Dietary Fat and Energy Content of Steeped, Germinated and Unprocessed Maize Grains Meant For Complementary Feeding In Nigeria

Household technologies such as fermentation, soaking, roasting and malting are traditionally used in many societies with the assumption that they can contribute to improving the safety and quality of complementary foods. To observe the dietary lipid quality, unprocessed, steeped and germinated maize grains were used to evaluate their effect on the enhancement of fatty acids, phospholipids and phytosterols. Maize samples were denoted as B1 (unprocessed) B2 (sprouted) and B3 (steeped) maize. In crude fat, B2 was enhanced by 0.47g/100g (9.23%). Calculated fatty acids had values (g/100g) of:B1(3.66)<B2(4.00)> B3(3.63). Highest levels of these fatty acids were observed as follows: SFA(B2, 27.2%), MUFA(B1,34.7%) and PUFA(B1,47.0%); but B3 was more concentrated in MUFA and PUFA than B2 but less than B1.Both oleic and linoleic fatty acids slightly increased during steeping stage of malting but later declined during germination phase particularly oleic acid. Total energy density (kcal/100g) concentration in the samples with the percentage linoleic acid had these values: B1(32.9, 43.7%), B2(36.0, 37.2%) and B3(32.7, 41.9%). Total phytosterol (mg/100g) values were low: B1(52.3), B2(43.7) and B3(45.1) with sitosterol predominating in all: 33.5 > 28.8 < 29.6 respectively. In phospholipids, values were generally higher than the phytosterols as we have total values (mg/100g) of: B1(74.4); B2(71.3) and B3(62.0) with phosphatidylinositol predominating in all samples: 25.5 > 25.1 > 22.4 respectively. Raw maize sample had highest concentration of phospholipids, phytosterols, MUFA and PUFA. The declines in B2 and B3 in the above parameters suggested that lipids were used for biochemical processes. However, B3 was better concentrated than B2 in phytosterols, MUFA, PUFA, linoleic and oleic acids. This showed germination reduced fat content due to hydrolysis and utilization of fat as an energy source in germination. Observations had depicted the contribution of maize to presence of high level phosphatidylinositol and sitosterol to the infant. It also contributed to information on discrepancies on the effect of fermentation/ germination on cereal lipids in literature. Either steeped or sprouted maize is good as complementary food.

Occurrence and Distribution of Aflatoxin in Maize from Selected Counties, Eastern Region, Kenya

Purpose: The study aimed to assess the occurrence and distribution of aflatoxin contamination on dry maize in different types of stores in Meru, Embu, Isiolo, Makueni and Machakos Counties of Eastern region of Kenya.Methodology: Automatic spear sampler was used to collect maize samples from each bag at even intervals. 280 maize samples were collected from 29 stores in five Counties. 100 g of each maize sample was ground, resampled into 50g, blended, extracted, centrifuged, filtered and a quantified for Aflatoxin B1, B2, G1 and G2. Samples were prepared and extracted with methanol/water. The bulky of the samples were analyzed with enzyme-linked immunoassay test kits. Confirmation of positive samples was done with high performance liquid chromatography (HPLC) coupled with fluorescence detector. Data analysis was done with SPSS and Microsoft excel.Findings: Maize samples from Counties in eastern region of Kenya had significantly high levels of (93.10%) aflatoxin contamination. The mean values for aflatoxin B1, B2, G1 and G2 were: 50.08± 4.42, 17.26±1.08, 30.17±2.06 and 10.54± 1.52 (ng/g) in that order. Only nine samples had total aflatoxin within the accepted limit for human consumption of 15 ng/g. The highest total aflatoxin contamination recorded was 198.45ng/g in Makueni county and the lowest recorded was 8.76ng/g in Embu county. Makueni and Embu had mean values for aflatoxin B1, B2, G1 and G2 being (83.07±7.53, 22.15± 1.36, 49.38±3.11, 20.52± 0.70 ng/g) and (18.71 ±2.63, 8.07 ±0.64, 17.02 ±1.38, 8.86 ±1.62 ng/g). Makueni NCPB depot had the highest mean contamination with aflatoxin B1 of 92.67± 5.78 ng/g and Embu had the lowest with 6.26 ± 4.14 ng/g. All the county markets recorded high aflatoxin B1 contamination with exception of Embu county which had a mean of 4.0 ±0.84, Makueni (83.67± 10.42 ng/g), Isiolo (51.27± 32.29 ng/g), Meru (46.02± 23.88 ng/g) and Machakos (36.34± 26.27 ng/g). The stores had aflatoxin load varied from on store to the other and county to county.Unique contribution to theory, policy and practice: The counties in the region had high occurrence and distribution of aflatoxin B1, B2, G1 and G2 in maize in all stores where samples were picked. Location for maize stores should be in areas with low levels of carbon dioxide because mycotoxins are produced under aerobic conditions. The design for maize threshing machines should not course shocks, breakage and cracks on maize grains to decrease chances of mycotoxins infestation during their storage.

