scholarly journals Detection of Leguminous Protein in Casein by Nitrogen Stable Isotopes

2018 ◽  
Vol 7 (3) ◽  
pp. 1
Author(s):  
Joachim Molkentin
Keyword(s):  
Stable Isotope ◽  
Limit Of Detection ◽  
Isotope Analysis ◽  
Screening Method ◽  
Food Samples ◽  
Rapid Screening ◽  
Food Control ◽  
Nitrogen Stable Isotopes ◽  
Imitation Cheese ◽  
Isotope Analyses

Casein can legally be substituted with cheaper leguminous proteins in processed foods, such as imitation cheese, as long as the ingredients are declared. The detection of illegal admixtures of leguminous protein requires analytical procedures to identify an undisclosed adulteration of milk products. To investigate the suitability of stable isotope analyses as an alternative to more sophisticated methods, variations in d15N of soya (n = 27) and peanut (n = 10) protein, as well as casein (n = 14) were determined. Significant differences were established between d15N of casein (4.45 – 6.94‰) and soya (0.25 – 2.37‰) as well as peanut (0.70 – 2.13‰) protein. An average limit of detection for leguminous protein in casein was determined to be 2.1%, provided both components were available for additional analyses. Under practical conditions of food control, i.e., without having access to the actual ingredients, the variability of d15N resulted in an average limit of detection of 26.4%. Because protein d15N can be determined rapidly in crude food samples without elaborate sample preparation, stable isotope analysis can be used as a rapid screening method to determine the presence of higher amounts of leguminous protein in cheese and, in particular, to easily distinguish imitation cheese from cheese.

scholarly journals Design, Synthesis, and Characterization of Tracers and Development of a Fluorescence Polarization Immunoassay for Rapid Screening of 4,4′-Dinitrocarbanilide in Chicken Muscle

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1822
Author(s):  
Qidi Zhang ◽  
Ming Zou ◽  
Wanyu Wang ◽  
Jinyan Li ◽  
Xiao Liang
Keyword(s):  
Fluorescence Polarization ◽  
Limit Of Detection ◽  
Screening Method ◽  
Sample Pretreatment ◽  
Cross Reactivity ◽  
Rapid Screening ◽  
Fluorescence Polarization Immunoassay ◽  
Design Synthesis ◽  
Chicken Muscle ◽  
Edible Tissues

The compound, 4,4′-dinitrocarbanilide (DNC), is the marker residue of concern in edible tissues of broilers fed with diets containing anticoccidial nicarbazin (NIC). In this study, 25 fluorescein-labeled DNC derivatives (tracers) are synthesized and characterized to develop a rapid fluorescence polarization immunoassay (FPIA) for the detection of DNC in chickens using DNC monoclonal antibodies (mAbs). The effect of the tracer structure on the sensitivity of the FPIA is investigated. Our results show that after optimization, the half maximal inhibitory concentrations (IC50) and limit of detection (LOD) of the FPIA in the buffer are 28.3 and 5.7 ng mL−1, respectively. No significant cross-reactivity (CR < 0.89%) with 15 DNC analogues is observed. The developed FPIA is validated for DNC detection in spiked chicken homogenates, and recoveries ranged from 74.2 to 85.8%, with coefficients of variation <8.6%. Moreover, the total time needed for the detection procedure of the FPIA, including sample pretreatment, is <40 min, which has not been achieved in any other immunoassays for DNC from literature. Our results demonstrate that the FPIA developed here is a simple, sensitive, specific, and reproducible screening method for DNC residues in chickens.

Rapid Screening Method for Aflatoxin M1 in Milk

1981 ◽  
Vol 64 (5) ◽  
pp. 1064-1066
Author(s):  
Charles E Holaday
Keyword(s):  
Limit Of Detection ◽  
Screening Method ◽  
Rapid Screening ◽  
Aflatoxin M1 ◽  
Fluorescent Band ◽  
Neutral Alumina ◽  
Rapid Screening Method ◽  
The Cost

Abstract A rapid screening method for detecting aflatoxin M1 in milk has been developed, based on minicolumn chromatography and requiring 8-10 min for each test. The minicolumn is packed with dry Florisil (100-200 mesh) on the bottom, anhydrous Na2S04 as the next layer, topped with neutral alumina (70-200 mesh) to which 8% water (wet basis) has been added. A blue fluorescent band at the Florisil-Na2SO4 interface indicates the presence of aflatoxin M1. The limit of detection is estimated to be about 0.2 μg/kg. Because several items are disposable, both the time to maintain glassware and the cost per determination are reduced.

