The Process of Pasting and Gelling Modified Potato Starch with LF-NMR

Currently, society expects convenience food, which is healthy, safe, and easy to prepare and eat in all conditions. On account of the increasing popularity of modified potato starch in food industry and its increasing scope of use, this study focused on improving the physical modification of native starch with temperature changes. As a result, it was found that the suggested method of starch modification with the use of microwave power of 150 W/h had an impact on the change in starch granules. The LF-NMR method determined the whole range of temperatures in which the creation of a starch polymer network occurs. Therefore, the applied LF-NMR technique is a highly promising, noninvasive physical method, which allows obtaining a better-quality structure of potato starch gels.

NMR analysis of pine tree oleoresin composition of the Pinus subgenus

Методом ЯМР проведен анализ состава живиц восьми видов сосен подрода Pinus: черной австрийской (P. nigra), аллепской (P. halepensis), горной (P. montana), жесткой (P. rigida), Коха (P. kochiana Klotsch), Муррея (P. murrayana Balf), обыкновенной (P. sylvestris) и Палласа (P. nigra subsp. pallasiana), произрастающих в различных районах. Кроме того, исследовано содержание смоляных кислот, выделенных в 1963 г. из живиц трех видов сосен того же подрода: черной австрийской, крючковатой (P. uncinata) и кулундинской (P. sylvestris ssp. Kulundensis). Установлено, что состав живиц названных видов сосен хорошо описывается наличием восьми смоляных кислот (абиетиновая, дегидроабиетиновая, изопимаровая, левопимаровая, неоабиетиновая, палюстровая, пимаровая и сандаракопимаровая) и девяти монотерпенов (камфен, 3-карен, лимонен, мирцен, α-пинен, β-пинен, терпинолен, βфелландреен, п-цимол). Количественное содержание этих смоляных кислот зависит от многих факторов (вида сосен, времени и места сбора живицы, а также условий сбора и хранения образцов). Кроме того, наблюдаются реакции изомеризации и окисления, приводящие к перераспределению состава. В изученных живицах содержание монотерпенов сильно отличается, являясь наименьшим у сосны аллепской и наибольшим у сосны обыкновенной. The NMR method was used to analyze oleoresin composition of eight species of Pinus subgenus: Austrian black (P. nigra), Alleps (P. halepensis), mountain (P. montana), hard (P. rigida), Koch (P. kochiana Klotsch), Murray (P. murrayana Balf), common (P. sylvestris) and Pallas (P. nigra subsp. pallasiana) growing in different areas. In addition, the content of resin acids isolated in 1963 from the oleoresins of three species of pines belonging to the same subgenus: black Austrian, hooked (P. uncinata) and Kulunda (P. sylvestris ssp. Kulundensis) was studied. It was found that the oleoresin composition of the named pine species is well described by the presence of eight resin acids (abietic, dehydroabietic, isopimaric, levopimaric, neoabietic, palustrine, pimaric and sandaracopymaric) and nine monoterpenes (camphor, 3-caren, limonene, myrcene, α-pinene, β-pinene, terpinolen, β-felandreene, p-cymol). The quantitative content of these resin acids depends on many factors (pine species, time and place of oleoresin collection, and sample collection and storage conditions). In addition, isomerization and oxidation reactions are observed, leading to a redistribution of the composition. In the studied oleoresins, the content of monoterpenes differs greatly, being the lowest in Alleps pine and the highest in Scots pine.

Development and Validation of a Simple Method to Quantify Contents of Phospholipids in Krill Oil by Fourier-Transform Infrared Spectroscopy

This study focuses on developing a quantification method for phosphatidylcholine (PC) and total phospholipid (PL) in krill oil using Fourier-transform infrared (FT-IR) spectroscopy. Signals derived from the choline and phosphate groups were selected as indicator variables for determining PC and total PL content; calibration curves with a correlation coefficient of >0.988 were constructed with calibration samples prepared by mixing krill oil raw material and fish oil in different ratios. The limit of detection (LOD, 0.35–3.29%) of the method was suitable for the designed assay with good accuracy (97.90–100.33%). The relative standard deviations for repeatability (0.90–2.31%) were acceptable. Therefore, both the methods using absorbance and that using second-derivative were confirmed to be suitable for quantitative analysis. When applying this method to test samples, including supplements, the PC content and total PL content were in good agreement with an average difference of 2–3% compared to the 31P NMR method. These results confirmed that the FT-IR method can be used as a convenient and rapid alternative to the 31P NMR method for quantifying PLs in krill oil.

Comparison of bacteria disintegration methods and their influence on data analysis in metabolomics

Metabolomic experiments usually contain many different steps, each of which can strongly influence the obtained results. In this work, metabolic analyses of six bacterial strains were performed in light of three different bacterial cell disintegration methods. Three strains were gram-negative (Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae), and three were gram-positive (Corynebacterium glutamicum, Bacillus cereus, and Enterococcus faecalis). For extraction, the methanol–water extraction method (1:1) was chosen. To compare the efficiency of different cell disintegration methods, sonication, sand mill, and tissue lyser were used. For bacterial extract metabolite analysis, 1H NMR together with univariate and multivariate analyses were applied. The obtained results showed that metabolite concentrations are strongly dependent on the cell lysing methodology used and are different for various bacterial strains. The results clearly show that one of the disruption methods gives the highest concentration for most identified compounds (e. g. sand mill for E. faecalis and tissue lyser for B. cereus). This study indicated that the comparison of samples prepared by different procedures can lead to false or imprecise results, leaving an imprint of the disintegration method. Furthermore, the presented results showed that NMR might be a useful bacterial strain identification and differentiation method. In addition to disintegration method comparison, the metabolic profiles of each elaborated strain were analyzed, and each exhibited its metabolic profile. Some metabolites were identified by the 1H NMR method in only one strain. The results of multivariate data analyses (PCA) show that regardless of the disintegration method used, the strain group can be identified. Presented results can be significant for all types of microbial studies containing the metabolomic targeted and non-targeted analysis.