Molecular tagging of seed size using MITE markers in an induced large seed mutant with higher cotyledon cell size in groundnut

A large seed mutant, TG 89 having a 76.7% increment in hundred kernel weight in comparison to its parent TG 26, was isolated from an electron beam-induced mutagenized population. Studies based on environmental scanning electron microscopy of both parent and mutant revealed that the mutant seed cotyledon had significantly bigger cell size than parent. A mapping population with 122 F2 plants derived from the mutant and a distant normal seed genotype (ICGV 15007) was utilized to map the QTL associated with higher HKW. Bulk segregant analysis revealed putative association of three markers with this mutant large seed trait. Further, genotyping of F2 individuals with polymorphic markers detected 14 linkage groups with a map distance of 1053 cM. QTL analysis revealed a significant additive major QTL for the mutant large seed trait on linkage group A05 explaining 12.7% phenotypic variation for the seed size. This QTL was located between flanking markers AhTE333 and AhTE810 having a map interval of 4.7 cM which corresponds to 90.65 to 107.24 Mbp in A05 chromosome, respectively. Within this genomic fragment, an ortholog of the BIG SEEDS 1 gene was found at 102,476,137 bp. Real-time PCR revealed down-regulation of this BIG SEEDS 1 gene in the mutant indicating a loss of function mutation giving rise to a large seed phenotype. This QTL was validated in 11 advanced breeding lines having large seed size from this mutant but with varied genetic backgrounds. This validation showcased a highly promising selection accuracy of 90.9% for the marker-assisted selection.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03909-0.

Effects of high oleic acid peanuts on mice's liver and adipose tissue metabolic parameters and gut microbiota composition

This study aimed to investigate the effects of two types of peanuts, regular Hanoch (HN) and a new high-oleic cultivar., Hanoch-Oleic (HO), on metabolic parameters and gut microbiota composition. Male C57BL/6 mice were fed with a normal diet (ND) or ND supplemented with HN (NDh) or HO (NDo). Following 18 weeks of diet regimen, the NDo group exhibited reduced body weight and peri-gonadal adipose-to-body weight ratio, paralleled to lesser food consumption. Although blood levels of total cholesterol, HDL-cholesterol, free fatty acids, and liver enzyme levels did not differ between groups, decreased insulin sensitivity was found in the NDh group. Within adipose tissue, the expression of lipolytic and lipogenic enzymes was higher, while those related to lipid oxidation were lower in the NDh group compared to the NDo group. Additionally, HO peanuts consumption promoted the establishment of a healthy microbiota, with an enhanced abundance of Bifidobacterium, Lactobacillus, and Coprococcus genera. In conclusion, the inclusion of the HO peanut cultivar., rather than the conventional peanut cultivar., in a balanced diet was related to better metabolic outcomes and was linked to a favorable microbiota profile.

Prevalence of Aflatoxin Contamination in Peanuts and Peanut Butter from an Informal Market, Harare, Zimbabwe

Peanuts and peanut butter play an important role nutritionally in improving the diets of individuals in many parts of Africa, especially in the fight against child malnutrition. However, in developing countries such as Zimbabwe, most of the raw peanuts and peanut butter produced in backyard industries are sold in informal markets and rarely undergo formal safety inspection for aflatoxin contamination. The objective of the study was to determine the prevalence of aflatoxins in raw peanuts and backyard peanut butter sold at Mbare informal market. Ten (10) raw peanut samples and twenty (20) peanut butter samples were collected from Mbare informal market. Aflatoxin contamination was determined using liquid chromatography-mass spectrometry (LC-MS). The results revealed that sixty percent (60%) of the raw peanut samples were contaminated with total aflatoxin ranging from <0.75 to 426.4 μg/kg. One hundred percent (100%) of peanut butter samples were contaminated with total aflatoxins ranging from 4.7 μg/kg to 435.0 μg/kg. Aflatoxin B₁ was the most prevalent aflatoxin in both raw peanuts (range, 1.2 μg/kg to 90.8 μg/kg) and peanut butter (range, 4.7 to 382.9 μg/kg). Forty percent (40%) of the raw peanuts and 95% of peanut butter samples exceeded the maximum limits of AFB₁ as set by Zimbabwe legislation. The results suggest that raw peanuts and especially the peanut butter from backyard industries are heavily contaminated with aflatoxins and could constitute a possible health risk to consumers who regularly purchase these food commodities from informal markets.

