6 May 2020 admin

Nutritional properties, cultivation and processing of Moringa oleifera leaves

The leaves of the “Miracle Tree” Moringa oleifera are becoming more and popular among health-conscious consumers all over the world. The leaves, eaten raw or powdered, are considered to be a novel superfood. In addition, development projects that fight against malnutrition use the leaves as a nutritional supplement. Various organizations and people make claims about the nutritional characteristics of theMoringa leaves. But, are these true? Dasha Gretchikhine – intern at Fair & Sustainable Consulting – dived into the complex matter of Moringa’s nutritional content and its retention throughout cultivation and processing.

The environmental conditions for Moringa cultivation should meet the tree’s requirements to be able to maintain optimal growth and nutrient uptake. Sand to loam soil texture, soil pH between 5.5 and 7.5, temperature range of 25-35°C and other requirements should be maintained for the tree’s growth. Poor cultivation practices can lead to high risks in terms of negatively impacting nutrient uptake and development of the tree as well as the environment. For example, over- and under-watering Moringa can cause root system degradation and soil erosion or lead to a poor nutrient uptake and photosynthesis rate of the tree. Therefore, this report has identified the preferable environmental requirement of the tree, together with the risks and opportunities of using various cultivation practices. One of the advises is to maintain a soil moisture content between 5-28% by applying irrigating practices, such as drip irrigation, that lead to a lower water loss, during the early morning or evening to reduce water evaporation rate.

Table 1: Requirement for an optimal nutrient uptake and retention by a Moringa tree

All processing steps, from harvesting to storing the powder, influence the nutrient composition and food safety of the leaves.The exposure to oxygen, light, heat, and metal contaminants can lead to nutrient denaturation, oxidation, leaching, etc. Preventive measures that can limit nutrient loss are presented in the report such as covering the leaves during harvesting and transportation to limit light exposure, applying freeze drying technique to lower the drying temperature and other. Nevertheless, processing steps that secure a higher nutrient retention do not always meet food safety standards. Room temperature drying, for instance, meets the nutrient stability requirements but does not reach the moisture content standards to prevent microbiological growth.

The research also compared thenutritional content of Moringa leaves with other commonly consumed around the world dark green leafy vegetables such as Amaranthus (Amaranthus spinosus), Cabbage (Brassica oleracea var. capitata), Cocoyam (Colocasia antiquorum), Coriander (Coriandrum sativum), Spinach (Spinacia oleracea), and came to the conclusion that fresh Moringa leaves have overall higher vitamin, mineral, and protein content. The research findings state that Moringa can positively contribute to the daily Recommended Nutrient Intake of an individual; however, the bioavailability and digestibility of the nutrients present in the leaves and powder are still debated upon in the scientific field.

Table 2: Comparison between Moringa and other common dark green leafy vegetables protein content.
Source: USDA, 2019 and National Institute of Nutrition, 2017

In conclusion, the research recommends applying preventive measures to lower the risk of nutrient and product quality loss during cultivation, processing, and storage of Moringa leaves and powder. This, however, can be troublesome for producers in developing countries because of hight cost and time involved in the procurement and application of preventive practices. The technical and financial feasibility as well as the efficacy of advised measures should be field-tested.

Click here to read the full report!

Do you want to learn more about Moringa and how this value chain can be further developed? Contact Jochem Schneemann: jochem.schneemann@fairandsustainable.nl