Method for evaluating anaerobic digester performance.

The degradation rate and efficiency of digestion processes is typically measured by introducing a substrate or pollutant into a digester and then monitoring the effluents for the pollutant or substrate, a costly and slow process. A new method for rapid measurement of the rates and efficiencies of anaerobic degradation of pollutants and lignocellulose substrates from various pretreatments is described. The method uses micro-reactors (10-30mL) containing a mixed culture of anaerobic bacteria obtained from a working anaerobic digester. The rate of degradation of pollutants and metabolic heat rate are measured in parallel sets of micro-reactors. Measurement of metabolic rate and pollutant degradation simultaneously is an effective means of rapidly examining pollutant degradation on a micro-scale. Calorimetric measurements alone allow rapid, relative evaluation of various substrate pretreatment methods.

Quantitative X-ray diffraction determination of alpha-lactose monohydrate and beta-lactose in chocolate.

UNLABELLED: Lactose is a constituent of milk chocolate. During processing and cooling, lactose may precipitate as alpha-lactose monohydrate and beta-lactose. The presence of alpha-lactose monohydrate has a deleterious effect on the quality of milk chocolate. A quantitative X-ray diffraction method for determination of alpha-lactose monohydrate and beta-lactose in chocolate is described. The alpha-lactose monohydrate signal at 19.9 degrees 2theta with Cu-Kalpha X-rays is a cubic function of concentration. The beta-lactose signal at 20.9 degrees 2theta is a linear function of concentration. alpha-Lactose monohydrate is detectible at about 0.1 weight% and can be quantified at >0.5 weight%. beta-Lactose is detectible at about 1 weight% and can be quantified at >3 weight%. About 10 min is required to prepare and run a sample. PRACTICAL APPLICATION: The crystalline form of lactose affects the quality of chocolate. A rapid method for quantifying crystalline forms of lactose in chocolate is described. The method can be used for quality control and for improving chocolate quality.