Browsing by Author "Kamala, Analice"

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Impact of local pre-harvest management practices in maize on the occurrence of Fusarium species and associated mycotoxins in two agro-ecosystems in Tanzania
(2016) Madege, Richard Raphael; Kamala, Analice; Audenaert, Kris; Ortiz Ulloa, Silvia Johana; Kimanya, Martin Epafras; De Meulenaer, Bruno; Degraeve, Szanne; Tiisekwa, Bendantunguka P.M.; Haesaert, Geert Jozej Willem
Knowledge on the presence of mycotoxins in Africa is fragmentary, although it can be assumed that both concentrations and prevalence in food commodities is high. The present study focuses on the presence of Fusarium species and their associated mycotoxins in maize from two geographically distant agro ecological systems in Tanzania. In a two-year survey, both Fusarium species and concomitant mycotoxins were surveyed in the Northern highlands (Hanang district) and the Eastern lowlands (Kilosa district). Parallel with this, a questionnaire on agricultural practices in both agro-ecosystems was included in this study. This allowed us to put the presence of the toxigenic Fusarium species and their mycotoxins within a relevant agricultural framework. Fusarium verticillioides, Fusarium graminearum and Fusarium poae were the predominant species in both locations although the population in the Eastern lowlands was slightly more complex comprising also Fusarium culmorum, Fusarium avenaceum and Fusarium sporotrichioides. The predominant presence of F. verticillioides resulted in a high prevalence of fumonisins in both regions. The importance of F. graminearum in the population was reflected by the presence of deoxynivalenol in the mycotoxin analysis. Although the agricultural practices differed significantly amongst both locations, only few significant correlations were detected between mycotoxin presence and crop rotation, storage conditions, and insect control measures.
Multiple mycotoxin co-occurrence in maize grown in three agro-ecological zones of Tanzania
(2015) Kimanya, Martin Epafras; De Meulenaer, Bruno; Tiisekwa, Bendantunguka P.m.; Kamala, Analice; Ortiz Ulloa, Silvia Johana; Haesaert, Geert Jozej willem; Donoso Moscoso, Silvana Patricia
In this study, the co-occurrence of multiple mycotoxins in maize kernels collected from 300 households' stores in three agro-ecological zones in Tanzania was evaluated by using ultra high performance liquid chromatography/time-of-flight mass spectrometry (TOFMS) with a QuEChERS-based procedure as sample treatment. This method was validated for the analysis of the main eleven mycotoxins of health concern that can occur in maize: aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2), ochratoxin A (OTA), deoxynivalenol (DON), fumonisin B1 (FB1), fumonisin B2 (FB2), HT-2 toxin, T-2 toxin and zearalenone (ZEN). From each zone one major maize producing district for home consumption was chosen and 20 villages for each district were randomly selected for sampling. All mycotoxins of health concern, except for T-2 toxin, were detected in the maize samples. Particularly high levels of AFB1 (50%; 3e1,081 mg kg 1 ), FB1 (73%; 16e18,184 mg kg 1 ), FB2 (48%; 178e38,217 mg kg 1 ) and DON (63%; 68 e2,196 mg kg 1 ) were observed. Some samples exceeded the maximum limits set in Tanzania for aflatoxins or in European regulations for other mycotoxins in unprocessed maize. Eighty seven percent of samples were contaminated with more than one mycotoxin, with 45% of samples co-contaminated by carcinogenic mycotoxins, aflatoxins and fumonisins. Significant differences in contamination pattern were observed among the three agro-ecological zones. The high incidence and at high levels (for some) of these mycotoxins in maize may have serious implications on the health of the consumers since maize constitute the staple food of most Tanzanian population. Effective strategies targeting more than one mycotoxin are encouraged to reduce contamination of maize with mycotoxins.
Risk of exposure to multiple mycotoxins from maize based complementary foods in Tanzania
(2016) Tiisekwa, Bendantuguka
This study estimated exposure to multiple mycotoxins in 249 infants aged between 6 and 12 months in three agroecological zones of Tanzania. Maize-based complementary food intakes were estimated using two 24 h dietary recalls. Using @ Risk software, probabilistic exposure assessment was conducted by modeling maize intake data (kg/kg body weight/day) with previously determined multiple mycotoxin (except for ochratoxin A (OTA) and zearalenone (ZEA), present in only a few samples) contamination data (μg/kg) in maize. Maize intakes ranged from 0.13 to 185 g/child/day (average = 59 ± 36 g/child/ day). The estimated mean exposures were higher for aflatoxins (6-fold), fumonisins (3-fold), and deoxynivalenol (2-fold) than health-based guidance values of 0.017 ng/kg body weight/day, 2 μg/kg body weight/day, and 1 μg/kg body weight/day, respectively. The population at risk of exposures above the limits of health concern ranged from 12% for HT-2 toxin through 35% for deoxynivalenol to 100% for aflatoxins. The exposure varied among the agro-ecological zones. Strategies targeting multiple mycotoxins in maize are urgently needed to minimize exposures in Tanzania