Food and Beverage Analysis

Researchers at the University of Castilla-La Mancha (Spain), Ecole Nationale des Sciences Appliquees (Agadir, Morocco), and Institut Agronomique et Veterinaire Hassan II (Agadir, Morocco) developed a method for screening paraquat and diquat in olive oil samples.

American and European Foulbrood in honeybees is caused by two bacterial species, Paenibacillus larvae and Melissococcus pluton, respectively. For control of these bacteria, only a few antibiotics are recommended in Europe and the U.S.A. However, a variety of antibacterial agents are used, the sulfa drugs being the most popular. Residues of these antibiotics are quite often found in honey samples and are of concern to consumers around the world due to toxic or allergic reactions. Earlier sample preparation methods involved using silica-based C18 or neutral polymers as sorbents with an aqueous wash prior to elution of sulfonamides. In this communication, we describe a simple and effective method for cleanup and quantitation of antibacterial sulfonamides from honey using the polymeric strong cation exchange SPE sorbent strata-X-C and a Gemini HPLC column.

In March 2007, several North American manufacturers of pet food voluntarily issued nationwide recall notices for some of their products that were reportedly associated with renal failure in pets. The raw material wheat gluten, used to manufacture the pet food, was imported from China and was identified as the source of contamination.

A new technique, QuEChERS, standing for Quick, Easy, Cheap, Effective, Rugged, and Safe, is readily accepted by both the AOAC International and the Committee of European Normalization (CEN) for the pesticide residues in foods and agriculture products. Waters DisQuEâ„¢ Dispersive Sample Preparation Kit contains conveniently-packaged centrifuge tubes with pre-weighed sorbents and buffers designed for use with the AOAC official QuEChERS methods.

Recent developments in HRes Fast-LC systems have enabled the use of sub-3 μm stationary phases at higher flow rates and elevated pressures. HRes Fast-LC can provide significant improvements in both resolution and throughput.

Organic acids are present in many matrices and play crucial roles. Extensive research involving low molecular mass organic acids (LMMOA) has been performed in food chemistry since these acids contribute to the organoleptic properties of food and beverages, including flavor, color, aroma, taste, shelf-life, and health effects. Developing a profiling method to monitor LMMOA levels in raw materials and final products is very desirable. Many reported methods focus on limited numbers of LMMOAs and are incapable of providing a complete LMMOA profile.

Mycotoxins, toxic secondary metabolites of several fungal species, represent food safety issues of high concern. Deoxynivalenol, the most abundant trichothecene mycotoxin, can be found worldwide as a contaminant of wheat, barley, maize and other cereals (1,2). The transmission of deoxynivalenol from barley into beer has been reported in several studies (3,4). Therefore, its levels should be controlled.

This article describes a straightforward ion chromatographic method that uses isocratic elution and pulsed amperometric detection (PAD) to sensitively determine water-soluble polyols and sugar alcohols as well as mono-, di- and oligosaccharides in essential and nonessential foodstuffs. While carbohydrate determination of most foodstuffs requires only minimal sample pretreatment such as dilution and filtration, samples with interfering matrices such as protein-containing dairy products have to be dialyzed prior to injection.

Researchers from the University of Barcelona (Barcelona, Spain) analyzed heterocyclic amines in meat samples using pressurized liquid extraction followed by liquid chromatography with tandem mass spectrometry detection (LC?MS-MS).

In March 2007, several North American manufacturers of pet food voluntarily issued nationwide recall notices for some of their products that were reportedly associated with renal failure in pets. The raw material wheat gluten, used to manufacture the pet food, was imported from China and was identified as the source of contamination.

Over the last 10 years, several solvent-free microextraction techniques for gas chromatography (GC) and mass spectrometry (MS) have been developed. Two of these techniques, solid-phase microextraction (SPME) and stir-bar sorptive extraction (SBSE), are available commercially for the analysis of volatile compounds, such as flavors in foods and beverages, and toxic organic compounds in environmental applications. Other techniques, such as open tubular trapping, inside needle capillary adsorption trap (1), in-tube SPME, capillary microextraction, needle trap, and headspace solid-phase dynamic extraction (2), were also developed for different applications. The basic principle for all of these techniques is essentially the same. Volatile and semivolatile compounds are adsorbed on a sorbent coating, often packed on the interior surface of a capillary column or stainless steel needle. After the sample is concentrated on the coating, the compounds are desorbed thermally in the heated injection port of a gas..

Researchers at the Universit? di Camerino in Camerino, Italy have developed a new GC-MS and LC-MS technique for the determination of five ink photoinitiator residues: 2-isopropylthioxanthone (ITX), benzophenone, 2-ethylhexyl-4-dimethylaminobenzoate (EHDAB), 1-hydroxycyclohexyl-1-phenyl ketone (IRGACURE 184) and ethyl-4-dimethylaminobenzoate (EDAB) in packaged beverages.

Researchers from the Nutrition and Bromatology Group, Analytical and Food Chemistry Department, and Faculty of Food Science and Technology at the University of Vigo (Ourense, Spain) have developed a GC-MS method for determining residues of 12 insecticides and 11 fungicides in leafy vegetables.

Mycotoxins, toxic secondary metabolites of several fungal species, represent food safety issues of high concern. Deoxynivalenol, the most abundant trichothecene mycotoxin, can be found worldwide as a contaminant of wheat, barley, maize and other cereals (1,2). The transmission of deoxynivalenol from barley into beer has been reported in several studies (3,4). Therefore, its levels should be controlled.

