Cassava pulp was hydrolyzed with acids or enzymes. A high glucose concentration (>100 g/L) was obtained from the hydrolysis with 1 N HCl at 121 degrees C, 15 min or with cellulase and amylases. While a high glucose yield (>0.85 g/g dry pulp) was obtained from the hydrolysis with HCl, enzymatic hydrolysis yielded only 0.4 g glucose/g dry pulp. These hydrolysates were used as the carbon source in fermentation by Rhizopus oryzae NRRL395. R. oryzae could not grow in media containing the hydrolysates treated with 1.5 N H2SO4 or 2 NH3PO4, but no significant growth inhibition was found with the hydrolysates from HCl (1 N) and enzyme treatments. Higher ethanol yield and productivity were observed from fermentation with the hydrolysates when compared with those from fermentation with glucose in which lactic acid was the main product. This was because the extra organic nitrogen in the hydrolysates promoted cell growth and ethanol production.

Thermal degradation rates of pyridoxal (PL-HCI), pyridoxine (PN. HCl) and pyridoxamine (PM.2 HCl) in 0.1 M phosphate buffer (pH 7.20) were determined over the temperature range llO-145"C using HPLC procedures. Thermal degradation of PM.2 HCl was modelled by a pseudo-first order rate constant. Thermal degradation of PN-HCI and PL.HCl was modelled by a 1.5 order and second order model, respectively. The temperature dependence of all three rate constants could be described by the Arrhenius equation. None of the degradation products from any of the vitamers exhibited antivitamin activity. Thermal degradation rates of vitamin B6 in cauliflower puree were measured over the temperature range 106-138°C and found not to be described by a rust-order model. The activation energy was markedly lower in this food system than in the model system and emphasizes the importance of conducting experiments on real food systems. The activation energy is in the range reported for several other water soluble nutrients.