Abstract:

This study covered the phenolic compounds extraction from tomato peels using microwave assisted extraction (MAE) system and their microencapsulation by spray drying technique. For this purpose, MAE conditions (microwave power: 250-500 W and extraction time: 1-60 min) for maximum recovery were optimized by response surface methodology. The highest values for total phenolic content (TPC) (3.58 mg GAE/g) and antioxidant capacity (29.85 mmol TE/g) were obtained at the point where the microwave power was 310 W and the extraction time was 35 min. Phenolic extracts produced under optimum conditions were mixed with maltodextrin (the ratio of soluble solids in the extracts to maltodextrin: 1/1 w/w) and converted into powder form using spray drying technique. The success of the microencapsulation process was confirmed by fourier transform infrared spectroscopy (FTIR). Powder yield, moisture content, water activity and solubility values for microcapsules were determined as 63.45%, 4.18, 0.19 and 92.34%, respectively. The antioxidant capacity of the final powder products was investigated by TFM (3.17 mg GAE/g), DPPH (23.10 mmol TE/g), ABTS (75.83 mmol TE/g) and FRAP (13.95 mmol TE/g) methods. The results show that it is not a reasonable approach to dispose of waste materials or use them in field with low economic value. On the contrary, they have the potential to transform value-added products.

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