An optimization of mixing process parameters for soy sauce production

Abstract

This research was done to reduce the variation of brixs in mixing process to produce sweet soy sauce. The objective of this research is to find the optimum setting in mixing process. Design of Experiment was used to analyze various combination of process parameters. The process parameters investigated were sugar, caramel, monosodium glutamate (MSG) for Experiment 1 and sugar, salt, water, acid acetic for Experiment 2 respectively. It was not economically practical to run experiments in the real life factory environment. As such, lab experiment was used in this study. Full factorial of design matrix has been used. The significant factors for Experiment 1 are sugar, MSG and caramel. This is including two way interactions between sugar and MSG, Sugar and caramel, MSG and caramel and the last one is three way interaction of all factors. Normally, 3 way interaction and above are assumed as insignificant factors. The significant factors for Experiment 2 are sugar, salt, water and caramel. This is including two way interactions between sugar and salt, Sugar and acetic acid, salt and acetic acid, water and acetic acid and three way interaction between sugar, salt and water and last three way interaction are sugar, water and acetic acid. The study reveals that the optimum setting is the low level (-1) of sugar (450~500 kilogram), caramel (200~225 kilogram) and MSG (64~68 kilogram) for Experiment 1. The optimum setting for Experiment 2 is the low level (-1) of sugar (1350~1450 kilogram), salt (45~55 kilogram), and acetic acid (0.35~0.45 litres) but higher level (+1) for water (800~900 litres) in order to ensure the brix reading fulfil the specification. Mathematical models have been proposed to predict the performance of mixing process with brix reading as the response within the investigated ranges. There are a few suggestions and suitable action plan were proposed to increase the quality of production.