Drying
Drying is also an appropriate processing method for removal of cyanogenic glycosides in food plants up to the permissible limits. Drying is mass transfer process which removes water from the product by evaporation and keeps the product free from microorganisms and quality decay. Drying methods such as sun, oven, freeze and
superheated steam can be employed for the reduction of cyanogen. In bamboo shoots around 80% of cyanogen glycoside was reduced after vacuum freeze drying for 24hours at -50ºC temperature. Superheated steam drying at 120-160 ⁰C decomposes the taxiphyllin which causes bitterness in shoots (Wongasakpaiorod 2000). Oven drying after grating at 60ºC even for brief (8 hrs) drying periods leads to very high reduction of cyanogen content up to 95% of the initial cyanide content (Lambri and Fumi 2014).
Oven drying at 50 ºC removes around 81 per cent of cyanogen glycoside within 24 hours (Iwuoha et al. 1997). In cassava, 80 to 99 per cent of cyanogen glycoside is removed by sun drying (Nambisan and Sundaresan 1985).