Aquaphotomics: an innovative application of near-infrared spectroscopy focusing on water



Authors: Flóra Vitális, Zsanett Bodor, John-Lewis Zinia Zaukuu, György Bázár, Zoltán Kovács

SUMMARY

In the field of food science, indirect methods which can be used to determine a certain property of the sample by correlating the measured physico-chemical characteristics are widely applied for the detection of food counterfeiting. Near infrared spectroscopy (NIR), complemented by multivariate statistical analyses, is a quick, non-destructive method that does not require sample preparation in most cases. The interactions that can be observed between aqueous systems or aqueous solutions and electromagnetic radiation (light), i.e., the effects of different perturbations on the structural and functional properties of water, are investigated by a new and dynamically evolving area of science called aquaphotomics. It has been proven by a number of research results that by applying the so-called “water-mirror approach”, the detection limits that can be obtained using the conventional approach can be overcome in aqueous systems, and in certain cases components that are present in concentrations that are a few orders of magnitude lower than usual can be detected. The technique of aquaphotomics has been tested in diverse areas of science such as medicine, microbiology, plant physiology or food analysis. In our series of experiments, the detectability of the counterfeiting of ground paprika samples using 0 to 40% corn flour has been investigated by applying the method of aquaphotomics to their solutions. During the evaluation of the results, the first harmonic range of water (1,300-1,600 nm) was used. Spectral patterns were represented on an aquagram, and then a model for estimating the corn flour content was constructed using the Partial Least Squares Regression (PLSR) method. PLSR results showed a strong correlation between the added amount of corn flour and the amount estimated by NIR (near-infrared) spectroscopy. Samples with a lower corn flour content (0-3%) showed a greater absorbance around 1,450 nm, while samples with a higher corn flour content (15-40%) exhibited a greater absorbance between 1,364 and 1,412 nm. These differences are explained by the spectral absorption of water bound with hydrogen bonds to varying degrees. Research results from recent years show that aquaphotomics is a promising technique in many areas of science, including food science.

 

 

VOL. 65, 2019 NO. 4

 

 

Welcome 2019/4

 

Dear Readers,

It’s the first decade of November when we are editing the last issue of the year. The landscape of the field is gloomy, humping, the city dressed in gray fog, the dusk is coming so soon. “It would be autumn yet, and the crows had already bugle the coming of freezing winter.” However, in a friendly warm office, during the time of compiling the December issue of JFI volume 65, I am gladly note that our editorial staff is constantly receiving valuable manuscripts for publication. Many thanks to the authors for the scientific articles! 

The leading material of our winter issue was written by Flora Vitális and her colleagues. The topic of their article is about the possibilities of examining the water molecule by vibrational spectroscopy, covering the field of food analysis and applied research. The analytical technique is aquaphotomics, is investigating the behavior of water molecules using infrared (NIR) spectroscopy promises revolutionary methods of rapid analysis of food and other products. This measurement technique involves the analysis of the absorption coordinates of the O-H valence vibrations of water typically in the 1300 and 1600 cm-1 range, applying multivariate mathematical statistics methods. The absorption profile is closely dependent on the chemical and physical matrix surrounding the water molecules. The particular significance of this topic is that, the second European Aquaphotomics Conference will be held in Budapest at the time of the closing date of JFI.

 

 

Sincerely,

 

Dr. Tamás János Szigeti
editor-in-chief

 

1 Sándor Kányádi: It would be fall

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Analysis of the amino acid composition of pollen and honey



Authors: Rita Végh, Zsuzsanna Mednyánszky, Mária Amtmann


Nowadays, an important direction in food analytical research is the development of methods for detecting honey counterfeiting. The amino acids in honey come mainly from pollen, raising the possibility of origin determination based on the examination of amino acid composition [1]. In our research, the free amino acid composition of single flower honeys and the pollen from their original plants were compared. According to our results, there is no correlation between the amino acid profiles of the pollen and the honeys, which is mainly due to the fact that it is rare that the pollen composition of single flower honeys strongly reflects the flower character. Our results support the hypothesis that proline comes from the bees, and the proline content of the pollen contributes to the high proline content of honey only marginally. Pollen pellet samples also contain large amounts of nectar and glandular secretions in addition to the pollen, and thus have a significantly lower free amino acid content than pollen samples collected directly from the flowers. In the course of the research, the total amino acid content of the pollen pellets was in the 6 to 16% range. Compared to other amino acids, proline was present in a significantly higher proportion in the free form than in the protein-bound form. There are contradictory data in the literature regarding the ability of bees to select among different pollens according to their needs [2, 3]. According to our results, the amino acid composition of pellets selected by the bees reflects their amino acid requirements better than unifloral samples. The rapeseed pellet, which is particularly preferred by the bees, has an amino acid composition that is different from the optimal one, but it has an outstanding essential amino acid content, so it is likely that a quantitative, and not qualitative protein intake regulation is carried out by the bees.

