This study applied Adaptive Neuro-Fuzzy Inference System (ANFIS) to predict the moisture ratio (MR) during the drying process of yam slices (Dioscorea rotundata) in a hot air convective dryer. Also the effective diffusivity, activation energy, and rehydration ratio were calculated. The experiments were carried out at three (3) drying air temperatures (50, 60, and 70 C), air velocities (0.5, 1, and 1.5 m/s), and slice thickness (3, 6, and 9 mm), and the obtained experimental data were used to check the usefulness of ANFIS in the yam drying process. The result showed efficient applicability of ANFIS in predicting the MR at any time of the drying process with a correlation value (R 2 ) of 0.98226 and root mean square error value (RMSE) of 0.01702 for the testing stage. The effective diffusivity increased with an increase in air velocity, air temperature, and thickness and the values (6.382E -09 to 1.641E -07 m 2 /s). The activation energy increased with an increase in air velocity, but fluctuate within the air temperatures and thickness used (10.59-54.93 KJ/mol). Rehydration ratio was highest at air velocityÂair tem-peratureÂthickness (1.5 m/sÂ70 C  3 mm), and lowest at air velocity  air temperatureÂthickness (0.5 m/ sÂ70 C  3 mm). The result showed that the drying kinetics of Dioscorea rotundata existed in the falling rate period. The drying time decreased with increased temperature, air velocity, and decreased slice thickness. These established results are applicable in process and equipment design, analysis and prediction of hot air convective drying of yam (Dioscorea rotundata) slices.

The study investigated fresh tomato fruits (Roma VF variety) prepared into paste, proportioned into different samples with each receiving different concentrations of ginger, ginger and garlic powder (2 and 4% w/w) and stored over a period of 8 weeks. The total viable (TVC), lactic acid bacteria (LAB) and yeast counts of the samples were enumerated on a weekly basis while the pure microbial isolates were identified. Results showed that TVC and LAB of control sample ranged from 3.42 to 13.45 and from 5.79 to 17.74, respectively, while samples with garlic and ginger had counts ranging from 3.34-4.87 to 3.39-4.86 (log cfu/g), respectively, over the period of storage. The microorganisms were identified as Lactobacillus brevis, Lactobacillus plantarum, Lactobacilli acidophilus, Lactobacillus delbrueckii, Lactobacillus fermentum, Leuconostoc mesenteroides, Saccharomyces cerevisiae, Saccharomyces lactis, Hansenula anomala, Rhodotorula glutinis, Rhodotorula flava and Rhodotorula rubra. The study concluded that combined garlic and ginger (2 and 4%) suitably preserved tomato paste for 8 weeks without deterioration at refrigeration temperature (4 ± 1C). PRACTICAL APPLICATIONSHealth-conscious consumers are wary of potential dangers of consuming chemical preservatives over a period of time. The use of natural products such as ginger and garlic as natural preservatives could significantly improve their utilization in industrial production of tomato paste and even in household production in Africa where refrigeration is greatly hampered by erratic power supply.

Two field experiments were conducted concurrently in 2019. The study investigated the effects of single and combined application of wood biochar (WB) and cow dung biochar (CDB) with green manure (GM) on soil properties, performance, and tuber qualities of tiger nut. The treatments consisted of: CDB at 10 t ha−1, WB at 10 t ha−1, GM—Tithonia diversifolia at 10 t ha−1, CDB + GM, WB + GM, control. The six treatments were arranged in RCBD with three replications. CDB, WB, and GM either sole or combined increased moisture content, SOC, nutrient contents, culturable microorganisms, performance, moisture, ash, fiber, and protein contents of the tiger nut compared with the control. CDB has a higher N, C: N ratio, P, K, Ca, Mg, CEC, and pH relative to. CDB alone and CDB + GM increased growth and yield compared with WB alone and WB + GM. CDB + GM has the highest value of growth and yield of tiger nut. GM alone improved growth and yield of tiger nut compared with the two sole biochar treatments. CDB + GM and WB + GM increased growth and yield of tiger nut compared with their sole forms. This was adduced to biochar allowing the retention of nutrients from rapidly decomposing Tithonia within the rooting zone, thereby promoting better effectiveness of nutrient uptake and increase in yield. Therefore, for good soil fertility and tiger nut yield, it is important that the addition of a fast releasing nutrient source to biochar be sought.

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