Grains of four oat varieties were enzymatically hydrolyzed, and the preparations produced thereof were chemically, sensory, and nutritionally assessed. Those preparations were also compared with ‘Oatrim 5’, a commercial preparation of hydrolysate, manufactured by a Meyhall Chemical AG Company in Kreuzlingen (The Netherlands). Furthermore, the effect of oat variety on the process of producing hydrolysate was assessed, as was its effect on the final product productivity. The organoleptic assessment did not prove significant differences to exist among the samples. However, it was found that the content of mineral compounds in the form of ash was higher in the preparations investigated compared to the ‘Qatrim 5’ preparation. This fact was attributed to the occurrence of chloride ions, higher DE value, and to a higher content of simple sugars (monosaccharides). The increase in the values of those indicators was caused by a method, different than the original one, of enzyme inactivation applied to manufacturing a commercial preparation. Particularly worth highlighting was the ability of preparations, used in the diet, to lower the total cholesterol and LDL fraction levels, and to simultaneously increase the HDL fraction level (the investigations were carried out on rats). This confirmed a well known fact of beta-glucans in oats to have high hypocholesterolemic abilities. It was also proved that amounts of the preparation produced were connected with the presence of lipids in the oat grain. The increase in the amount level of this compound contributed to the decrease in the process productivity, and, also, obstructed the production process of preparation during the filtration and decantation phases.