scholarly journals Development of Lateral Flow Immunochromatographic Assays Using Colloidal Au Sphere and Nanorods as Signal Marker for the Determination of Zearalenone in Cereals

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 281 ◽  
Author(s):  
Mingfei Pan ◽  
Tianyu Ma ◽  
Jingying Yang ◽  
Shijie Li ◽  
Shengmiao Liu ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Fumonisin B1 ◽  
Test Strip ◽  
Food Samples ◽  
Cross Reactivity ◽  
Lateral Flow ◽  
Rapid Screening ◽  
Colloidal Au ◽  
Short Time

This paper describes the development of lateral flow immunochromatographic assays (ICAs) using colloidal Au sphere (SP) and nanorods (NRs) as signal markers for the determination of zearalenone (ZEN) in cereals. The developed ICAs can detect the analyte ZEN within a short time (10 min), and achieve lower limit of detection (LOD). This is the first time that the AuNRs are used as signal probe in immune test strip for ZEN detection. For colloidal AuSP immunochromatographic analysis (AuSP-ICA), the LODs in solution and spiked cereal sample were 5.0 μg L−1 and 60 μg kg−1, and for AuNRs immunochromatographic analysis (AuNRs-ICA) the two LODs achieved 3.0 μg L−1 and 40 μg kg−1, respectively. These two proposed ICAs have minor cross-reaction to the structural analogs of ZEN, and no cross-reactivity with aflatoxin B1, T-2 toxin, ochratoxin A, deoxynivalenol, fumonisin B1. Both of the developed ICAs can specifically and sensitively detect ZEN in cereals, providing an effective strategy for rapid screening and detection of ZEN in a large number of food samples.

Early herding at Măgura-Boldul lui Moş Ivănuş (early sixth millennium BC, Romania): environments and seasonality from stable isotope analysis

2013 ◽  
Vol 16 (2) ◽  
pp. 221-246 ◽  
Author(s):  
Marie Balasse ◽  
Adrian Bălăşescu ◽  
Anneke Janzen ◽  
Joël Ughetto-Monfrin ◽  
Pavel Mirea ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Sequential Analysis ◽  
Tooth Enamel ◽  
Isotope Analysis ◽  
Farming Systems ◽  
Bone Collagen ◽  
Late Winter ◽  
Faunal Remains ◽  
Agricultural Communities ◽  
Isotope Analyses

Stable isotope analyses were conducted on faunal remains from the site of Măgura-Boldul lui Moş Ivănuş with the objective of characterizing the environments and seasonality of husbandry in the earliest Neolithic (Gura Baciului-Cârcea/Starčevo-Criş I) of southern Romania. Results from bone collagen analysis indicate extensive herding strategies for cattle and pigs. However, sequential analysis in tooth enamel also provides evidence for winter leaf foddering in one bovine, potentially kept by the settlement over winter. In some instances, sheep were fed a13C-enriched resource in late winter, which may have also coincided with lactation. It could not be determined whether this contribution was from C3or C4plants. Although isolated, these findings may be important in evaluating how early agricultural communities dealt with environmental constraints. These results are also interpreted with reference to the models of intensive mixed farming systems recently proposed by Bogaard (2004) and Halstead (2006).

scholarly journals Adaptive radiation of barbs of the genus Labeobarbus (Cyprinidae) in the East African river

2018 ◽  
Author(s):  
B.A. Levin ◽  
M. Casal-López ◽  
E. Simonov ◽  
Yu.Yu. Dgebuadze ◽  
N.S. Mugue ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Adaptive Radiation ◽  
Isotope Analysis ◽  
Sympatric Speciation ◽  
Foraging Strategies ◽  
Geographic Isolation ◽  
East African ◽  
Sympatric Forms ◽  
Isotope Analyses ◽  
Mtdna Markers

AbstractLarge African barbs of the genus Labeobarbus are widely distributed in African freshwaters, and exhibit profound phenotypic plasticity that could be a prerequisite for adaptive radiation. Using morphological, molecular, and stable isotope analyses, we investigated whether an adaptive radiation has occurred in a riverine assemblage of the L. gananensis complex. This complex is composed of six phenotypically distinct sympatric forms inhabiting the Genale River (Ethiopian highlands, East Africa). Of the six forms, five were divergent in their mouth morphology, corresponding to ‘generalized’, ‘lipped’, ‘scraping’ (two forms) and ‘large-mouthed’ phenotypes. Stable isotope analysis revealed differences in 15N and 13C among these forms, representing different foraging strategies (omnivorous, scraping and piscivorous). Phylogenetic analysis of two mtDNA markers confirmed the monophyly of L. gananensis, suggesting an intra-riverine radiation. However, the Genale assemblage appears to have originated through a combination of allopatric and sympatric events. Some of the specialized forms within this drainage originated independently from the local generalized forms in three different river regions within local ‘mini-flocks’ composed of two to three sympatric forms. Our study shows that adaptive radiation in rivers can be enhanced by a combination of sympatric speciation and temporal geographic isolation, leading to local sympatric speciation followed by migration.

