Effects of sugar addition on total polyphenol content and antioxidant activity of frozen and freeze-dried apple purée.
The objective of this study was to investigate the influence of simple sugar addition including (glucose, G; fructose, F; sucrose, S; and trehalose, T) on the total polyphenol content (TPC) and antioxidant activity (AOA) of apple purée processed by freezing and freeze-drying and stored for 6 months. The apple polyphenol profile was mostly preserved in the freeze-dried samples with sugar addition during 6 months of storage, whereas the polyphenol profile in frozen samples consists only of quercetin glycosides, of which rutin had the largest share. After 6 months, the highest level of polyphenols was detected in frozen 'Idared' and 'Fuji' apple purée with addition of T 5% (12.2 and 16.7 mg/100 g FW, respectively), whereas in freeze-dried apple purée the highest TPC was in 'Idared' and 'Fuji' with addition of T 1% (16.3 and 13.6 mg/100 g FW, respectively). Results indicate that sugar addition before processing could have potential for enhancing product quality.
Department of Food Technologies, Faculty of Food Technology Osijek , Osijek 31000, Croatia.
Ante
A
Loncaric
Krunoslav
K
Dugalic
Ines
I
Mihaljevic
Lidija
L
Jakobek
Vlasta
V
Pilizota
D000975:Antioxidants / Q000032:analysis*; D002241:Carbohydrates / Q000032:analysis; D005503:Food Additives / Q000032:analysis*; D005519:Food Preservation; D005612:Freeze Drying; D005638:Fruit / Q000737:chemistry; D027845:Malus / Q000737:chemistry*; D059808:Polyphenols / Q000032:analysis*
D000975:Antioxidants; D002241:Carbohydrates; D005503:Food Additives; D059808:Polyphenols