act-dog

Scientists hypothesized that heating tomatoes affects the concentration of nutrients such as vitamin C and lycopene (a red pigment) in the tomatoes. They conducted 2 experiments to test their hypothesis. Experiment 1 Two kilograms of a particular variety of raw tomatoes were sliced and then blended in a food processor until a homogeneous (uniform) tomato mixture was produced. The mixture was divided into 4 equal samples (Samples 1−4). Each sample was placed in a separate plastic bag, and the bags were sealed. The bag containing Sample 1 was immediately frozen at −40°C. The bags containing Samples 2−4 were each incubated in a water bath at 88°C for a different period of time (see Table 1) and then frozen at −40°C. Table 1 Incubation time at 88°C Sample (min) 1 0 3 15 4 30 Then, 2 days later, Steps 1−3 were performed for each sample. 1. The sample was thawed, and then 100 g of the sample was placed in a beaker containing 200 mL of Solvent A. 2. The contents of the beaker were mixed for 5 min at 25°C and then filtered using a paper filter. The filtered liquid was collected. 3. The filtered liquid was analyzed to determine the vitamin C concentration in micromoles per gram of tomato (μmol/g tomato). The results for each sample are shown in Figure 1. Figure 1 0.8 no 0.7 it a ) r o 0.6 t t n a ec m 0.5 o no t c g 0.4 /l C o 0.3 n m i m ( 0.2 a ti 0.1 v 1 2 3 4 Sample Experiment 2 Experiment 1 was repeated except that in Step 3 the filtered liquid was analyzed to determine the lycopene concentration in milligrams per gram of tomato (mg/g tomato). The results for each sample are shown in Figure 2. Figure 2 no it a ) r t o n t a 4 ec m no o t 3 c g e / g n 2 e m po ( c 1 y l 1 2 3 4 Sample Figures 1 and 2 adapted from Veronica Dewanto et al., “Thermal Processing Enhances the Nutritional Value of Tomatoes by Increasing Total Antioxidant Activity.” ©2002 by American Chemical Society.