http://hdl.handle.net/123456789/123 2026-04-08T01:12:15Z 2026-04-08T01:12:15Z SALAMI, Latifat Olajumoke http://hdl.handle.net/123456789/2179 2024-04-26T14:29:38Z 2023-04-01T00:00:00Z

CHEMICAL PROPERTIES OF TREATED NEEM (Azadirachta indica A. Juss) SEED AND PRESERVATIVE POTENTIALS OF ITS OIL ON ONIONS, SELECTED GRAINS AND FERMENTED LOCUST BEANS SALAMI, Latifat Olajumoke Neem seed is known to serve as antimicrobial agent on agricultural commodities. However, the consumption of its high dosage pose a health risk due to presence of other antinutritional factors. There is limited information on appropriate treatments for reduction of the antinutrients in neem seed to safe consumption level. There is need to further determine effects of some treatments on neem seed chemical properties to ensure safety for consumption. Thus, this study was designed to investigate the effects of steeping in water, alkaline solution and roasting on neem seed and toxicity of using its oil as a food preservative. Neem seeds were subjected to three treatments based on preliminary studies such as; steeping in water, and 40% NaOH solution for 24 h, and roasting for 10 min at 60oC. Proximate (crude protein, oil, crude fibre, ash, moisture and carbohydrate contents), minerals (Ca, Na, Mg, P, K, Cu, Zn, Fe, Mn and Se) and anti-nutrients contents (cyanide, nitrate, oxalate, phytate, tannin and azadirachtin) ofun-treated and treated seeds were determined using AOAC methods. Oil was extracted from raw and roasted seeds using hydraulic press.Fatty acid profile and bioactive compounds of the oil were determined using standard method. Weevil infested grains (maize, beans and rice), Fermented Locust Beans (FLB), and mouldy onions were treated with different concentrations (0.6. 0.7, 0.8, 1.0, 2.0 and 3.0 mL/200g) of oil extracted from roasted seed. The samples were stored at ambient conditions (26.0±2.0oC, RH 70%) for 45 days.Weevils population in grains and microbial growth on FLB and onions were determined weekly, using established procedure. Toxicity of roasted seed oilwas conducted using male and female rats (100.0±5.0g) in a group of three (n = 5), fed with FLB (control, 1.0, 2.0 and 3.0µL/100g) for 13 days. Haematology and histopathology of kidney, liver, heart, testes and ovaries for rats were done. Data were analysed usingANOVA at α0.05. Crude protein, oil, crude fibre, ash, moisture and carbohydrate contents of untreated seed were 18.6±0.07, 41.2±0.03, 3.6±0.04, 2.6±0.05, 6.0±0.02 and 28.1±0.02%; while treated were 16.9- 19.1, 40.4-41.8, 3.5-3.6, 2.4-2.6, 5.9-12.1 and 24.4-28.1%, respectively. The seeds had high contents (mg/100g) of Fe (16364.0-16482.0), Zn (2463.0-2398.0) and Mn (1164.3-1182.0). Steeping in water significantly reduced cyanide (45.0%), nitrate (12.5%), tannin (50.0%) and Azadirachtin (16.7%) contents. Major fatty acids in neem oil were oleic (39.10±0.03), linoleic (18.60±0.03), stearic (17.70±0.02) and palmitic (14.5±0.01%) acids. Roasting significantly affected the oil profiles. Fourteen bioactive compounds were detected with dominants being nHexadecanoic acid (28.62%), 9,12, 15-Octadecatrienoic acid (17.1%), Neophytadiene (13.7%), Hexadecanoic acid (10.0) and 9,12-Octadecadienoic (8.3%). Highest percentage weevils’ mortality of 59.2% in maize, 41.25% in beans and 36.67% in rice were recorded at 0.6, 0.7 and 0.8 mL/200g, respectively. E-coli, Pseudomonas, Staphylococcusaureusand Bacillus sp were the organisms detected in stored FLB. The microbe populations were significantly reduced by the oil. No spoilage was recorded from treated onions. Reduced erythrocytes and degradation of hepatocyte were observed in rat tissues fed with 3 µL/100g dose, an indication that the concentration was outside the safe limit for rat. The treatments reduced antinutritional factors in neem seed. Oil from roasted neem seed reduced weevils in grains and retarded microbial multiplication on fermented locust beans and onion. Low oil dosage is recommended.

