Quantitative modelling approaches for ascorbic acid degradation and non-enzymatic browning of orange juice during ultrasound processing

• Published in: Journal of food engineering 2010-02, Vol.96 (3), p.449-454
• Main Authors: Valdramidis, V.P., Cullen, P.J., Tiwari, B.K., O’Donnell, C.P.
• Format: Article
• Language: English
• Subjects: Ascorbic acid; Biological and medical sciences; Citrus; degradation; Food engineering; Food industries; food nutrient losses; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; General aspects; juice quality; kinetics; Maillard reaction; Maillard reaction products; mathematical models; Modelling; Non-enzymatic browning; orange juice; ultrasonic treatment; ultrasonics; Ultrasound
• ISSN: 0260-8774; 1873-5770
• DOI: 10.1016/j.jfoodeng.2009.08.025

The objective of this study was to develop a deterministic modelling approach for non-enzymatic browning (NEB) and ascorbic acid (AA) degradation in orange juice during ultrasound processing. Freshly squeezed orange juice was sonicated using a 1500 W ultrasonic processor at a constant frequency of 20 kHz and processing variables of amplitude level (24.4–61.0 μm), temperature (5–30 °C) and time (0–10 min). The rate constants of the NEB and AA were estimated by a primary model (zero and first order) while their relationship with respect to the processing factors was tested for a number of models, i.e., second order polynomial, different types of Ratkowsky-type model, and an Arrhenius-type model. The non-monotonic behaviour of NEB has been described more accurately by the use of a polynomial model. The rate constants of AA were described by a similar type of model having a monotonic behaviour. A synergistic effect of temperature for different amplitudes on the rate constant of both NEB and AA was observed, while an antagonistic effect of amplitude on the rate of NEB was evident. The models with the best fit were integrated to produce contour plots for the combined amplitude and temperature. The constructed contour plots illustrate that low temperatures and intermediate amplitudes, i.e., 42.7 μm, result in lower NEB and AA deterioration and consequently better quality orange juice. The overall developed modelling approaches exploit quality data in order to identify the optimal processing regions for eliminating quality deterioration of orange juice during ultrasound processing which is of high importance to the food industry.