Evaluation of calcium carbonate in eggshells using thermal analysis

The eggshell of the hen is an important structure which provides protection for the developing chick, and also a container for the egg in the food industry. Egg breakage can reach up to 10% of total egg production, causing considerable economic losses. The eggshell consists of membranes, composed mainly of proteins, and the mineral shell composed mainly of the calcite polymorph of CaCO₃. The average CaCO₃ content of a chicken eggshell is between 93 and 97%, depending on animal genotype, age, housing system of laying hens and mineral nutrition. In the present study, eggs of the same breed and approximately same age were collected from four different production systems: organic farming, free-range production, deep litter system and battery cage system. The CaCO₃ content was determined by the standard titration method and by atomic absorption spectroscopy. Thermal properties of dried eggshell powder were measured by thermogravimetric measurements between 30 and 900 °C in air, showing a significant mass loss of?≈?43% between 600 and 850 °C corresponding to the decomposition of CaCO₃ to CaO and CO₂. The relations between the thermal mass loss and CaCO₃ content determined by the titration method/atomic absorption spectroscopy were studied using predictive models fitted by the linear regression method. A good prediction ability with an average prediction error of 0.01% was obtained between CaCO₃ determined by titration and the thermal mass loss, indicating that TG could provide a reliable method for evaluation of CaCO₃ content in eggshells.

     

Ionothermal synthesis, crystal structure and solid-state NMR spectroscopy of a new organically templated gallium oxalatophosphate: (H2TMPD)0.5[Ga3(C2O4)0.5(PO4)3] (TMPD=N,N,N',N'-tetramethyl-1,3-propanediamine)

A new organically templated gallium oxalatophosphate, (C7H20N2)0.5[Ga3(C2O4)0.5(PO4)3], has been synthesized by using a low-melting-point eutectic mixture of choline chloride and oxalic acid as a solvent and characterized by single-crystal X-ray diffraction, thermogravimetric analysis and solid-state NMR spectroscopy. It is the first example of ionothermal synthesis of organically templated metal oxalatophosphate. The structure contains double 6-ring units of the composition Ga6(PO4)6 which are connected by oxalate ligands and P-O-Ga bonds to form a 3-D framework. The charge-compensating organic ammonium cations which are disordered over two positions are located at the intersections of two types of 8-ring channels. 1H MAS and 13C CPMAS NMR studies confirm the presence of N,N,N',N'-tetramethyl-1,3-propanediammonium cation. The 71Ga and 31P MAS NMR spectra are also consistent with the crystal structure analysis results.     

Herkunft und Authentizität von Lebensmitteln: Stabilisotopenanalytik

The correlations between isotope ratios in water, organic mass, and trace elements of food and beverages, and the circumstances and sites of their origin and production are outlined, and the methods of mass spectrometric isotope ratio determination and the positional ²H analysis by quantitative NMR measurement are explained. In context with the application of these methods for origin and authenticity investigations of food, examples are given for the proof of watering or sugar addition to wine and fruit juices and methods for the identification of nondeclared additions of L‐malic and Lascorbic acids are described. The possibilities of multielement isotope ratio analysis for the identification of origin of animal products (eggs, milk products, meat) and methods for the discriminations between natural and nature identical aroma compounds are outlined. Finally, the possibilities of isotope ratio measurements for the discrimination between plant and animal food from conventional and organic production are discussed.     

Comparative analysis of lipophilic compounds in eggs of organically raised ISA Brown and Araucana hens

Hens?? eggs represent a rich source of important nutrients, including lipids and carotenoids. The lipid composition of hens?? eggs is influenced by genetic factors, age, and diet. The aim of this study was to compare the fatty acids, cholesterol, and carotenoids content of the egg yolk of ISA Brown and Araucana hens grown in free-range housing systems. Fatty acids and cholesterol were analysed by GC-FID and GC-MS and carotenoids were quantified by RP-HPLC-PDA. The Araucana egg yolk has a higher lipid content and higher egg-to-albumen ratio than the ISA Brown yolk, while the total cholesterol, carotenoids content and profile are not significantly different. The lipids of the Araucana egg yolk have a higher content of mono-unsaturated fatty acids (MUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) and a better n-6/n-3 ratio than the ISA Brown egg yolk lipids. The major carotenoids were lutein and zeaxanthin, which account for more than 83 % in egg yolk. Eggs of both breeds, when raised organically, represent very good sources of highly bio-available lutein and zeaxanthin, pigments which are related to lower risk of age-related macular degeneration. We report for the first time on the fatty acids composition in lipid fractions and the profile and content of carotenoids of the Araucana egg yolk.     

