The effect of the addition of 2 kinds of chemically modified starches (the anti-caking agents; tapioca starch and com starch) on caking of ramen soup was observed using a low-resolution proton-pulsed nuclear magnetic resonance (NMR) technique. After storing ramen soup samples with diverse compositions of modified starch at 20-40% relative humidity for 4 weeks, changes in the spin-spin relaxation time constant ($T_2$) were measured as a function of temperature. $T_2-Temperature$ curves for ramen soup containing modified starches showed that the caking initiation temperature (glass transition temperature) was increased by $5^{circ}C$ following the addition of only 0.5% modified cornstarch. The results indicate that the modified com starch used in this study would be an effective anti-caking agent for ramen soup, thus prolonging the shelf life of the product.