Buckwheat—the source of antioxidant activity in functional foods

Antioxidant activities of buckwheat seeds, dehulled seeds, hulls, straws and leaves were evaluated and compared with those of oats and barley. Schaal oven test at 70 °C with gravimetric indication and lard as the substrate was applied. Protection factors ranged from 1.3 to 8.0 and increased in the order: buckwheat straws < buckwheat hulls = oats <barley <buckwheat seeds <buckwheat dehulled seeds <buckwheat leaves. Methanol extract of buckwheat seeds showed higher antioxidant activity in comparison with petrolether extract, protection factors amounted to 2.9 and 1.9, respectively Total phenolics, rutin and tocol contents in tested samples were determined and related to the antioxidant activities. Statistically significant relationship between total phenolics content as well as rutin content and antioxidant activity of buckwheat material was observed (R² = 0.987, P <0,002, R² = 0.972, P<0.002, respectively) Significant correlation between tocol content and antioxidant activity was not found.     

Determination of mineral oil paraffins in foods by on-line HPLC–GC–FID: lowered detection limit; contamination of sunflower seeds and oils

A method is described to lower the detection limit for mineral oil saturated hydrocarbons (MOSH) in foods as compared to the on-line HPLC–LC–GC–FID method described previously: samples are preseparated (enriched) by conventional liquid chromatography on activated silica gel and activated aluminum oxide. The silica gel retains up to 1 g of fat or oil, the aluminum oxide up to 2 mg n-alkanes of at least 24 carbon atoms, i.e. plant paraffins which may severely hinder the analysis of the mineral paraffins. The efficacy of the method is shown for an apple and sunflower oil. Oils extracted from manually harvested seeds grown in fields or gardens contained between 0.14 and 0.77 mg/kg MOSH. In the oils from seeds sampled in an oil mill, this value was increased to 3.3–9.3 mg/kg, indicating a contamination during harvest, transport and/or storage. Concentrations in commercial refined sunflower oils ranged between 2.7 and 32 mg/kg, averaging 11.2 mg/kg. Since deodorization removes a substantial part of the MOSH, this suggests a further contamination in the oil mill. The contamination affected all samples at a similar level, indicating that it occurs systematically by the presently used technology.     

Determination of protein in foods: comparison of net protein and crude protein (N × 6.25) values

The purpose of the present study was: (1) to determine net (true) protein (NP) values as sums of amino acid residues and to compare them with crude protein (PA) values; and (2) to calculate the nitrogen-to-NP conversion factors by means of linear regression analyses between the NP values and nitrogen content. The differences between NP and PA values varied between food groups. The NP values in milk and milk products were, on average, 5.5% smaller than the corresponding PA values. The corresponding figures for other foods were: meat and meat products 15.4%, fish and fish products 20.6%, cereals and bakery products 12.2%, vegetables, fruits and berries 13.9% and miscellaneous processed foods 16.1%. In the present study the nitrogen-to-NP conversion factor for milk and milk products was 5.94, meat and meat products 5.17, fish and fish products 4.94, cereals and bakery products 5.40, vegetables, fruits and berries 5.36 and miscellaneous processed foods 5.51; the general conversion factor for all foods was 5.33. The above respective factors were 5.0, 17.3,21.0, 13.6, 14.2, 11.8 and 14.7% smaller than the official factor of 6.25. We conclude that the traditional PA values (N × 6.25) deviate significantly from the NP values. We recommend that protein definitions and methods of determination should be re-evaluated in the appropriate international organizations and updated in line with current knowledge and analytical capabilities for both scientific and other purposes.     

Utilization of plant extracts to control the safety and quality of fried foods—A review

Frying is one of the most common methods of preparing foods. However, it may lead to the formation of potentially hazardous substances, such as acrylamide, heterocyclic amines, trans fatty acids, advanced glycation end products, hydroxymethyl furfural and polycyclic aromatic hydrocarbons, and adversely alter the desirable sensory attributes of foods, thereby reducing the safety and quality of fried foods. Currently, the formation of toxic substances is usually reduced by pretreatment of the raw materials, optimization of process parameters, and the use of coatings. However, many of these strategies are not highly effective at inhibiting the formation of these undesirable reaction products. Plant extracts can be used for this purpose because of their abundance, safety, and beneficial functional attributes. In this article, we focus on the potential of using plant extracts to inhibit the formation of hazardous substances, so as to improve the safety of fried food. In addition, we also summarized the effects of plant extracts, which inhibit the production of hazardous substances, on food sensory aspects (flavor, color, texture, and taste). Finally, we highlight areas where further research is required.     