Natural Occurrence of Deoxynivalenol and Its Acetylated Derivatives in Chinese Maize and Wheat Collected in 2017

Deoxynivalenol (DON), along with 3-acetyl-deoxynivalenol (3-ADON) and 15-acetyl-deoxynivalenol (15-ADON), occur in grains and cereal products and is often hazardous to humans and livestock. In this study, 579 wheat samples and 606 maize samples intended for consumption were collected from China in 2017 and analyzed to determine the co-occurrence of type-B trichothecenes (DON, 3-ADON, and 15-ADON). All the wheat samples tested positive for DON, while 99.83% of the maize samples were DON-positive with mean DON concentrations of 165.87 and 175.30 μg/kg, respectively. Per the Chinese standard limits for DON, 3.63% of wheat and 2.97% of the maize samples were above the maximum limit of 1000 μg/kg. The DON derivatives (3-ADON and 15-ADON) were less frequently found and were present at lower levels than DON in wheat. 3-ADON and 15-ADON had incidences of 13.53% and 76.40%, respectively, in maize. By analyzing the distribution ratio of DON and its derivatives in wheat and maize, DON (95.51%) was the predominant toxin detected in wheat samples, followed by 3.97% for the combination of DON + 3-ADON, while DON + 3-ADON + 15-ADON and DON + 15-ADON were only found in 0.17% and 0.35% of wheat samples, respectively. Additionally, a large amount of the maize samples were contaminated with DON + 15-ADON (64.19%) and DON (22.11%). The samples with a combination of DON + 3-ADON and DON + 3-ADON + 15-ADON accounted for 1.32% and 12.21%, respectively. Only one maize sample did not contain all three mycotoxins. Our study shows the necessity of raising awareness of the co-occurrence of mycotoxin contamination in grains from China to protect consumers from the risk of exposure to DON and its derivatives.

A 2019 STUDY ON TOTAL AFLATOXINS IN ROMANIAN MAIZE (ZEA MAYS L.) SAMPLES

Mycotoxin contamination represents a clear public health concern. In this context, a maize survey was conducted in Romania, to monitor the occurrence of total aflatoxins in maize samples collected during the 2019 growing season from fields located in all counties. A total of 95 maize samples were collected along with information regarding the specific location of fields, the applied agronomic practices and cropping systems. ELISA method was used for the quantification of AFs. The results showed 88 contaminated samples. Only one sample registered aflatoxin levels higher than the limit of 10.00 μg/kg, settled by the Commission Regulation (EC) No 1881/2006 for maize to be subjected to soring or other physical treatment before human consumption or use as an ingredient in foodstuffs. The highest AFs level was 77.59 μg/kg, noted by a maize sample from Argeș County (the South-Muntenia development region, macro region 3). When referring to the analysed samples, the total aflatoxin contamination was independent of the type of hybrid, but strongly influenced by the pedo-climatic differences between counties. The southern counties proved to represent critical risk areas for aflatoxin contamination when referring to maize crops. These results highlight the importance of an effective and sustainable mycotoxin management along the food and feed chain, as well as the need of mapping the mycotoxin risk areas.