2023-04-01T00:00:00Z AJEWOL, Abiodun Oluwasola http://hdl.handle.net/123456789/2177 2024-04-26T14:13:59Z 2023-08-01T00:00:00Z

EFFICACY OF SELECTED SPICES IN MITIGATION OF FUNGAL GROWTH AND MYCOTOXINS PRODUCTION IN TEA AND COFFEE AJEWOL, Abiodun Oluwasola Tea and coffee, consumed for their neutraceutical, health and stimulating benefits, can be easily contaminated by mycotoxin-producing fungi, due to agro-ecological factors, poor handling and storage. Spices such as Curcuma longa, Xylopia aethiopica and Piper guineense possess antimicrobial properties with potential to reduce fungal growth in tea and coffee. However, there is limited information on their use and effectiveness in mitigating mycotoxins production in processed tea and coffee. This study was designed to investigate the extent of fungal contamination and possibility of inhibiting growth of fungi and their metabolites in tea and coffee using the selected spices. Tea and coffee, randomly obtained from fourteen warehouses each in Ibadan and Mambilla, were subjected to microbial screening and mycotoxins quantitation following ISO methods. Fungal isolates were characterised using RAPD analysis, and metabolites recovered were quantified using HPLC. Freshly harvested tea and coffee from Ibadan and Mambilla were processed to green and black products using standard procedures, and treated with milled Curcuma longa roots, as well as Xylopia aethiopica and Piper guineense seeds at 1000, 2000, 3000 and 4000 µg/g. The treated and untreated (control) samples were packaged in tea bags and stored at ambient condition (28±3oC; 70±5% Relative Humidity) for 24 weeks. During the storage period, microbial activities were monitored and polyphenol levels determined bi-weekly using AOAC methods. Data were analysed using ANOVA at α0.05. Aspergillus flavus, Aspergillus niger, Penicillium georgiense, Fusarium solani and Gliocladium cibotti were prominent fungal species identified in the tea and coffee. The tea and coffee contained metabolites of Aspergillus (15, 2), Penicillium (8, 6), Fusarium (4, 5) and other fungal species (18, 12). Mambilla tea and coffee had significant higher level of contamination than Ibadan samples. Seventy toxins were quantified, with Aflatoxin B1 (85.3-427.2 µg/kg), deoxynivalenol (1.3-5.2 µg/kg), beauvericin (2.5-5.0 µg/kg), brevianimide (33.6-106.2 µg/kg), and sporidesmolide II (7.3-10.8 µg/kg), being major in the tea and coffee. Aflatoxin B1 and deoxynivalenol, which are of major public health concern, were dominant in black tea and coffee. Green tea and coffee were also contaminated with abscisic acid, unspecific rugulusovin, sporidesmolide II, unspecific emodin and unspecific tryptophol. Curcuma longa (4000 µg/g), Piper guineense (4000 µg/g) and Xylopia aethiopica (1000 µg/g) had 92.0±1.1%, 92.0±1.8% and 91.3±2.4% microbial activity reduction on Aspergillus flavus and 53.2±0.8%, 36.4±1.5% and 37.8±2.7% on Fusarium solani, respectively. Microbial inhibition of the spices varied significantly with concentration. The source of samples did not significantly influence the efficacy of the treatment. Total phenolic content increased with spice addition, in black tea and coffee (3.0-7.1 mg/g), and in green tea and coffee (15.5-22.0 mg/g), respectively. High number of Fungi species and their metabolites were present in the tea and coffee. Xylopia aethiopica was most effective in reducing fungal growth and mycotoxin production in the tea and coffee.

