scholarly journals Moisture and Aflatoxin Contents of Kenyan Market Peanuts and Decontamination with Water, Lime and Ultraviolet Radiation Treatments

2020 ◽  
pp. 48-57
Author(s):  
Joyce W. Wanjiru ◽  
Jasper K. Imungi ◽  
Lucy G. Njue

In the recent past, aflatoxin in peanuts and products has been a subject of controversy in Kenya. In the early 2019, some brands of locally manufactured peanut butter were withdrawn from the market shelves on account of containing aflatoxin higher than the national tolerance. It has been established that Kenyan market peanuts contain high levels of aflatoxin. Roasting is reported to have little effect on the aflatoxin content. This study was designed to assess the effect of specific treatments prior to roasting in reducing the aflatoxin levels to below the tolerance. This would then ensure compliance of the toxin levels in the roasted peanuts and the products with the national tolerance. The treatments included soaking in water, in lime, and UV irradiation. The peanut samples were collected from 20 vendors in the Main Cereal Market in Nairobi and brought to the laboratory of the Kenya Bureau of Standards (KEBS). They were analysed for moisture and aflatoxin content. Each sample was subjected to the treatment and reduction was evaluated in aflatoxin to the tolerance. The moisture content of the peanuts varied from 5.2 – 8.4% with mean of 6.5%. Moisture almost complied with the optimum for storage of 8.0%. The total aflatoxin contents varied from 3.3 – 38.5 ppb with mean of 14.8 ppb. Up to 45% samples had aflatoxin above tolerance of 10 ppb. There was positive and significant (p < 0.01) correlation between aflatoxin levels and moisture content. Treatment of the peanuts with water (cold & warm) and warm lime and irradiation with UV all managed to reduce the aflatoxin contents to below the tolerance, in the order lime>warm water>cold water>UV irradiation. The study concluded that the moisture content of the market peanuts in Kenya, almost complies with recommended optimum for storage the tolerance, but the mean aflatoxin content was well above the tolerance. However, the aflatoxin levels can be lowered effectively by soaking in water, lime, and by irradiation with UV.

1999 ◽  
Vol 87 (1) ◽  
pp. 243-246 ◽  
Author(s):  
John W. Castellani ◽  
Andrew J. Young ◽  
James E. Kain ◽  
Michael N. Sawka

This study examined how time of day affects thermoregulation during cold-water immersion (CWI). It was hypothesized that the shivering and vasoconstrictor responses to CWI would differ at 0700 vs. 1500 because of lower initial core temperatures (Tcore) at 0700. Nine men were immersed (20°C, 2 h) at 0700 and 1500 on 2 days. No differences ( P > 0.05) between times were observed for metabolic heat production (M˙, 150 W ⋅ m−2), heat flow (250 W ⋅ m−2), mean skin temperature (T sk, 21°C), and the mean body temperature-change in M˙(ΔM˙) relationship. Rectal temperature (Tre) was higher ( P < 0.05) before (Δ = 0.4°C) and throughout CWI during 1500. The change in Tre was greater ( P < 0.05) at 1500 (−1.4°C) vs. 0700 (−1.2°C), likely because of the higher Tre-T skgradient (0.3°C) at 1500. These data indicate that shivering and vasoconstriction are not affected by time of day. These observations raise the possibility that CWI may increase the risk of hypothermia in the early morning because of a lower initial Tcore.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Claudio Bravo ◽  
Deniz Bozkurt ◽  
Andrew N. Ross ◽  
Duncan J. Quincey

AbstractThe Northern Patagonian Icefield (NPI) and the Southern Patagonian Icefield (SPI) have increased their ice mass loss in recent decades. In view of the impacts of glacier shrinkage in Patagonia, an assessment of the potential future surface mass balance (SMB) of the icefields is critical. We seek to provide this assessment by modelling the SMB between 1976 and 2050 for both icefields, using regional climate model data (RegCM4.6) and a range of emission scenarios. For the NPI, reductions between 1.5 m w.e. (RCP2.6) and 1.9 m w.e. (RCP8.5) were estimated in the mean SMB during the period 2005–2050 compared to the historical period (1976–2005). For the SPI, the estimated reductions were between 1.1 m w.e. (RCP2.6) and 1.5 m w.e. (RCP8.5). Recently frontal ablation estimates suggest that mean SMB in the SPI is positively biased by 1.5 m w.e., probably due to accumulation overestimation. If it is assumed that frontal ablation rates of the recent past will continue, ice loss and sea-level rise contribution will increase. The trend towards lower SMB is mostly explained by an increase in surface melt. Positive ice loss feedbacks linked to increasing in meltwater availability are expected for calving glaciers.


