Recoveries of coliforms in water and food samples were increased by adding sodium pyruvate to the Tryptic Soy Agar (TSA) base layer, and Violet Red Bile (VRBA) overlay, of the Modified VRBA procedure described in Standard Methods for the Examination of Dairy Products. Six pyruvate levels (0, 0.005, 0.01, 0.05, 0.1, and 1.0%) were tested. Counts were significantly lower (P≤0.05) on media containing 0% and 1.0% pyruvate than on the other media. Although 0.05% yielded the highest counts overall, there were no significant differences (P≤0.05) among 0.005, 0.01, 0.05, and 0.1% pyruvate. Analysis by using a general linear model procedure revealed that 0.02% pyruvate was the statistically predicted optimal level to use in the Modified VRBA procedure.

A domestic microwave oven was used to measure the water content, a useful index of protein and energy content, of more than 8000 samples of cooked food in three villages in The Gambia, West Africa. The microwave oven offers several advantages over conventional freeze-dryers; it is inexpensive, small and maintenance-free. Values for water content are obtained within a few minutes, in contrast to the many hours required for freeze-drying.