2023-08-01T00:00:00Z IBITOYE, Wuraola Omolola http://hdl.handle.net/123456789/2175 2024-04-26T14:09:30Z 2023-06-01T00:00:00Z

PHYSICAL, FUNCTIONAL, PASTING AND MICROBIAL PROPERTIES OF SORGHUM (Sorghum bicolor M.) OGI AS INFLUENCED BY FERMENTATION METHODS IBITOYE, Wuraola Omolola Ogi is a widely consumed food product but could possess low nutritional value when poorly processed. Fermentation had been found to improve its nutritional value, sensory properties and shelf life. However, information on fermentation of ogi using inocula from palm wine, burukutu and yoghurt is sparse. This study was designed to investigate the effect of processing and selected modified fermentation methods on quality attributes of sorghum ogi. Based on preliminary studies, ogi was processed from unmalted, malted (germinated for 72 hours, dried at 48oC for 24 hours) and milled sorghum using Spontaneous Fermentation (SF) method for between 24 and 72 hours. These samples were subjected to sensory evaluation using panelists. Ogi was also produced using sample with highest overall sensory score (control), and fermented with each of palm wine, burukutu and yoghurt inocula (0.08– 0.12 µL/500mL) as starter culture. Microorganism in SF samples, palm wine, burukutu, and yoghurt; Palm Wine Fermented Sorghum (PWFS), Burukutu Fermented Sorghum (BFS) and Yoghurt Fermented Sorghum (YFS) were cultured and isolated using ISO methods. Molecular characterisation of the isolates was done by polymerase chain reaction sequencing. Chemical, physical, functional and pasting properties, and in-vitro protein digestibility of samples were determined by AOAC methods. Sensory properties of the products were determined using panelists. Data were analysed using ANOVA at α0.05. Ogi from unmalted-whole sorghum spontaneously fermented for 72 hours had lowest overall acceptability of 5.51, while 48 hours spontaneous fermented malted-milled sorghum had highest score of 7.34. Lactobacillus plantarium, Bacillus subtilis, and Lactobacillus lactis were dominant in SF samples. Lactobacillus spp. were present in palm wine, burukutu, and yoghurt. Lactobacillus, Leuconostoc, Bacillus, Streptococcus and Saccharomyces spp.; Lactobacillus, Staphylococcus, Acetobacter, Weissella, Leuconostoc, Lactococcus, Bacillus and Saccharomyces spp.; and Streptococcus, Lactobacillus, Bacillus, Micrococcus and Pseudomonas spp. were the isolated organisms in PWFS, BFS and YFS, respectively. The concentrations of the inocula significantly affected starter culture activities, with 0.1 µL/500 mL being appropriate. Carbohydrate, protein, fibre and ash contents of the samples varied significantly. The SF sample had least protein content of 5.7%, while YFS had highest protein of 10.3%. Potassium was the dominant mineral in all the samples. The YFS sample had lowest tannin (0.08±0.01%), phytate (0.08±0.01%) and oxalate (0.99±0.01%) contents. The L*, a* and b* colour values of samples ranged from 51.27 to 65.66, 10.08 to13.27 and 11.35 to 18.79, respectively. The loose and packed bulk density was 0.44-0.62 and 0.58-1.82 g/mL, respectively. Total titratable acidity ranged from 0.20 to 1.83 g/L and pH from 3.50 to 5.72. Spontaneously fermented samples had lowest pH. The swelling power and solubility of samples was 3.11-7.20 and 0.03-2.04%, respectively. Fermenting using starter culture significantly reduced peak viscosity of sorghum ogi with SF samples being highest (126.83±2.59 RVU). Introduction of starter culture significantly increased protein digestibility of sorghum ogi. The PWFS had highest overall acceptability score of 7.28. Grain milling before fermentation and induced fermentation using palm wine, burukutu and yoghurt inocula improved the nutritional properties of sorghum ogi and were recommended for improving qualities of similar fermented food products.

