Journal of Agriculture, Science and Technology最新文献

{"title":"Effect of citric acid pretreatment on drying kinetics of tamarillo in a greenhouse solar dryer","authors":"Joel M. Mweu, U. Mutwiwa, F. G. Kiburi, Chelsea Okelo, Faith Chepkwony","doi":"10.4314/jagst.v22i6.3","DOIUrl":"https://doi.org/10.4314/jagst.v22i6.3","url":null,"abstract":"The production and consumption of tamarillo (Solanum betaceum) is gaining momentum due to its immense nutritional, health, and commercial potential. However, like many other horticultural products, high postharvest losses are incurred in tamarillo production. In particular, decay is a major problem. Drying is a viable option that can address this problem and significantly increase the shelf life of tamarillo. Consequently, the objective of this study was to evaluate the effect of citric acid pretreatment on the drying kinetics and quality of tamarillo slices. The tamarillos were dried in a passively operated even-span greenhouse solar dryer (8 m long, 4 m wide, and 3.6 m high to the ridge) covered with a 200 μm thick ultraviolet-stabilised polyethylene film. Solar radiation, temperature, relative humidity, moisture content, colour, firmness, and vitamin C content were periodically measured, and the data were analysed statistically. The citric acid-pretreated and control (untreated) tamarillo slices were dried from an initial moisture content of 655% (db) to a final moisture content of 16.25% and 22.50% (db), respectively, in 10 hours. In addition, the pretreated slices attained a higher average drying rate of 42.01±0.23 g/g/hr compared to 40.23±0.12 g/g/hr attained by the control slices. Further, the Page model best described the drying kinetics of both tamarillo samples with R², χ2, and RMSE values of 0.9975, 0.0004, and 0.0005, respectively. The pre-treated samples had better colour retention with a total colour change of 15.07±1.12 compared to 35.99±0.98 attained in the control samples. Moreover, the pretreated tamarillo slices attained a lower percentage firmness increment of 281.82±3.21% compared to 337.5%±1.54 attained in the untreated samples. Further, the pretreated tamarillo slices had 42.94±0.41% vitamin C retention compared to 40.17±0.67% retention in the control samples. Generally, pre-treating tamarillo slices with citric acid improves their drying kinetics and both physical and nutritional qualities.","PeriodicalId":516571,"journal":{"name":"Journal of Agriculture, Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140498463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of different pretreatments on thin-layer drying kinetics, vitamin A retention and rehydration of orange-fleshed sweet potato slices","authors":"Erick O. Ayonga, Diana M. Ondieki, E. Ronoh","doi":"10.4314/jagst.v22i6.2","DOIUrl":"https://doi.org/10.4314/jagst.v22i6.2","url":null,"abstract":"Orange-fleshed sweet potato (OFSP) is a bio-fortified sweet potato with a high beta-carotene content. OFSP deteriorates rapidly due to its high moisture content. Conventional air drying is one of the most common methods employed but has the disadvantage of low rates of moisture removal, hence the longer drying time, which affects the quality of the final product. Pretreatments prevent quality deterioration and hasten the drying rate. This study investigated the effects of different pretreatments on thin-layer drying kinetics and the quality of OFSP slices. Three-mm-thick OFSP slices were pretreated using three different pretreatments: lemon juice, salt solution, and hot water blanching (HWB). Pretreated slices were dried in a solar dryer. Data collection (weight, temperature, relative humidity, and solar radiation) was done at 1-hour intervals. Four mathematical models (Page, Logarithmic, Modified Page, and Henderson and Pabis) were fitted to the experimental data. Also, the quality parameters of vitamin A and rehydration were investigated. The dryer inside temperatures and relative humidity ranged from 26.93–44.53 oC and 36.87%–65.30%, respectively. The moisture content of fresh OFSP slices for both treated and untreated samples was found to be in the range of 291.55–302.24% (dry basis, db), which reduced to 25.25–35.25% (db) after drying. The drying time ranged between 11 and 13 hours. The page model was found to be the best model for untreated samples, with R2 of 0.9948, RMSE of 0.0151, and χ2 of 0.0097, while the logarithmic model best described the drying behaviour of all the pretreated samples because it had the highest values of R2 and the lowest values of RMSE and χ2. Lemon juice-pretreated samples had the best quality parameters (vitamin A retention and rehydration ratio). A maximum rehydration ratio of 1.6765 was obtained for samples pretreated with lemon juice, and a minimum rehydration ratio of 1.1390 was obtained from HWB-pretreted samples. The results, therefore, indicate that lemon juice can be used as a pretreatment for thin-layer drying of OFSP slices. Pretreatments help minimise postharvest losses associated with OFSP, thus contributing to solving food and nutrition insecurity challenges.","PeriodicalId":516571,"journal":{"name":"Journal of Agriculture, Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140499048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performances of plantlets from selected cassava (Manihot esculenta Crantz) genotypes under Semi - Autotrophic Hydroponics (SAH) using different substrates","authors":"Binzunga Makumbu Mamy, Kintche Kokou, M. Sikirou, Najimu Adetoro, Kajibwami Angelique, A. Nyende","doi":"10.4314/jagst.v22i6.5","DOIUrl":"https://doi.org/10.4314/jagst.v22i6.5","url":null,"abstract":"The cassava seed system faces challenges due to limited seed stock caused by a slow propagation rate and a lengthy growth period. Conventional methods lacking phytosanitary guarantees further compound these issues. To address these limitations, the Semi-Autotrophic Hydroponics (SAH) technology was adopted for the rapid mass propagation of healthy, disease-free cassava plants. This research aimed to evaluate the performance of cassava planting materials using different substrates for stem-cutting multiplication in the laboratory at the IITA Kalambo research station in DR Congo. The experiment followed a split-plot design of five replications of three consecutive sub-culture periods lasting four weeks each. Four different genotypes: IB961089A, MM060083, Nase14, and Albert28 as the main plots, with four different substrates: KlasmannTS3, Vermiculite, Local Peat, and Sawdust as the sub-plots, were laid out. Cuttings were placed in 500-ml substrate-filled boxes and watered weekly with a 100-ml Miracle-Gro solution. Data were collected on survival, height, leaf and internode numbers, and cutting numbers at the end of each subculture period. The data were analysed using ANOVA in R software. The Fisher's Least Significant Difference (LSD) test was utilised to separate means when significant differences among treatments were present (p <0.05). The results showed that survival was primarily influenced by the substrate used, with KlasmannTS3 demonstrating the highest rate, exceeding 90%. Significant differences (p < 0.05) among genotypes for survival rate and performance parameters mentioned above (p < 0.001) were observed. Similarly, there were significant differences (p < 0.001) among substrates for survival rate and performance parameters. Furthermore, the interaction between genotype and substrate significantly (p < 0.001) affected performance parameters. MM060083 performed the best across all traits. KlasmannTS3 was the superior substrate and had the highest average cutting number regardless of genotype, with a notable increase of 292% from 20 to 58.4 cuttings, representing a ratio of 1:3 within three months. Sawdust had the lowest multiplication rate, with a 5% decrease. The superior performance of KlasmannTS3 was attributed to its rapid growth and favourable properties. The interaction between MM060083 and KlasmannTS3 consistently showed the highest number of cuttings (70.4). Sawdust consistently showed poor growth performance, regardless of genotype. The study concludes that the SAH offers the potential for rapid multiplication of disease-free cassava planting materials in reduced space and time.","PeriodicalId":516571,"journal":{"name":"Journal of Agriculture, Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140498077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Operational cost uncertainty and financial performance of manufacturing firms in Kenya","authors":"J. Pila, Willy Muturi, T. Olweny","doi":"10.4314/jagst.v22i6.8","DOIUrl":"https://doi.org/10.4314/jagst.v22i6.8","url":null,"abstract":"The main objective of this study was to find out if uncertainty about the operational costs of manufacturing firms in Kenya affects financial performance. Kenyan manufacturing firms have not been performing as expected. They are meant to contribute to economic growth through GDP increments and market share, attract the largest strategic investments in the key processing industry, increase sales locally and internationally, and employ 20% of the Kenyan population. However, manufacturing firms have been facing various financial and non-financial