Effects of Micronization on Protein and Rheological Properties of Spring Wheat

Abstract

This research investigated the effects of micronization, at different moisture levels, on the chemical and rheological properties of wheat. A set of tests designed to analyze protein fraction characteristics and rheological behaviors were conducted on samples from four wheat cultivars (AC Karma, AC Barrie, Glenlea, and Kanata). After being subjected to infrared radiation at three moisture levels (as‐is, 16%, and 22%), the seeds were milled to produce straight‐grade flour. The protein fractionation test revealed significant decreases (P ≤ 0.01) in both monomeric proteins (from 54% of total protein in the control to 37% in the tempered micronized sample) and soluble glutenins (9.4–2.5%). There was a strong negative correlation (r = ‐0.98) between the percentages of monomeric proteins and insoluble glutenins. Total extractable proteins of micronized samples tempered to 22% moisture decreased 43.5% when compared with nonmicronized control samples using size‐exclusion HPLC (SE‐HPLC). Micronization had a significant effect on gluten properties, as seen from a decrease in water absorption (P ≤ 0.01) and dough development time (P ≤ 0.01). Results showed that micronization at 100 ± 5°C had detrimental effects on wheat flour gluten functionality, including a decrease in protein solubility and impairment of rheological properties. These phenomena could be due to the formation of both hydrophobic and disulfide bonds in wheat during micronization.

Composition, digestibility, and functional properties of yellow pea as affected by processing

“…The distribution of the proteins in the pre‐germinated flour were; ∼40% >30 kDa, 30% between 30 and 16 kDa and 30% <16 kDa. This is consistent with the report of Hsu et al () who also observed more small protein subunits after germination compared with the nongerminated (control) yellow pea and with Sun et al () who reported no differences in the electrophoretic profile of the control and micronized wheat sample. Lipoxygenase (97.2 kDa), convicilin (77.9–72.4 kDa), legumin (63.6 kDa; α: 40.8 kDa; β: 23.1–22.3 kDa), vicilin (47.3 kDa, 37–31.8 kDa, and 28.7 kDa) were observed in different pea bean varieties (Barac et al, ).…”

“…The distribution of the proteins in the pre-germinated flour were; 40% >30 kDa, 30% between 30 and 16 kDa and 30% <16 kDa. This is consistent with the report of Hsu et al (1982) who also observed more small protein subunits after germination compared with the nongerminated (control) yellow pea and with Sun et al (2006)…”

“…The proximate composition of the untreated flour was similar to those reported by Boye and Ma (2012) (even though the N factor used in is study was 5.52). These results were also consistent with Sun, Watts, Lukow, and Arntfield (2006) who reported no changes in the protein and ash contents of micronized wheat. Other authors (Hsu et al, 1980;Shah et al, 2011) on the other hand reported increases in protein content after germination, contrary to El-Adawy, Rahma, El-Bedawey, and…”

Infrared Radiation: Impact on Physicochemical and Functional Characteristics of Grain Starch

“…However, a reduction in dough development time was reported. [46] The above studies clearly demonstrated that the disintegration of starch granules causes the reduction in values of pasting profile in all the IR treated grains and starches, except waxy varieties of barley indicating the importance of amylose in deciding the rheological properties. In addition to starch, the protein content also seemed to affect the rheological properties which might be the reason for the difference in the behavior of monocots and dicots to IR radiations.…”

Effect of High-Temperature Short-Time ‘Micronization’ of Grains on Product Quality and Cooking Characteristics

“…IR can be used for stabilization of rice bran as it was effective in retarding FFA increase during the course of storage. The effect of micronization on protein solubility characteristics of wheat having different gluten strength was elucidated by Sun et al [43]. Wheat grains were micronized after tempering to 16 and 22 % moisture content, and the performances were compared with that of grains not subjected to tempering.…”