Kinetic study for ascorbic acid degradation, hydroxymethylfurfural and furfural formations in Orange juice.

• Low HMF/furfural and high AA contents were determined at moderate temperature. • Formation of HMF/furfural and AA degradation depend mainly on thermal process time. • HMF formation rate was higher than furfural during thermal process and storage. • Storage temperature affects remarkably accumulation of HMF/furfural in OJ. • Shelf-life values were higher for OJs treated at mild temperature and kept at 4 °C. In this study, changes in ascorbic acid-(AA), hydroxymethylfurfural-(HMF) and furfural content of orange juice (OJ) were investigated during processing with different thermal treatments and storage conditions. According to the AA degradation kinetics; the half-lifes of thermally processed OJ at 70, 75, 80, 85 and 90 °C ranged between 666.5–1136.3 s. D- values for the same temperatures were calculated as 3774.7, 3337.1, 2914.7, 2646.6 and 2214s, respectively. z , Ea and Q 10 -values of AA were also calculated as 86.32 °C, 26.87 kJ mol−1, and 1.31; respectively. HMF formation kinetics showed that the doubling time of thermally processed OJ (70−90 °C) were determined between 42.0 and 77.0 s. D -values at those temperatures ranged from 139.6–255.8 s. z , Ea and Q 10 -values of HMF were also calculated as 75.98 °C, 31.34 kJ mol−1, and 1.35, respectively. For furfural formation kinetics, doubling time of thermally processed OJ at 70−90 °C was determined between 52.1–74.5 s. The D -values of furfural were calculated between 173.1–274.1 s at the same temperatures. z , Ea and Q 10 -values of furfural were also calculated as 100.21 °C, 24.98 kJ mol−1, and 1.26, respectively. The most obvious changes were determined during storage at 25 °C for the investigated compounds when compared to 4 °C. OJ samples processed at moderate temperatures performed better AA retention, and lower HMF and furfural formation was determined for those samples during shelf-life. [ABSTRACT FROM AUTHOR]