Tomato Paste Testing Broth is used to detect and isolate Lactobacillus, yeast, and molds that cause spoilage in tomato-based products. Gelatin Peptone and Yeast Extract provide peptides, peptones, vitamins, and certain trace materials. Fructose and Dextrose are the carbohydrate sources. Tartaric Acid is a selective agent suppressing the growth of several bacterial species.