challenges, including declining profit and sales, and some firms have moved out of the market. Many factors have been cited as contributing to declining financial performance. However, the influence of operational cost uncertainty on the financial performance of manufacturing firms in Kenya is not conclusive. Some studies found a negative relationship, while others found a positive relationship. Hence, the current study necessitates examining the influence of firm operational cost uncertainty on the financial performance of manufacturing firms in Kenya. The study anchored its variable on agency theory, which states that during financial uncertainty, operational costs are volatile. Indicators of operational cost uncertainty were the labour cost ratio and the research and development ratio, and proxies of performance were ROS and ROE. The study adopted positivism, philosophy, and an explanatory design. The target population was 856 manufacturing firms registered with the Kenya Association of Manufacturers. A sample of 90 firms was drawn from the population using the Nasuirma (2000) formula. The stratified random sampling technique was applied to 14 sectors, and each sample was picked by random sampling. The study covered 12 years, starting from 2009 to 2020. Panel data was collected from audited financial statements using a data collection instrument. Results showed that operational cost uncertainty had a positive and significant influence on the financial performance of manufacturing firms in Kenya. The labour cost ratio had a negative and significant relationship with the financial performance of manufacturing firms in Kenya. The research and development ratio had a positive and significant impact on the financial performance of manufacturing firms in Kenya. The study recommends manufacturing firms have enhanced technology in place to help reduce production costs. The study recommends having enhanced research and development in place that will take advantage of the market niche for products and technology for production.","PeriodicalId":516571,"journal":{"name":"Journal of Agriculture, Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140498579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Association between work-related musculoskeletal disorders’ risk factors and different body parts affected among housekeepers in selected hotels in Mombasa County","authors":"Enid K Gikunda, Charles M Mburu, C. Kibiti","doi":"10.4314/jagst.v22i6.6","DOIUrl":"https://doi.org/10.4314/jagst.v22i6.6","url":null,"abstract":"Work-related musculoskeletal disorder (WRMSDs) affects primarily muscles, tendons, joints, intervertebral discs, peripheral nerves, and the vascular system. WRMSDs are a worldwide issue and are experienced in both developed countries and industrially developing countries (IDCs). The prevalence of WRMSDs and their risk factors are not well known among hotel housekeepers in Kenya. Therefore, this study aimed to establish the annual prevalence of work-related musculoskeletal disorders among housekeepers in selected hotels in Mombasa County. The study also sought to assess the common body parts affected by pain as well as the WRMD risk factors associated with these body parts among housekeepers at selected hotels in Mombasa County. The study employed a cross-sectional approach. The sample size of 276 study participants’ housekeepers was obtained by considering housekeepers’ availability at the time of study at 18 purposefully selected hotels. Data collection was done through standardized questionnaires. Qualitative and quantitative methods were used for data analysis. Quantitative data was coded and entered into the Statistical Package for Social Sciences (SPSS 23) for analysis. Descriptive and inferential statistical analyses were utilized to analyze the quantitative data collected from the structured questionnaires. To establish the link between variables, descriptive statistical analysis, including frequencies and percentages, and inferential statistical analysis, including the Chi-square test and linear regression, were utilized, with findings displayed in frequency tables, bar graphs, and pie charts. On the other hand, the qualitative analysis utilized thematic analysis, with findings presented in narrations. WRMDs were found to be prevalent in 91.7% of hotel housekeepers in Mombasa County. The most widely reported WRMD by housekeepers was lower back pain. The study cohort also reported leg, neck, and shoulder joint and muscle pains as a result of carrying, lifting, pulling, or pushing heavy objects weighing more than 20 kilograms. Hotels ought to