Supercritical fluid chromatography (SFC) is a normal phase separation technique. In SFC, supercritical CO2 in combination with one or more polar organic solvents, most commonly alcohols, is used as the mobile phase. Owing to the lack of intermolecular interactions, supercritical fluid typically possesses lower viscosity and higher diffusivity than those solvents used in traditional high performance liquid chromatography (HPLC). This allows for higher flow rates, faster analyses, and the use of longer columns for higher chromatographic efficiencies. Initially deemed a niche chromatographic technique for chiral separation, the horizon of SFC applications has rapidly expanded to include achiral analyses of natural products, biodiesel, oligomer, pesticides/herbicides, and peptides. This is due, in part, to the improvements in detection choices and performances for SFC. Evaporative light scattering detectors (ELSDs) coupled with SFC have found wide use in many pharmaceutical and chemical laboratories (1).

In March 2007, several North American manufacturers of pet food voluntarily issued nationwide recall notices for some of their products that were reportedly associated with renal failure in pets. The raw material wheat gluten, used to manufacture the pet food, was imported from China and was identified as the source of contamination.

Gel permeation chromatography (GPC) has been used as an effective cleanup procedure for removing high molecular weight interfering molecules such as lipids, pigments, proteins, and polymers before GC or HPLC analysis. The GPC cleanup method has been extensively documented (1–3) and is also recommended in US EPA SW-846 Method 3640A. To demonstrate the efficacy of this method to extract polar and nonpolar substances by using the KNAUER Smartline GPC Cleanup Unit 6500, olive oil samples were investigated by spiking these with different types of organic pollutants, including PAHs, phthalates, phenols, and triazine.

The natural colors of the food we eat add greatly to the enjoyment of life. Consequently, the art and science of recreating food's natural colors through the use of synthetic colorants is an important success factor in the food industry.

Labtronics has been pleased to announce that a leading food and beverage manufacturer has selected its Nexxis sample tracker to upgrade their existing in-house sample tests and result tracking system.

The potential of the time-of-flight mass spectrometry (TOF-MS) to innovate the analysis of soft drinks is described using gas chromatography (GC) hyphenated to TOF-MS and a new type of ion source, direct analysis in real time (DART), coupled to high-resolution TOF-MS. Head-space solid-phase microextraction (SPME) was used to isolate/extract volatile compounds followed by GC–TOF-MS to identify tainted compound in contaminated soft drinks. Direct analysis in real time–time-of-flight mass spectrometry (DART–TOF-MS) was also used to obtain negative and positive ion profiles of different soft drinks to determine the presence of various compounds, including antimicrobial preservatives, artificial sweeteners, acidulants and saccharides, without any sample preparation and chromatographic separation.

The determination of inorganic elements in food substances is critical for assessing nutritional composition and identifying food contamination sources. The inorganic elements of interest can be divided into two classes: nutritional and toxic. It is important to determine the levels of both sets of elements accurately to assess both the nutritional and the harmful impacts of food substances. Nutritional elements such as Mg, P, and Fe are present at high levels (milligrams per kilogram), while toxic elements such as Pb, Hg, and Cd should be present only at trace levels (nanograms or micrograms per kilogram).

A simple and inexpensive sample preparation method followed by reversed-phase high performance liquid chromatography (RP-HPLC) was developed to quantify oxytetracycline (OTC), chlortetracycline (CTC), and tetracycline (TC) residues in prawns. The total analytical time, including sample preparation, was 15 min for each sample and no organic solvents were used in the sample preparation or chromatography stages.

Well, it's Pittcon Day 2, and I followed the suggestion of LCGC Columnist John Hinshaw and attended session 410, "Food Science: UV-Vis, NIR, AA, LC, GC, and Electric Nose."

The techniques involved in successfully separating and quantifying amino acids vary from instrument to instrument. However, the processes for amino acid analysis are similar, involving hydrolysis, labeling, separation, and detection followed by data analysis.

The authors use GPC coupled online to multiangle laser light scattering, refractive index, and ultra violet (UV) detectors for the characterization of Acacia gum (gum arabic).

The flavours of malt whisky result from a complex blend of long chain esters and alcohols, derived from the distillation products and the composition of the wooden barrels in which the finished product is aged. As shown below, the new VF-WAXms column from Varian, Inc. is ideal for analysing whisky, especially when trace analysis is needed. The column's ultra-low bleed increases sensitivity, extends column life and improves accuracy, even at higher temperatures. In addition, VF-WAXms columns are suitable for use with MS detectors, as the ultra low bleed eliminates interferences and permits more sensitive detection.

Calvados is an apple-brandy of Normandy (France). Mashed apples are fermented to obtain cider, which is then distilled to give the young spirit.

Liquid chromatography–mass spectrometry (LC–MS) is a popular technique for the analysis of wine. This article gives an overview of wine analysis and new insights this technique has revealed regarding the composition of wine, possible health benefits, customer safety and the understanding of winemaking processes.

This month's instalment of "Sample Prep Perspectives" describes a new extraction technique called QuEChERS (standing for quick, easy, cheap, effective and safe and is pronounced "catchers") for the sample preparation of pesticides in foods and agricultural samples. The technique uses simple glassware, a minimal amount of organic solvent and various salt/buffer additives to partition analytes into an organic phase for clean up by dispersive solid-phase extraction (d-SPE). The technique provides good recoveries, is reproducible and costs less than other sample preparation approaches. The technique is being adopted by many laboratories worldwide. It has the potential for applications outside of the pesticide in foods area.