Effects of Attrition Milling on Air Classification Properties of Hard Wheat Flours

Abstract

Effects of attrition milling on yield and composition of air‐classified fractions from fifth break and first middling flours of HRS wheat were investigated using image analysis to characterize flour particle size distributions. Roller‐milled flours had high proportions of particles < 45 μ diameter but particles > 105 μm diameter constituted most of the flour volume. Attrition milling caused less starch damage than pin milling but increased the degree of reduction (<45 μm diameter), based on volume, from 10.3 to 100% for fifth break and from 6.9 to 100% for first middling flours. Two cuts on the air classifier produced a high protein fraction with high ash (30.5% protein, 41% starch, 2% ash, 14% moisture basis), which would have application as a gluten substitute in baking, and a medium protein fraction (14% protein, 66% starch, 0.65% ash) which could be blended into Bakers Patent. The major fraction of air classified middlings flour contained 6.5% protein, 77% starch and 0.3% ash.

Production of Starch with Very Low Protein Content from Soft and Hard Wheat Flours by Jet Milling and Air Classification

“…Grinding principle remains close to that of the pin mill, adding in more of a cavitation effect (pressure-depressure). Attrition-milled flours have lower starch damage content than those produced by pin mills (Nowakowski et al 1986;Sosulski et al 1988). Fluid energy impact, or jet milling, is another interesting option for reducing all aggregates; it produces superfine powders (Helle 1988).…”

Efektifitas Fraksinasi Kering pada pengolahan Empulur Sagu dan Pemanfaatan Produk untuk Produksi Etanol

“…Untuk memisahkan partikel pati dari serat, digunakan metode klasifikasi udara yang memanfaatkan gaya sentrifugal dan gaya gravitational, yang diisebabkan oleh aliran udara yang masuk ke dalam ruang klasifikasi sehingga terjadi pemisahan partikel berdasarkan ukuran, bentuk dan berat jenisnya (Wang & Maximiuk, 2019). Untuk meminimalkan kerusakan pati, Sosulski et al (1988) menyarankan penggunaan metode attrition mill pada tahap reduksi ukuran dan disintegrasi bahan berpati.…”