Application of response surface methodology for optimization of wheat flour milling process

Abstract

Background and objectives: Flour millers are faced with constraints of having to meet proximate specifications, usually defined by supply contracts, while trying to maximize yield. The study investigated the application of response surface methodology (RSM), in a commercial scale flour mill, as a means of maximizing yield while meeting quality constraints. Findings: This study utilized a Box-Behnken design to develop mathematical models using RSM to describe the effect of three independent variables, wheat conditioning level (12%-18%), first break roll gap (350-600 µm), and second break roll gap (200-600 µm) on the responses. The model R 2 for the responses was .98, .96, .98, and .98 for ash, protein and moisture contents, and flour yield, respectively. All models were statistically significant (p < .05) and validated with four independent experiments. RSM models were used to optimize the process to produce flour with a protein content greater than 12.0%, ash content less than 0.54%, moisture content less than 14.5%, and yield greater than 84.2% on a clean wheat, unconditioned basis. This was achieved with conditioning wheat to 18.4%, first break roll gap of 450 µm,and second break roll gap of 250 µm. Conclusion:The optimum mill settings resulted in a flour yield increase of 1.45% and reduction in ash content from 0.58% to 0.53%. Significance and novelty: Using RSM, significant financial gains could be achieved by producing more flour from a given quantity of wheat with lower levels of bran contamination.

Optimizing the extrusion conditions for the production of expanded intermediate wheatgrass (Thinopyrum intermedium) products

“…RSM is a statistical method used to study the relationships between several independent variables or factors and one or more response variables, with the aim of obtaining optimal responses. Compared to a full factorial design, the RSM's experimental design reduces the number of experiments required to evaluate independent variables and their interactions (Kalitsis et al., 2021). RSM has been extensively used for process optimization in the production of extruded cereal grains (Charunuch et al., 2014; Román‐Gutiérrez et al., 2021; Singha, Singh, et al., 2018).…”

Comparison of flour mill stream blending approaches: Linear programming versus ash curve

“…Figure 1 shows the process flow diagram with all the associated ancillary equipment. Modifications to the mill have achieved repeatable results using 450-500 kg samples, as demonstrated in the study by (Kalitsis et al, 2021). In addition, these modifications resulted in the ability to reduce the feed rate to the first break from 700 kg/hr to 150 kg/hr.…”

“…The grist was milled to flour using the AEGIC Pilot Mill (Kalitsis et al., 2021), which is a small commercial scale Robinson wheat mill (Thomas Richardson & Sons Pty Ltd). Figure 1 shows the process flow diagram with all the associated ancillary equipment.…”

“…To meet these requirements, flour millers produce a range of flour types with different specifications. The flour is produced by milling wheat in a process that utilizes sequential grinding and separation stages to extract the endosperm from the bran and germ and reduce the endosperm's size (Kalitsis et al., 2021; Posner, 2005). Each part of the successive process produces flour extracted from a different part of the wheat kernel.…”

“…and reduce the endosperm's size (Kalitsis et al, 2021;Posner, 2005). Each part of the successive process produces flour extracted from a different part of the wheat kernel.…”