School of Food Technology, Nutrition and Bioengineering (SFTNB) Collections

Permanent URI for this collection

http://10.29.1.53:4000/handle/10570/170

Browse

Browsing School of Food Technology, Nutrition and Bioengineering (SFTNB) Collections by Subject "Aflatoxins"
  • Item
    Food control in Uganda: a case of the rice value chain
    (Makerere University, 2023-01) Namubiru, Leatitiah
    Food control is of national strategic interest to guarantee food safety and protect human health. Uganda has a multi-agency food control system where mandates and quality infrastructure are fragmented into different government ministries. Fragmentation leads to lack of accountability for food safety issues and weaknesses that unscrupulous food handlers exploit to compromise food safety. The level of knowledge, attitude and practices (KAP) of food handlers in rice value chain of Uganda is not known. Similarly, the incidence, level of contamination and potential health risks associated with consumption of rice on the Ugandan market are unknown. The purpose of this research was to assess the effectiveness of the food control system on the rice value chain of Uganda. A desk-based study was done to identifying gaps and opportunities for improvement of food control along the rice value chain. Knowledge, attitude, and practices (KAP) of rice handlers were assessed in a cross sectional study using 252 rice handlers. The incidence and level of aflatoxins, heavy metals and pesticide residues in imported and locally produced rice were analysed using High Performance Liquid Chromatography (HPLC), Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and Gas Chromatography-Mass Spectrometry, respectively. Estimated Daily Intake (EDI), Hazard Index (HI) and Incremental Lifetime Cancer Risk (ILCR) were determined to define the dietary exposure, non-carcinogenic and carcinogenic risk from contaminants, respectively. The food policy and subsequent laws are outdated hence the ineffective control food system. The study on KAP established that about 221 (87.7%) food handlers knew about the occurrence and effects of aflatoxins, and pesticides in rice. The incidence of total aflatoxin (TAF) contamination in imported rice (63.3%) was higher than (22.5%) reported in locally produced rice. The mean cadmium (Cd) and lead (Pb) levels in imported rice (0.52±1.15 mg/kg and 0.79±1.27 mg/kg) exceeded the Ugandan Standard (US 738:2019) and Codex Standard (CXS 193-1995) specifications of 0.1 mg/kg and 0.2 mg/kg, respectively. Organochlorine pesticides (OCPs) detected in imported rice were higher than the maximum residual limits of Codex Alimentarius Commission. The potency of liver cancer cases in Uganda was 1.02×10-5 and 1.05×10-5 adults/year/100,000, and 6.50×10-4 and 6.72×10-5 infants /year/100,000 for open traded and packed rice, respectively. The values obtained for the Incremental Life Cancer Risk (ILCR) for Arsenic (As) detected in rice were 1.14×10-2 and 7.28×10-2 for adults and infants, respectively. The ILCR of all detected OCPs in adults and infants were higher than 1.0×10-4, in both open traded and packed rice. In conclusion, the food safety law in Uganda is antediluvian and there is need to amend it to address challenges in food control. Food handlers were generally knowledgeable about aflatoxin and pesticide contamination but not heavy metals. Imported rice had a higher incidence and mean total aflatoxin, cadmium and lead concentration as compared to locally grown rice. This study further revealed that there is a potential As and OCP- based carcinogenic risk from consumption rice in both infants and adults at the current level of contamination and consumption rate.
