A response surface methodology approach to optimise pretreatments to prevent enzymatic browning in potato (Solanum tuberosum L) cubes

Abstract

The objective of this work was to find the best combinations of ascorbic acid concentration/soaking time (Pretreatment 1), 4-hexylresorcinol concentration/soaking time (Pretreatment 2) and ascorbic acid concentration-4-hexylresorcinol concentration/soaking time (Pretreatment 3) to prevent the development of enzymatic browning in raw potato cubes (10mm x 10mm x 10mm). Potato variety Alpha was used as study model because of its low susceptibility to enzymatic browning. Response surface methodology was applied in all pretreatments on two response variables (Hunter L value and total colour difference) to find the best conditions for carrying out the pretreatments. The various pretreatments had variation levels for ascorbic acid (AA) concentration (1 and 3) and 4-hexylresorcinol (4HR) concentration (2 and 3) of 1-4 and 0.04-0.20 g1-1 respectively; in all pretreatments the variation level for soaking time was 3-6 h. A central composite experimental design with two factors at five levels was used. Predictive models for Hunter L value and total colour difference were developed as a function of process or independent variables. The optimisation technique was applied to obtain maximum Hunter L values and minimum values of total colour difference. Surface superposition of these variables allowed identification of the best combinations of process variables for each pretreatment as (1) 2.9 g1-1 AA/4.8h, (2) 0.04 g1-1 4HR/2.6 h and (3) 2.42 g1-1 t AA-0.15 g1-1 4HR/5.41 h. © 2001 Society of Chemical Industry.