CONICET | Buscador de Institutos y Recursos Humanos

In this study the analysis by Response Surface Methodology (RSM) was used to optimize the osmotic dehydration (OD) process of kiwifruit. The objective was to maximize water loss (WL) and solid gain (SG) along with low loss of hardness (D), color difference (ΔE) and weight reduction (WR) respect to fresh fruit. The selected treatment factors were: contact time (2?6 h), xylitol concentration (40º-60 ºBrix) and solution temperature (25º-35 ºC). Optimal conditions were established by means of a Central Composite Design 2^3 with 2 central points, that allowed evaluate the effect of experimental factors in 3 levels, with a total of n = 32 determinations. ANOVA indicated that the second order polynomial model fitted by means of a multiple linear regression method is adequate for describing and predicting the values of WR, WL and SG, hardness and color change, given that the p-value for the lack-of-fit test was not significant (p>0.05). Results indicated that, to obtain a maximal WL (22.77%), SG (8.538%) and D (63.32N) and a minimal WR (16.864 %) and ΔE (2.326), dehydration should be performed with an osmotic solution of xylitol at 47.5 ºBrix, using a dehydration time of 6 h and a temperature of 32 ºC. 3 with 2 central points, that allowed evaluate the effect of experimental factors in 3 levels, with a total of n = 32 determinations. ANOVA indicated that the second order polynomial model fitted by means of a multiple linear regression method is adequate for describing and predicting the values of WR, WL and SG, hardness and color change, given that the p-value for the lack-of-fit test was not significant (p>0.05). Results indicated that, to obtain a maximal WL (22.77%), SG (8.538%) and D (63.32N) and a minimal WR (16.864 %) and ΔE (2.326), dehydration should be performed with an osmotic solution of xylitol at 47.5 ºBrix, using a dehydration time of 6 h and a temperature of 32 ºC.