Multiple-Optimization of the Impregnation and Dehydration of Stone Fruits

RODRIGUEZ, MARIA MARCELA; ARBALLO, JAVIER RAMIRO; CAMPAÑONE, LAURA ANALÍA; PAGANO, ANA; MASCHERONI, RODOLFO HORACIO

Stellenbosch

Simposio; 2012 CIGR Section VII International Technical Symposium on: Innovating the Food Value Chain, Postharvest Technology and Agri-Food Processing; 2012

The objective of the present work was to optimize the osmotic dehydration of stone fruits using regressional-desirability function methodology. Each nectarine or plum was cut into 16 or 8 pieces, respectively and immersed into hypertonic solution with different osmotic agents (sorbitol and glucose). The experimental conditions were process time (15-120min), sugar concentration (40-60ºBrix), temperature (25-40ºC) and solution/fruit ratio (4/1-10/1); and the kinetic responses were water loss (WL) and solid gain (SG). Modified second-order polynomial models for each response were obtained by multiple linear regressions from experimental data. Individual analyses were conducted for each osmotic agent and solution/fruit ratio. A complete solution algorithm for desirability function method was coded in Matlab® 7.2 (Mathworks, Natick, MA) with the purpose of maximize WL and minimize SG. Applying the multiple optimization methodology the optimum conditions for nectarines were: process time of 86-120min, sugar concentration of 40ºBrix and depending the osmotic agent used temperature of 25ºC or 40ºC for sorbitol or glucose, respectively; and for plums: process time of 120min, sugar concentration of 40ºBrix and temperature of 40ºC; no differences were found between treatments with different solution/fruit ratio.