2013 ◽  
Vol 2 (5) ◽  
pp. 10 ◽  
Author(s):  
John Maina Wagacha ◽  
Charity K. Mutegi ◽  
Maria E. Christie ◽  
Lucy W. Karanja ◽  
Job Kimani

<p>Peanut kernels of Homabay Local, Valencia Red, ICGV-SM 12991 and ICGV-SM 99568 cultivars were stored for six months in jute, polypropylene and polyethylene bags to assess the effect of storage bags, temperature and R.H. on fungal population and aflatoxin contamination. Moisture content (M.C.), fungal population and aflatoxin levels were determined before storage and after every 30 days during storage. Isolates of <em>Aspergillus flavus</em> and <em>A. parasiticus</em> were assayed for production of aflatoxin B1, B2, G1 and G2. The correlation between MC, population of <em>A. flavus</em> and <em>A. parasiticus</em> and aflatoxin levels in peanuts was also determined. Six fungal pathogens were commonly isolated from the peanut samples and occurred as follows in decreasing order: <em>Penicillium</em> spp. (106.6 CFU/g), <em>A. flavus</em> L-strain (4.8 CFU/g), <em>A. flavus</em> S-strain (2.9 CFU/g), <em>A. niger </em>(2.6 CFU/g), <em>A. parasiticus </em>(1.7 CFU/g) and <em>A. tamarii </em>(0.2 CFU/g). The overall population of <em>A. flavus</em> L-strain was 66% higher than that of <em>A. flavus</em> S-strain. Ninety one percent of <em>A. flavus</em> and <em>A. parasiticus</em> isolates produced at least one of the four aflatoxin types assayed, with 36% producing aflatoxin B1. Total aflatoxin levels ranged from 0 - 47.8 µg/kg with samples stored in polyethylene and jute bags being the most and least contaminated, respectively. Eighty nine percent and 97% of the peanut samples met the EU (? 4 µg/kg) and Kenyan (? 10 µg/kg) regulatory standards for total aflatoxin, respectively. Peanuts should be adequately dried to safe moisture level and immediately packaged in a container - preferably jute bags - which will not promote critical increases in fungal population and aflatoxin contamination.</p>


2020 ◽  
Vol 11 (3) ◽  
pp. 199-205
Author(s):  
Arum Sekar Wulandari ◽  
Afrida Rizka Farzana

The presence of Pericopsis mooniana (Thw.) Thw. in nature is endangered. Meanwhile, Pericopsis mooniana plants have its obstacles in generative propagation because the seeds have mechanical dormancy. Studies carried out to: (1) observe the morphology of pods, seeds and sprouts of Pericopsis mooniana; (2) determine the physical quality of Pericopsis mooniana seeds, and (3) analyze the proper dormancy breaking treatment for Pericopsis mooniana seeds. Research is conducted in laboratories and in greenhouses. The physical quality of the seeds measured was the weight of 1,000 seeds and the moisture content. The treatment for breaking the dormancy of the Pericopsis mooniana seeds were control, scarification of the seeds using nail clippers and soaking in hot to cold water for 48 hours. Morphologically, the fruit of Pericopsis mooniana is pod-shaped, with orange seeds, oval-shaped and curved edges. Pericopsis mooniana sprouts include in the epigeal type. In 1 kg of weight there are ± 4,000 Pericopsis mooniana seeds, with the post harvest seed moisture content amounting to 7.62%. The dormancy breaking treatment of Pericopsis mooniana seeds increased seeds germination by 60% compared to controls. The scarification of Pericopsis mooniana seeds using nail clippers for breaking mechanical dormancy is the best treatment because it can increase the number of seeds germinating in a short time and simultaneously. Key words: breaking seed dormancy, morphology, Pericopsis mooniana, physical quality, seed scarificatio


