NUTRITIONAL AND AMINO ACID ANALYSIS OF RAW, PARTIALLY FERMENTED AND COMPLETELY FERMENTED LOCUST BEAN ( Parkia biglobosa ) SEEDS

The nutritional and amino acid analysis of raw and fermented seeds of Parkia biglobosa were carried out. Parameters investigated include moisture, crude protein, crude fat, ash, crude fibre and mineral contents; and the effect of the degree of fermentation on these parameters was also investigated. The amino acid compositions of all the samples were evaluated and amino acid quality determined by calculating amino acid scores and the predicted protein efficiency ratio (P-PER). Results showed that the proximate composition was significantly affected by fermentation, although there was little difference between the parameters for the partially fermented and completely fermented samples. Based on dry matter percentage, protein content was in the 39.77 – 43.74 % range while crude fibre ranged between 5.55 – 7.42 %. The ash content was lowest in the raw sample (2.34 %), while the fermented samples had ash contents between 4.27 and 8.33 % for the fully fermented and the partially fermented seeds, respectively. The fat content increased from 8.65 % in the raw seed to 24.4 % and 27.6 % for the partially and completely fermented samples, respectively. Results of the amino acid analysis showed that the partially fermented sample had the lowest quantities of all amino acids determined and had lysine as the limiting amino acid, whereas the raw and completely fermented samples had very similar amino acid profile with amino acid scores of 100, indicating that there are no limiting amino acids. All the samples were rich in essential amino acids. The P-PER also showed that the partially fermented sample had the lowest protein efficiency while the raw seed had the highest. Mineral contents generally increased from the raw, through the partially fermented, to the completely fermented seeds and results showed the samples to be good sources of potassium (K), calcium (Ca), manganese (Mn) and copper (Cu) in addition to being complementary sources of other metals. Locust bean seed does not accumulate lead and is, therefore, safe for consumption without the potential of food poisoning.

Antifungal activity of extracts from Atacama Desert fungi against Paracoccidioides brasiliensis and identification of Aspergillus felis as a promising source of natural bioactive compounds

Fungi of the genus Paracoccidioides are responsible for paracoccidioidomycosis. The occurrence of drug toxicity and relapse in this disease justify the development of new antifungal agents. Compounds extracted from fungal extract have showing antifungal activity. Extracts of 78 fungi isolated from rocks of the Atacama Desert were tested in a microdilution assay against Paracoccidioides brasiliensis Pb18. Approximately 18% (5) of the extracts showed minimum inhibitory concentration (MIC) values ≤ 125.0 μg/mL. Among these, extract from the fungus UFMGCB 8030 demonstrated the best results, with an MIC of 15.6 μg/mL. This isolate was identified as Aspergillus felis (by macro and micromorphologies, and internal transcribed spacer, β-tubulin, and ribosomal polymerase II gene analyses) and was grown in five different culture media and extracted with various solvents to optimise its antifungal activity. Potato dextrose agar culture and dichloromethane extraction resulted in an MIC of 1.9 μg/mL against P. brasiliensis and did not show cytotoxicity at the concentrations tested in normal mammalian cell (Vero). This extract was subjected to bioassay-guided fractionation using analytical C18RP-high-performance liquid chromatography (HPLC) and an antifungal assay using P. brasiliensis. Analysis of the active fractions by HPLC-high resolution mass spectrometry allowed us to identify the antifungal agents present in the A. felis extracts cytochalasins. These results reveal the potential of A. felis as a producer of bioactive compounds with antifungal activity.