Effects of Simulated Microgravity and Hyper Gravity Environments on Cooking Phenomena

Abstract

To investigate the effects of gravity on basic cooking phenomena, experiments were conducted on water soaking ability of rice, bread swelling ability, and yogurt fermentation under simulated microgravity (1/1,000 G) and hyper gravity (5 G) conditions using a clinostat. The moisture content of the rice was measured after it absorbed water, specific loaf volume of the bread was measured after baking, and with respect to the yoghurt, its pH, sugar content, and acidity were measured. The results showed no difference in the moisture content at the two gravities for non-glutinous and glutinous rice; however, with respect to brown rice a considerably higher moisture content was observed at 1/1,000 G condition compared to 5 G. Similarly, no difference in the specific loaf volume of the bread was observed at the two gravities. However, the yogurt formed under 1/1,000 G condition showed a slower pH decrease with respect to time compared to the 1 G and 5 G condition. Moreover, the sugar content was substantially higher in the 1/1,000 G sample compared to the 1 G and 5 G samples at 8 h. The acidity was considerably lower in the 1/1,000 G samples than in the 1 G and 5 G samples after 8 h and 24 h. Thus, the results suggest that a change in gravity may affect yogurt fermentation in particular.