Characterization of Schinziophyton rautanenii (Manketti) nut oil from Namibia rich in conjugated fatty acids and tocopherol

"Exotic" seeds from Southern Africa as potential Novel Foods? - Chemical composition of manketti nuts (Schinziophyton rautanenii) and ushivi beans (Guibourtia coleosperma)

Various species of Southern African plants and their edible seeds have gained huge importance due to positive health aspects, and there is increasing interest to introduce such seeds as Novel Food on the international market. Especially the seeds of Schinziophyton rautanenii (manketti) and Guibourtia coleosperma (ushivi) could have great potential as a food and food ingredient. Hence, extensive analyses on the chemical composition of manketti nuts and ushivi beans including the analysis of total solids, protein and fat content, soluble carbohydrates, ash, total and free amino acids, biogenic amines and polyamines, fatty acid profile as well as the content of certain B-vitamins and tocopherols were performed. Results obtained showed a valuable nutritional composition, e.g., a true protein content of 22.6% with a ratio of essential amino acids to total amino acid composition of 48% in manketti nuts, while ushivi beans had a true protein content of 8.2% with a similar ratio of essential to total amino acids (45%). Lipid content was 54.1% in manketti nuts, ushivi beans had a value of 7.7%. In both, linoleic acid was the most abundant. Furthermore, ushivi beans had high amounts of vitamin B1 and B2.

The Chemical Composition of Oils and Cakes of Ochna serrulata (Ochnaceae) and Other Underutilized Traditional Oil Trees from Western Zambia

Currently, the negative effects of unified and intensive agriculture are of growing concern. To mitigate them, the possibilities of using local but nowadays underused crop for food production should be more thoroughly investigated and promoted. The soybean is the major crop cultivated for vegetable oil production in Zambia, while the oil production from local oil-bearing plants is neglected. The chemical composition of oils and cakes of a three traditional oil plant used by descendants of the Lozi people for cooking were investigated. Parinari curatellifolia and Schinziophyton rautanenii oils were chiefly composed of α-eleostearic (28.58-55.96%), linoleic (9.78-40.18%), and oleic acid (15.26-24.07%), whereas Ochna serrulata contained mainly palmitic (35.62-37.31%), oleic (37.31-46.80%), and linoleic acid (10.61-18.66%); the oil yield was high (39-71%). S. rautanenii and O. serrulata oils were rich in γ-tocopherol (3236.18 μg/g, 361.11 μg/g, respectively). The O. serrulata oil also had a very distinctive aroma predominantly composed of p-cymene (52.26%), m-xylene (9.63%), γ-terpinene (9.07%), o-xylene (7.97), and limonene (7.23%). The cakes remaining after oil extraction are a good source of essential minerals, being rich in N, P, S, K, Ca, and Mg. These plants have the potential to be introduced for use in the food, technical, or pharmaceutical industries.

Comparison of CaO-NPs and Chicken Eggshell-Derived CaO in the Production of Biodiesel from Schinziophyton rautanenii (Mongongo) Nut Oil

The ever-increasing population growth and economic developments have heightened demand for energy. This has resulted in depletion and ever-rising prices of petroleum diesel, thus increasing environmental degradation. These complications have motivated this study for the search of an alternative eco-friendly and renewable source of energy such as biodiesel. Biodiesel has been found to be a potential alternative fuel for diesel. Biodiesel was produced by transesterification reaction of Schinziophyton rautanenii (mongongo) nut oil in the presence of a base heterogeneous catalyst: CaO derived from eggshell ash and synthesised CaO-nanoparticles (CaO-NPs). The catalysts were calcined at a temperature of 800°C for 3 h and characterized by scanning electron microscope-energy dispersive X-ray (SEM-EDX) where both catalysts showed agglomerated particles and high elemental composition of Ca and O. Powder X-ray diffraction (XRD) showed that CaO was present in both catalysts, and the average crystalline size obtained was 42 and 50 nm for CaO-NPs and eggshell ash, respectively. Fourier transmission infrared (FTIR) spectrometer showed absorption bands of CaO in both catalysts which were at 875 and 713.46 cm−1 for CaO-NPs and eggshell ash, respectively. The analysis of mongongo nut oil (MNO) and mongongo methyl esters (MMEs) was done according to the European biodiesel specification (EN 1421) and American Society for Testing and Materials (ASTM D675). Statistically, there was no significant difference between CaO-NPs and eggshell in terms of optimum yield ( $P>0.05$ ) using a sample t-test. However, in terms of catalyst loading, the eggshell was a better catalyst as it required a low catalyst load to obtain an optimum yield of 83% at 6 wt.% compared to CaO-NPs with an optimum yield of 85% at 12 wt.%. The reactions were all performed at constant reaction conditions of 9 : 1 methanol to oil ratio, 3 h reaction time, and 65°C reaction temperature.

Production of conjugated fatty acids: A review of recent advances

Conjugated fatty acids (CFAs) have received a deal of attention due to the increasing understanding of their beneficial physiological effects, especially the anti-cancer effects and metabolism-regulation activities. However, the production of CFAs is generally difficult. Several challenges are the low CFAs content in natural sources, the difficulty to chemically synthesize target CFA isomers in high purity, and the sensitive characteristics of CFAs. In this article, the current technologies to produce CFAs, including physical, chemical, and biotechnical approaches were summarized, with a focus on the conjugated linoleic acids (CLAs) and conjugated linolenic acids (CLNAs) which are the most common investigated CFAs. CFAs usually demonstrate stronger physiological effects than other non-conjugated fatty acids; however, they are more sensitive to heat and oxidation. Consequently, the quality control throughout the entire production process of CFAs is significant. Special attention was given to the micro- or nano-encapsulation which presented as an emerging technique to improve the bioavailability and storage stability of CFAs. The current applications of CFAs and the potential research directions were also discussed.