  • Item
    Food safety knowledge, attitudes and practices of food handlers along the rice value chain of Uganda
    (Journal of Food Industry, 2022-02) Namubiru, Leatitiah ; Male, Denis ; Mukisa, Ivan Muzira ; Byaruhanga, Yusuf Byenkya
    Food handlers play a critical role in controlling food contamination from “farm to fork”. Therefore, inadequate knowledge, poor attitudes and improper practices by food handlers pose a serious challenge to food safety. The aim of this study was to assess the knowledge, attitudes, and practices (KAP) of food handlers along the rice value chain of Uganda with the view of understanding factors that influence contamination of rice with aflatoxins, heavy metals and pesticides. A cross-sectional study, using a structured questionnaire through face-to-face interviews with 252 respondents was conducted in Butaleja, Gulu, Hoima, Kampala, Mutukula, Mbale and Mbarara districts. Categorical data was expressed as frequencies and percentages. The unique predictors of the KAP of rice handlers were defined using multivariate linear regression analysis. About 221 (87.7%) food handlers knew about the occurrence and causes of aflatoxins contamination in rice. Changes in colour (81.7%) and a musty smell (82.9%) were perceived to indicate the presence of aflatoxins. The main pre and post-harvest aflatoxin preventative practices identified were growing resistant rice varieties (82.9%) and proper drying (79.8%). Food handlers were generally not knowledgeable (73.4%) about heavy metal contamination in rice. All food handlers used pesticides; however, 68.3% had never received formal training in pesticide use. Majority (86.1%) of food handlers were aware of the harmful effects of pesticides but on the contrary, this did not significantly change their practices towards safe pesticide use. At multivariate level, education was the unique predictor for aflatoxins and heavy metal contamination. Pesticide contamination was mainly influenced by district of residence. Therefore, appropriate educational programs organized to train food handlers can promote food safety in the rice value chain of Uganda. Interventions by regulatory agencies to strengthen enforcement of laws related to contaminants through regular surveillance at the farm and retail outlets are necessary to ensure compliance by food handlers.
  • Item
    Incidence of aflatoxins, heavy metals and pesticide residues contamination in imported and locally grown white rice in Uganda
    (International Journal of Science and Research (IJSR), 2021-11) Namubiru, Leatitiah ; Byaruhanga, Yusuf Byenkya ; Male, Denis
    There is increased global interest in the safety of rice because rice is a staple food for half of the world’s population and its safety influences consumers’ health. This study aimed at assessing the levels of aflatoxins (B1, B2, G1, and G2), heavy metals (Arsenic, Lead, and Cadmium), and organochlorine pesticide residues (OCPs) in imported and local rice in Uganda so as to compare their incidence and level of contamination. Rice (n = 305 samples) was collected from 4 major rice-producing districts and 4 rice entry points in Uganda from January 2018 to December 2019. Thin-layer chromatography was used to analyze samples for aflatoxins, atomic absorption spectrophotometry for heavy metals, and gas chromatography for organochlorine pesticide residues. The mean total aflatoxin contamination in imported rice (2.14±3.73 μg/kg) was higher than (0.01±0.09μg/kg) reported in local rice; with 14 (11.9%) samples above the Ugandan standard specification of 10 µg/Kg. The mean cadmium and lead levels (0.52±1.15mg/kg and 0.79±1.27mg/kg) exceeded the Ugandan Standard (US 738: 2019) and Codex Standard (CXS 193-1995) specifications of 0.1 mg/kg and 0.2mg/kg, respectively. OCPs including Aldrin, Endosulfan sulphate, 4, 4-DDE detected in imported rice were higher than the maximum residual limit (MRL) of Codex Alimentarius Commission. Heavy metal and OCP contamination of imported rice in Uganda may predispose rice consumers to toxicological risks. Handling and transit conditions for imported rice should be improved to reduce on aflatoxin contamination. Contamination of low land rice with heavy metals can be managed through enforcement of environmental laws that control wetland pollution. Continuous monitoring of heavy metals and OCPs in both local and imported rice is proposed to promote food safety and protect human health.
