Stone Milling versus Roller Milling in Soft Wheat: Influence on Products Composition

Abstract

Wholegrain wheat flours are in great demand from consumers worldwide because they are considered healthier then refined flours. They can be obtained by either stone milling, which is experiencing a revival in Europe, or roller milling. In order to study compositional differences due to the milling technology and to explore the possibility of a better qualification of wholegrain flours by means of nutritionally oriented quality parameters, eight mixes of soft wheat grains were stone milled and roller milled and the milling products were analyzed for their protein, ash, lipids, total dietary fibre, total polyphenols and alkylresorcinols content. A wholegrain flour milled with a laboratory disk mill was used as a comparison and a set of seven wholegrain flours purchased on themarket were also analyzed and compared. The particle size distribution of stone milled and recombined roller milled flour was also studied. Considering the above mentioned parameters, we found that there is no compositional difference between a stone milled or a roller milled flour if, in this latter one, the milling streams are all recombined, but the particle size distribution was different. This might have an impact on the technological quality of flours and on the bioavailability of components.

Understanding whole‐wheat flour and its effect in breads: A review

“…This is supported by the results of Carcea et al. (2019), who found that flours obtained with stone mills have a higher percentage of fractions with smaller particle size. However, the bran obtained from the roller milling process may also be reworked or micronized before being incorporated back into the flour from the endosperm.…”

“…Roller mills reduce particle size of endosperm flour while maintaining the bran particles in relatively large pieces, while stone and hammer mills lack this system (Posner & Hibbs, 2005). This is supported by the results of Carcea et al (2019), who found that flours obtained with stone mills have a higher percentage of fractions with smaller particle size. However, the bran obtained from the roller milling process may also be reworked or micronized before being incorporated back into the flour from the endosperm.…”

Nutritional Features and Bread-Making Performance of Wholewheat: Does the Milling System Matter?

“…In accordance with the AACC International definition of whole grain [33], neither milling process selected the anatomical regions, and endosperm, bran and germ have to be present in the same proportions as in the intact caryopsis. In agreement with other authors [17,20,22], no significant changes in the proximate composition were found regardless of the milling process used ( Table 3). The few differences between SWFs and RWFs concerned moisture, which was significantly higher in RWFs from Bona Vita and Skorpion cvs.…”

“…Although the occurrence of several macronutrients was unchanged in the compared WFs, RWFs of pigmented cvs resulted in a higher content of antioxidant compounds than SWF. Carcea et al [20] reported no compositional difference regarding the total polyphenol and alkylresorcinol contents between stone milled or roller milled flours. In our study, in particular, a significantly higher content of CWBPAs and TAC were present in RWFs.…”

“…Despite the great interest in stone milling and increasing demands for WF-produced food, few studies have compared the effects of stone and roller milling on the same wheat varieties to identify and evaluate analogies and differences between the two kinds of WF [ 15 , 19 ]. Some research has found similarities in proximate chemical composition and phenolic profile of WF from stone milling (SWF) and roller milling (RWF) [ 17 , 20 , 21 ]. On the contrary, by promoting high heat development due to friction, compression and shear phenomena, stone milling leads to a significant loss in aminoacids and unsaturated fatty acids [ 17 ].…”