Recent Advances for the Developing of Instant Flavor Peanut Powder: Generation and Challenges

Instant flavor peanut powder is a nutritional additive that can be added to foods to impart nutritional value and functional properties. Sensory acceptability is the premise of its development. Flavor is the most critical factor in sensory evaluation. The heat treatment involved in peanut processing is the main way to produce flavor substances and involves chemical reactions: Maillard reaction, caramelization reaction, and lipid oxidation reaction. Peanut is rich in protein, fat, amino acids, fatty acids, and unsaturated fatty acids, which participate in these reactions as volatile precursors. N-heterocyclic compounds, such as the pyrazine, are considered to be the key odorants of the “baking aroma”. However, heat treatment also affects the functional properties of peanut protein (especially solubility) and changes the nutritional value of the final product. In contrast, functional properties affect the behavior of proteins during processing and storage. Peanut protein modification is the current research hotspot in the field of deep processing of plant protein, which is an effective method to solve the protein denaturation caused by heat treatment. The review briefly describes the characterization and mechanism of peanut flavor during heat treatment combined with solubilization modification technology, proposing the possibility of using peanut meal as material to produce IFPP.

Global Warming and Toxicity Impacts: Peanuts in Georgia, USA Using Life Cycle Assessment

Fertilizers and pesticides have been widely used in agriculture production, causing polluted soil, water, and atmosphere. This study aims to quantify air emissions from pesticides and fertilizers applied for peanut production in Georgia during selected years (1991, 1999, 2004, 2013, and 2018). Specifically, the oral and dermal potential impacts from pesticide emissions and the global warming potential (GWP) impact from fertilizers to air were investigated. This study followed the ISO 14040 series standards for life cycle assessment (LCA) methodology to assess six active ingredients (AIs) (2,4-DB, Bentazon, Chlorothalonil, Ethalfluralin, Paraquat, and Pendimethalin) and one greenhouse gas (nitrous oxide N2O). Their physical and chemical characteristics and the temporal scales greatly influenced the oral and dermal toxicity impacts. According to the low values obtained for Henry’s law (KH) and vapor pressure (VP), 2,4-dichlorophenoxy butanoic (DB), Pendimethalin, and Chlorothalonil have a higher impact on the continental air scale. The effect factor (EF) from oral exposure was higher in 2,4-DB, Bentazon, and Pendimethalin than dermal exposure, according to the relatively low lethal dose (LD50) for oral exposure, while the EF of Ethalfluralin and Chlorothalonil was the same for oral and dermal exposure according to their similar LD50.

Tree Nuts and Peanuts as a Source of Beneficial Compounds and a Threat for Allergic Consumers: Overview on Methods for Their Detection in Complex Food Products

Consumption of tree nuts and peanuts has considerably increased over the last decades due to their nutritional composition and the content of beneficial compounds. On the other hand, such widespread consumption worldwide has also generated a growing incidence of allergy in the sensitive population. Allergy to nuts and peanuts represents a global relevant problem, especially due to the risk of the ingestion of hidden allergens as a result of cross-contamination between production lines at industrial level occurring during food manufacturing. The present review provides insights on peanuts, almonds, and four nut allergens—namely hazelnuts, walnuts, cashew, and pistachios—that are likely to cross-contaminate different food commodities. The paper aims at covering both the biochemical aspect linked to the identified allergenic proteins for each allergen category and the different methodological approaches developed for allergens detection and identification. Attention has been also paid to mass spectrometry methods and to current efforts of the scientific community to identify a harmonized approach for allergens quantification through the detection of allergen markers.

Cloning and Functional Characterization of a Pericarp Abundant Expression Promoter (AhGLP17-1P) From Peanut (Arachis hypogaea L.)

Peanut (Arachis hypogaea L.) is an important oil and food legume crop grown in tropical and subtropical areas of the world. As a geocarpic crop, it is affected by many soil-borne diseases and pathogens. The pericarp, an inedible part of the seed, acts as the first layer of defense against biotic and abiotic stresses. Pericarp promoters could drive the defense-related genes specific expression in pericarp for the defense application. Here, we identified a pericarp-abundant promoter (AhGLP17-1P) through microarray and transcriptome analysis. Besides the core promoter elements, several other important cis-elements were identified using online promoter analysis tools. Semiquantitative and qRT-PCR analyses validated that the AhGLP17-1 gene was specifically expressed only in the pericarp, and no expression was detected in leaves, stem, roots, flowers, gynophore/peg, testa, and embryo in peanut. Transgenic Arabidopsis plants showed strong GUS expression in siliques, while GUS staining was almost absent in remaining tissues, including roots, seedlings, leaf, stem, flowers, cotyledons, embryo, and seed coat confirmed its peanut expressions. Quantitative expression of the GUS gene also supported the GUS staining results. The results strongly suggest that this promoter can drive foreign genes’ expression in a pericarp-abundant manner. This is the first study on the functional characterization of the pericarp-abundant promoters in peanut. The results could provide practical significance to improve the resistance of peanut, and other crops for seed protection uses.

