Effects of moisture barrier and initial moisture content on the storage life of some horticultural produce in evaporative coolant

Shelf-life of five horticultural produce were studied. These include three leafy vegetables: Telfairia occidentalis, Celosia argentea and Amaranthus cruentus and two fruit vegetables: Lycopersicum esculentum and Abelmuschus esculentus. The layout plan of the experiment was a 3x2 factorial in a completely randomized design and each treatment replicated three times. The two factors examined were moisture barrier at three levels namely: thick lining, thin lining and non-lining. The other factor included initial moisture content of the produce, namely, turgid and partially wilted. Partial wilting of the produce was achieved by exposing freshly harvested materials at ambient temperature to dry for 45 min. During this period, about 20% of the moisture content was lost. Eighteen (18) vegetable baskets which work on the principle of evaporative cooling system were used. Each type of produce was stored at a time inside the vegetable basket. Some quantity of each produce were kept on the laboratory benches to serve as controls. Data recorded includes length of storage of produce, severity of disease infection, visual quality, disease incidence, ambient temperature and relative humidity of the storage baskets. The result indicates that there was a significantly higher relative humidity (P< 0.05) in the lined baskets than in the non-lined baskets. Consequently, the shelf-life of produce in lined basket was prolonged. Turgid produce had better quality retention and stored much longer than partially wilted produce. Generally, the evaporative coolant baskets provided an average temperature of 3°C lower than the ambient condition. The shelf-life of leaf vegetables T. occidentalis, C. argentea and A. cruentus was extended appreciably for 78 days compared to the controls.Keywords: Evaporative coolant, moisture barrier, shelf-life of horticultural produce

Pre-concentration of toxic metals using electrospun amino-functionalized nylon-6 nanofibre sorbent

This paper presents a new approach for pre-concentrating toxic metals (As, Cd, Ni and Pb) in aqueous environments using an amino-functionalized electrospun nanofibre sorbent. The sorbent, composed of nanofibres of average diameter 80 ± 10 nm and specific surface area of 58m2 g–1, exhibited fast adsorption kinetics ( adsorption (0.34)>HNO3+H2O2 (0.23) digestion.Asimilar trend was observed for Ni in river water as well as Ni andCdin tap water samples. Pb ions in the river water samples were pre-concentrated slightly better using the two digestion methods pre-concentration factors ~22) compared to adsorption method (pre-concentration factor ~21). The use of the electrospun amino-functionalized nanofibre sorbent presentsanefficientand cost-effective alternative for pre-concentration of toxic metals inaqueousenvironments

Pre-concentration of Toxic Metals using Electrospun Amino-functionalized Nylon-6 Nanofibre Sorbent

This paper presents a new approach for pre-concentrating toxic metals (As, Cd, Ni and Pb) in aqueous environments using an amino-functionalized electrospun nanofibre sorbent. The sorbent, composed of nanofibres of average diameter 80 ± 10 nm and specific surface area of 58 m2 g–1, exhibited fast adsorption kinetics (<20 min) for As, Cd, Ni and Pb. The optimal pH for the uptake of As, Cd, Ni and Pb were 5.5, 6.0, 6.5 and 11, respectively. The adsorption process best fitted the Freundlich isothermand followed the first-order kinetics. The highest pre-concentration achieved using the sorbent was 41.99 (Ni in treated wastewater). The capacity of the sorbent to pre-concentrate the toxic metals was compared with those of aqua regia and HNO3 + H2O2 digestions. The pre-concentration factors achieved for Cd in river water samples can be ranked as aqua regia digestion (0.73) > adsorption(0.34) > HNO3 + H2O2 (0.23) digestion. A similar trend was observed for Ni in river water as well as Ni and Cd in tap water samples. Pb ions in the river water samples were pre-concentrated slightly better using the two digestion methods (pre-concentration factors ~22) compared to adsorption method (pre-concentration factor ~21). The use of the electrospun amino-functionalized nanofibre sorbent presents an efficient and cost-effective alternative for pre-concentration of toxic metals in aqueous environments.Keywords: Electrospinning, pre-concentration, heavy metals, nylon-

