The biogas and biomethane production in a 50 litre closed stirred tank anaerobic bioreactor treating palm oil mill effluent (POME) supplemented with oil palm biomass in the form of oil palm empty fruit bunch (OPEFB) under mesophilic condition was evaluated. With OPEFB supplementation, the biogas and biomethane generation increased by 63% and 52%, respectively. During this process, we found changes in the OPEFB morphology and microbial community through microbiota analysis using 16S rRNA gene clone library method, after OPEFB was added, suggesting that the increased biogas and biomethane production would be due to enhanced lignocellulosic biomass degradation.
The effect of partial gelatinization of starch during precooking operation on the final viscosity of retort curry at serving temperature was investigated. While the increase in the viscosity of retort curry is largely due to the starch gelatinization during the heating processes of cooking and sterilization, it is known empirically that a high temperature during the material mixing operation before cooking may result in a lower final viscosity. The relationship between the temperature and the partial starch gelatinization during material mixing was therefore studied by measuring amylose leaching, swelling ratio, dynamic viscoelasticity, and by differential scanning calorimetry (DSC). When the mixing temperature was at or higher than 65℃, the starch was partially gelatinized under the low water condition, and as the result, the increase in the viscosity during cooking and sterilization was suppressed. This finding is expected to be useful in controlling the viscosity of starch-containing retort foods.