Objective. The aim of this study was to determine the chemical characteristics and antibacterial activity of Fontitrygon margarita liver oil against the bacteria responsible for food poisoning. Methods. Oils were extracted from F. margarita liver using two methods (exudation and cooking-pressing) and analyses by Fourier transform infrared (FTIR) spectroscopy. Quality indexes were determined using standard methods and the fatty acid profile was carried out by gas chromatography with a flame ionization detector (GC-FID). Antibacterial activities of these oils, their emulsion, and their interactions with common antibiotics were evaluated by the broth microdilution method. Results. Extraction yield was higher with cooking-pressing (16.90) compared to exudation (14.49). The quality indexes of both oils were conformed to Codex Alimentarius Standard. Thiobarbituric acid index was higher with exudation compared to cooking-pressing (3.200.14 and 2.360.14μmol MDA/kg, respectively) while acid, iodine, peroxide, and anisidine values did not significantly vary with the extraction methods (2.15-2.30 mgKOH/g, 102.42-106.65 gI₂/100g, 3.34-3.57 meqO₂/kg, and 2.85-3.32 respectively). FTIR analyses clearly show that the two spectra are similar (no differences in the frequency and absorbance of their bands). The fatty acid profile revealed that, regardless of the extraction methods, F. margarita oil is richer in monounsaturated (55.97-55.41) followed by polyunsaturated (28.17-28.52) and saturated fatty acids (15.86-16.07). Moreover, these oils showed antibacterial activity on all the bacteria strains tested with MICs between 16 and 256mg/ml. Regardless of the extraction methods, emulsions showed higher activity (6.25MIC 25mg/ml) compared to crude oils. Additionally, F. margarita liver oil potentiated the antibacterial activity of ciprofloxacin, tetracycline, gentamicin, amoxicillin, and chloramphenicol. Conclusion. These results showed the effectiveness of Fontitrygon margarita liver oil against some bacteria responsible for food poisoning, thus demonstrating their antibacterial properties which could be due to their chemical composition.

This study determined for the first time the structure of the peptides (i.e., peptidomics) in soy protein hydrolysates and elucidated their effects on an oil’s oxidative stability during frying cycles. The oil investigated was palm olein during 0, 4, 8, and 12 frying cycles of plantain banana chips. Proteins were extracted and hydrolyzed with two proteases. Trypsin hydrolysate (HTRY) exhibited higher anti-radical activity (DPPH, 70.2%) than the control (unhydrolyzed proteins, 33.49%) and pepsin hydrolysate (HPEP, 46.1%) at 200 µg/mL. HPEP however showed a 4.6-fold greater reduction of ferric ions (FRAP) while also possessing a higher peroxyl radical scavenging ability (716 ± 30 µM Trolox Eq/g) than HTRY (38.5 ± 35 µM Trolox Eq/g). During oil oxidative stability tests, HPEP improved the oxidative stability of the palm olein oil after 8 and 12 frying cycles, characterized by lower concentrations of hydroperoxides, and carbonyl and volatile compounds. HTRY however exerteda pro-oxidant activity. Structural data from SDS-PAGE and tandem mass spectrometry showed that the mechanism for the greater activity of the pepsin hydrolysate occurred due to unique structural features and a higher percentage of short-chain peptides. This was justified by a 25, 31, and 48% higher contents of tryptophan, histidine, and methionine, respectively (important amino acids with hydrogen atom transfer and electron-donating capacities) in the peptides identified in the pepsin hydrolysate.

Due to their significant health benefits, fish oils have garnered increasing interest in recent decades. However, Cameroons fish oil market remains insignificant, and the few available products are imported, despite the countrys abundant marine resources. Additionally, research on Cameroonian fish oils is relatively recent and scarce. Therefore, this manuscript provides an overview of research on fish oils in Cameroon, focusing on their physicochemical characteristics, as well as their nutritional and biological properties. As of March 2023, 26 studies on fish oils in Cameroon have been published, with a focus on 23 species collected in the littoral, far-north, and west regions of Cameroon. Filets were the main parts used, and the Bligh Dyer and Soxhlet methods were the primary oil extraction techniques. Depending on the species, tissues, and extraction methods, oil contents ranged from 4.57 to 32.10 dry matter or yielded 0.36 to 66.83 wet weight. These oils generally meet recommended standards for markers of acidity and oxidation. Fatty acid profiles from 16 species showed a total of 48 fatty acids, including those that are beneficial to human health. Oils from eight species were found to significantly reduce weight, hyperlipidemia, hyperglycemia, hepatomegaly, and adipomegaly, while four species showed activity against bacteria responsible for food poisoning. Future work should include all fish species found in Cameroon, with a focus on by-products, and explore the physicochemical, functional, nutritional, and biological properties of these oils.

Egusi pudding is one of the most popular traditional dishes of the Cameroonian population. Besides its nutritional values, it is also endowed with a sociocultural character. Nowadays, consumer demand for Egusi pudding has increased and the dish is sold as street food in several cities of Cameroon and mostly under uncontrolled hygienic conditions. The objective of this study was to assess the microbiological quality of Egusi pudding sold in the city of Yaoundé taking into consideration the protein sources and the sampling sites. Five types of Egusi pudding samples based on protein sources were randomly collected from 25 sellers distributed in 7 districts in the city of Yaoundé and their microbiological quality were assessed. The results showed that the total aerobic count of the different samples (2.97±0.03 to 4.43±0.05 Log CFU/g) was under the threshold value (5.47 Log CFU/g) recommended for food intended for human consumption. Loads of fecal coliforms (1.47±0.00 to 5.47±0.00 Log CFU/g) in 40 of samples, Escherichia coli (2.39±0.12 to 5.43±0.05 Log CFU/g) in 60 of samples, fecal streptococci (2.90±0.15 to 4.74±0.05 Log CFU/g) in 88 of samples, Pseudomonas spp. (3.39±0.15 to 5.43±0.06 Log CFU/g) in 100 of samples, and the presence of Salmonella spp. in 56 of samples revealed a poor level of hygiene of the vendors. Pathogens associated with unsafe food handling such as Staphylococcus spp. were found in 100 of samples at loads (3.84±0.18 to 5.43±0.05 Log cfu/g) higher than the norms of the European Commission. Potential toxigenic pathogens such as Clostridium perfringens, Yersinia enterocolitica, Bacillus cereus, and moulds were also found, respectively, in 100, 96, 96, and 100 of samples. Overall, the most contaminated samples were those made with sardine as protein source, 92.85 (n=23/25), followed with beef (88.57), mackerel (84.28), cod (82.85), and control (77.1). The results of this study suggest that important measures should be taken by the Public Health Service in order to sensitize the producers and vendors of Egusi pudding on the respect of good hygiene, manufacturing practices, and the continuous monitor of the quality of traditional products sold in markets.