Naslov
Jam processing effect on phenolics and antioxidant capacity in strawberry fruit

Autori
Bursać Kovačević, Danijela ; Levaj, Branka ; Dragović-Uzelac, Verica

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
UFOST 2010 15th World Congress of Food Science and Technology / Robertson, Gordon ; Lupien, John - , 2010

ISBN
978-0-9810247-0-7

Skup
15th World Congress of Food Science and Technology

Mjesto i datum
Cape Town, Južnoafrička Republika, 22.08.2010. - 26.08.2010

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
strawberry; phenolics; anthocyanins; antioxidant capacity

Sažetak
Introduction: Three cultivars of strawberry fruit (Fragaria ananassa × Duch.) grown in Croatia, Clery, Honeoye and NF 421 (Asia), were used to prepare low sugar jams with variations of added sugar (sucrose vs. fructose). Fresh fruits, as well as prepared jams, were analyzed for total phenolics (TPC), total flavonoids (TF), total nonflavonoids (TN), total anthocyanins (TA) and antioxidant capacity (AC). Methodology: The content of TPC, TF and TN were determined according to the Folin- Ciocalteu assay. Anthocyanins were determined by spectral method based on the bisulfite bleaching of monomeric anthocyanins. The antioxidant activity was evaluated by 2, 2- diphenyl-1-picrylhydrazil radical (DPPH). Results and Discussion: Fresh fruits had total phenolics ranging from 2, 74 to 4, 01 mg gallic acid equivalent GAE/g of dry weight. Cultivars Clery and NF 421 (Asia) had higher amounts of TF than Honeoye, in which NF were predominant. Total anthocyanins of fruits ranged from 1, 47 to 3, 29 mg cyanidin-3-glucoside equivalent (CGE)/g of dry weight. All strawberry cultivars showed high antioxidant capacity (88, 76-90, 25 %).Thermal processing resulted in marked losses of all investigated phenolics. However, in all jams, TPC were more stable in comparison with TA. The influence of added sugar was observed in greater stabilty of TPC, TF and TN in jams with addition of fructose. In oppostie, TA were more stable in jams with added sucrose. In spite of phenolics' losses during processing, all jams showed high AC (88, 05-90, 73 %). For fresh strawberry fruit, the highest correlation was found between TA contents and DPPH, while among jams, ones with added sucrose, showed the highest correlation in the TPC contents and DPPH. Conclusions: Overall, results indicated that besides fresh strawberry fruits, jams can also represent a good source of antioxidant compounds with high antioxidant capacity, although compared to the fruit important losses seem to occur.

Izvorni jezik
Engleski

Znanstvena područja
Prehrambena tehnologija

POVEZANOST RADA