Folate Content and Yolk Color of Hen Eggs from Different Farming Systems

This study aimed to compare folate contents in hen eggs from four different farming systems, namely organic, free range, barn, and cage one. Folate retention during egg boiling was studied as well. The contents of individual folate vitamers were determined using the high-performance liquid chromatography method (HPLC), following trienzyme treatment. Folate content in eggs differed significantly (p < 0.05) due to the rearing system, with the highest mean content determined in the eggs from organic farming (113.8 µg/100 g). According to this study, one egg (60 g) may provide 40–86 µg of folates, which corresponds to 10–22% of the recommended daily intake for adults, 400 µg according to the Nutrition Standards for the Polish Population. The predominant folate form found in egg was 5-methyltetrahydrofolate, which showed considerably greater stability under boiling compared to 10-formylfolic acid present in a lower amount. In most eggs tested, the losses in total folate content did not exceed 15%. The color of yolk of the most folate-abundant organic eggs, had the highest value of lightness (L*) and the lowest value of redness (a*). This, however, does not correspond to consumer preferences of intense golden yolk color.     

Amphiphilic egg-derived carbon dots: rapid plasma fabrication, pyrolysis process, and multicolor printing patterns

How do you like your eggs? Amphiphilic carbon dots (CDs) with intense blue fluorescence have been produced from chicken eggs by treatment with plasma. They are used as effective "fluorescent carbon inks" for multicolor luminescent inkjet and silk-screen printing.     

Automated structure elucidation of organic molecules from (13)c NMR spectra using genetic algorithms and neural networks.

The automated structure elucidation of organic molecules from experimentally obtained properties is extended by an entirely new approach. A genetic algorithm is implemented that uses molecular constitution structures as individuals. With this approach, the structure of organic molecules can be optimized to meet experimental criteria, if in addition a fast and accurate method for the prediction of the used physical or chemical features is available. This is demonstrated using (13)C NMR spectrum as readily obtainable information. (13)C NMR chemical shift, intensity, and multiplicity information is available from (13)C NMR DEPT spectra. By means of artificial neural networks a fast and accurate method for calculating the (13)C NMR spectrum of the generated structures exists. The approach is limited by the size of the constitutional space that has to be searched and by the accuracy of the shift prediction for the unknown substance. The method is implemented and tested successfully for organic molecules with up to 20 non-hydrogen atoms.     

Discriminant Analysis of the Nutritional Components between Organic Eggs and Conventional Eggs: A 1H NMR-Based Metabolomics Study

The difference of nutrient composition between organic eggs and conventional eggs has always been a concern of people. In this study, ¹H nuclear magnetic resonance (NMR) technique combined with multivariate statistical analyses was conducted to identify the metabolite different in egg yolk and egg white in order to reveal the nutritional components information between organic and conventional eggs. The results showed that the nutrient content and composition characteristics were different between organic and conventional eggs, among which the content of glucose, putrescine, amino acids and their derivatives were found higher in the organic eggs yolk, while phospholipids were demonstrated higher in conventional eggs yolk. Organic acid, alcohol, amine, choline and amino acids were higher in conventional eggs white, but glucose and lactate in organic egg were higher. Our study demonstrated that there are more nutritive components and higher nutritional value in organic eggs than conventional eggs, especially for the growth and development of infants and young children, and conventional eggs have more advantages in promoting lipid metabolism, preventing fatty liver, and reducing serum cholesterol. Eggs have important nutritional value to human body, and these two kinds of eggs can be selected according to the actual nutrient needs.     

Is high‐resolution magic angle spinning NMR a practical speciation tool for cheese samples? Parmigiano Reggiano as a case study

High-resolution magic angle spinning (HRMAS) NMR is probably the most apt NMR method to analyze complex materials involving a solid phase, e.g. foodstuffs. We present here an HRMAS analysis of grated cheese (Parmigiano Reggiano). A full NMR characterization of this cheese allows the identification of the presence of fatty acids (saturated and unsaturated), amino acids and other small organic molecules. Since the presence and relative concentration of these molecules have previously been shown to correlate with organoleptic, origin and age characterization, HRMAS NMR of cheese is likely to provide a good complimentary tool for the analysis of this food material.     

Structural characterization and thermal decomposition of layered double hydroxide/poly(p-dioxanone) nanocomposites

Nanocomposites based on layered double hydroxides (LDH) and poly(p-dioxanone) (PPDO) were prepared by melt processing using dodecylbenzene sulfonate (DBS) and 4-hydroxybenzene sulfonate (HBS) as organic modifiers. The incorporation of organic anions in LDH was demonstrated by wide-angle X-ray scattering (WAXS) and Fourier transform infrared (FTIR). The dispersion degree of the organically modified LDHs in the PPDO matrix was analyzed by WAXS, indicating that only the LDH modified with HBS was exfoliated. The effect of the organically modified LDHs on the thermal stability of PPDO was studied using thermogravimetric analysis (TGA). The thermal stability of PPDO matrix was enhanced by the incorporation of the LDH modified with HBS due to the shielding effect of the exfoliated layers. In contrast, the LDH modified with DBS produced a decrease of the thermal stability of PPDO, probably due to hydrolytic decomposition of ester group. The thermogravimetric analysis also showed that the organo-modified LDH did not modify the thermal decomposition mechanism of the polymer, but had an effect on the thermal stability.     