identify the common WRMDs among housekeepers and determine specific risk factors associated with these pains. The study's key recommendations are for hotels to evaluate their labor practices to mitigate understaffing, invest in the mechanization of equipment to ensure that staff have reasonable working hours per day with adequate breaks in between chores, and take reasonable leave. Implementing health and safety standards is crucial, with an emphasis on good posture and techniques while performing tasks. The study recommends strengthening labor regulations by raising awareness and sensitizing labor unions and health committees on musculoskeletal disorders and preventing undue work-related injuries among hotel housekeepers.","PeriodicalId":516571,"journal":{"name":"Journal of Agriculture, Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140498988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The intra-uterine effects of phenobarbital on fetal growth and development in albino rats (Rattus Norvegicus)","authors":"J. Segut, J. Kweri, Ann Mwangi, C. Sigei, James Kanyoni, Peris Macharia, Walter Rono, Cyrus Kamau, Anne Njoki, Cynthia Chebii, J. Kuria, Joseph Wachira, Christopher Mramba, Jane Karanja","doi":"10.4314/jagst.v22i6.7","DOIUrl":"https://doi.org/10.4314/jagst.v22i6.7","url":null,"abstract":"The intrauterine developmental consequences of phenobarbital, when administered in varied doses, on foetal growth and development remain poorly understood. This study is therefore set to evaluate the intrauterine effects of phenobarbital at differing doses when administered at different incubation periods in albino rats. In carrying out this study, a post-test only control experimental study design was adopted, and a sample size of 30 Albino rats was used. These rats were obtained from the Small Animal Facility for Research and Innovation in the School of Biomedical Sciences at Jomo Kenyatta University of Agriculture and Technology. They were arbitrarily allocated into two large study groups of 3 control rats and 27 experimental rats. The 27 rats in the experimental group were further subdivided into three study groups of 9 rats, each with low, medium, and high phenobarbital doses. On gestation day 20, all the rats were humanely sacrificed, and three fetuses from each rat were selected. The parameters evaluated in this study included the foetal weight, bi-parietal diameters, and crown lump length. The data was collected using a structured checklist, then entered into the computer using an Excel spreadsheet. The data was then exported to the Statistical Package for the Social Scientist (SPSS). To determine the causal effects, the statistical significance was determined by using Tukey’s post hoc multiple comparison tests, and all values with a p value less than 0.05 were considered to be significant. This research discovered that there was a reduction in all foetal parameters, which was statistically significant (P<0.05), especially during trimesters one and two. The effects of phenobarbital administered on foetal parameters depended on the time of exposure and dose administered. Phenobarbital, administered prenatally, had dose- and time-dependent effects on foetal parameters. Therefore, more studies need to be done on higher primates to ascertain their teratogenic safety in pregnancy.","PeriodicalId":516571,"journal":{"name":"Journal of Agriculture, Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139640419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of temperature variation on yield and quality of field crickets (Gryllus bimaculatus) and black soldier flies (Hermetia illucens)","authors":"Leonard C. Korir, E. Ronoh, Stephen N. Ondimu, John N. Kinyuru, M. Gicheha","doi":"10.4314/jagst.v22i6.1","DOIUrl":"https://doi.org/10.4314/jagst.v22i6.1","url":null,"abstract":"Insect rearing provides an affordable alternative source of animal nutrition for most small-scale farmers. However, current rearing technology with uncontrolled environmental conditions suppresses insect yields, leading to low adoption of insect production. The objective of this study was to assess the effect of temperature variation, using an adaptive control structure, on the yield of field crickets (Gryllus bimaculatus) and black soldier fly larvae (Hermetia illucens). Temperature values of 25°C, 27°C, and 30°C constant relative humidity of 50%, and constant air speed of 3 m/s were adopted for the study. Throughout the study, weighing of the insect wet yield was done on a daily basis for larvae and after three days for cricket pinheads. Black soldier fly larvae and adult crickets