Genetic mapping and QTL analysis for peanut smut resistance

BACKGROUND

Peanut smut is a disease caused by the fungus Thecaphora frezii Carranza & Lindquist to which most commercial cultivars in South America are highly susceptible. It is responsible for severely decreased yield and no effective chemical treatment is available to date. However, smut resistance has been identified in wild Arachis species and further transferred to peanut elite cultivars. To identify the genome regions conferring smut resistance within a tetraploid genetic background, this study evaluated a RIL population {susceptible Arachis hypogaea subsp. hypogaea (JS17304-7-B) × resistant synthetic amphidiploid (JS1806) [A. correntina (K 11905) × A. cardenasii (KSSc 36015)] × A. batizocoi (K 9484)^4×} segregating for the trait.

RESULTS

A SNP based genetic map arranged into 21 linkage groups belonging to the 20 peanut chromosomes was constructed with 1819 markers, spanning a genetic distance of 2531.81 cM. Two consistent quantitative trait loci (QTLs) were identified qSmIA08 and qSmIA02/B02, located on chromosome A08 and A02/B02, respectively. The QTL qSmIA08 at 15.20 cM/5.03 Mbp explained 17.53% of the phenotypic variance, while qSmIA02/B02 at 4.0 cM/3.56 Mbp explained 9.06% of the phenotypic variance. The combined genotypic effects of both QTLs reduced smut incidence by 57% and were stable over the 3 years of evaluation. The genome regions containing the QTLs are rich in genes encoding proteins involved in plant defense, providing new insights into the genetic architecture of peanut smut resistance.

CONCLUSIONS

A major QTL and a minor QTL identified in this study provide new insights into the genetic architecture of peanut smut resistance that may aid in breeding new varieties resistant to peanut smut.

Allergenicity, antioxidant activity and ACE-inhibitory activity of protease hydrolyzed peanut flour

Regularly consuming peanuts has been reported to have many health benefits. Peanut flour, a by-product of peanut oil processing, has higher protein and dietary fiber contents than peanut kernels, but its application as protein source in foods and dietary supplement is limited due to the fear of peanut allergy. This study indicates that hydrolysis of peanut flour (12% lipid) up to 4 h with Alcalase lowered the immunoreactivity of both soluble and insoluble portions of peanut flour, generated peanut flour hydrolysate (PFH) with good in vitro antioxidant and ACE-inhibitory activities. Importantly, the fraction smaller than 5 kDa did not bind IgE of peanut allergic patients, but exhibited higher ACE-inhibitory activity than the crude PFH. Thus, peanut flour could be an inexpensive protein source of antioxidant and anti-hypertensive ingredient. These findings are important for the value added application of peanut flour. However, studies with food and animal/human models are needed to confirm the benefits.

Development and nutritional evaluation of local ingredients-based supplements to treat moderate acute malnutrition among children aged below five years: A descriptive study from rural Wolaita, Southern Ethiopia

In Ethiopia, moderate acute malnutrition (MAM) is a persistent public health problem. The current management approaches for MAM among children are counseling in food-secure settings and food supplementation in chronically food-insecure areas. The objective of this study was to develop a local ingredients-based supplement (LIBS) for treating MAM among children. Collection of food ingredients (pumpkin seed, amaranth grain, flaxseed, peanut, and emmer wheat) was made. Sorting, soaking, drying, roasting, and milling of ingredients were done. Nutrient analysis was done using triplicate measurements of each nutrient. One-way ANOVA was used to analyze differences in means with ± standard deviation of nutrient measurements among the supplements. The nutrient content of four developed LIBS ranged from 20.3 g to 22.5 g for protein, 29.3 g to 33.5 g for fat, 509.5 kcal to 570.0 for kcal, 6.0 g to 8.5 g for fiber, 2.8 g to 3.7 g for moisture, and 2.1 g to 4.3 g for ash. The mineral and antinutrient components ranged from 75.6 mg to 115.6 mg for calcium, 473.1 mg to 570.2 mg for potassium, 79.3 mg to 114.4 mg for sodium, 4.1 mg to 5.6 mg for zinc, 8.2 mg to 10.2 mg for iron, 442.6 mg to 470.4 mg for phosphorous, and 2.1 mg to 4.3 mg for phytate. The LIBS with the highest portion of pumpkin seed had significantly highest amounts of protein, fat, calories, iron, zinc, and potassium. The results found were within the recommended range of required nutrients for the treatment of children with MAM. Therefore, LIBS may be used for the management of children with MAM.

