Effect of ultrasonic and osmotic dehydration pre-treatments on the colour of freeze dried strawberries

• Published in: Journal of food science and technology Vol. 51; no. 9; pp. 2222 - 2227
• Main Authors: Garcia-Noguera, Juan, Oliveira, Francisca I. P., Weller, Curtis L., Rodrigues, Sueli, Fernandes, Fabiano A. N.
• Format: Journal Article
• Language: English
• Published: India Springer India 01-09-2014; Springer Nature B.V
• Subjects: Berries; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Dehydration; Drying agents; Experiments; Food; Food Science; Freeze drying; Freezing; Fruits; Moisture content; Nutrition; Original; Original Article; Osmosis; Strawberries; Studies; Sucrose; Brazil; Keywords; Ultrasound; Strawberry; Freeze-drying; Osmotic dehydration; Colorimetric analysis
• ISSN: 0022-1155; 0975-8402
• DOI: 10.1007/s13197-012-0724-x

The effect of pre-treatments on the colour of freeze-dried strawberries was studied. Strawberries were subjected to different ultrasound and osmotic dehydration conditions followed by freeze-drying. Two concentration levels of sucrose solution (25 and 50 % w/w) and four levels of processing time (from 10 min to 45 min) were studied. Also, ultrasound application without using an osmotic solution was studied. Colour was quantified with a colorimetric analysis (CIE LCh). Sonicated strawberries presented higher lightness (L) and lower hue (h) than fresh and non-treated strawberries (control samples). The sonicated and osmo-sonicated strawberries have presented a more reddish and vivid colour then the control samples.