Effect of lactic acid bacteria fermentation on nutrients and anti-nutrients of African black nightshade and African spider plant

Abstract

African black nightshade is a leafy vegetable consumed in many parts of Africa. African spi- der plant is also a very important indigenous leafy vegetable consumed all around Africa. Both the African black nightshade and African spider plant are popular despite their te- dious preparation techniques which involve boiling and discarding the first water or a lengthy boiling duration to remove bitterness. However, this preparation technique reduces heat-labile and water-soluble nutrients. Fermentation can be a better alternative process- ing technique since it has been observed that fermented products have better nutritional content and increased safety. However, there is still limited literature on the effect of fermentation on the nutrients and anti-nutrients content of these vegetables. This study aimed to ferment African black nightshade and African spider plant using Lactobacillus fermentum and Lactococcus lactis cultures and determined the effect of the fermentation on their nutrients and anti-nutrients content. Both vegetables were submerged in a 3% sugar and 3% salt brine solution. Total ash, crude proteins and crude fibres significantly increased in starter culture inoculated vegetables. However, both β-carotene and ascorbic acid were slightly reduced in all fermented batches. Anti-nutrients were significantly re- duced in all fermented batches. In conclusion, lactic acid fermentation of these vegetables demonstrated the ability to maintain or increase nutrients while reducing of anti-nutrients.