title: Effect of ultrasonic and osmotic dehydration pre-treatments on the colour of freeze dried strawberries.
abstract: 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.
authors.affiliation: Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588 USA.
authors.forename: Juan
authors.initials: J
authors.lastname: Garcia-Noguera
authors.affiliation: Departamento de Engenharia Química, Universidade Federal do Ceará, Campus do Pici, Bloco 709, 60455-760 Fortaleza, CE Brazil.
authors.forename: Francisca I P
authors.initials: FI
authors.lastname: Oliveira
authors.affiliation: Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588 USA.
authors.forename: Curtis L
authors.initials: CL
authors.lastname: Weller
authors.affiliation: Departamento de Tecnologia de Alimentos, Universidade Federal do Ceará, Campus do Pici, Bloco 858, 60455-760 Fortaleza, CE Brazil.
authors.forename: Sueli
authors.initials: S
authors.lastname: Rodrigues
authors.affiliation: Departamento de Engenharia Química, Universidade Federal do Ceará, Campus do Pici, Bloco 709, 60455-760 Fortaleza, CE Brazil.
authors.forename: Fabiano A N
authors.initials: FA
authors.lastname: Fernandes
keywords: Colorimetric analysis; Freeze-drying; Keywords; Osmotic dehydration; Strawberry; Ultrasound