Stable isotope analysis as a minimal-invasive method for dietary studies on the highly endangered Common hamster (Cricetus cricetus)

Mammalia ◽  
2018 ◽  
Vol 82 (6) ◽  
pp. 600-606 ◽  
Author(s):  
Anna Roswag ◽  
Nina I. Becker ◽  
Eva Millesi ◽  
Matthias S. Otto ◽  
Sara Ruoss ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Isotope Analysis ◽  
Food Samples ◽  
Minimal Invasive ◽  
Food Sources ◽  
Stable Isotope Ratios ◽  
Cricetus Cricetus ◽  
Invasive Method ◽  
Agricultural Areas

Abstract This study applied the analysis of stable isotope ratios as a minimally-invasive tool to estimate the diet of Cricetus cricetus for the first time. We took hair and food samples of three different populations of C. cricetus and analyzed stable carbon and nitrogen ratios. The stable isotope ratios in hamster hairs differed significantly within and between populations according to different sampling seasons and animal ages. Additionally, the isotopic signatures of potential food samples differed between sampling sites and food categories. The isotopic mixing models illustrated that diet composition varied with season and food availability. During the summer season hamsters living in agricultural areas mainly fed on green and ripe crop. In contrast to this, during the winter season ripe crop was the main food component for hamsters in agricultural areas while hamsters living in urban areas fed almost exclusively on nuts. These are, despite a wide variety of available food sources, most suitable for hoarding in the burrow. We conclude that stable isotope analysis of hamster hairs is an appropriate minimal-invasive method to investigate correlations between available and consumed food sources throughout the overall distribution of this species.

scholarly journals DEVELOPMENT AND APPLICATION OF A RAPID SCREENING METHOD FOR DETERMINATION OF NEW PSYCHOACTIVE SUBSTANCES AND THEIR METABOLITES IN URINE

2019 ◽  
Vol 16 (33) ◽  
pp. 206-224
Author(s):  
K. M. SHESTAKOVA ◽  
S. A. SAVCHUK ◽  
N. V. MESONZHNIK ◽  
A. V. KUHARENKO ◽  
S. A. APPOLONOVA
Keyword(s):  
Mass Spectrometry ◽  
Limit Of Detection ◽  
Screening Method ◽  
Mass Spectrometry Analysis ◽  
Rapid Screening ◽  
New Psychoactive Substances ◽  
Preparation Technique ◽  
Psychoactive Substances ◽  
Urine Specimens

The ongoing appearance of new psychoactive substances on the black market of illegal drugs, as well as the lack of information on their influence on the human body, faces several challenges in their determination by standard analytical techniques. Moreover, the rapid metabolism of new psychoactive substances reveals in the absence of possibility in the identification of their native structures in biological fluids. This study presents a new screening method for determination 137 psychoactive substances including their metabolites. 'Dilute-and-shoot' method was chosen as the preferable sample preparation technique, and consisted of 1:5 dilution of urine specimens with the solution of acetonitrile and water (30:70) followed by electrospray ionization – liquid chromatography-tandem mass spectrometry analysis. The developed qualitative method was validated according to United Nations Office on Drugs and Crime requirements that included assessment of selectivity, limits of detection, precision, and stability. In addition, the presented method was tested on 50 certified positive urine specimens containing different drugs of abuse. The confirmatory analysis was performed using a high-resolution mass-spectrometry approach. The presented screening method provides the possibility of simultaneous determination of synthetic cannabinoids (96), opioid analgesics (16), stimulators (13), hallucinogens (5), benzodiazepines (5) and non-classified drugs (10) during one run. The validation assessments of the novel method have shown high rates of its specificity, selectivity, intra- and inter-day precision and stability with the limit of detection ranged from 1 to 5 ng?mL-1. At the same time, tests of 50 positive samples showed excellent applicability of the developed screening method for routine preliminary screening analysis in toxicological laboratories.

Feeding ecology of non-native Siberian prawns, Palaemon modestus (Heller, 1862) (Decapoda, Palaemonidae), in the lower Snake River, Washington, U.S.A.

