Predictive Research On Pre-sprouting And Safe Storage Time Of Barley As Measured By RVA

The RVA-SN (stirring number) method for predicting pre-germination of barley wasmainly studied in this paper. The application of this method and its influencing factor wereinvestigated. The correlation between RVA method and pearling method was analyzed.Meanwhile, the SN value were classified according to the pearling degree and the rate ofgermination energy decline，and the safe storage period of barley of different SN degrees wasdetermined too. The effects of pre-germination on barley quality were also studied.The standard deviation of reproducibility for RVA-SN method was4.10%~14.86%, andrelative standard deviation was below0.10%. The factors affecting SN value including barleycrushing grain size, variety, initial condition, moisture content and plant region were indicated.The results showed that the most significant factor was initial condition, the SN value wasbetween10RVU~150RVU. Moisture content had minimal impact on RVA-SN value.After comparing the correlation between RVA method and pearling method in predictingdifferent levels of pre-germination， it was found that both methods could predictpre-germination of barley, and the correlation coefficient was-0.77. But the correlationchanged for different degrees of pre-germination existed. The correlation coefficients forslight pre-germination, moderate pre-germination and serious pre-germination were-0.08,-0.53, and-0.75respectively.The RVA-SN value and pearling value for normal barley and pre-germination barleywere determined and the changes of germination energy were observed as well. According tothe pearling value and germination energy decline rate, the degree of pre-germination wasdivided into four levels. The RVA-SN degree of each level and the corresponding safe storageperiod was determined. I class for normal barley without pre-germination, RVA-SN>140RVU,safe storage period is15months. II class for slight pre-germination barley,100RVU<RVA-SN<140RVU, safe storage period is10~15months. III class for moderatepre-germination barley,45RVU<RVA-SN<100RVU, safe storage period is5~10months. IVclass for serious pre-germination barley, RVA-SN<45RVU, safe storage period is less than6months.Specifications of malts made with barleys of different RVA-SN degrees throughmicro-malting system were investigated. The results showed that the barley malt with lowRVE-SN degree had higher content of β-glucan, most of them were more than120mg/100g,this would reduce the filtering rate. Besides, the difference between the thickness and thinnessof the powder of pre-germinated barley malt was more than3%.