scholarly journals Development of ic-Elisa for the screening of aflatoxin contamination in the peanut production chain

2018 ◽  
Vol 53 (3) ◽  
pp. 361-370
Author(s):  
André Ribeiro da Silva ◽  
Lívia Montanheiro Médici Zanin ◽  
Angélica Tieme Ishikawa ◽  
Cassia Reika Takabayashi Yamashita ◽  
Felipe Pedote Fracalossi ◽  
...  

Abstract: The objective of this work was to standardize and validate an indirect competitive enzyme-linked immunosorbent assay (ic-Elisa), as a low-cost tool, to monitor the presence of aflatoxin in common and blanched peanuts (Arachis hypogaea) in the production chain. The presence of aflatoxin B1, moisture content, and water activity were analyzed in 60 samples of the peanut cultivar Runner IAC 886, from the 2014/2015 and 2015/2016 harvests of the region of Alta Paulista, in the state of São Paulo, Brazil. The validation showed an adequate linearity (R2 = 0.999), and limits of detection and quantification of 1.13 and 3.59 μg kg-1, respectively. Recovery rates of 104, 102, and 107% at the concentrations of 4, 10, and 20 μg kg-1 aflatoxin B1, respectively, were also recorded. The ic-Elisa showed a good reproducibility with a high-intraday precision, with 1.87% coefficient of variation (CV), and interday precision with 6.75% CV. The moisture content ranged from 4.0 to 7.2% (mean of 5.8%), and the water activity from 0.4848 to 0.6997 (mean of 0.5990) for the tested samples. Aflatoxin B1 was present in concentrations ranging from 1.13 to 29.2 μg kg-1, with only two samples (3.3%) exceeding the maximum allowed limit of 20 μg kg-1. The ic-ELISA developed here is an accessible tool for the rapid monitoring of aflatoxin contamination in the peanut production chain.

2016 ◽  
Vol 79 (5) ◽  
pp. 795-800 ◽  
Author(s):  
SAMUEL M. C. NJOROGE ◽  
LIMBIKANI MATUMBA ◽  
KENNEDY KANENGA ◽  
MOSES SIAMBI ◽  
FARID WALIYAR ◽  
...  

ABSTRACT A 3-year comprehensive analysis of aflatoxin contamination in peanut butter was conducted in Zambia, sub-Saharan Africa. The study analyzed 954 containers of 24 local and imported peanut butter brands collected from shops in Chipata, Mambwe, Petauke, Katete, and Nyimba districts and also in Lusaka from 2012 to 2014. For analysis, a sample included six containers of a single brand, from the same processing batch number and the same shop. Each container was quantitatively analyzed for aflatoxin B1 (AFB1) in six replicates by using competitive enzyme-linked immunosorbent assay; thus, aflatoxin contamination level of a given sample was derived from an average of 36 test values. Results showed that 73% of the brands tested in 2012 were contaminated with AFB1 levels >20 μg/kg and ranged up to 130 μg/kg. In 2013, 80% of the brands were contaminated with AFB1 levels >20 μg/kg and ranged up to 10,740 μg/kg. Compared with brand data from 2012 and 2013, fewer brands in 2014, i.e., 53%, had aflatoxin B1 levels >20 μg/kg and ranged up to 1,000 μg/kg. Of the eight brands tested repeatedly across the 3-year period, none consistently averaged ≤20 μg/kg. Our survey clearly demonstrates the regular occurrence of high levels of AF B1 in peanut butter in Zambia. Considering that some of the brands tested originated from neighboring countries such as Malawi, Zimbabwe, and South Africa, the current findings provide a sub-Saharan regional perspective regarding the safety of peanut butter.


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 16 (3) ◽  
pp. 403-409
Author(s):  
Fardin Javanmardi ◽  
Mir-Michael Mousavi ◽  
Afsaneh T. Ghazani ◽  
Mansour Mahmoudpour ◽  
Faran Taram ◽  
...  