Determination of Pesticides in Organic Carrots by High-Performance Liquid Chromatography/High-Resolution Mass Spectrometry

Food contamination by pesticide residues, which may cause serious human health problems, is an ongoing challenge. Safer organically grown food is therefore needed. However, best practices are not always followed for farming organic foods, necessitating analytical testing. To this end, this report describes an analytical method for the evaluation of 82 pesticides by high-performance liquid chromatography–high-resolution mass spectrometry in organically grown carrots. The method was validated in terms of linearity, precision, and limits of detection and quantification that ranged from 0.3 to 5 and 5–40?µg?kg^?1, respectively. From the 82 pesticides evaluated in this multiresidue method, three were detected in real samples, with bendiocarb detected at the highest concentration (199.11?µg?kg^?1), which was above the maximum residue limit. Chlorpyriphos (43.20?µg?kg^?1) and amitraz (11.22?µg?kg^?1) were also detected. Measurement of contaminants in organic foods should be a standard practice, which would contribute to improved food safety. It is observed that even organic foods can be contaminated by pesticides, intentionally or unintentionally, perhaps by cross-contamination. Pesticides in organic foods are a public health problem because consumers expect organic foods to be free of pesticide contamination, but this is not necessarily the case.     

Determination of additives and organic contaminants in food by CE and CEC

The application of CE to the analysis of additives and organic contaminants in food since 2001 has been reviewed. Additives included in the review are dyes, preservatives, antioxidants and sweeteners. Organic contaminants included in the review are pesticides, antibiotics and those produced during processing or cooking food. The review highlights the strategies and approaches adopted in making CE suitable for the determination of analytes at residue level and in complicated matrices.     

CE microchips: an opened gate to food analysis

CE microchips are the first generation of micrototal analysis systems (-TAS) emerging in the miniaturization scene of food analysis. CE microchips for food analysis are fabricated in both glass and polymer materials, such as PDMS and poly(methyl methacrylate) (PMMA), and use simple layouts of simple and double T crosses. Nowadays, the detection route preferred is electrochemical in both, amperometry and conductivity modes, using end-channel and contactless configurations, respectively. Food applications using CE microchips are now emerging since food samples present complex matrices, the selectivity being a very important challenge because the total integration of analytical steps into microchip format is very difficult. As a consequence, the first contributions that have recently appeared in the relevant literature are based primarily on fast separations of analytes of high food significance. These protocols are combined with different strategies to achieve selectivity using a suitable nonextensive sample preparation and/or strategically choosing detection routes. Polyphenolic compounds, amino acids, preservatives, and organic and inorganic ions have been studied using CE microchips. Thus, new and exciting future expectations arise in the domain of food analysis. However, several drawbacks could easily be found and assumed within the miniaturization map.     

1H NMR-Based metabolomics and 13C isotopic ratio evaluation to differentiate conventional and organic soy sauce

Organic foods gaining popularity due its connection with the health, high nutritional value, and high quality. Therefore, it is of prime importance to develop the analytical methods to combat with food authentication and protect consumer from the food fraud. Conventional soy sauce (CS) and organic soy sauce (OS) were characterized and differentiate for the first time using ¹H NMR-based metabolomics approach. Classification methods like orthogonal partial least squares of discriminant analysis (OPLS-DA) showed a significant (p < 0.01) separation among CS and OS yielding important metabolites contributing towards this separation. OS was characterized by increased levels of leucine, threonine, isoleucine, valine, choline, phenylalanine, tyrosine, lactate, and acetate whereas, CS showed elevated concentrations of glutamate, glucose, and sucrose. The abundance ratio of ¹³C to ¹²C was determined by ¹H NMR spectroscopy which showed an increased ratio of ¹³C isotope in OS samples indicating the organically grown wheat and soybean used for the preparation of OS. The results can be helpful to convey the information to the end-user to prevent them from economically motivated adulteration. This information could also pave the way to further trace and authenticate the raw materials used in the production of soy.     

固相萃取-超高效液相色谱-串联质谱法同时测定动物源性食品中11种禁限兽药及代谢物

建立了固相萃取-超高效液相色谱-串联质谱(SPE-UPLC-MS/MS)同时检测鸡蛋、液态奶、鸡肉及淡水鱼中4类(氯霉素类、硝基咪唑类、林可酰胺类与大环内酯类)8种禁限兽药与3种代谢物残留的分析方法.对样品前处理及色谱条件进行优化,样品经0.1 mol/L pH 9.0的磷酸盐缓冲液水解分散,乙腈提取,提取液经乙酸乙酯...     

