friendly postharvest treatments with salicylic acid solution, colloidal silver solution and ozone, affect the antioxidant activity of strawberry fruits (Fragaria x ananassa Duch. cv. Albion) during 7 days of storage at 4°C. The content of ascorbic acid, total phenols and antioxidant activity of strawberry fruits were determined spec-trophotometrically. After 7 days of storage in strawberry fruits treated with all three treatments separately, the contents of ascorbic acid were higher than in the control fruits, supporting the usefulness of these treatments for preserving fruit quality and nutritional value during storage. The treatment with salicylic acid solution showed the most beneficial effect during storage causing a significant increase in the content of ascorbic acid, phenols and antioxidant activity at the end of the storage period.Pravilno skladištenje voća učinkovit je način za održavanje kvalitete i nutritivne vrijednosti plodova nakon berbe. Cilj ovog istraživanja bio je utvrditi kako ekološki prihvatljivi tretmani (otopina salicilne kiseline, otopina koloidnoga srebra i ozon) utječu na ukupnu antioksidacijsku aktivnost u plodovima jagoda (Fragaria x ananassa Duch.) sorte Albion tijekom 7 dana skladištenja pri 4°C. Koncentracije askorbinske kiseline, ukupnih fenola i ukupna antioksidacijska aktivnost u plodovima jagoda određeni su spektrofotometrijski. Svi primijenjeni tretmani prouzročili su povećanje koncentracije askorbinske kiseline u plodovima jagoda, što potvrđuje povoljno djelovanje navedenih tretmana na očuvanje kvalitete i nutritivne vrijednosti plodova. Tretman otopinom salicilne kiseline bio je najučinkovitiji, jer je prouzročio značajno povećanje koncentracije fenola, askorbinske kiseline i ukupne antioksidacijske aktivnosti na kraju perioda skladištenja

THE IMPACT OF ENVIRONMENTALLY FRIENDLY POSTHARVEST TREATMENTS ON THE ANTIOXIDANT ACTIVITY OF STRAWBERRY FRUITS DURING STORAGE

Proper postharvest storage is an effective way to maintain the quality and nutritional values of fruits. The aim of this study was to determine how environmentally friendly postharvest treatments with salicylic acid solution, colloidal silver solution and ozone, affect the antioxidant activity of strawberry fruits (Fragaria x ananassa Duch. cv. Albion) during 7 days of storage at 4°C. The content of ascorbic acid, total phenols and antioxidant activity of strawberry fruits were determined spec-trophotometrically. After 7 days of storage in strawberry fruits treated with all three treatments separately, the contents of ascorbic acid were higher than in the control fruits, supporting the usefulness of these treatments for preserving fruit quality and nutritional value during storage. The treatment with salicylic acid solution showed the most beneficial effect during storage causing a significant increase in the content of ascorbic acid, phenols and antioxidant activity at the end of the storage period