2019 ◽  
Author(s):  
Timothy Omara

The moisture content and total aflatoxin (AF) content of 27 samples of freshly harvested white maize (Zea mays L.) from Mubende (n = 3), Ibanda (n = 3), Jinja (n = 3), Mayuge (n = 3) , Buikwe (n = 3), Hoima (n = 3), Mpigi (n = 3), Masindi (n = 3) and Bugiri (n = 3) districts of Uganda representing the agroecological zones: Lake Victoria crescent, Western Highlands, South East and Lake Albert Crescent were determined in the second season harvest of January 2019 to March 2019. Moisture content ranged from 12.9 to 18.8% (mean moisture content varied from 13.9±0.35-17.2±1.55%) with the highest moisture recorded in maize from Ibanda. The highest mean AF contamination of 11.0±3.01 μg/kg was recorded in maize from Hoima while the lowest AF content of 3.8±1.30 μg/kg was recorded in maize from Mpigi. Despite the fact that all the samples had detectable aflatoxins, none of the maize samples had aflatoxin greater than WHO regulatory limit of 20 μg/kg. White maize in Uganda are precontaminated by aflatoxins prior to harvest. Whereas the spectre of aflatoxigenic contamination of foods remains a ticklish challenge to address, strategic adaptation and deployment of appropriate interventions can help secure a safe harvest. Farmers should plant maize varieties with established maturity periods to ensure timely harvesting. Further research should assess the presence of other mycotoxins as zearalenone, sterigmatocystin, ochratoxin A, citrinin, vomitoxin and diacetoxyscirpenol that may co-occur with aflatoxins in freshly harvested maize.


Author(s):  
Mingjian Zhang ◽  
Feng Huang ◽  
Qing Chen ◽  
Le Wang ◽  
Haisheng Wang ◽  
...  

A mathematical model was established to predict the mean value and variance of tobacco strip during drying processing, based that the physical and chemical properties of tobacco strip as agriculture products show probability distributions. The results show that the model can predict the mean value of moisture content at different times, and there is a certain deviation in predicting the variance of moisture content at initial stage of drying process. However, the prediction value of the variance of tobacco strip is much more accurate while the moisture content is between 8% and 10%, which is the interval of quality requirements.Keywords: tobacco strip; drying; mean value;variance model.  


Author(s):  
Tega A Emurigho ◽  
Canice O.O Kabuo ◽  
Arinze N Ifegbo

The physical and engineering properties of fresh and dried tiger nut (Cyperus esculentus) were determined at moisture content of 41.20% and 16.40% on wet basis respectively. The mean values for the three principal axes (length, width and thickness) were 9.52mm, 8.16mm, and 8.16mm for fresh tiger nut and 9.14mm, 7.72mm and 8.03mm for dried tiger nut respectively, showing a decrease with decrease in moisture content and was significantly different at p?0.05. The mean values of the bulk density, true density and porosity of both fresh and dried tiger nut were 0.59g/cm3 , 0.97g/cm3 , 40.61 and 0.58g/cm3, 0.94g/cm3 , 40.35 respectively and were not significantly different at p?0.05. The mean angle of repose and coefficient of static friction over formica, stainless steel, glass and plywood surfaces of fresh tiger nut were 50.11o , 2.73, 2.45, 2.22 and 1.77 while that of dried tiger nut were 48.23o , 2.41, 2.03, 2.11 and 2.00 respectively. The mean rupture force increased with compression force of 90.08N on the major axis to 116.88N for fresh tiger nut and from 120.55N to 161.10N for dried tiger nut and were significantly different at p?0.05. These properties determined are necessary in the design and fabrication of hoppers, conveyor equipment and the force tiger nut can withstand before it is ruptured.


