Thermal degradation characteristics and antioxidant activity of fructose solution with heating temperature and time.
This study investigated the thermal degradation characteristics of fructose. A 20% fructose solution was heated to 110-150°C for 1-5 hours. Chromaticity, pH, organic acid, 5-hydroxymethylfurfural (HMF), fructose content, electron-donating ability (EDA) (as a percentage), and ascorbic acid (AA) equivalent antioxidant capacity (AEAC) of heated fructose solutions were evaluated. With increasing heating temperature and time, the L-value decreased, and the a- and b-values increased to 120°C for 4 hours and 2 hours, respectively, and then decreased thereafter; however, total color difference increased. The pH and fructose content decreased. Organic acids, such as formic acid, lactic acid, and levulinic acid, and HMF content increased with increasing heating temperature and time. Antioxidant activity increased with increasing heating temperature and time (no antioxidant activity in 20% fructose solution). The EDAs after heating at 130°C for 3 and 4 hours were 17.21% and 31.73%, respectively, and the highest antioxidant activity was 94.57% (150°C for 4 hours). The AEAC was 1.71 mg of AA eq/g before heating and 24.43 mg of AA eq/g after heating at 150°C for 4 hours. These results suggest that heat treatment may be a useful method for increasing the antioxidant activity of fluid foodstuffs such as fruit juices and fructose-containing foods.
Department of Functional Crop, National Institute of Crop Science, Rural Development Administration, Miryang City, Gyeongnam, Republic of Korea.
Koan Sik
KS
Woo
In Guk
IG
Hwang
Hyun Young
HY
Kim
Keum Il
KI
Jang
Junsoo
J
Lee
Tae Su
TS
Kang
Heon Sang
HS
Jeong
D000975:Antioxidants / Q000737:chemistry*; D005632:Fructose / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D013696:Temperature; D013997:Time Factors
D000975:Antioxidants; D005632:Fructose