Electrostatic powder coating of foods – State of the art and opportunities

Edible coatings and incorporation of active ingredients can improve food quality (appearance, taste, flavours, and increased shelf life). In this paper, specific emphasis is given to electrostatic application of powder coatings that is known for high transfer efficiency and even coating. This application technique has the potential to reduce excessive use of coating material (up to 68%) and minimise dust release (up to 84%) to the environment. Different parameters (e.g. powder particle size) are discussed that influence powder coating quality and efficiency for both non-electrostatic and electrostatic powder application. Typical food processing systems are reviewed that can be combined with electrostatic powder coating. Finally, an overview of electrostatically coated food products and a short outlook of electrostatic powder coating of foods are given.     

Undesirable and harmful metals in wines—Determination and removal

A method is described for the lowering or removal of the metal content of wines. For this purpose, a chelating material is employed, formed from cellulose functionalized with iminodiacetic acid. Its use allows, first, a preconcentration of metals present at trace levels and, secondly, a lowering or removal of undesirable metals. Possible matrix effects, both by organic and inorganic components, have been considered and allowed for in the analytical determination.     

Determination of free α-lipoic acid in foodstuffs by HPLC coupled with CEAD and ESI-MS

A simple and rapid method for determination of free α-lipoic acid in different food matrices has been developed. It consists of extraction of α-lipoic acid with 0.5% glacial acetic acid in methanol by sonication, quantitative analysis of the extract by isocratic RP-HPLC (acetonitrile/methanol/50 mM potassium dihydrogen phosphate buffer adjusted to pH 3 with phosphoric acid: 350/65/585, v:v:v) at a flow rate of 0.45 ml/min coupled with coulometric electrode array detection at potentials between +300 and +700 mV and qualitative analysis by LC–ESI-MS in the negative ion mode for confirmation. Egg, dried egg powder, mayonnaise, fine peas and potatoes were analysed and free α-lipoic acid contents ranged from 0.1 to 4.2 μg/g with recoveries between 70% and 94%. Limits of quantitation were between 0.1 and 0.3 μg/g. This newly developed method can be used to establish a database for the content of free α-lipoic acid in different foodstuffs.     

International investment in developing country agriculture—issues and challenges

The recent surge of international investment in developing country agriculture has generated considerable debate. Some of the largest transactions involve investors from the Gulf States purchasing or leasing land in poor, food-insecure African countries, to grow food that will be exported back to the investing country. Unlike the investments of the past, these are resource-seeking rather than market-seeking, and involve acquisition of land and actual production rather than looser forms of joint venture. Investing countries appear to be driven by food security concerns, including price volatility and market risks faced by large food importers. Host countries have been equally keen to attract such investment, for various potential benefits—but there are concerns about whether these benefits will be realized, and about lack of community involvement in the decision process. This paper discusses the nature and driving forces behind these investments, and the economic, political, institutional, legal and ethical issues they raise for host countries, investors and the international community. The paper suggests that alternative approaches might be as effective, and more acceptable, than long-term leases or outright purchases. Further, an international initiative (voluntary code of conduct, guidelines, statement of principles etc.) could highlight host country interests and also guide investors toward socially responsible investment.     

The microbiological profile of foods in the Republic of Cyprus: 1991–2000

In Cyprus, as part of the exercised official food microbiological control, 28 835 of a large variety of foodstuffs were examined during the years 1991–2000. Parameters examined included Salmonella spp., Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Vibrio spp., E.coli and aerobic plate count. The results indicate a prevalence of 1·8% for Salmonella spp. and L. monocytogenes, with desserts ranking first as the primary vehicle for Salmonella spp. and cured meats for L. monocytogenes. S. aureus was isolated in 0·7% of the samples examined in significant, potentially hazardous levels (>10⁴ cfu g⁻¹), whereas B. cereus in 1% of the samples in numbers (>10⁴ cfu g⁻¹). The most common food vehicle for both pathogens was found to be traditional Cyprus cheese. V. parahaemolyticus and V. cholerae non-01 were isolated exclusively from imported frozen, raw prawns and shrimps at isolation rates of 6·9% and 1·3%, respectively. The incidence of E. coli at levels >10² g⁻¹ amounted to 6% of the samples examined, with traditional Cyprus cheese being the leading food vehicle. High aerobic plate counts were found in desserts, ready-to-eat meals, sandwiches and cured, non-fermented meats. The results presented in this paper indicate for the most part the good microbiological quality achieved by the majority of the food industry in Cyprus.     

