46E-1 |
Xylose from hydrolysis of sorghum straw using sulphuric acid at 80ºC |
J. A. RAMÍREZ, S. J. Téllez-Luis, and M. Vázquez. Dept. of Food Science & Technology, Univ. Autónoma de Tamaulipas, UAM Reynosa-Aztlán, Calle 16 y Lago de Chapala. Col Aztlán, Reynosa, Tamaulipas, 88740, Mexico The hydrolysis of sorghum straw to obtain xylose solutions is very interesting because the xylose solutions can be used as fermentation media to produce food additives using microorganisms. Xylose solutions has been used to obtain food sweetener (xylitol) and pigments (astaxanthin). Xylose solutions with low concentration of microbial growth inhibitor can be obtained using sulphuric acid at relative low temperatures. The objective of this work was evaluated the hydrolysis of sorghum straw using sulphuric acid at 80ºC to obtain solutions with a maximum xylose concentration and minimum furfural and acetic acid concentrations, which are growth inhibitors. Xylose production can be considered a first step to produce biotechnological food additives. Sorghum straw was collected at a local farm. Moisture was determined gravimetrically, xylose, glucose and acetic acid were determined by HPLC with IR detector, and furfural were determined by UV-Vis spectrometry. The effect of several sulphuric acid concentrations (2, 4 or 6%) at 80ºC were evaluated in the hydrolysis of sorghum straw during 5 hours. Hydrolysates with 15.2±1.1 g xylose/L, 6.2±0.3 g glucose/L, 1.1±0.1 g acetic acid/L and 0.44±0.03 g furfural/L were obtained in the optimum conditions (6% of sulphuric acid and 5 h). Mathematical models were applied to modelling the process. The results showed that it is possible to obtain xylose solutions with low concentration of growth inhibitor from sorghum straw using sulphuric acid at 80ºC. Therefore, these solutions can be used as media for biotechnological production of food additives.
Session 46E, International
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