  • Item
    Studies on the safety of Obushera and probiotic potential of selected lactic acid bacteria
    ( 2019-10-22) Byakika, Stellah
    The rising demand for Obushera, a traditional fermented sorghum/millet beverage originally from south western Uganda, is increasing its commercialization in cities such as Kampala. Haphazard production is currently a trend owing to the lax enforcement of food safety regulations thus threatening consumer safety. This study examined bacterial and total aflatoxin contamination of Obushera in Kampala. The criteria and methods for probiotics screening were also reviewed. Consequently, the probiotic potentials of Obushera starters: Lactobacillus plantarum MNC 21, Lactococcus lactis MNC 24 and Weisella confusa MNC 20 with regard to improving the beverage‟s safety were examined. Lactobacillus rhamnosus yoba 2012, a known probiotic was the reference. Obushera (n=59), sorghum flour (n=20) and millet flour (n=20) were analyzed for E. coli, total and thermo-tolerant coliforms, staphylococci, Salmonella spp., molds and total aflatoxins. Data on processors‟ food safety knowledge, attitudes and practices (KAP) were collected using researcher administered questionnaires. Obushera had 0.0 – 7.3 log cfu/mL total and thermo-tolerant coliforms, 0.0 – 6.2 log cfu/mL E. coli, 0.0 – 8.1 log cfu/mL staphylococci, 2.0 – 5.5 log cfu/mL molds and 10.4 ± 6.1 ppb total aflatoxins. Flours had 3.2 – 7.3 log cfu/g total and thermo-tolerant coliforms, 1.0 – 4.9 log cfu/g E. coli, 2.4 – 7.3 log cfu/g staphylococci, 0.0 – 6.5 log cfu/g molds and 9.9 – 22.3 pp total aflatoxins. Salmonella spp. was undetected. Obushera samples (95%) had coliforms and staphylococci above the safety limits. Processors had fairly good knowledge (63.0% ± 2.3) and attitudes (52.2% ± 3.0) but fairly poor practices (38.7% ± 2.4). There was no association between the KAP and Obushera safety. Probiotics screening entails evaluation of isolates for tolerance to gastric conditions, safety and probiotic benefit. The starters tolerated pH=3, 1% bile and had Bile Salt Hydrolase activity. MNC 20 and MNC 21 produced agmatine. The three starters were: non mucolytic, resistant to 10 of the 21 antibiotics tested, slightly hydrophobic, autoagrgregative, co-aggregative and had ileal binding abilities. They were antagonistic against virulent, acid tolerant and antibiotic resistant E. coli isolated from Obushera. They bound 19.3 – 69.4% aflatoxin B1 in a solution spiked with 1000 ppb of the toxin. Binding efficiency was: yoba 2012 = MNC 21 > MNC 20 = MNC 24. Therefore, the starters could be used to improve Obushera safety whilst also improving health.
  • Item
    Toxicological risk associated with consumption of rice sold in Uganda
    (International Journal of Scientific Advances, 2021-11) Namubiru, Leatitiah ; Male, Denis ; Mukisa, Ivan Muzira ; Byaruhanga, Yusuf Byenkya
    Previous studies have reported the presence of aflatoxins (AFB1, AFB2, AFG1 and AFG2), heavy metals (As, Cd and Pb) and organochlorine pesticide residues (OCPs) in rice sold in Uganda. However, the potential health effects associated with consumption of rice have not been evaluated. The aim of this study was to evaluate the health risk of consuming rice sold in Uganda. A total of 45 packed and 30 open traded rice samples were randomly collected from retail outlets in the main rice trading areas of Uganda. Rice was analysed for AFB1, AFB2, AFG1 and AFG2, As, Cd, Pb and OCPs using AOAC standard methods. Dietary exposure of the consumers to contaminants was assessed using the estimated daily intake (EDI). The Hazard index (HI) and the incremental lifetime cancer risk (ILCR) were determined to define the non-carcinogenic and carcinogenic risk from contaminants, respectively. The potency of liver cancer cases in Uganda was 1.02E-5 and 1.05E-5 adults/year/100,000, and 6.50E-4 and 6.72E-5 infants /year/100,000 for open traded and packed rice, respectively. The values obtained for the ILCR for Arsenic detected in rice were 1.14E-2 and 7.28E-2 for adults and infants, respectively. The ILCR of all detected OCPs in adults and infants were higher than 1.0E-4, in both open traded and packed rice. This study established a potential carcinogenic risk from consumption of rice sold in Uganda in both infants and adults at the current level of contamination and consumption rate. Establishment of a monitoring system along the entire rice value chain; enforced by a national regulatory body can provide timely feedback on the levels of contamination and the progress in reducing the contamination burden.