Duration of Exposure and Mortality of Different Strains of Prostephanus truncatus (Horn) (Coleoptera: bostrichidae) Exposed to Bifenthrin Insecticide in the Laboratory

The length of exposure time to Bifenthrin on four strains of larger grain borer Prostephanus truncatus Horn (Coloeoptera: Bostrichidae) was studied in the laboratory at 28 -330C and 7

Design and development of fluted pumpkin (Telfairia occidentalis) leaves slicing machine

A motorized fluted pumpkin leaves slicer was designed, fabricated and tested. The machine comprises a conveyor system made from a rubber belt, two pairs of bearings and two hollow metal rods, a frame made from metal sheets for support. The slicing unit comprising the cutting blades and a drive (transmission) shaft, and finally a 746 W (1 hp) power drive mechanism (electric motor). Tests carried out on the machine involved placing 1 kg of fluted pumpkin leaves on the conveyor belt, which was then conveyed to the slicing unit, where it was chopped to desired size. It took an average of 9 minutes to process 1kg of the fluted pumpkin leaves during the test. Series of tests were carried out on the machine, which showed that it had an efficiency of 73.2% and is much faster than hand/manual slicing method.Keywords: design, development, fluted pumpkin, slicing machin

The Relationship between Selected Anthropometric Indices and Cardiorespiratory Fitness in Apparently Healthy Young Adults in a Nigerian Community

Background and Aim: Cardiorespiratory fitness (CRF) is a useful tool for establishment of baseline fitness status and monitoring of physical activity level. Therefore, it may by extension serve as health risk index. However, studies that have determined the correlation between anthropometric indices and CRF in apparently healthy young adults is difficult to find in other to preempt preventive actions before pathology develops. Materials and Methods: Using a descriptive correlational research design, 325 participants (160 males, 165 females) with mean age of 21.87±2.41 years were sampled. Tape measure, stop watch, metronome, sphygmomanometer, stethoscope, height meter, bathroom weighing scale, modified Borg’s exertion scale and step benches were used to obtain the blood pressure, heart rate, respiratory rate, rate of perceived exertion, height, weight, waist circumference and cardiorespiratory fitness was estimated using the mean heart rate responses of the participants. The data was summarized using frequency count, percentages, range, mean, standard deviation, Independent t-test and Pearson’s Product Moment Correlation at alpha level of 0.05. Results: CRF significantly correlated with post-test systolic blood pressure (p= 0.004), post-test diastolic blood pressure (p= 0.010) and resting heart rate (p= <0.0001) but not with BMI (p= 0.133), waist circumference (p= 0.098), pre-test systolic blood pressure (p= 0.155), pre-test diastolic blood pressure (p= 0.121), resting respiratory rate (p= 0.631), and respiratory rate recovery (p= 0.478). Conclusion: CRF can be used as an index to quantify in apparently healthy participants, level of cardiovascular and respiratory related disease risks. It is necessary to emphasize the importance of physical activity in order to improve one’s cardiorespiratory fitness and minimize the risk of cardiorespiratory associated diseases

Screening of Locally Available Lemon Grass (Cymbopogon citratus) for Repellency Action against Aedes aegypti

In Nigeria, re-emergence of diseases caused by Aedes mosquito borne pathogens, and challenges associated with existing control tools occur. This necessitates an improved insecticide-based tool for use in Integrated Vector Management. So, repellent action of Cymbopogon citratus essential oil (EO) on Aedes aegypti (Linn.) was tested. The EO from C. citratus plant sourced from Awka, was extracted by hydro distillation, and the phytochemicals analyzed by Gas Chromatography-Mass Spectrometry. Repellent action of the EO on unfed Ae. aegypti was assessed using "WHO arm-in-cage" method. In triplicate, arms of human volunteers were treated with different concentrations (50.0, 25.0, 12.5, 6.25 and 3.125 % v/v) of the EO and submitted to 25-caged, unfed Ae. aegypti for 1 minute in every 30 minutes. β-cedrenes, kaempferol, and thujopsene dominated the 13 phytochemicals identified. The standard (Odomos®) and all EO concentrations recorded 100 % repellency on application. At 30 minutes, EC99.9 value was25.0 %, concentrations ≥ 62.5 % v/v gave 100 % repellency (p > 0.05). At 60 minutes, EC99.9 value was 30.68 %, concentrations ≥ 12.5 % v/v gave 100 % repellency (p > 0.05). At 90 to 120 minutes, 50 % concentration maintained 100 % repellency (p < 0.05), EC99.9 value was 48.79 % at 120 minutes. Recording 120 minutes protection time with no adverse effect, 50 % concentration showed equal potency as Odomos®. Research to isolate the active ingredients in the EO for incorporation into beneficial health and economic products is desirable.