Disinfestation of Sitophilus zeamais Motschulsky in stored maize using microwave

This study aimed primarily to investigate on disinfestation of maize weevil (Sitophilus zeamais Motschulsky) in maize storage by using microwave method. Specimens of Maize weevils were cultured for 30 days in a maize sample with 17% moisture content (wet basis). Several different life stages of the maize weevil (egg, young larva, old larva, pupa and adult) were then infested in the sample. Next, the maize sample was exposed to 200, 300 and 450 W of microwave power for 60, 120 and 180 s, and the number of weevils were counted after each treatment. Moreover, the sample was kept for another 2 months to see whether the eggs have survived the treatment and grown to be adults. In addition, the effects of the level of microwave power and exposure time on the property of the maize sample were observed. The quality parameters investigated were moisture content, colour and protein and fat contents. It was found that, at 300 W of power for 180 s, the microwave was able to disinfect weevils at all life stages successfully, while the quality of the maize sample did not change significantly at the tested microwave settings and exposure times, except for the protein content. These findings indicate that microwave can be a good alternative to harmful chemical methods for disinfestation of maize weevils.

Complete Genome Sequence of a New Maize-Associated Cytorhabdovirus

ABSTRACT A new 11,877-nucleotide cytorhabdovirus sequence with 6 open reading frames has been identified in a maize sample. It shares 50 and 51% genome-wide nucleotide sequence identity with northern cereal mosaic cytorhabdovirus and barley yellow striate mosaic cytorhabdovirus, respectively.

Characteristics of defensin1 gene and designing structure to create resistant transgenic corn lines to weevils

Plant defensins are multifunctional proteins, inhibiting the growth of fungal, anti-bacterial, altering membrane channels, inhibiting activity of trypsin and α-amylase. Plant defensin consists of 18 groups in which the group 1 includes defensins to inhibit either α-amylase enzyme or trypsin. Defensins bind to the active site of α-amylase in the weevil gut, thus inhibit starch digestion in weevils. In this report, we present the results of cloning and determining the ZmDEF1 gene sequence isolated from mRNA and DNA of Sonla province local maize and LVN99 hybrid maize cultivar. The coding region of ZmDEF1 gene isolated from some maize samples had the size of 243 nucleotides, encoding 80 amino acids. Gen ZmDEF1 isolated from DNA had the size 345bp consists of two exons and one in tron (102 bp). The nucleotide sequences of ZmDEF1 gene (DNA) of the samples have 6 positions nucleotide difference, on exon 1 has two points difference (position 43, 53), on intron has a difference (position 150), on exon 2 has 3 nucleotide site difference (203, 263 and 297 position). Deduced amino acid sequences of defensin of the Sonla local maize sample has 8 cysteines to make 4 disulfide bridges, while LVN99 hybrid maize has 7 cysteines, which can formed only 3 disulfide bridges. Transformation vector pBetaPhaso-ZmDEF1 has been designed successfully, in which ZmDEF1 is controlled by seed specific Phasoline promoter. The correct insertion and expression of ZmDEF1 was examinated in transgenic tobacco plants throught PCR and RT-PCR, respectively. These results provide an firm evident for using the designed transformation vector to produce transgenic maỉze lines with an improved resistant ability to weevils.

Determination of T-2 and HT-2 toxins from maize by direct analysis in real time mass spectrometry

Direct analysis in real time (DART) ionisation coupled to mass spectrometry (MS) was used for the rapid quantitative analysis of T-2 toxin (T-2) and the related HT-2 toxin (HT-2), extracted from maize. Sample preparation procedures and instrument parameters were optimised to obtain sensitive and accurate determination of the toxins. The lowest calibration levels were 50 μg/kg for T-2 and 300 μg/kg for HT-2. Quantitative analysis was performed with the use of matrix-matched standards employing the 13C-labelled internal standard for T-2. DART-MS of maize extracts spiked with T-2 gave a linear response over the range of 50-1000 μg/kg. With the isotope dilution technique, good recoveries (99-110%) and repeatabilities (relative standard deviaiton 7.4-11.6%) were obtained at T-2 spiking levels of 100 and 1000 μg/kg. Adaptability of the developed method was demonstrated by analysis of T-2 and HT-2 from an oat flour quality control material. The results here further indicate the potential for application of ambient ionisation mass spectrometry to provide accurate, convenient quantitation of mycotoxins from grains.