Predicting chemical, enzymatic and nutritional properties of fermented barley (Hordeum vulgare L.) by second derivate spectra analysis from attenuated total reflectance-Fourier transform infrared data and its nutritional value in Japanese quails.

Nutrient concentrations, enzyme activities, viable probiotic counts and organic acid levels of fermented barley (FB) produced by solid state fermentation (SSF) and of its unfermented counterpart (unfermented barley (UFB)) were determined by quantitative methods, and compared with the second derivate spectra analysis (SDSA) of their attenuated total reflectance-Fourier transform infrared measurements. Moreover, in order to test the nutritional value of FB and UFB feeds, 3-d old Japanese quails were fed FB or UFB at 400 g/kg diet for 4 weeks. Chemical analysis indicated that FB had significantly increased crude protein, ether extract and ash contents, associated with lowered fibre and sugar contents, as compared with UFB. IR spectra pattern of FB and UFB samples were similar, but their SDSA parameters, particularly peak areas, differed significantly. The differences between FB and UFB in peak areas were highly correlated with the differences between two feeds in lipid, protein, total fibre, starch and sugar contents (p < 0.05). Furthermore, SDSA analysis found new peak areas only available in FB samples, indicating fortification with new biomolecules due to the effect of SSF. Feeding the FB containing diet for 3 or 4 weeks enhanced growth performance significantly and increased the carcass yield of quails, indicating its nutritional benefits in young growing quails. The results indicated that the further analysis of IR spectra data revealed important information on the chemical and biological properties of feed materials, which are found to be highly correlated with the results of compositional analysis and their biological value in animal model.