Effect of Cooking Methods on Bioactive Compounds of Eggplant (Solanum melongena L.) and its Use in Preparing and Evaluating Frozen Baba Ghanoush Product During Storage

Abstract

This research was undertaken to find out the effects of different cooking methods on bioactive compounds of eggplant. The effect of freezing and storage on microbial growth and sensory properties of the common Egyptian dish called Baba ghanoush were also studied. The results showed that eggplant contained a high percentage of crude fiber, crude protein, crude fat, and total ash. It can be noted that the mineral contents of fresh eggplant were Ca, Mg, Na and K as the major minerals. On the other hand, the results of total phenolics in the fresh, dry fresh, oven and steamed samples were 9.32, 75.78, 42.31 and 41.53 mg/100 g, respectively as gallic acid equivalent. The total flavonoids of the different eggplant treated samples varied between 0.46 to 0.7 mg equivalents of quercetin per 100 g. The results indicated that the antioxidant activity as well as IC50 of fresh, dry fresh, oven and steamed samples were 8.82, 87.20, 82.78, 90.23 and 10.86, 1.18, 1.21 and 1.12, respectively. Also, eighteen phenolic compounds were identified by HPLC. The color attributes L*, a*, and b* in case of Baba ghanoush prepared from oven eggplant slightly decreased with increasing the storage period. Significant reduction was noted in microbial growth with increasing the storage period up to 4 months in case of Baba ghanoush prepared either from oven and steamed eggplant. Sensory attributes of Baba ghanoush were well accepted by the panelists even after 4 months of storage.