engleski

Control of enzymatic browning in parsley

Fresh and processed fruits and vegetables undergo various desired and undesired changes as a consequence of numerous chemical and biochemical reactions. One of the objectives of fruits and vegetables processing industry is to prevent enzymatic browning on cut surface of fresh fruits and vegetables, as well as on the surface of processed products. The aim of this work was to prevent browning or discoloration of parsley during infrared (IR) drying at 80 °C with 1mg of water loss in sample in 50 seconds steps. The vegetable was prepared by washing, trimming, cutting in the pieces (20 x 20 x 2 mm) and dipping in solutions of potassium metabisulfite (0.2, 0.5, 1.0, and 1.5 %), or sodium chloride (0.5 and 1.0 %). Colorimetry (Minolta CR-300 Chroma Meter) was performed on the cut surface of fresh prepared samples (control), and on the cut surface of treated samples and dried samples. L*, a* and b* values were determined initially and during 4 weeks storage of fresh-cut parsley at 4 °C (after 4, 8, 12, 20, 25 and 30 days). Colour measurements of dried parsley samples (by HR 73 Mettler Toledo dryer) stored in dark glass yars at room temperature, were performed on 0 day through 60 days (after 4, 8, 12, 20, 30, 40, 50 and 60 days). Visual observations of sample appearance were made by three of the investigators. Results indicated that the best results in browning inhibition were obtained with samples treated with 1 % sodium chloride solution for fresh parsley samples, and with dried parsley samples dipped, before IR drying, into 0.5 % potassium metabisulfite solution.

parsley; inhibition of enzymatic browning; drying

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