Ethyl carbamate in fermented foods and beverages: dietary exposure of the Hong Kong population in 2007–2008

To evaluate the potential public health risk of ethyl carbamate (EC), EC exposure from fermented foods and beverages for Hong Kong population was estimated. In 276 samples analysed, EC was detected (limit of detection (LOD) at 0.4?µg?kg^?1) in 202 samples (73%), with higher levels in fermented red bean curd (150–650?µg?kg^?1) and yellow wine (140–390?µg?kg^?1), while low or non-detected (ND) in preserved vegetables (ND–10?µg?kg^?1) and fermented tea (ND–15?µg?kg^?1). The estimated dietary exposure from all fermented foods and beverages was 8.27?ng?kg^?1?bw?day^?1, while exposure excluding alcoholic beverages was 5.42?ng?kg^?1?bw?day^?1, with calculated margins of exposure (MOEs) at 3.6?×?10⁴ and 5.5?×?10⁴ respectively. The risk of adverse health effects was low for the average population but higher (MOE?of?10³) for high consumers of alcoholic beverages especially habitual drinkers of alcoholic types with high EC contents.     

Influence of different extraction conditions on the detection of glycinin and β-conglycinin in model processed foods by ELISA

ABSTRACT

The presence of undeclared soy proteins in food can cause severe reactions in soy allergic individuals. The extraction of target proteins from processed foods is a crucial step in allergen detection by immunoassays, as only successfully extracted target proteins can be detected by the specific antibodies. The effectiveness was studied of different conditions (type of buffer, temperature and time of incubation) on the extraction of total protein, and concentration of glycinin and β-conglycinin from different food matrices. The yields were determined using a soy protein isolate and three processed foods (sausage, bread and pâté) incurred with soy proteins. The yields were affected by the processing of analysed products and the composition and pH of the extraction buffers. Neutral and alkaline buffers (pH from 7.4 to 10.6) exhibited good protein extraction capacity and detectability of the specific target proteins. Denaturing additives and highly alkaline buffer (pH 12) extracted more crude protein but they were incompatible with the ELISA assay. Overall, the best results were obtained using phosphate (pH 7.4) and Tris/HCl (pH 8.5) buffers in the presence of 0.5 M NaCl. Crude protein yield of food extracts did not correlate with that of glycinin and β-conglycinin, whereas a good relationship was found between the yields of the two proteins.     

Determination of phthalate esters in non-alcoholic beverages by GC–MS and optimization of the extraction conditions

A quantificational method for 7 phthalate esters in non-alcoholic beverages was developed. Dimethyl phthalate, di-ethyl phthalate, di-propyl phthalate (DPP), di-butyl phthalate (DBP), benzyl butyl phthalate, di-(2-ethylhexyl) phthalate (DEHP), and di-octyl phthalate (DOP) were extracted from non-alcoholic beverages with the optimized solid-phase extraction method, and quantification was achieved by gas chromatography–mass spectrometry with isotope internal standard of d₄-di-(2-ethylhexyl) phthalate (DEHP-d₄). The inter-day method repeatability (RSD) was 8–13 %, whereas the intra-day method repeatability (RSD) was 9–15 %. The mean spiking recoveries were 84–105 %. A wide variety of phthalate concentrations was observed in 48 non-alcoholic beverages. DEHP was the most abundant phthalate compound followed by DBP, DPP, and DOP. DEHP was found in sport drinks (0.015–0.098 mg L^?1), tea (0.016–0.123 mg L^?1), coffee (0.028–0.159 mg L^?1), and fruit juices (0.022–0.126 mg L^?1).     

Building professionals’ attitudes towards the use of wood in building design and construction in Taiwan

This study aims to analyse the attitudes of building professionals towards the use of wood in building design and construction in Taiwan, and to investigate how professionals’ backgrounds affect their attitudes upon the wood usage using statistical analysis. 123 valid questionnaires were collected from various building professionals, including architecture students, architects, interior designers and building construction engineers. It has been shown that wood is regarded as the most environmentally-friendly material in building design and construction. ‘Beauty’ and ‘proprietor’ are the most two essential factors identified by professionals that may influence their decisions to use wood, whereas the deconstruction phase and post-use of demolished wood are considered less important. With respect to the wood utilisation in construction, building professionals prefer using wood in the substructure to main structure at present. On the other hand, the differences between professionals’ experience in designing wood houses or wood elements, and their attitudes towards the importance of reasons in using wood are generally insignificant, except for the easy assembly (p = 0.03) and easy disassembly (p = 0.02) of wood construction. Professionals in favour of wood substitution are more likely to choose wood in column, beam, window, outdoor wall and door. Moreover, there are significant differences between professionals’ occupations and their opinions upon the recyclability issues of materials (p = 0.02). In the future, more sufficient communications are required through the design process among various professional groups.     

Novel foods and food ingredients: what is the mission of scientists and technologists?

The situation concerning world food production is changing dramatically. On the one hand, the world population is expected to grow still further, reaching about 8 billion people in the middle of the 21st century. Novel phenomena, such as ageing of the human population and excess weight in developing countries pose new nutrition problems. Food scares, which were enhanced by recent BSE and toxicological outbreaks, hinder the applicability of some solutions. Under these conditions, scientists and technologists should participate actively in the tasks of informing the population as well as finding new ways to provide people with the optimal amount of nutritious food.     

