Effect of Antioxidants on Enzymatic Browning of Eggplant Extract and Fresh-Cut Tissue

Abstract

The effect of antioxidants controlling enzymatic browning of eggplants was studied in extract and fresh-cut tissue. Initially, the effect of ascorbic acid (AA), citric acid (CA), peracetic acid (PA), calcium chloride, cyclodextrin, cysteine (Cys), hexametaphosphate and 4-hexylresorcinol (Hexyl) at different concentrations was studied in extracts and precipitates of eggplant. Cys and Hexyl were effective at 10 mM in both the extract and pellet. Higher concentrations were needed to have an effective control of enzymatic browning in samples treated with AA (20 mM), CA (50 mM) and PA (50 mM). Next, the application of AA, CA, PA, Cys and Hexyl at different concentrations was studied on fresh-cut eggplant tissues during storage at 5C. Cys was effective as antioxidant, extending the shelf life till 9 days of storage at 5C when applied at a concentration of 1%. Tissue browning increased as AA and Hexyl concentrations increased. Practical Applications Commercialization of eggplants as a fresh-cut product is limited by its relatively short shelf life due to a rapid onset of enzymatic browning. The main approach to reduce enzymatic browning is the use of antioxidant solutions. However, little information can be found about effective technologies to control browning of fresh-cut eggplants. This work studies the effect of a wide range of antibrowning agents at different concentrations, combining in vitro (in extracts and precipitates) with in vivo (in tissue) studies and provides relevant information for further development of minimally processed eggplants during storage at 5C.