Background: As the main sweetener in sponge cakes, sucrose provides not only energy and structure, but also acts as a stabilizer and tenderizer. Due to its high-calorie content, alternative sweeteners such as xylitol and maltitol are used in its place. Objective: The purpose of this study is to substitute sugar with xylitol and maltitol in sponge cake. Methods: In this study, the possibility of producing sugar free sponge cakes with xylitol and maltitol was evaluated (control: 100% sucrose, M1: 100% xylitol, M2: 75% xylitol-25% maltitol, M3: 50% xylitol-50% maltitol and M4: 25% xylitol- 75% maltitol). Sensory evaluations and physicochemical properties of the final product such as water activity, moisture content, firmness, cake volume, crust color and sensory analyses were determined. Results: Based on the results obtained from the four samples, M3 and M4 resulted in a significant decrease in volume. The highest specific volume was obtained in M2. The last two samples, M1 and M2 showed lower water activity than the control. In addition, the highest dark crust color was obtained in M1. M2 produced a softer texture and thus produced cakes with the highest flavor. Conclusion: The results of the study showed that complete substitution of sucrose with 75% xylitol and 25% maltitol (M2) produced samples with similar crust color, firmness, volume and porosity in comparison with control cakes.


2021 ◽  
Vol 21` (01) ◽  
pp. 17178-17194
Author(s):  
T Tsehaynesh ◽  
◽  
Mohammed Abdi ◽  
S Hassen ◽  
W Taye ◽  
...  

Pepper (Capsicum annuum L.) is an important spice and source of income for smallholder producers in Ethiopia. Since the larger proportion is for the market, it takes a significant share of the national income from export commodity. However, often the product was rejected by some of the European Union markets due to the maximum aflatoxin level accumulations beyond their acceptable limits. So, the present study was carried out to highlight the importance of Aspergillus species invasion in pepper, and levels of aflatoxin contamination at maturity in the field (pod form), farmers' storage and local market (powder form)in West Gojjam, Ethiopia. A total of 135 pepper samples were collected from three districts of West Gojjam(Burie, Jabitehnan, and Fnoteselam), Ethiopia for fungal and aflatoxin analysis.The producers used a pre-validated structured questionnaire to obtain information on pepper production practices. Aspergillus species isolates were recovered using potato dextrose agar (PDA) medium and counting was through dilution method (cfu g-1). The pepper pods were ground to a fine powder for aflatoxin analysis using Enzyme-Linked Immunosorbent Assay(ELISA). The prevalence of infected samples revealed that, pre-harvest samples(51%) were less infected by Aspergillus species, compared to local markets (65 %) and storage (79 %).Aspergillus flavus species were recovered in pre-harvest samples, whilst A.niger were found in local market samples. Aflatoxin contamination at pre-harvest, storage, and local market were 10, 47, and 42 % with levels which ranged from non-detected to 10.6, 0.3 -17.1 and 3.1 -19.2 ppb, respectively.The mean aflatoxin concentration detected from storage samples (10.6 ppb)and local market (12.6 ppb)were found to be above the tolerable limits set byEU (5 ppb) in pepper products.From the findings in this study, proper drying, physical separation of molded pods and use of clean storage structures should be implemented along the production chain in order to reduce aflatoxin contamination in pepper in Ethiopia.


2017 ◽  
Vol 7 (1) ◽  
pp. 976-985
Author(s):  
Rhoda N. Kuisa ◽  
Josphert N. Kimatu ◽  
Titus I. Kanui

There are factors that contribute to aflatoxin contamination like conducive ecological zones, stressed crops, virulent Aspergillus strains and unconventional agricultural practices. Kenyans especially in the South-Eastern region are exposed to regular doses of mycotoxins. Even after campaigns on aflatoxin mitigation in 2004, this region has had continuous cases of aflatoxin poisoning. These have not been systematically studied to identify the key entry points and contributory factors. This research was instituted to evaluate the farmers perception of the factors which contribute to chronic aflatoxin contamination in maize grains along the pre-harvest, post-harvest and marketing stages of the production chain. We studied the moisture content of maize on seven major highway centers and found that the maize was largely within the accepted levels of moisture of 11-14%.  The agri-practices investigated showed that most farmers knew the basic standard practices but were not consistent in adhering to them. We found 88%approved that close spacing of maize can stress crop, 87% agreed that poor farm plant nutrition causes stress, 78 % agreed that plant residue act as reservoirsfor fungi. It was remarkable that 95 % of farmers agreed that delayed harvesting and storing of grains when the moisture content is more than 13% encouraged growth of the fungus was the main contributor of aflatoxin contamination. Furthermore, 91% indicated that, if maize combs were dropped on the soil during harvest, it increased the chances of fungal contamination. 80% of farmers agreed that the use of plastic bags to store maize in combs after harvesting could cause contamination. However, most farmers could not adequately relate contamination with the health repercussions of aflatoxin contamination. Hence, there is need to train and constantly contact understandable-sensitizations of all stakeholders; farmers, extension staff, researchers, traders, consumers, on the dangers of aflatoxin contamination along the whole maize production chain.


