Studies On The Pearling Technology Of Wheat And Effect Of It On Nutrition And Security Of Flour

Wheat germ and aleurone layer are rich in micronutrients, but most of them are lostalong with bran or mixed in wheat middling in the traditional milling process. This paperstudied the effect of the wheat pearling technology parameters on the milling characteristicsof wheat. Grains of three wheat varieties were pearled by a rice polisher, harmfulcontaminants (heavy metals residues and microorganisms) were removed from wheat,meanwhile, the most nutrition constituents were reserved in kernels. Primay studing theeffects of two kind pearling technology (pearling-traditional milling and pearling-hammerblade milling) on the physicochemical, nutritional and safety properties of wheat flour. Thatcan provide theoretical basis and datum reference for the wheat milling industry when millinghigh nutritional health standards flour.The main results in the paper were as follows：1. The effect of wheat pearling technology parameters on wheat milling performance andmilling effects: pearling time>tempering water>tempering time. The wheat pearling techno-logy parameters of AK58: Tempering water1.5%, tempering time6minutes, pearling time40-50S.2.Pearling-traditional milling had a positive effect on flour yield; The grain properties(hardness、Single-grain weight、diameter)、flour milling characteristics (ash、Whiteness、Color、particle size) were significantly affected by different pearling degree．Pearling-traditio-nal milling also had positive effects on gluten, lowered starch damage and increased fallingnumber, pasting properties (Except Pasting temperature).Pearling-hammer blade milling lowered the content of protein, wet gluten and starchdamage, increased gluten index, falling number and particle size; improved pasting propertiesof starch. Pearling-hammer blade milling lowered the white of flour.3. The content of VB and minreals were significantly improved by Pearling-traditionalmilling; Pearling milling lowered contant of heavy metals residues and microorganisms inflour. But pearling increased the contant of phytic acid in flour. Synthesize analysis ofnutritional and safety properties of flour, when the degree of pearling was4%-6%, there willbe high micronutrients contant (VB, minreals) and low harmful contaminants (heavy metalsresidues, microorganisms) in wheat flour.Pearling-hammer blade milling made the most nutrition constituents reserved in flour, and significantly lowered contant of microorganisms, phytic cid and heavy metals; The resultsshowed the most desirable pearling degree of whole wheat flour (Europe) was2%.