Potentiality of Diethylamine as Agent of Deproteination and Deacetylation in the Extraction of Chitosan from Scylla serrata Shell

The potentiality of diethylamine as deproteination and deacetylation agent in the extraction of chitosan from Scylla serrata (giant mud crab) shell was investigated. The aim was to find an alternative agent to inorganic alkalis as possible replacement for use in the production of high quality chitosan with the right stability. Pretreatment of the shell was carried out and followed by demineralization using hydrochloric acid. Diethylamine was used for deproteination and deacetylation by modifying some published protocols. Moisture, ash, fat and protein contents of the extracts were determined using their respective standard methods. Fourier Transform Infrared (FTIR) technique was used for spectroscopic analysis. Scylla serrata shell was composed of 14.25% protein, 32.84% mineral (CaCO3), 31.52% chitin and 21.39% chitosan. Moisture, ash, fat and protein contents of chitin extracted from Scylla serrata shell were 2.35%, 3.03%, 1.79% and 3.85% respectively while those of chitosan were 1.65%, 3.84%, 0.53% and 2.80% respectively. Degree of deacetylation (DDA) and carbon to nitrogen ratio were 69.24% and 5.67 respectively. FTIR spectra of the extracted chitin and chitosan from Scylla serrata showed the presence of some active compounds of carbonyl, amide, amine and hydroxyl groups. However, CH3 waging along chain (952 cm-1), CO stretching at 1026 cm-1 and 1073 cm-1, and amide II band (1563 cm-1) were not found in the extracted chitin while HPO42- and amide III were also not found in the extracted chitosan. These moieties were present in the standard chitin and chitosan respectively. This study has shown that diethylamine (organic base) has great potential as agent of deproteination and deacetylation in the extraction of chitosan from Scylla serrata. Consequently, academic activity in the area of investigation of the stability of the extracted chitosan from Scylla serrata using diethylamine as deproteination and deacetylation agent is strongly recommended. Keywords: Diethylamine, deproteination, deacetylation, chitin and chitosan, Scylla serrata shell. DOI: 10.7176/CMR/12-7-07 Publication date:October 31st  2020

Investigating the cyclic breaking of butyl-, methyland ethyl-biodiesel from waste vegetable oil using ultraviolet-visible spectrophotometry

The main advantage of biodiesel to fossil-diesel is attributed to the ester functional group in its structure. Many researchers have affirmed that the functional group assists the diesel engine to function at its peak. However, the efficiency of the biodiesel to keep the mechanical piston-strokes in the diesel engine is experimentally presumed low especially if the engine works for a long time. In this research, it was proposed that the cyclic break down of the ester functional group of biodiesel is a major disadvantage. Butanol, ethanol and methanol biodiesel were produced in the laboratory using waste vegetable oil from restaurant. The Ultraviolet-visible spectroscopy or spectrophotometer (UV–Vis) was used to investigate the cyclic break down in the Butyl-, Methyl- and Ethyl- biodiesel. The Ultraviolet-visible spectroscopy or spectrophotometer (UV–Vis) was used to probe the various biodiesel samples with a start and stop wavelength of 500 and 900 nm respectively. The wavelength interval was 1 nm at a high scanning speed. Between 500–550 and 800–850 nm, the Ethyl- and Butyl- biodiesel had an absorbance of 2.7 and 1.6 respectively with 3 peaks each. Methyl-biodiesel had the highest absorbance of 1.7 at 600–650 nm with 1 peak. The computational extrapolation of all outcomes affirms that cyclic breaking is highest in Butylbiodiesel. The most resilient biodiesel type was the Ethyl-biodiesel. However, it was recommended that cyclic breaking may be preserved by ratio-mixing of biodiesel with fossil-diesel