were harvested at the ages of two weeks and six weeks, respectively, and oven dried at 105°C for 24 hours for subsequent analysis of proteins. Results indicated that black soldier fly larvae reared at 25°C, 27°C, and 30°C had a maximum mean wet yield of 0.216 ± 0.022 g, 0.234 ± 0.019 g, and 0.248 ± 0.016 g, respectively, at the age of two weeks. Similarly, crickets reared at 25°C, 27°C, and 30°C had a mean yield of 0.807 ± 0.167 g, 0.933 ± 0.102 g, and 1.306 ± 0.254 g at the age of six weeks. Dried cricket reared at 25°C, 27°C, and 30°C had 25.566 ± 0.012%, 46.811 ± 0.647%, and 58.216 ± 1.510% protein, respectively. Contrary to this, black soldier flies reared at 25°C, 27°C, and 30°C yielded 42.655 ± 1.732%, 47.121 ± 0.015%, and 62.536 ± 0.014%, respectively. Larval yield recorded significant different yields (f = 4.935, p = 0.03), whereas crickets failed to record significant different yields (f = 0.777, p = 0.388) under different temperature levels. A higher temperature regime yielded higher body mass and protein turnover. The findings of this study boost the future prospects of insects as food and feed for enhancing food and nutrition security.","PeriodicalId":516571,"journal":{"name":"Journal of Agriculture, Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140498466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effects of non-bitter Cucumis metuliferus fruit extract on blood sugar of high-fat/fructose diet and streptozotocin-induced type II diabetic Wistar Albino rats","authors":"Muriuki Dennis Mwangi, Kamau David Muchina, K. J. Kariuki, Karanja Simon, T. Reuben","doi":"10.4314/jagst.v22i6.4","DOIUrl":"https://doi.org/10.4314/jagst.v22i6.4","url":null,"abstract":"Globally, diabetes mellitus (DM) remains one of the leading debilitating non-communicable diseases, with its prevalence projected to increase from 8.8% in 2015 to 10.0% in 2030. The management of diabetes mellitus remains a major challenge, and the number of diabetes-related deaths is projected to rise from 3.1 million in 2015 to 4.2 million in 2030. This continues to be a public health concern, particularly in developing countries where the majority of people are poor and predominantly live in rural areas, facing challenges in accessing healthcare services. However, the non-bitter Cucumis metuliferus fruit is being used for managing type 2 diabetes mellitus by some communities in Kenya, although its therapeutic benefits have not been adequately studied and proven. The study aimed to determine the effects of non-bitter Cucumis metuliferus fruit extract on blood sugar in high-fat/fructose diet and streptozotocin-induced type II diabetic Wistar albino rats. This study adopted an experimental laboratory-based design. A sample size of 64 male Wistar albino rats, aged 5 weeks and weighing between 90 and 130 grams, was randomly assigned to two major study groups: the control group and the experimental group. The experimental group received a high-fat/fructose diet plus streptozotocin (STZ) injection to induce diabetes mellitus, whereas the control group received a standard rodent pellet diet plus 0.9% normal saline injection. The experimental group was further divided into a positive control group treated with pioglitazone (the standard drug) at a dose of 20 mg/kg body weight, a low-dose CMFE group at 200 mg/kg body weight, and a high-dose CMFE group at 400 mg/kg body weight. Fasting blood sugar (FBS), oral glucose tolerance test (OGTT), and haemoglobin A1c (Hb A1c) tests were used as indicators, and the results were compared between the groups. The study findings revealed a significant statistical rise (P <0.001) of FBS in the treatment group after induction of type II DM, followed by a decline to pre-induction levels after treatment. Similarly, there was a statistically significant increase (P <0.001) of the OGTT after induction of type II DM, with the OGTT declining to pre-induction levels following treatment (P =0.106). The findings on both the FBS and OGTT tests indicate that treatment with CMFE controlled the blood sugar. Consequently, there was no significant difference (P =0.712) in Hb A1c test results between the control group and the treatment group at the end of the experiment, indicating that treatment with CMFE had a long-term control effect on blood sugar. This study concludes that the non-bitter CMFE possesses both short-term and long-term hypoglycemic properties in type II diabetes mellitus.","PeriodicalId":516571,"journal":{"name":"Journal of Agriculture, Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140498497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}