New tools to screen wild peanut species for aflatoxin accumulation and genetic fingerprinting.
BACKGROUND: Aflatoxin contamination in peanut seeds is still a serious problem for the industry and human health. No stable aflatoxin resistant cultivars have yet been produced, and given the narrow genetic background of cultivated peanuts, wild species became an important source of genetic diversity. Wild peanut seeds, however, are not abundant, thus, an effective method of screening for aflatoxin accumulation using minimal seeds is highly desirable. In addition, keeping record of genetic fingerprinting of each accession would be very useful for breeding programs and for the identification of accessions within germplasm collections. RESULTS: In this study, we report a method of screening for aflatoxin accumulation that is applicable to the small-size seeds of wild peanuts, increases the reliability by testing seed viability, and records the genetic fingerprinting of the samples. Aflatoxin levels observed among 20 wild peanut species varied from zero to 19000 ng.g-1 and 155 ng.g-1 of aflatoxin B1 and B2, respectively. We report the screening of 373 molecular markers, including 288 novel SSRs, tested on 20 wild peanut species. Multivariate analysis by Neighbor-Joining, Principal Component Analysis and 3D-Principal Coordinate Analysis using 134 (36 %) transferable markers, in general grouped the samples according to their reported genomes. The best 88 markers, those with high fluorescence, good scorability and transferability, are reported with BLAST results. High quality markers (total 98) that discriminated genomes are reported. A high quality marker with UPIC score 16 (16 out of 20 species discriminated) had significant hits on BLAST2GO to a pentatricopeptide-repeat protein, another marker with score 5 had hits on UDP-D-apiose synthase, and a third one with score 12 had BLASTn hits on La-RP 1B protein. Together, these three markers discriminated all 20 species tested. CONCLUSIONS: This study provides a reliable method to screen wild species of peanut for aflatoxin resistance using minimal seeds. In addition we report 288 new SSRs for peanut, and a cost-effective combination of markers sufficient to discriminate all 20 species tested. These tools can be used for the systematic search of aflatoxin resistant germplasm keeping record of the genetic fingerprinting of the accessions tested for breeding purpose.
Heavy Metal Levels and Mineral Nutrient Status of Natural Walnut (Juglans regia L.) Populations in Kyrgyzstan: Nutritional Values of Kernels.
In this study, mineral nutrient and heavy metal (Al, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn) contents of the walnut kernels and their co-located soil samples collected from the four different zones of natural walnut forests (Sary-Chelek, Arslanbap, and Kara-Alma in Jalal-Abad Region and Kara-Shoro in Osh Region) in Kyrgyzstan were investigated. The highest concentrations for all elements determined in the soil samples were observed in the Sary-Chelek zone whereas the Arslanbap zone was found to be having the lowest concentrations except Fe and Zn. The highest concentrations in the kernels of walnut samples were found to be in the Sary-Chelek zone for Ca, Fe, K, Mg, and Zn; in the Kara-Shoro zone for Cu; in the Arslanbap zone for Mn; and in the Kara-Alma zone for Na whereas the lowest concentrations were found to be in the Arslanbap zone for Ca, Fe, K, Mg, Na, and Zn and in the Sary-Chelek zone for Cu and Mn, respectively. Also, the levels of Al, Cd, Ni, and Pb in kernel samples could not be detected by ICP-OES because their levels were lower than the threshold detection point (10 μg.kg-1). Additionally, our data indicated that the walnut kernels from Kyrgyzstan have higher values for RDA (recommended daily allowances) in comparison with the walnut kernels from other countries.
Multi-class polar lipid profiling in fresh and roasted hazelnut (Corylus avellana cultivar “Tonda di Giffoni”) by LC-ESI/LTQOrbitrap/MS/MSn.
Hazelnuts are a popular tree nut used whole or as an ingredient in a variety of bakery, candy and chocolate products. Based on the nutritional value and nutraceutical properties, mainly due to the lipid content, US Food and Drug Administration has recognized hazelnut as "heart-healthy" food. "Nocciola di Giffoni" is a Protected Geographical Indication (PGI) Italian hazelnut largely consumed but lacking of a comprehensive lipid profile. To acquire a detailed characterization of the polar lipids in fresh and roasted "Nocciola di Giffoni" hazelnut, an extensive analysis based on high-performance liquid chromatography coupled to multiple-stage linear ion-trap and orbitrap high-resolution mass spectrometry (LC-ESI/LTQOrbitrap/MS/MSn) was carried out. This analytical approach (statistically validated) allowed for the detection of a wide range of polar lipids from oxylipins and long chain bases to high molecular weight lipids (phospholipids, sphingolipids, and glycolipids). Most of the polar lipids are here described for the first time in hazelnut.
Hazelnut as functional food component and fat replacer in fermented sausage.