2008 ◽  
Vol 35 (2) ◽  
pp. 77-80 ◽  
Author(s):  
J. W. Dorner

Abstract The water activity (aw) and kernel moisture content (KMC) of individual Florunner cv. peanut kernels representing five different maturity stages were measured during a period of late-season drought stress leading up to normal harvest time. Curves were generated describing the relationship between aw and KMC for yellow 1, yellow 2, orange, brown, and black maturity stages as determined by the peanut hull scrape method. As peanuts matured, the KMC for a given aw decreased. KMC in the most immature yellow 1 stage was extremely variable at higher aw levels, indicative of the rapidly changing composition of kernels at that stage. The variation in KMC at high aw decreased with increasing maturity. Equations to predict KMC for given aw showed that KMC varied greatly among maturity stages, particularly at higher aw. For example, at an aw of 0.99 the predicted KMCs for yellow 1 (least mature) and black (most mature) stages were 62.7 and 30.7%, respectively. The degree of variation among stages decreased as aw decreased in response to drought stress. Because preharvest aflatoxin contamination of peanuts is highly dependent on both the maturity stage of peanuts during periods of late-season drought stress and the resulting aw of kernels, these KMC-aw relationships can be utilized in efforts to breed peanuts for reduced susceptibility to aflatoxin contamination by focusing on genotypes that can maintain higher water activities during such late-season drought periods.


2007 ◽  
Vol 70 (12) ◽  
pp. 2824-2828 ◽  
Author(s):  
HYUN EE OK ◽  
HYUN JUNG KIM ◽  
WON BO SHIM ◽  
HYOMIN LEE ◽  
DONG-HO BAE ◽  
...  

Aflatoxin B1 (AFB1) is an unavoidable food contaminant. To evaluate the potential health risk of AFB1 to Koreans posed by food consumption, we determined the natural occurrence of AFB1 in food and estimated the excess risk for liver cancer through dietary exposure to AFB1. A total of 694 food samples collected from six different regions of South Korea were analyzed for their AFB1 content. One hundred four of the 694 samples were found to give positive enzyme-linked immunosorbent assay (ELISA) readings for AFB1 and were further investigated with high-performance liquid chromatography. Thirty-two samples, including 2 maize samples, 3 soybean products, 20 peanut samples, nut samples, and their products, and 7 spices, were found to be contaminated with AFB1 (4.6% incidence), up to 48.6 μgkg−1. The level of AFB1 contamination in 28 of the 32 food products was below 10 μgkg−1, which is the legal tolerance limit in Korea. From data on daily food consumption, the exposure dose of AFB1 was estimated to be 6.42 × 10−7 mg kg−1 body weight (bw) day−1. The major contributors to the dietary intake of AFB1 were soybean paste and soy sauce, which composed 91% of the total exposure to AFB1. The excess risk of liver cancer for those exposed to AFB1 through food intake was estimated to be 5.78 × 10−6 for hepatitis B–negative individuals and 1.48 × 10−4 for hepatitis B–positive individuals. These results suggest that special consideration is required to reduce the intake of AFB1 in hepatitis B–positive individuals.


