EXPERT DESIGNEXPERT DESIGN

By: Nooshin NoshirvaniBy: Nooshin Noshirvani

Analysis of volatile aroma compounds of fresh Analysis of volatile aroma compounds of fresh chilli (Capsicum annuum) during stages of chilli (Capsicum annuum) during stages of

maturity using solid phase microextraction maturity using solid phase microextraction (SPME)(SPME)

Software for Design of Experiments

Design Expert is a piece of software designed to help with the design and interpretation of multi-factor experiments

Optimization of SPME extraction of selected aroma compounds was done using a central composite design (CCD)

consisting of a 22 factorial design with resulting in 13 treatments

For the optimization method, CCD is one of the most useful design for estimating a multifactor response surface which keeps to a minimum number of experiments

And allows the simultaneous variation of all the experimented factors studied and the distinguishing of interaction among them

Experimental design showing coded and uncoded variables

The evaporation of the volatile compounds can be adequately represented by the model equations as shown in Table

Results from response surface methodology (RSM) showed that heating at 60ºC for 30 min gave the optimum parameter, as indicated by the high desirability

This study, therefore, tried developing a mathematical model capable of predicting the aw at fixed temperature (25º C ) of some foods, from easily measured, pertinent physicochemical food properties, namely pH and Brix values.

The study established a predictive model in simulated food solutions (SFS), which contained varying levels of water, sucrose and acid.

The predictive performance of the established model was assessed through validations using a different set of SFS and various actual food systems.

The SFS were formulated based on the data supplied to and processed using the Design Expert Version 7.0.3 software package

A Central Composite Rotatable Design (CCRD) was applied, to determine the appropriate combinations of various levels of pH and Brix

Response surface plot showing the influences of pH and Brix on aw

Optimization of the basic formulation of a Optimization of the basic formulation of a traditional baked cassava cake using response traditional baked cassava cake using response

surface methodologysurface methodology

Effects of amount of ingredients such as sugar (10–30%) and coconut milk (15–35%) on the textural characteristics (hardness and chewiness) and sensory qualities (colour, firmness, cassava flavour and overall acceptability) of cakes were investigated.

The three coded levels of sugar: -1 (10%), 0 (20%), 1(30%) coconut milk: -1 (15%), 0 (25%), 1(35%)

Central composite design arrangement and experimental result for the response

variables

Optimum formulation of baked cassava cake was 25% of sugar and 20% of coconut milk.