Moisture and total nitrogen content are considered very important factors that influence barley malt quality, as well as moisture and lipid content for maize quality. In the present study, the feasibility of using Near-Infrared (NIR) spectroscopy to measure the moisture, total nitrogen and lipid content of the whole malt grains and maize grits was examined. The NIR spectra of the following samples were examined: 295 malt whole grains for moisture, 281 malt whole grains for total nitrogen, 128 maize grits for moisture and 102 maize grits for total lipids. Validation was carried out both by means of cross-validation and test set validation. Coefficients of determination (R2) were higher than 93% for both malt and maize moisture and higher than 71 and 80 for malt total nitrogen and maize total lipids, respectively. The Root Mean Square Error (RMSE) values (both in Cross Validation (RMSECV) and in Prediction through external validation (RMSEP)) ranged from 0.127 to 0.165% for both malt and maize moisture, whereas they ranged from 0.043 to 0.053% for malt total nitrogen and from 0.065 to 0.079% for maize total lipids. Repeatability (r95) ranged from 0.105 to 0.222% and from 0.012 to 0.155% for malt moisture and total nitrogen content, respectively, and from 0.086 to 0.192% and from 0.020 to 0.171% for maize moisture and total lipid content, respectively. The findings showed that NIR spectroscopy has potential for the rapid prediction of quality of whole malt grains and maize grits for brewing.
Near-Infrared spectroscopy for proficient quality evaluation of malt and maize in beer industry.
SILEONI, VALERIA;PERRETTI, Giuseppe Italo Francesco;MARTE, Luisa;MARCONI, Ombretta;FANTOZZI, Paolo
2010
Abstract
Moisture and total nitrogen content are considered very important factors that influence barley malt quality, as well as moisture and lipid content for maize quality. In the present study, the feasibility of using Near-Infrared (NIR) spectroscopy to measure the moisture, total nitrogen and lipid content of the whole malt grains and maize grits was examined. The NIR spectra of the following samples were examined: 295 malt whole grains for moisture, 281 malt whole grains for total nitrogen, 128 maize grits for moisture and 102 maize grits for total lipids. Validation was carried out both by means of cross-validation and test set validation. Coefficients of determination (R2) were higher than 93% for both malt and maize moisture and higher than 71 and 80 for malt total nitrogen and maize total lipids, respectively. The Root Mean Square Error (RMSE) values (both in Cross Validation (RMSECV) and in Prediction through external validation (RMSEP)) ranged from 0.127 to 0.165% for both malt and maize moisture, whereas they ranged from 0.043 to 0.053% for malt total nitrogen and from 0.065 to 0.079% for maize total lipids. Repeatability (r95) ranged from 0.105 to 0.222% and from 0.012 to 0.155% for malt moisture and total nitrogen content, respectively, and from 0.086 to 0.192% and from 0.020 to 0.171% for maize moisture and total lipid content, respectively. The findings showed that NIR spectroscopy has potential for the rapid prediction of quality of whole malt grains and maize grits for brewing.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
