The Assessment of Temperature and Sample Size on Color Variations, Pirovic Acid and Allicin in Local Shushtar Garlic after Drying

Dried garlic with various nutritional and medicinal values is used in food industry as flakes or powder. The nutritional and medicinal properties of garlic are attributed to Allicin. This substance (a compound of Tyosulfinates) is produced enzymatically after crushing. Since the temperature affects the enzymatic action that results in pirovic acid and allicin. The size and temperature are two critical factors to prevent color change and reduce allicin and pirovic acid present in garlic during drying process.
This study investigated the effects of sample size and temperature on qualitative characteristics such as color of powder and pirovic acid and alicin retention in a convective hot-air dryer. For this reason whole and half and minced Shushtar garlics (Allium sativum L.) were dried at air temperatures of 50 and 70°C with the relative humidity of 22%.
According to the obtained results by increasing the temperature from 50 to 70 C the color of half garlic have changed and allicin and pirovic acid have been increased. The quantity of pirovic acid and color of the minced samples were not affected significantly by the temperature of drier but allicin content of minced samples were reduced by increased temperature. Whole garlic dried at 70 °C was not affected by change in color but the quantities of present allicin and pirovic acid were reduced considerably.
According to the findings in this research work the condition that the halved samples were dried at 70 °C could be regarded as the best condition for producing garlic powder.