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Functional bread, or the effects of garlic and its products on certain parameters of bread



Authors: Andrea Kántor, László Ádám Fischinger, Loránd Alexa, Emőke Papp-Topa, Béla Kovács, Nikolett Czipa


Nowadays, bread is consumed almost every day. Since the beneficial effects of garlic are well-known, we thought that by baking it into bread, a delicious product with physiological benefits could be created. For the experiment, garlic, garlic paste and granulated garlic were used in different concentrations, which were selected on the basis of preliminary studies. For the finished products, it was examined to what extent the enrichments changed the amount of antioxidants and macronutrients in the finished products compared to our control bread. Results were also analyzed using a statistical program, based on which it was found that there were verifiable differences between the experimental loaves in the parameters examined. There was a clear increase in the total polyphenol content, however, varied results were obtained in the case of element content.

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Comparison of chemical characteristics and technological parameters in durum wheat based breads enriched with hemp seed flour



Authors: Eszter Benes, Ildikó Szedljak


Society is getting increasingly food-conscious these days. It can be observed that, in addition to basic cereals such as wheat, rye or maize, the grains of other cereals, pseudocereals and other types of plants that had not been on the market in significant amount have also been appearing. The nutritional values of these plants contribute greatly to the improvement of flour quality. By making various flour blends, we can help produce complete bakery products that are more valuable than the usual ones.Bread is a food whose production uses simple ingredients such as wheat flour, salt, yeast and water. This is why, in many countries, it is the most commonly consumed cereal product that serves as the basis for the diet of many people. Due to its simplicity and widespread consumption, bread is suitable for enrichment with ingredients that provide additional health benefits to consumers. In order to prevent diseases [1], laypeople, as well as professionals consume increasing amounts of foods considered to be healthier than average these days, with the intention, inter alia, of preventing or at least reducing the use of medicinal products obtained in order to maintain or improve their health. Foods with a higher polyphenol content, which may contribute to the prevention of harmful oxidation processes in the human body, may be suitable for this purpose [2]. In the spirit of the above, for the breads prepared by us, flour blends of various compositions were made using durum flour (Triticum durum L.) and hemp seed flour (Cannabis sativa L.). Certain chemical parameters were analyzed in the course of the measurements during the preparation of the breads.

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Environmental impact of food products and difficulties in quantifying them



Authors: Éva Erdélyi, Tímea Jakuschné Kocsis, Judit Lovasné Avató


Agricultural production, the food industry and the transportation of foods all pollute our environment. Of the various aspects of the environmental impact, more and more attention is paid to the contribution of the food industry to greenhouse gas emission, and thus to climate change. There is a large number of studies in the international literature on comparing the gas emissions during the manufacture of plant and animal products, or on the measurement of greenhouse gas emissions during the manufacture of various agricultural and food products. These quantities may be given cumulatively in carbon dioxide equivalent, which is called the carbon footprint of the product, but the methods used to calculate them are not standardized. The guidance of PAS 2070 or standard ISO14067 may be used. These methods are based on product life cycle analysis (LCA), i.e., they provide the amount of greenhouse gas produced in the manufacturing process, after taking into account the resources used in manufacture of the product, the raw materials used, the production of the packaging materials, transportation and the energy use. In many cases, food reaches the consumer at the end of a long supply chain. The part of the product life cycle related to becoming waste and waste management can also be considered. In this case, a “from cradle to cradle” approach to life cycle analysis is followed. However, it is difficult to gather the appropriate data for the compilation of the raw material map and for process mapping; in our paper, this is presented through an example that may seem simple at first. It is particularly difficult if the goal is to determine the carbon footprint of not foods to be placed on the counters, but prepared foods consumed in restaurants. It is important to set boundaries during process evaluation within which the carbon footprint of a certain part of the entire chain can be calculated reliably on the basis of reliable data.

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Local Panorama 2019/4



They made it from the lake to the table: the excellent Hungarian fish! 

The first comprehensive research project in Hungary, investigating the contamination level of fish ponds, inorganic and organic pollutant content of fish, the impact of processing and transportation as well as microbiological risks provided promising results.

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Outlook 2019/4



EFSA News

Xylella fastidiosa: ‘Together we can find solutions’

The whole EU territory is at risk from Xylella fastidiosa, and the more the scientific community works together on this issue, the quicker we’ll be to find solutions to tackle this pest.” That was how Claude Bragard, chair of EFSA’s Panel on Plant Health, summed up the importance of the conference on X. fastidiosa held in Corsica this week.

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