# Vitreosity as a Major Grain Quality Indicator--Upgrading the Grain-Cutter Method with a New Blade
###### Abstract  
One of the main quality characteristics of cereals, especially wheat is its hardness which is closely related with grain's vitreous, one of the main quality indicators of a variety. Determination of vitreous is usually done visually: namely, after the grain is cut with a commercially available grain-cutters, the cut can result in broken or crushed grains which disables the reading and hinders the precision and accuracy. Also, the moment produced from the manual force on the grain-cutter crank, needed to cut the sample of cca. 50 grains placed in the cutter is an average of 30 Nm. Due to the resistance of the grain, yank force appears. This force can cause the whole instrument to be displaced during cutting. To minimize the errors using a commercially available cutter, a new knife/blade has been implemented and tested. The blade of the new knife is turned at the inclination angle of 49\({}^{\circ}\) in relation to the cutting objects (grains). This design solution enables achievement of the grain \"cutting\", not grain \"tearing\", as observed with the existing commercial design solution. With the proposed new design solution, amount of the moment is reduced to 2.72 Nm and the yank force is completely avoided. Also, a significantly lower amount of the cutting force, on the knife blade is achieved. The results obtained with the new knife gave a better read, were more precise, and the gadget was easier to operate since it demanded lower force to cut the grains. The novelty introduced by this research provided better and more reliable insight into determining the vitreousness of grains. Providing a clearer cut and better readability, this solution goes beyond the current literature by reducing the force required for analysis and speeding up the analysis process. grain hardness; cut; knife; precision; cutting force +
Footnote †: journal: _Sciences_  
002330  
by the agrotechnical measures and weather conditions during vegetation [5; 6]. Vitreous grains are commonly hard and have a natural opacity (vitreosity); they also have a higher protein share (glutenin and gliadin) in comparison to starchy part of the endosperm [1; 7]; and they have a higher density that is manifested as increased hardness and is exhibited as a resistance toward mechanical shearing during milling [4; 8]. Grain classification based on hardness or vitreous is very similar [9]. According to hardness, wheats are generally divided to hard and soft varieties [5]. Recently, an updated classification included several classes of hardness since many of the European cultivars and varieties that make up the biggest share at the market are actually a transition between soft and hard. They are prone to convert, that is that they formally have the designated hardness, but when subjected to industrial processing they act like soft wheats. This is called a fake or transient vitreous, a vitreous that is lost after the grain has been soaked in water. Thus, most authors consider a variety as hard if it has >85% of vitreous grains [10]. Based on vitreous, wheat can be classified into three main classes: vitreous, mealy and partly vitreous. Vitreous wheat is different from mealy wheat by the look of the endosperm (starchy and non-transparent starch granules). It is considered to be of better quality than the mealy varieties due to the more quality grits proteins, yellowish grits color and more even coarse granulation [11]. Wheat vitreous is a quality property that can be, as opposed to hardness, protein share and structure, visually determined. Today's non-invasive techniques for vitreous determination include X-ray, Transmitted light image analysis, VIS/NIR spectroscopy. However, all these methods ask for sophisticated equipment, that is hard to relocate and requires large series of samples to be profitable. This is why this property is commonly determined using a visual ICC Method Standard 129, that relies on [PERSON]'s grain cutter measurement technique [12; 13].