Physico-chemical and Microbiological Characterizations of the Leaf and Flower Powder of Lippia multiflora Moldenk, a Leaf Vegetable Consumed in Benin

Abstract

Background: Lippia multiflora Moldenk is a shrub that is present in Benin. It is used as nutritious food and its leaves and flowers are rich in mineral salts and especially vitamin A and C. Also, these leaves and flowers transformed into powders, are sold and used to flavor sauces and for other purposes. Aim/Objectives: Our work aims to provide consumers with information on the sanitary and hygienic quality of the powders from the leaves and flowers of Lippia multiflora in order to determine their shelf life. Methods: The study was carried out on three different powders, namely leaf-based powder; those from the flowers and those purchased from the sellers. Physico-chemical analyses and microbiological evaluation were made on these different powders at different dates for 18 months to see the growth of the microorganisms in these powders. Results: These analyses revealed that the means of the physico-chemical parameters in the leaf-based powders, the flowers and those sampled are respectively: water content (7.42%; 9.89% and 11.67%); ash content (15.83%; 10.77% and 6.52%); pH (7.25; 6.22 and 5.95) and titrable acidity (0.55%; 2.46% and 1.84%). Microbial loads in total flora are below the standard for 18 months in leaf and flower powders but are above the standard in powders sampled after 12 months of storage. The growth of yeasts and molds was observed during the first 6 months and their load is well below the standards from the 7th month until the end of storage. Coliform, Salmonella, Staphylococcus aureus, faecal Streptococci and Clostridium sulfito-reducers loads are below the detection threshold throughout the shelf life. Conclusion: Therefore the powders based on the leaves and flowers can be kept for a period of eighteen months without risk to the consumer. But those sampled can be kept for up to 12 months.