Gender determination of fertilized unincubated chicken eggs by infrared spectroscopic imaging

Each year, billions of day-old layer chicks are produced in the world. Since only female chicks are reared for egg production, the chicks must be sexed and the unwanted male layer chicks are culled. The culling of male chicks is a serious problem, both in terms of animal welfare and waste disposal. The germinal disc in fertilized but unincubated eggs contains already several thousands of blastoderm cells. The cellular DNA in birds is different for male and female chicks. The difference in DNA content between male and female chicks is around 2% and is measurable by Fourier transform infrared (FT-IR) spectroscopy. In this study, small amounts of blastoderm cells from 22 chicken eggs were characterized by attenuated total reflection FT-IR spectroscopic imaging and classified by linear discriminant analysis. Polymerase chain reaction (PCR) was used as a reference method to determine the gender. The spectroscopic results demonstrate that male blastoderm cells exhibit a higher content of DNA than cells from female blastoderm. The spectroscopic-based gender determination led to the same result as the PCR analysis. FT-IR spectroscopic imaging allows the gender determination of unincubated eggs within a few seconds based on the accurate determination of the different DNA contents in blastoderm cells of both sexes.     

高效液相色谱法测定鸡组织与鸡蛋中氯苯胍的残留量

建立了测定鸡组织与鸡蛋中氯苯胍残留的高效液相色谱法。试样用乙腈提取,经HLB固相萃取柱净化和流动相定容后,采用高效液相色谱法测定。以乙腈-0.05 mol/L NH4H2PO4缓冲液(6:4, v/v, pH 6.5)为流动相,流速为1.0 mL/min,于317 nm波长下检测。氯苯胍在10～1000 μg/L范围内具有良好的线性关系;方法的检出限(信噪比为3)为10 μg/L,定量限(信噪比为10)为15 μg/kg;回收率为73.1%～88.7%。该法操作简便、快速、灵敏、准确,样品处理简便易行,适用于测定鸡组织与鸡蛋中残留的氯苯胍。     

Territorial origin of olive oil: representing georeferenced maps of olive oils by NMR profiling

ABSTRACT Proton NMR profiling is nowadays a consolidated technique for the identification of geographical origin of food samples. The common approach consists in correlating NMR spectra of food samples to their territorial origin by multivariate classification statistical algorithms. In the present work, we illustrate an alternative perspective to exploit territorial information, contained in the NMR spectra, which is based on the implementation of a geographic information system (GIS). Nuclear magnetic resonance spectra are used to build a GIS map permitting the identification of territorial regions having strong similarities in the chemical content of the produced food (terroir units). These terroir units can, in turn, be used as input for labeling samples to be analyzed by traditional classification methods. In this work, we describe the methods and the algorithms that permit to produce GIS maps from NMR profiles and apply the described method to the analysis of the geographical distribution of olive oils in an Italian region. In particular, we analyzed by ¹H NMR up to 98 georeferenced olive oil samples produced in the Abruzzo Italian region. By using the first principal component of the NMR variables selected according to the Moran test, we produced a GIS map, in which we identified two regions incidentally corresponding to the provinces of Teramo and Pescara. We then labeled the samples according to the province of provenience and built an LDA model that provides a classification ability up to 99% . A comparison between the variables selected in the geostatistics and classification steps is finally performed. Copyright © 2016 John Wiley & Sons, Ltd.     

Monitoring of chicken meat freshness by means of a colorimetric sensor array

A new optoelectronic nose to monitor chicken meat ageing has been developed. It is based on 16 pigments prepared by the incorporation of different dyes (pH indicators, Lewis acids, hydrogen-bonding derivatives, selective probes and natural dyes) into inorganic materials (UVM-7, silica and alumina). The colour changes of the sensor array were characteristic of chicken ageing in a modified packaging atmosphere (30% CO(2)-70% N(2)). The chromogenic array data were processed with qualitative (PCA) and quantitative (PLS) tools. The PCA statistical analysis showed a high degree of dispersion, with nine dimensions required to explain 95% of variance. Despite this high dimensionality, a tridimensional representation of the three principal components was able to differentiate ageing with 2-day intervals. Moreover, the PLS statistical analysis allows the creation of a model to correlate the chromogenic data with chicken meat ageing. The model offers a PLS prediction model for ageing with values of 0.9937, 0.0389 and 0.994 for the slope, the intercept and the regression coefficient, respectively, and is in agreement with the perfect fit between the predicted and measured values observed. The results suggest the feasibility of this system to help develop optoelectronic noses that monitor food freshness.