2014 ◽  
Vol 28 (4) ◽  
pp. 543-548 ◽  
Author(s):  
Thasaiya A. Selvam ◽  
Musuvadi R. Manikantan ◽  
Tarsem Chand ◽  
Rajiv Sharma ◽  
Thirupathi Seerangurayar

Abstract The present study was carried out to investigate the compression loading behaviour of five Indian sunflower varieties (NIRMAL-196, NIRMAL-303, CO-2, KBSH-41, and PSH- 996) under four different moisture levels (6-18% d.b). The initial cracking force, mean rupture force, and rupture energy were measured as a function of moisture content. The observed results showed that the initial cracking force decreased linearly with an increase in moisture content for all varieties. The mean rupture force also decreased linearly with an increase in moisture content. However, the rupture energy was found to be increasing linearly for seed and kernel with moisture content. NIRMAL-196 and PSH-996 had maximum and minimum values of all the attributes studied for both seed and kernel, respectively. The values of all the studied attributes were higher for seed than kernel of all the varieties at all moisture levels. There was a significant effect of moisture and variety on compression loading behaviour.


2019 ◽  
Vol 19 (5) ◽  
pp. 3417-3432 ◽  
Author(s):  
Sabine Haase ◽  
Katja Matthes

Abstract. Recent observational and modeling studies suggest that stratospheric ozone depletion not only influences the surface climate in the Southern Hemisphere (SH), but also impacts Northern Hemisphere (NH) spring, which implies a strong interaction between dynamics and chemistry. Here, we systematically analyze the importance of interactive chemistry with respect to the representation of stratosphere–troposphere coupling and in particular the effects on NH surface climate during the recent past. We use the interactive and specified chemistry version of NCAR's Whole Atmosphere Community Climate Model coupled to an ocean model to investigate differences in the mean state of the NH stratosphere as well as in stratospheric extreme events, namely sudden stratospheric warmings (SSWs), and their surface impacts. To be able to focus on differences that arise from two-way interactions between chemistry and dynamics in the model, the specified chemistry model version uses a time-evolving, model-consistent ozone field generated by the interactive chemistry model version. We also test the effects of zonally symmetric versus asymmetric prescribed ozone, evaluating the importance of ozone waves in the representation of stratospheric mean state and variability. The interactive chemistry simulation is characterized by a significantly stronger and colder polar night jet (PNJ) during spring when ozone depletion becomes important. We identify a negative feedback between lower stratospheric ozone and atmospheric dynamics during the breakdown of the stratospheric polar vortex in the NH, which contributes to the different characteristics of the PNJ between the simulations. Not only the mean state, but also stratospheric variability is better represented in the interactive chemistry simulation, which shows a more realistic distribution of SSWs as well as a more persistent surface impact afterwards compared with the simulation where the feedback between chemistry and dynamics is switched off. We hypothesize that this is also related to the feedback between ozone and dynamics via the intrusion of ozone-rich air into polar latitudes during SSWs. The results from the zonally asymmetric ozone simulation are closer to the interactive chemistry simulations, implying that under a model-consistent ozone forcing, a three-dimensional (3-D) representation of the prescribed ozone field is desirable. This suggests that a 3-D ozone forcing, as recommended for the upcoming CMIP6 simulations, has the potential to improve the representation of stratospheric dynamics and chemistry. Our findings underline the importance of the representation of interactive chemistry and its feedback on the stratospheric mean state and variability not only in the SH but also in the NH during the recent past.


Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6190
Author(s):  
Łukasz Cieślikiewicz ◽  
Piotr Łapka ◽  
Radosław Mirowski

The in situ hygro-thermal behavior of a wet masonry wall during its drying process is presented in this paper. The considered wall is a part of a basement of a historic building that was subjected to renovation works. The building is located in the City of Łowicz (Poland). The drying process was implemented by applying the thermo-injection method and a novel prototype of the drying device used for this method. The dedicated acquisition system was developed to in situ monitor parameters of the drying process. The air temperature and relative humidity in various locations in the basement, temperatures and moisture contents at several points of the wet wall as well as the electrical parameters of the drying device were registered. Based on variations of the monitored parameters, the hygro-thermal behavior of the wall during drying was studied. After 6 days of drying, the wall temperature in the drying zone was increased to approximately 40–55 °C, while the moisture content was reduced to the mean level of 3.76% vol. (2.35% wt.). These wall parameters allowed for effective impregnation of the wall with the hydrophobic silicone micro-emulsion, which created horizontal and vertical waterproofing. Moreover, the specific energy consumption during the drying process defined as energy consumption divided by the mean volumetric moisture content drop (MC) between the initial and final state in the wall and by the length of the dried wall section was estimated to be 11.08 kWh/MC%/m.


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