2.3. Chemical analyses
Standard methods of analysis (AOAC, 2000) were used to determine crude protein (Official Method No. 950.36), fat (Official Method No. 935.38), cellulose (Official Method No. 950.37), ash (Official Method No. 930.22) and moisture contents (Official Method No. 926.5). In the protein determination, a nitrogen-to-protein conversion factor of 6.25 was used. Total carbohydrate content was calculated as a sum of reducing sugar and starch contents determined by the AOAC Official Method No. 975.14 and ICC Standard No. 123/1 (1994), respectively.
The mineral content of cookies was determined by atomic absorption spectrophotometry after digestion of ground samples by HNO3 and HClO4. A detailed description of the sample preparation, determination of elements, used reagents and analytical quality control data was reported by Škrbić and Čupić (2005). The whole procedure applied in this work was validated with certified reference material (IAEA-V-8-Rye flour) analysed in the same manner as the samples. The recovery values, ranging from 70% to 110%, were in agreement with the certified values, confirming the accuracy of the procedure applied.
The tocopherol content was determined by standard method ISO 9936:2006. The chromatographic system consisted of a Liquid Chromatograph HP 1090 (Hewlett–Packard) and fluorescence detector HP 1100 (λex = 300 nm, λem = 330 nm). The analytical column was InterSil Si (5 μm, 150 × 4.6 mm) (Chrompack). The mobile phase was a 0.3% solution of ethanol in hexane, at a flow rate 1.0 ml/min. The samples were prepared by classical treatment, which included saponification with KOH and ethanol. The extraction of unsaponificable matters was performed with diethyl ether.
β-Glucan content of samples was determined enzymatically, in accordance with the method of McCleary and Glennie-Holmes (1985) modified by McCleary and Nurthen (1986).
All determinations were performed in triplicate.
2.3. Chemical analysesStandard methods of analysis (AOAC, 2000) were used to determine crude protein (Official Method No. 950.36), fat (Official Method No. 935.38), cellulose (Official Method No. 950.37), ash (Official Method No. 930.22) and moisture contents (Official Method No. 926.5). In the protein determination, a nitrogen-to-protein conversion factor of 6.25 was used. Total carbohydrate content was calculated as a sum of reducing sugar and starch contents determined by the AOAC Official Method No. 975.14 and ICC Standard No. 123/1 (1994), respectively.The mineral content of cookies was determined by atomic absorption spectrophotometry after digestion of ground samples by HNO3 and HClO4. A detailed description of the sample preparation, determination of elements, used reagents and analytical quality control data was reported by Škrbić and Čupić (2005). The whole procedure applied in this work was validated with certified reference material (IAEA-V-8-Rye flour) analysed in the same manner as the samples. The recovery values, ranging from 70% to 110%, were in agreement with the certified values, confirming the accuracy of the procedure applied.The tocopherol content was determined by standard method ISO 9936:2006. The chromatographic system consisted of a Liquid Chromatograph HP 1090 (Hewlett–Packard) and fluorescence detector HP 1100 (λex = 300 nm, λem = 330 nm). The analytical column was InterSil Si (5 μm, 150 × 4.6 mm) (Chrompack). The mobile phase was a 0.3% solution of ethanol in hexane, at a flow rate 1.0 ml/min. The samples were prepared by classical treatment, which included saponification with KOH and ethanol. The extraction of unsaponificable matters was performed with diethyl ether.β-Glucan content of samples was determined enzymatically, in accordance with the method of McCleary and Glennie-Holmes (1985) modified by McCleary and Nurthen (1986).All determinations were performed in triplicate.
การแปล กรุณารอสักครู่..