High oleic peanuts improve parameters leading to fatty liver development and change the microbiota in mice intestine

Background

Oleic-acid consumption can possibly prevent or delay metabolic diseases. In Israel, a Virginia-type peanut cultivar with a high content of oleic acid has been developed.

Objective

This study examined the effect of consuming high oleic peanuts (D7) on the development of fatty liver compared to the standard HN strain.

Design

The two peanut cultivars were added to normal diet (ND) and high-fat (HF) mouse diet. Male C57BL/6 mice were fed for 8 and 10 weeks on a 4% D7, 4% HN, or control diet. At the end of the experiments, blood and tissues were collected. Triglyceride, lipid levels, histology, and protein expression were examined. The diets’ effects on intestinal microbiota were also evaluated.

Results

Both D7 and HFD7 led to a reduction in plasma triglycerides. Lipids, triglycerides, and free fatty acids in the liver were low in diets containing D7. Additionally, CD36 expression decreased in the D7 group. Consumption of D7 led to higher Prevotella levels, and consumption of ND that contained HN or D7 led to a lower Firmicutes/Bacteroidetes ratio.

Conclusion

These findings suggest that consumption of peanuts high in oleic acid (D7) may have the potential to delay primary fatty liver symptoms.

Edible Nuts for Memory

Nuts hold prime significance throughout the world as they offer multiple health benefits owing to their highly nutritious profile. A number of scientific studies have demonstrated their actions against inflammation, oxidative damage, the aging process, as well as dementia or memory loss. However, only walnuts, followed by almonds, hazelnuts and pistachios, have shown promising results in empirical studies for memory improvements. So, the current review focuses on presenting hypotheses regarding anti-dementia property of nine different nuts: almond, walnut, pistachio, Brazil nut, peanut, pecans, cashew, hazelnut, and chestnut. The nutritious profile of nuts contains essential fats (mostly mono- and poly-unsaturated fatty acids), proteins (source for arginine, lysine and tryptophan), vitamins (riboflavin, folate, and various tocopherols), fibers, minerals (calcium, sodium, magnesium, phosphorus and potassium) and trace elements (copper, zinc, and selenium). Interestingly, the constituents of natural products, nuts being an excellent example, work synergistically and/or in a side-effect neutralizing manner. These latter properties can make nuts an alternate therapy for humankind to fight against memory loss.

Protein digestion of different protein sources using the INFOGEST static digestion model

In vitro digestion systems are valuable tools for understanding and monitoring the complex behavior of food degradation during digestion, thus proving to be good candidates for replacing in vivo assays. The aim of the present work was to study protein hydrolysis in a selection of different protein sources using the harmonized INFOGEST static protocol: three isolated proteins (collagen, zein, and whey protein) and five foods (sorghum flour, wheat bran cereals, peanuts, black beans, and pigeon peas). The proteins of all the substrates were analyzed by SDS-PAGE and HPLC-MS/MS. Individual amino acid composition was analyzed by high-performance liquid chromatography (HPLC). EAA/NEAA (essential amino acids/ nonessential amino acids) ratios in the substrates from low to high were as follows: wheat bran cereals, peanuts, collagen, zein, whey protein, sorghum, pigeon peas, and black beans. The results revealed sorghum, whey protein, and zein as good sources of BCAA. In all substrates, no intact protein from the substrates was visually detected by SDS-PAGE after the intestinal phase of in vitro digestion with the INFOGEST protocol. However, digestion-resistant peptides were detected in all substrates after the intestinal digestion phase. Protein hydrolysis was high in whey protein isolate and pigeon pea and low for wheat bran cereals and bovine collagen.

