Naslov
Effect of sugars addition on anthocyanins and antioxidant activity of sour cherry juice during storage

Autori
Kopjar, Mirela ; Lončarić, Ante ; Fotez, Ana ; Barbarić, Bernardica ; Pichler, Anita

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

Izvornik
EUROFOODCHEM XVIII: Upcoming challenges in food science / - , 2015

Skup
EUROFOODCHEM XVIII

Mjesto i datum
Madrid, Španjolska, 13.10.2015. - 16.10.2015

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
sour cherry juice; sugars addition; anthocyanins; antioxidant activity; storage

Sažetak
Generally, the phenolics are recognized as the compounds with the health benefits due to their antioxidant activity. Anthocyanins are one of the group of phenolics that are characterized by the colour and antioxidant activity. These pigments are highly unstable during processing, and their colour is easily lost, leading to the product colour loss (1). In this study, influence of the addition of different sugars to the sour cherry juice on the phenolics, anthocyanins and antioxidant activity was investigated. Chosen sugars were monosaccharide glucose and disaccharides maltose and trehalose, both containing two glucose units. Also, change of mentioned parameters during storage was monitored. A control sample was sour cherry juice without sugar addition. Sugars were added to the juice and heated at 90 °C. All parameters were evaluated after preparation and after the storage at room temperature for 7 months. After preparation, the phenolic and anthocyanin content of control sample were 1.22 g/L and 141.14 mg/L, respectively. Samples with the addition of sugars had higher phenolic content, 1.35 - 1.48 g/L, than control sample. Sample with the addition of glucose had slightly lower anthocyanin content (135.26 mg/L), while addition of maltose and trehalose didn’t have an effect on anthocyanins. During storage, the degradation of phenolics and anthocyanins occurred. The control sample had 0.93 g/L of phenolics, while samples with sugars had much lower content, 0.45 - 0.51 g/L. Anthocyanin content of the control sample was 8.71 mg/L while samples with addition of sugars had higher content of anthocyanins, ~19 mg/L. For the determination of antioxidant activity different methods were used (DPPH, ABTS and FRAP), differing in free radicals and their selectivity. The highest values were obtained by ABTS method, and the lowest by DPPH method. Results of ABTS method showed that after preparation similar values were obtained for all samples (~12 mmol TE/100 mL), while with FRAP method control sample had the highest antioxidant activity. After storage higher values were obtained in samples with sugars addition by application of ABTS and FRAP method. Using DPPH method, the highest antioxidant values were obtained for juice with the glucose addition (5.6 mmol TE/100 mL), and after storage for the juices with the glucose and trehalose addition (4.5 and 4.0 mmol TE/100 mL, respectively). The results of this study showed that complex interactions between sugars and antioxidants can happen in the product leading to change quality.

Izvorni jezik
Engleski

Znanstvena područja
Prehrambena tehnologija

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