A high-performance liquid chromatographic (HPLC) method has been developed to (etermine fructose, glucose, and sucrose content of potatoes. Tl~e HPLC system consisted of a pBondapak/ carbohydrate columr , a solvent system of acetonitrile-water (75: 25), a flowrate of 1.1: ml/min, and a refractive index detector. Analysis, including samf le preparation, was complete in 30 min. With the exception of big! concentrations of sucrose (8 mg/g or above), the method recoverer! 93% or more.of all sugars. The coefficients of variation for the prcpcedure ranged from 1.39-13.31s. TLC indicated that there wer,: no interfering compounds eluting with any of the three sugars.

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Phosmet-adapted bacteria isolated from lowbush blueberries (Vaccinium angustifolium) were evaluated for their ability to degrade phosmet on blueberry fruit and in minimal salt solutions. Microbial metabolism of phosmet by isolates of Enterobacter agglomerans and Pseudomonas fluorescens resulted in significant reductions (P < 0.05; 33.8%) in phosmet residues on blueberry fruit. Degradation was accompanied by microbial proliferation of phosmet-adapted bacteria. Preferential utilization of phosmet as a carbon source was investigated in minimal salt solutions inoculated with either E. agglomerans or P. fluorescens and supplemented with phosmet or phosmet and glucose. Microbial degradation concurrent with the proliferation of P. fluorescens was similar in both liquid systems, indicative of preferential utilization of phosmet as an energy substrate. E. agglomerans exhibited the ability to degrade phosmet as a carbon source, yet in the presence of added glucose, phosmet degradation occurred within the 1st 24 h only followed by total population mortality resulting in no appreciable degradation. Characteristic utilization of glucose by this isolate suggests a possible switch in carbon substrate utilization away from phosmet, which resulted in toxicity from the remaining phosmet. Overall, microbial metabolism of phosmet as an energy source resulted in significant degradation of residues on blueberries and in minimal salt solutions. Thus, the role of adapted strains of E. agglomerans and P. fluorescens in degrading phosmet on blueberries represents an extensive plant-microorganism relationship, which is essential to determination of phosmet persistence under pre- and postharvest conditions.