Enrichment of sweet potato leaves and peelings (ipomoea batatas) in protein through fermentation

In the north of Côte d'Ivoire, sweet potato is a very abundant raw material. The peelings and leaves which constitute by-products are likely to be enriched in proteins. This study proposes to use the fermentation process as a means to increase the nutritional value of sweet potato by-products. Thus, cultivable bacteria and yeasts from sweet potato leaves and peels were counted and isolated following spontaneous fermentation. Subsequently, a controlled fermentation was carried out with twelve (12) microorganisms isolated on a shredded leaf, a shredded peel then on a proportional mixture of shredded leaf and peelings of two varieties of sweet potato. Samples were taken on day 0, on the 5th and 10th day of fermentation in order to determine the pH as well as the protein content of the various substrates. The results showed a diversity of bacteria and yeasts capable of producing protein from sweet potato leaves and peels. Among these microorganisms used, the LevE03 yeast provided a satisfactory result with an increase in the amount of protein ranging from 2.56g/100g to 17g/100g, i.e. an enrichment rate of more than 500% after fermentation of the leaves of sweet potato by this yeast. The LevE03 yeast is of particular interest for the enrichment of the leaf substrate in protein.