2019 ◽  
Vol 35 (1) ◽  
pp. 75-78 ◽  
Author(s):  
Mahbuba Akter Lubna ◽  
Mita Debnath ◽  
Farzana Hossaini

Current study investigated the occurrence of aflatoxin contamination in poultry feed and feed materials in different poultry farms and feed factories in Bangladesh. A total of 100 samples of finished feed and raw feed materials were collected and tested through direct competitive Enzyme-Linked Immunosorbent Assay (ELISA) for total aflatoxin detection. Overall, 97% samples (n=97/100) in our study, were found positive for aflatoxin contamination. Among finished feed categories, layer grower feed contained highest level of aflatoxin with a mean value of 21.64 ppb whereas layer feed was less susceptible for aflatoxin contamination (mean value 9.49 ppb). Between raw feed materials, maize samples were highly contaminated (n=15/15, 100%) with aflatoxin while 86.67% soybean samples showed positive result. Twenty one percent (21%) of the samples in our study contained aflatoxin concentration more than the acceptable limit employed by USFDA and many other countries which might pose severe health risk to poultry and human consumer. Proper surveillance and immediate control measures should be taken to ensure safe poultry feed and feed materials. Bangladesh J Microbiol, Volume 35 Number 1 June 2018, pp 75-78


2020 ◽  
Vol 58 (11) ◽  
pp. 1857-1864
Author(s):  
Elisa M. Castells ◽  
Aramis Sánchez ◽  
Amarilys Frómeta ◽  
Yanin Mokdse ◽  
Nelson Ozunas ◽  
...  

AbstractBackgroundIn Cuba, no screening program for cystic fibrosis (CF) has been implemented yet. The ultramicro enzyme-linked immunosorbent assay (UMELISA)® TIR NEONATAL has been developed for the measurement of immunoreactive trypsin (IRT) in dried blood spots on filter paper. The analytical performance of the kit was evaluated in the national network of laboratories.MethodsNewborn dried blood samples (DBS) were evaluated in 16 laboratories. An IRT/IRT/DNA protocol was followed using a cut-off value of 50 ng/mL. The mean, median and percentiles of the distribution were calculated and a two-sample t-test with unequal variance was used for statistical analysis. Influence of perinatal factors on IRT levels was analyzed.ResultsFrom January to June 2018, 6470 newborns were studied, obtaining a mean IRT value of 12.09 ng/mL (ranging 0–358 ng/mL) and a median of 8.99 ng/mL. Fifty-two samples (0.78%) were above the cut-off level and 16 samples (0.24%) were elevated in the re-screening process. One of them was confirmed positive by molecular biology (phe508del/c.3120 + 1G > A), constituting the first newborn screened and diagnosed early in Cuba. Second DBS samples were collected on average at 14 days and processed in the laboratory at 16 days of birth. Significant differences were observed (p < 0.05) when evaluating the influence of gender, birth weight (BW) and gestational age (GA) on the IRT values. Lower IRT concentrations were found in samples processed after 10 days of collection.ConclusionsThe performance of UMELISA® TIR NEONATAL in the laboratories has been satisfactory; hence CF newborn screening (NBS) was extended throughout the country from January 2019.


Foods ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 5
Author(s):  
Paola Littardi ◽  
Massimiliano Rinaldi ◽  
Maria Grimaldi ◽  
Antonella Cavazza ◽  
Emma Chiavaro

Green coffee parchment (GCP) is becoming interesting, due to the diffusion of wet processing in which coffee parchment is collected separately; it is one of the less studied coffee by-products, but it is reported to be rich in phenolic compounds and dietary fiber. The addition of GCP (355–500 μm) at 2 % to gluten-free breads was investigated in terms of physical properties (volume, moisture content, water activity, crumb grain, texture, and color), total antioxidant capacity (TAC) and total phenol content during three days of storage. Moreover, the effects of GCP on sensorial characteristics, 5-hydroxymethylfurfural (HMF), and oxidative stability was evaluated. From the sensorial analysis, bread with 2% addition resulted in being acceptable for consumers with no significant differences from the control, while 4% of GCP was discarded by consumers, as it resulted in being too bitter. Moreover, GCP at 2% addition did not modify volume, moisture content, and water activity. On the contrary, GCP deeply affected the color with a darker aspect that was appreciated by consumers. Regarding texture, 2% of GCP did not affect hardness, cohesiveness, and staling process during storage. Interestingly, 2% of GCP significantly improved the TAC and oxidative stability of the bread; in accordance with these results, 2% of GCP reduced the HMF content, thanks to its antioxidant compounds.


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