Naturally-occurring folates in foods: Method development and analysis using liquid chromatography–tandem mass spectrometry (LC–MS/MS)

An accurate method for detecting and quantifying both synthetic (folic acid) and naturally-occurring folates in foods is described. A system capable of analysing the five most commonly occurring folates (pteroylglutamic acid, 5-methyltetrahydrofolate, tetrahydrofolate, 10-formylfolate and 5-formyltetrahydrofolate) in 20 min using liquid chromatography–tandem mass spectrometry (LC–MS/MS) was developed. Quantification of folates was performed using ¹³C labelled internal standards. This paper outlines the development of a comparatively fast LC–MS/MS method, method validation using commercially available folate standards and establishment of the method’s suitability for quantification using selected reaction monitoring (SRM) mass spectrometry. The application of the system was verified by analysing several certified reference materials and comparing results with certified values as determined by microbiological assay. LC–MS/MS promises to be an ideal tool for the quantitative analysis of folates in food.     

Simultaneous Determination of Biogenic Amines and Methylxanthines in Foodstuff—Sample Preparation with HPLC-DAD-FL Analysis

Chromatographic system for simultaneous determination of levodopa, biogenic amines, and methylxanthines in food has been developed. Chromatographic column and pre-column with octadecylsilane phase and simultaneously fluorescence and DAD detectors have been used. Gradient elution with acetate buffer (pH?=?4.66) with acetonitrile has been applied. Examination included levodopa, norepinephrine, dopamine, normetanephrine, tyramine, and serotonin as well as caffeine, theophylline, and theobromine. Limit of detection (LOD) and limit of quantitation (LOQ) have been determined for all compounds with signal to noise ratio (S/N) equal to 3 and 10, respectively. LOD of 10 ng/mL and LOQ of 30 ng/mL for levodopa and biogenic amines as well as LOD of 70 (60)?ng/mL and LOQ of 210 (180)?ng/mL for methylxanthines have been determined. Authors have also developed method for simultaneous separation of all analytes from food matrix. Developed chromatographic system with sample preparation method has been applied for determination of examined compounds in cocoa products, vegetables, and fruits.     

Application of GC–MSD and LC–MS/MS for the determination of priority pesticides in baby foods in Serbian market

Babies and small children are especially sensitive population to the exposure to environmental contaminants. Their small mass and developing systems, including brain development may show adverse health effects from even low levels of contamination on a chronic or single dose case. In this paper one extraction method and two chromatographic techniques for the determination of pesticide residues in baby food were evaluated. A liquid chromatography–tandem mass spectrometry technique combined with electrospray ionization (ESI), (LC–MS/MS) and gas chromatography–mass spectrometry detection (GC–MSD) technique were applied in the detection of 50 pesticides in baby food. So-called QuEChERS (quick, easy, cheap, effective, rugged and safe) method was used as a sample preparation procedure. The recoveries were investigated at three levels (5, 10 and 50 μg/kg) and the results obtained showed compliance with the contemporary EU requirements with a few exceptions. LOQs for most of the tested pesticides were below the EU MRLs (10 μg/kg), except deltamethrin, cypermethrin, fenvalerate, phosalone and beta-cyfluthrin (LOQs were 10 μg/kg). Both techniques were applied in the analysis of 50 samples of baby food manufactured in Serbia.     

Determination of ochratoxin A in traditional Chinese medicinal plants by HPLC–FLD

Traditional Chinese medicinal plants (TCMPs), commonly used as spices, additives or foods, are also widely used in China to prevent and cure human disease. Due to their provenance, TCMPs may be contaminated by various fungal species, including ochratoxigenic fungi, during growth, collection, transportation and, especially, storage. A reliable method for the determination of ochratoxin A (OTA) in TCMPs of different origins was developed to monitor OTA levels in China. Analyses involved the extraction of OTA by methanol/water, immunoaffinity column (IAC) clean-up and HPLC quantification with fluorescence detection (FLD). Positive results were further confirmed by LC–ESI–MS/MS. The limit of detection (LOD) was 0.3 µg kg^?1, based on a signal-to-noise ratio of 3 : 1. Among the total of 57 TCMPs samples collected from six different areas, 31 were visibly moldy due to inappropriate storage; 26 sample, purchased from local TCMPs markets, were not visibly moldy. The results showed that 23 of the visibly moldy samples and two of the not visibly moldy were contaminated with OTA at levels ranging 1.2–158.7 and 2.5–5.6 µg kg^?1, respectively. This is the first report of the natural occurrence of OTA in TCMPs.