It is intended to develop a fat substituted, low fat and functional fermented sausage by determining the effects of fat substitution (15, 30 and 45% ratio) with hazelnut paste in traditional fermented sucuks. The increase in fat substitution ratio increased the dry matter but decreased the fat and cholesterol content in hazelnut added sausages. Control samples cholesterol content were 89.47 ± 0.55 mg/100 g while 15, 30 and 45% hazelnut substituted samples were 87.33 ± 1.20, 84.93 ± 0.61 and 82.28 ± 0.50, respectively. Hazelnut added sucuks had lower cholesterol level and a functional fatty acid profile with a indexes of atherogenicity and thrombogenicity. However hazelnut added sucuks had increased TBARS values. The sensory properties of sucuk did not adversely affect by replacement of fat with hazelnut.
Influence of maturation stages in different varieties of wine grapes (Vitis vinifera) on the production of Ochratoxin A and its modified forms by Aspergillus carbonarius and Aspergillus niger.
Ochratoxin A is the main contaminant mycotoxin of grapes produced mainly by Aspergillus niger and Aspergillus carbonarius. Besides, it is possible that the formation of modified mycotoxin occurs through the plant defense mechanism or also by fungus actions itself. The objective of this study was to evaluate the influence of grape variety and maturation stage on the formation of OTA and modified mycotoxin. The determination of OTA was performed by high-performance liquid chromatography, and a high-resolution mass spectrometry was used for the detection of modified ochratoxin. A positive correlation was observed between the following grapes physicochemical parameters: pH, total soluble solids, total glycosides in glucose, total anthocyanin and OTA levels produced by A. niger and A. carbonarius. Therefore, the higher the concentrations of these parameters, the greater the production of mycotoxin in grapes. Among the elected targets, we identified the 14-decarboxy-ochratoxin A in Muscat Italia variety at veraison and 15 days after the beginning of veraison stages; and ethylamide-ochratoxin A as a biomarker in the Syrah variety at the ripeness stage.
Industrial prune processing and its effect on pesticide residue concentrations.
The aim of this study was to determine the insecticide residue processing factor (PF) from plums to prunes and the effect of the industrial processing of prunes residue concentrations. Our results show an increase of insecticide concentrations during plum dehydration that is explained by fruit water loss; however, the normalized insecticide residue concentration, based on plum dry weights to compensate dehydration, was reduced. The water washing and tenderizing of prunes produced insecticide residue reductions of 22.9 ± 4.5% and 21.9 ± 4.2%, respectively. PF were: 1.157, 1.872, 1.316, 0.192, 2.198, 0.775 and 0.156 for buprofezin, l-cyhalothrin, spirodiclofen, indoxacarb, acetamiprid, imidacloprid and emamectin benzoate, respectively, being directly related to water solubility, aqueous hydrolysis and degradation point and inversely related to molecular mass and melting point. In plums for the dehydrated agroindustry the final product is prunes, therefore, it is crucial to consider the PF to determine the specific preharvest interval for this important agroindustry.
Detection, Purity Analysis, and Quality Assurance of Adulterated Peanut (Arachis Hypogaea) Oils.
The intake of adulterated and unhealthy oils and trans-fats in the human diet has had negative health repercussions, including cardiovascular disease, causing millions of deaths annually. Sadly, a significant percentage of all consumable products including edible oils are neither screened nor monitored for quality control for various reasons. The prospective intake of adulterated oils and the associated health impacts on consumers is a significant public health safety concern, necessitating the need for quality assurance checks of edible oils. This study reports a simple, fast, sensitive, accurate, and low-cost chemometric approach to the purity analysis of highly refined peanut oils (HRPO) that were adulterated either with vegetable oil (VO), canola oil (CO), or almond oil (AO) for food quality assurance purposes. The Fourier transform infrared spectra of the pure oils and adulterated HRPO samples were measured and subjected to a partial-least-square (PLS) regression analysis. The obtained PLS regression figures-of-merit were incredible, with remarkable linearity (R² = 0.994191 or better). The results of the score plots of the PLS regressions illustrate pattern recognition of the adulterated HRPO samples. Importantly, the PLS regressions accurately determined percent compositions of adulterated HRPOs, with an overall root-mean-square-relative-percent-error of 5.53% and a limit-of-detection as low as 0.02% (wt/wt). The developed PLS regressions continued to predict the compositions of newly prepared adulterated HRPOs over a period of two months, with incredible accuracy without the need for re-calibration. The accuracy, sensitivity, and robustness of the protocol make it desirable and potentially adoptable by health departments and local enforcement agencies for fast screening and quality assurance of consumable products.
Sensory and Chemical Stabilities of High‐Oleic and Normal‐Oleic Peanuts in Shell During Long‐Term Storage.