Crustaceana ◽  
2016 ◽  
Vol 89 (6-7) ◽  
pp. 721-736 ◽  
Author(s):  
Kenneth F. Tiffan ◽  
William R. Hurst
Keyword(s):  
Stable Isotope ◽  
Feeding Ecology ◽  
Isotope Analysis ◽  
Trophic Levels ◽  
Juvenile Salmon ◽  
Snake River ◽  
Caridean Shrimp ◽  
Opossum Shrimp ◽  
Isotope Analyses ◽  
Food Consumed

We used both stomach content and stable isotope analyses to describe the feeding ecology of Siberian prawns Palaemon modestus (Heller, 1862), a non-native caridean shrimp that is a relatively recent invader of the lower Snake River. Based on identifiable prey in stomachs, the opossum shrimp Neomysis mercedis Holmes, 1896 comprised up to 34-55% (by weight) of diets of juvenile to adult P. modestus, which showed little seasonal variation. Other predominant items/taxa consumed included detritus, amphipods, dipteran larvae, and oligochaetes. Stable isotope analysis supported diet results and also suggested that much of the food consumed by P. modestus that was not identifiable came from benthic sources — predominantly invertebrates of lower trophic levels and detritus. Palaemon modestus consumption of N. mercedis may pose a competitive threat to juvenile salmon and resident fishes which also rely heavily on that prey.

Dietary Histories

2018 ◽  
pp. 261-293
Author(s):  
Melanie J. Miller ◽  
Sabrina C. Agarwal ◽  
Carl H. Langebaek
Keyword(s):  
Stable Isotope ◽  
Isotope Analysis ◽  
Dietary Practices ◽  
Life Course Approach ◽  
The Social ◽  
Consumption Practices ◽  
Northern South America ◽  
Isotope Analyses

Chapter 8 reviews some of the stable isotope analysis studies of human skeletal remains that have taken a life course approach to understand childhood dietary practices in relation to adult dietary practices and concludes with a bioarchaeological case study from the Muisca of northern South America, in present-day Colombia. Archaeological dietary studies continue to contribute new understandings to human food practices and the layers of biological and social meaning that accompany that information, including evidence of the role of food in the socialization of children, gendered food differentiation, and the social relationships that become evidenced through repetitive food consumption practices. For dietary studies, carbon, nitrogen, and sulfur stable isotope analyses are used.

scholarly journals Use of carbon and nitrogen stable isotopes to study the feeding ecology of small coastal cetacean populations in southern Brazil

2013 ◽  
Vol 13 (4) ◽  
pp. 90-98 ◽  
Author(s):  
Fernando Augusto Sliva Hardt ◽  
Marta Jussara Cremer ◽  
Antonio José Tonello Junior ◽  
Antonio Bellante ◽  
Gaspare Buffa ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Feeding Ecology ◽  
Resource Sharing ◽  
Isotope Analysis ◽  
Nitrogen Stable Isotopes ◽  
Nitrogen Stable Isotope ◽  
Cetacean Species ◽  
Carbon And Nitrogen ◽  
Pontoporia Blainvillei ◽  
Guiana Dolphin

Samples from individuals of the populations of Sotalia guianensis (Guiana) and Pontoporia blainvillei (Franciscana) dolphins living in the Babitonga Bay estuary (26° 28′ S/48° 50′ W), and samples from individuals of a second population of P. blainvillei from a nearshore area (26° 38′ S/48° 41′ W), were collected and analyzed along with their prey between 2000 and 2006, to determine the carbon and nitrogen stable isotope ratios and to verify differences in their feeding ecology. No differences were found in the median ð15N values of Guiana (15.2‰) and Franciscana (15.9‰) dolphins living in Babitonga Bay, nor of nearshore Franciscana (15.0‰) individuals, suggesting no variation in the trophic level of these populations. However, the lack of more information on the isotopic compositions of their putative prey in the nearshore areas prevents the ability to draw definitive conclusions on this issue. The estuarine Franciscana and Guiana dolphin populations presented mean ð13C values of approximately −15.7‰, which were not statistically different from nearshore Franciscana individuals (−14.8‰). Based on stomach content analyses of these species from a previous study, it was reported that there was little overlap in the diet of estuarine Franciscanas and Guiana dolphins. However, based on the similarity of the ð13C values between these two species and of their putative prey, it appears that in fact there is an overlap in the diet of these two species. Based solely on stable isotope analysis, it was not possible to differentiate between estuarine and nearshore Franciscana populations, making it difficult to conclude whether captured nearshore specimens were indeed yearlong residents of these areas. Finally, this study suggests that Franciscana and Guiana dolphin populations are sharing the same resources, mostly L. brevis, D. rhombeus, and S. rastrifer. Therefore, the combination of resource sharing and commercial exploitation of their prey makes these two cetacean species vulnerable.

Sign in / Sign up

Export Citation Format

Share Document