Effect of Physiochemical Factors and Peanut Varieties on the Charge Stability of Oil Bodies Extracted by Aqueous Method

In order to explore the scientific basis for the application of oil bodies (OBs) from different peanut varieties in food, the effect of NaCl (0-100 mM), thermal processing (25-45°C, 1 h) and pH (3.0, 7.4, and 9.0) on their zeta potentials was analyzed in this study. The zeta potentials of OB suspensions (in 10 mM phosphate buffer) prepared from five peanut varieties in different salt concentrations (0-100 mM) were positive at pH 3.0, while they remained negative at pH 7.4 and 9.0. The absolute values of zeta potentials were over 20 mV at a lower salt concentration (< 10 mM NaCl) at pH 3.0 and 7.4. Particularly, the values of zeta potentials of Yuhua27 and Yuhua9830 were as high as 40 mV in the absence of NaCl at pH 7.4. The OBs exhibited diverse change trends between the five peanut varieties in the temperatures from 25 to 45°C (0 mM NaCl, pH 7.4). The OBs from Yuhua9830 exhibited the best thermal adaptability at the different temperatures tested than the other four peanut varieties. These outcomes suggested that OBs extracted from different varieties possess diverse properties and may provide a new insight into choosing a suitable peanut variety for the food industry.

Major QTLs for Resistance to Early and Late Leaf Spot Diseases Are Identified on Chromosomes 3 and 5 in Peanut (Arachis hypogaea)

Early and late leaf spots (LLSs) are the major foliar diseases of peanut responsible for severely decreased yield in the absence of intensive fungicide spray programs. Pyramiding host resistance to leaf spots in elite cultivars is a sustainable solution to mitigate the diseases. In order to determine the genetic control of leaf spot disease resistance in peanut, a recombinant inbred line population (Florida-07 × GP-NC WS16) segregating for resistance to both diseases was used to construct a SNP-based linkage map consisting of 855 loci. QTL mapping revealed three resistance QTLs for LLS qLLSA05 (phenotypic variation explained, PVE = 7-10%), qLLSB03 (PVE = 5-7%), and qLLSB05 (PVE = 15-41%) that were consistently expressed over multi-year analysis. Two QTL, qLLSA05 and qLLSB05, confirmed our previously published QTL-seq results. For early leaf spot, three resistance QTLs were identified in multiple years, two on chromosome A03 (PVE = 8-12%) and one on chromosome B03 (PVE = 13-20%), with the locus qELSA03_1.1 coinciding with the previously published genomic region for LLS resistance in GPBD4. Comparative analysis of the genomic regions spanning the QTLs suggests that resistance to early and LLSs are largely genetically independent. In addition, QTL analysis on yield showed that the presence of resistance allele in qLLSB03 and qLLSB05 loci might result in protection from yield loss caused by LLS disease damage. Finally, post hoc analysis of the RIL subpopulation that was not utilized in the QTL mapping revealed that the flanking markers for these QTLs can successfully select for resistant and susceptible lines, confirming the effectiveness of pyramiding these resistance loci to improve host-plant resistance in peanut breeding programs using marker-assisted selection.

A comprehensive review of the value-added uses of peanut (Arachis hypogaea) skins and by-products

Globally, peanut seeds are grown for oil production, peanut butter, confections, snacks and protein extenders, leaving the peanut by-products (skins, peanut hulls) as waste for disposal. Numerous studies have identified the value added attributes of peanut skins and/or peanut skin extracts as an antioxidant, functional food ingredient, animal production feed ingredient, and antimicrobial agent. This manuscript presents a comprehensive review of the food and non-food uses of peanut skins and/or extracts, and new uses of this significant agricultural waste product produced in the peanut industry. An improved comprehensive knowledge and better understanding of the value added uses of peanut skins enables us to better define future food and non-food uses of this agricultural by-product.

Peanuts, Aflatoxins and Undernutrition in Children in Sub-Saharan Africa

Peanuts (Arachis hypogaea) is an important and affordable source of protein in most of Sub-Saharan Africa (SSA) and a popular commodity and raw material for peanut butter, paste and cooking oil. It is a popular ingredient for foods used at the point of weaning infants from mother's milk. It is at this critical point that childhood undernutrition occurs and the condition manifests as stunting, wasting and growth restriction and accounts for nearly half of all deaths in children under five years of age in SSA. Undernutrition is multi-factorial but weaning foods contaminated with microbiological agents (bacteria and fungi) and natural toxins have been shown to play a big part. While peanuts may provide good nutrition, they are also highly prone to contamination with mycotoxigenic fungi. The high nutritive value of peanuts makes them a perfect substrate for fungal growth and potential aflatoxin contamination. Aflatoxins are highly carcinogenic and mutagenic mycotoxins. This article reviews the nutritional value and aflatoxin contamination of peanuts, the role they play in the development of childhood malnutrition (including the different theories of aetiology) and immunological problems in children. We also discuss the control strategies that have been explored and advocacy work currently taking shape in Africa to create more awareness of aflatoxins and thus combat their occurrence with the goal of reducing exposure and enhancing trade and food safety.

