Naslov
Influence of jam processing upon the contents of phenolics and antioxidant capacity in strawberry fruit (Fragaria ananassa × Duch.)

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

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

Izvornik
7th International Congress of Food Technologists, Biotechnologists and Nutritionists / Medić, Helga - : Hrvatsko društvo prehrambenih tehnologa, biotehnologa i nutricionista, 2011, 131-131

ISBN
978-953-99725-3-8

Skup
7th International Congress of Food Technologists, Biotechnologists and Nutritionists

Mjesto i datum
Opatija, Hrvatska, 20.09.2011. - 23.09.2011

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
strawberry; phenolics; anthocyanins; jam; antioxidant capacity

Sažetak
Seven cultivars of strawberry (Diamante, Elsanta, Honeoye, Madeleine, Marmolada, Miranda and Miss) were analyzed for total phenols (TP), total flavonoids (TF), total nonflavonoids (TN), total anthocyanins (TA) and antioxidant capacity (AC) before and after low sugar jam production to evaluate their changes after thermal processing. The content of TP, 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 capacity was evaluated by 2, 2- diphenyl-1-picrylhydrazil radical (DPPH). Fresh fruits had total phenolics ranging from 251.97 to 713.06 mg gallic acid equivalent GAE/g of dry weight. In all investigated samples, fresh strawberries and jams, nonflavonoids were predominant phenols. Cultivar Honeoye had the highest amounts, while cultivar Miss had the lowest amounts of TP and TN. Cultivar Miranda had TF in the highest concentrations, while the lowest concentrations were found in cultivar Marmolada. TA for investigated cultivars was 63.55-177.71 mg Cy-3-G/100 d.w. with strong differences among cultivars. On the basis of dry weight the processing and heating during jam making generally decreased the contents of TP for 37-70 %. During processing, cultivar Madeleine showed the greatest stability of TP, TN and TF, while cultivar Elsanta showed the greatest anthocyanins stability. In comparison with fresh strawberry fruit, whose antioxidant capacity were in the range of 0.23 mmol TE/kg f.w. to 0.67 mmol TE/kg f.w., the jams also represent a noticeable source of antioxidant compounds, even considering the lower content of phenolic compounds, with the antioxidant capacity of 0.20 mmol TE/kg f.w. to 0.62 mmol TE/kg f.w. Hence, the obtained results showed that besides fresh strawberry fruit, the strawberry jams also possess noticeable content of important bioactive compounds with considerable antioxidant capacity.

Izvorni jezik
Engleski

Znanstvena područja
Prehrambena tehnologija

POVEZANOST RADA