EFFECT OF TREATMENT PARAMETERS ON THE CAROTENOID EXTRACTION FROM TOMATO PEELS OF BULGARIAN INDUSTRIAL VARIETIES.

Tomato by-products are an attractive source of natural carotenoids. This study was carried out to investigate the extractability of carotenoids from tomato peels of two Bulgarian industrial varieties, named "Stela" and "Karobeta", and to assess the effects of the extraction parameters (time, extraction steps, temperature, solid/liquid ratio and solvent type) on the yield of carotenoids. Individual carotenoid identification in dried tomato peels was carried out by using a HPLC system. The content of total carotenoids, lycopene and β-carotene in the obtained extracts was measured spectrophotometrically. Carotenoid recovery was significantly (p < 0.05) affected by the investigated extraction parameters. The maximum amounts of total carotenoids (111.58±2.11 and 76.59±2.13 mg/100g), β-carotene (54.69±2.15 and 64.70±1.42 mg/100g) and lycopene (49.07±0.19 and 6.51±0.57 mg/100g) extracted from dried tomato peels of "Stela" and "Karobeta" varieties, respectively, were obtained by using acetone as solvent, for three successive extraction steps of 30 min, at 40°C and solid/liquid ratio of 1:30. It was experimentally established that tomato peels of "Stela" variety are suitable for lycopene and β-carotene recovery, while those of "Karobeta" variety for the recovery of β-carotene only. [ABSTRACT FROM AUTHOR]