Efectos de microondas e infrarrojo en la calidad maltera de cebada (Hordeum vulgare l)

Since 10,000 years ago or more, barley (Hordeum vulgare L.) in its various forms has been among the world?s most important cereal. Today, barley is harvested in nearly every corner of the globe, serving as a staple food for humans and animals, and a key ingredient in beer production. In Mexico, the marketing of barley grain is regulated under the standards of NMX-FF-043-SCFI-2003, which specifies the quality parameters to meet the kernel to be considered as malting barley. In recent years, genetic breeding has been used to increase the quality of barley for use in the brewing industry; this process can last from 5 to 10 years. In recent years, the genetic improvement has been used to increase the quality of barley for use in the brewing industry; the formation of a good malting cultivar can take as long as 5 to 10 years. A new alternative that was proposed in this study is was the physical modification of the barley kernel of feed and malting barley with microwave and infrared (IR) irradiation to increase the industrial quality in a short period of time. Therefore, the aim of this study was evaluate the effects of microwave and IR irradiation on the mechanical properties, malting quality and changes in some biochemistry components of kernel of different barley varieties. The barley cultivars evaluated were two malting cultivars and two feed cultivars. Preliminary tests showed that treatments with temperature higher than 50°C decreased the grain germination performance. The microwave irradiation times selected were 4 and 8 sec, for IR 37 and 54 sec. The kernels treated for 4 sec with microwave and 37 sec of IR irradiation showed an increment in the malt extract around 7 % with microwave and 4 % with IR respectively. Also to those treatments showed a better quality performance related to a decreament of the wort viscosity, kernel hardness, elastic modulus, dietary fiber and wort ?-glucans. The microwave or IR irradiation did not show any negative effects on the enzymatic systems. The micrographs showed some effects of the iradiation treatments on the starch granule surfaces that reduced the starch peak viscosity of RVA and cristallinity detected by X-ray diffraction. On the other hand the DRIFT spectroscopy showed that the microwaves and IR had an effect on the secondary structure of the proteins, by breaking hydrogen bonds in ?-helix and ?-sheet, as well as between proteinstarch; resulting in changes in the hydrophobicity of prolamins, without changing its molecular weight. Changes were also observed in the structure of polysaccharides such as ?-glucans. However, treatments with longer irradiation times yielded a reversible effect on the secondary structure of proteins and protein-starch interactions, as well as quality.