Plant-based milk alternatives an emerging segment of functional beverages: a review

Plant-based or non-dairy milk alternative is the fast growing segment in newer food product development category of functional and specialty beverage across the globe. Nowadays, cow milk allergy, lactose intolerance, calorie concern and prevalence of hypercholesterolemia, more preference to vegan diets has influenced consumers towards choosing cow milk alternatives. Plant-based milk alternatives are a rising trend, which can serve as an inexpensive alternate to poor economic group of developing countries and in places, where cow's milk supply is insufficient. Though numerous types of innovative food beverages from plant sources are being exploited for cow milk alternative, many of these faces some/any type of technological issues; either related to processing or preservation. Majority of these milk alternatives lack nutritional balance when compared to bovine milk, however they contain functionally active components with health promoting properties which attracts health conscious consumers. In case of legume based milk alternatives, sensory acceptability is a major limiting factor for its wide popularity. New and advanced non-thermal processing technologies such as ultra high temperature treatment, ultra high pressure homogenization, pulsed electric field processing are being researched for tackling the problems related to increase of shelf life, emulsion stability, nutritional completeness and sensory acceptability of the final product. Concerted research efforts are required in coming years in functional beverages segment to prepare tailor-made newer products which are palatable as well as nutritionally adequate.

Voluntary fortification of breakfast cereals with folic acid: contribution to dietary intake in Australia

Ready-to-eat breakfast cereals have been voluntarily fortified with folic acid since 1995, with the purpose of reducing the prevalence of neural tube defects in utero. Using data from the recent Australian Health Survey, this study aimed to estimate folate intake from one serving of breakfast cereals (median amount). Various commercial brands were purchased in 2002 (n = 19) and in 2014 (n = 14); folate was determined by microbiological assay and high-pressure liquid chromatography (HPLC). Total folate (μg/100 g) in 2002 and 2014 selections were 144-633 and 147-564, respectively, and mostly comparable to nutrition labels. Folic acid (2014 selection) using HPLC, ranged from 85 to 411 μg/100 g. Intake of 51 g cereals/serving by individuals ≥ 2 years could contribute 75-288 μg dietary folate equivalent. It seems that folic acid intake among children (2-3 years) exceeds the recommended dietary intake, when certain brands of breakfast cereals are consumed. Accordingly, the benefits and potential detrimental effects of the voluntary fortification need to be further explored.

Natural occurrence of aflatoxins in peanuts and peanut butter from Bulawayo, Zimbabwe

Mycotoxins are toxic secondary metabolites produced by filamentous fungi that may contaminate food and pose a health risk, especially in developing countries, where there is a lack of food security and quality is subsumed by food insufficiency. Aflatoxins are the most toxic known mycotoxins and are a significant risk factor for liver and kidney cancer, teratogenicity, undernutrition, and micronutrient malabsorption in both humans and animals. The main aim of the study was to determine the extent of fungal and aflatoxin contamination in peanuts and peanut butter being sold in both the formal and informal markets in Bulawayo, Zimbabwe. Eighteen peanut samples and 11 peanut butter samples were purchased from retail shops and the informal market. Fungal contamination was determined using standard mycology culture methods, while aflatoxin contamination was determined using high-performance liquid chromatography-fluorescence detection. Four of the six peanut samples tested for fungal contamination were infected with Aspergillus flavus/parasiticus, ranging from 3 to 20% of the kernels examined, while 27% (3 of 11) of the peanut butter samples were infected with A. flavus/parasiticus. Ninety-one percent (10 of 11) of the peanut butter samples were contaminated with aflatoxins (mean, 75.66 ng/g, and range, 6.1 to 247 ng/g), and aflatoxin B1 was the most prevalent (mean, 51.0 ng/g, and range, 3.7 to 191 ng/g). Three of the 18 peanut samples were contaminated with aflatoxins (range, 6.6 to 622 ng/g). The commercial peanut butter samples had very high aflatoxin levels, and manufacturers should be sensitized to the detrimental effects of aflatoxins and measures to reduce contamination.