2023-06-01T00:00:00Z OSUNRINADE, OLUDOLAPO AKINYEMI http://hdl.handle.net/123456789/1643 2022-03-02T15:19:46Z 2021-08-01T00:00:00Z

IDENTIFICATION AND CHARACTERISATION OF FLAVOURANTS ASSOCIATED WITH OFADA RICE (Oryza sativa LINNAEUS) PADDY PRE-TREATMENTS OSUNRINADE, OLUDOLAPO AKINYEMI Ofada rice(Oryza sativa, variety OS-6) is an indigenous rice variety highly sought mostly for its flavour. However, there are subjective noticeable variations in these flavour attributes which sometimes cast doubt on the rice quality. Profiling of rice flavour compounds and their formation during processing is sparsely documented. Hence, this study was to identify and characterise flavour compounds in Ofada rice as affected by paddy pre-treatment process. The D-optimal mixture design of steeping time (1, 3 and 5 days), initial steeping temperature (30, 65 and 100oC), parboiling temperature (80, 100 and 120oC) and drying temperature (30, 50 and 70oC) as pre-treatment variables were adopted to condition Ofada rice paddy sourced from Ogun State Agricultural Development Program (OGADEP). The pre-treated 25 samples were processed into parboiled rice using standard procedures. The pH and total Titratable Acidity (TTA) of the fermenting steep water were determined, and bacterial type identified by standard methods. Proximate composition, amylose, Free Fatty Acid (FFA), flavonoid, Total Phenolic Content (TPC), Total Antioxidant Capacity (TAC), Ferric Reducing Antioxidant Power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay (DPPH) of the processed rice were determined by standard procedures. Amino and organic acids in processed rice were analysed by liquid chromatography-mass spectrometry,while rice extracts from solvent extraction method were analysed using gas chromatography-mass spectrometry.Parboiled rice was cooked and evaluated using 25-member panelists. Data were analysed using descriptive statistics and ANOVA at α0.05. The pH and TTAranged from 4.9 to 6.9, and 0.1 to 0.4 mg/mL, respectively. Predominant bacteria in the fermenting steep water were proteobacteria (Acinetobacter, Azotobacter, Pseudomonas, Enterobacter and Citrobacter) and firmicutes(Lactobacillus, Bacillus, Paenibacillus, Brevibacillus and Aneurinibacillus). Moisture, ash, fat, protein, crude fibre, carbohydrate, amylose contents and FFA of the rice were 4.2-10.2, 0.2-0.7, 0.6-1.7, 7.4-9.5, 0.6-1.7, 78.3-84.6, 17.4-22.3, and 0.7-3.8%, respectively. Flavonoid (0.6-1.5 mgQuercetin/g), TPC (25.4-62.6 mg GAE/g), TAC (0.5-3.9 mgGAE/g), FRAP (19.0-33.4 mgTrolox/g) and DPPH (277.8-1372.7 µg/mL) were obtained. Glutamic acid (8.5–26.1%), alanine (7.4-23.6%), proline (2.4-18.8%), asparagine (2.2-4.8%), aspartic acid (1.3–4.1%), threonine (1.2-3.6%), methionine(0.6-3.2%), serine (0.8-2.1%) and glycine (0.6-1.9%) were the major amino acids detected. Organic acids identified were 2-aminobutyric, nicotinic, pantothenic, pyruvic, lactic, citric, succinic and fumaric acids. The samples extracts contained 30 alcohols, 28 aldehydes, 50 hydrocarbons, 13 nitrogenous compounds, 36 ketones, 33 esters, 15heterocyclics, and 12 phenols. Aroma impacting compounds [pentanoic acid (green), 2-methyl-butanoic acid (cheese-like), butanoic acid (rancid), 1-octanol (metallic), decanal (citrusy), hexanal (fatty), 2-octenal (nutty), 4-methyl-2-heptanone (spicy) and 2-methoxy-4-vinylphenol (clove-like)] were detected mostly among samples steeped for five days.Only initial steeping temperature and duration significantly influenced composition of the compounds.Rice produced from paddy steeped for a day at 30oC initial steeping temperature, parboiled at 80oC and dried at 50oC was most acceptable to the panelists. Flavourants identified in Ofada rice predominantly contained fatty, metallic, clove-like, citrusy, nutty and green flavour notes which varied with steeping treatments. Ofada paddy rice should not be steeped beyond a day for flavourants acceptability.

2021-08-01T00:00:00Z