Investigation of Color Changes of Sour Orange Juice During Thermal Processing

Aghajanzadeh Suraki, Sara; Ziaiifar, Aman Mohammad; Kashaninejad, Mahdi; Maghsoudlou, Yahya; Esmailzadeh, Ebrahim

doi:10.22069/ejfpp.2017.6486.1114

Investigation of Color Changes of Sour Orange Juice During Thermal Processing

Document Type : Complete scientific research article

Authors

¹ Department of Food Science and Technology, Gorgan University of Agricultural Sciences and Natural Resources

² Food Engineering Department of Food Process Engineering, Gorgan University of Agricultural Sciences and Natural Resources

³ Food Science and Technology. Department of Food Science and Technology, Gorgan University of Agricultural Sciences and Natural Resources

⁴ Gorgan University of Agricultural Sciences and Natural Resources

10.22069/ejfpp.2017.6486.1114

Abstract

Especially in Iran, sour orange juice is known as a desirable food seasoning. Although thermal processing is a common method to improve safety of sour orange juice, it induced the nutritional loss and undesirable compounds formation. Generally, chemical changes in food products influence the product color. By considering the relation between product color and its chemical compounds, the objective of this work is to investigate the effect of thermal processing (temperature and time) on color changes of sour orange juice. The browning index of product was studied using two different methods, image processing and spectral analysis. The color changes was investigated using L*, a* and b* color parameters. The results showed that as temperature and time processing increase, Luminance (L*) of sour orange juice decreases. As well as, a* (redness) and b* (yellowness) parameters increase during thermal processing. Chroma index changes showed an increase in the color intensity during thermal processing. Total color changes (TCD), as an appropriate index in product color change, increased during processing. The reaction constant rate (k) of TCD, representing the color temperature affinity, increased about 1.66 times as temperature increases. The high amount of activation energy (Ea) signifies the high temperature tolerance of components color and TCD. Sour orange juice browning is highly dependent to juice ascorbic acid content. In conclusion, a good correlation was found between both of the applied methods to investigate the browning index.

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