Microbial Fermentation by Traditional Process using Intrinsic Microflora Reduces the Cyanide Content of Bamboo Shoots

Abstract

Ethnic people living in the North-East India, Nepal and Bhutan prepare and consume a variety of domesticated and wild bamboo tender shoots. Fermented bamboo shoots are consumed as a component of regular delicacies. However, presence of potentially toxic compounds called cyanogenic glycosides has been a matter of concern in its consumption. In this study, several bamboo shoot samples (fermented and unfermented-succulent bamboo shoots) were collected from different sites of Manipur. The cyanide content of fermented bamboo shoot samples were analyzed and compared with succulent bamboo-shoots, boiled bamboo-shoots, soaked in saline water or without overnightsoaking. The pHs of all the fermented samples were found to be around 4.0 while that of unfermented bamboo shoot was recorded to be of pH 6.Bacterial counts of samples were determined and colony forming unit (CFU)ranges 3×107 – 724×107per gram. The nutritional parameters were also recorded. Protein content of succulent bamboo shoot and fermented bamboo shoot ranged between 500mg- 800mg/100g. The reducing sugar content ranged between 100 – 1200mg/100g. Unfermented – succulent bamboo shoot had high cyanide content (approx. 43.55 mg/g) as compared to the fermented samples (8.78-17.89mg/g). It was observed that boiling the succulent bamboo shoots as well as fermented bamboo shoots removed all the cyanide content from the samples.