Oxidative rancidity is one of the major causes of peanut quality deterioration. The in-shell nut industry's greatest concern is to preserve high quality and extended the shelf life of these products. This research determined the sensory and chemical stabilities of raw in-shell high-oleic and normal-oleic peanuts during long-term storage. In-shell peanuts samples of normal- and high-oleic types were stored at room temperature (23 °C) for 675 days. The quality parameters, like the fatty acid composition, moisture content, free fatty acids (FFA), peroxide value (PV), conjugated dienes (CD), and p-anisidine value (pAV), as well as sensory attributes, were analyzed every 45 days. High-oleic samples showed a 4.36-fold higher oleic acid/linolenic acid (O/L) ratio (O/L = 10.65) than normal-oleic peanuts (O/L = 2.44). FFA, PV, CD, pAV, and oxidized and cardboard flavors increased in all stored samples but especially in normal-oleic peanuts. Conversely, roasted peanutty flavor decreased in all samples during storage but in lower proportion in high oleic peanut samples. The sensory and chemical changes that occurred in unshelled normal- or high-oleic peanut samples were not remarkable, suggesting that the shell may protect peanut kernels against deterioration. However, in-shell high-oleic samples show greater stability and shelf life than normal-oleic peanuts under the studied storage condition. PRACTICAL APPLICATION: Quality preservation of peanuts is important for the food industry using peanuts as an ingredient. Peanut processors are concerned as to the best ways to preserve peanut quality for long-term storage. Raw high oleic peanuts kept in the shells show better preservation of their sensory and quality properties during storage. In-shell peanuts constitute an appropriate alternative to preserve chemical and sensory properties of this product.
Microbiological Quality and Risk Assessment for Aflatoxins in Groundnuts and Roasted Cashew Nuts Meant for Human Consumption.
Nuts are one of the commonly consumed snacks but poor handling and storage practices can make them prone to foodborne infections. The study aimed at assessing the microbiological quality and risk assessment for aflatoxins in groundnuts and cashew nuts consumed in selected locations in Nigeria. The moisture content, colony counts, incidence of pathogenic bacteria, aflatoxin contamination, and risk assessment for aflatoxins were evaluated using standard methods. The moisture content and total viable count ranged from 5.00-8.60% and 5.5-89 × 103 cfug-1, respectively, while the fungal count was between 4-24 × 103 and 1.0-4.5 × 102 cfug-1, respectively. Eleven fungal species belonging to 5 genera were isolated from the nuts, with Aspergillus flavus, Rhizopus oryzae, and Fusarium oxysporum having the highest percentage occurrence of 50%. In addition, the aflatoxin concentration ranged 0.1-6.8 and 29-33.78 ng kg-1 for cashew nuts and groundnuts, respectively. The margin of exposure (MOE) to aflatoxin contamination was 6.10 for groundnuts and 1000 for cashew nuts and the nuts consumers were at a risk of exposure to foodborne diseases and aflatoxin contamination with mean exposure values of 27.96 and 0.17 ng kg-1bwday-1, respectively. The risk of primary liver cancer for groundnuts and cashew nuts consumers was also estimated to be 1.38 and 0.01 canceryear-1100,000-1person, respectively. This calls for mitigation measures from appropriate governmental organizations.
Comparison of cold-pressing and soxhlet extraction systems for bioactive compounds, antioxidant properties, polyphenols, fatty acids and tocopherols in eight nut oils.
Antioxidant activities of different nut oils ranged from 11.43 (peanut) to 65.58% (pistachio) in cold pressed oils whereas in case of soxhlet extracted oils they were in the range of 11.32 (hazelnut) to 51.28% (pistachio). β-Carotene contents of oils obtained by cold pressing and soxhlet extraction changed between 7.53 (almond) and 13.58 µg/100 g (pistachio). The highest total phenol contents (2.36 mg gallic acid equivalent/100 g) were observed in pistachio oils obtained by cold press. The oleic acid contents of cold pressed and soxhlet extracted oils were between 19.88 (walnut) and 69.43% (pecan) to 19.07 (walnut) and 68.53% (pecan), respectively. The linoleic acid contents of nut oils from cold press system vary between 12.78 (hazelnut) and 63.56% (walnut), whereas in case of soxhlet extraction, it changed between 11.78 (hazelnut) and 62.41% (walnut). The α-tocopherol contents of cold pressed nut oils changed between 0.07 (walnut) and 257.42 mg/kg (hazelnut) α-tocopherol contents of nut oils extracted by soxhlet extraction changed between 0.03 (pistachio) and 209.73 mg/kg (hazelnut). The catechin contents of cold pressed nut oils were between 0.56 (cashew) and 3.76 µg/100 g (pistachio), whereas that of soxhlet extracted oil varied between 0.64 (cashew) and 3.82 µg/100 g (cashew).