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  • Author: Nastasia Belc x
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Evaluation of Fatty Acids Composition of Some Food Samples by Using GC-MS and NMR Techniques

Abstract

The purpose of this paper was to compare the composition (weight % of total identified FA) in saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids from 3 food matrices (sunflower oil, palm oil and lard) by 2 different techniques, gas chromatography - mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR). For GC-MS technique, fatty acid methyl esters (FAMEs) identification in the samples was performed by comparison of the retention times (RT) and the mass/charge (m/z) ratio characteristic of each FAME component in the reference standards used (F.A.M.E. Mix C4 - C24 and SRM®2377). FAMEs quantification from food samples was realized by applying correction factors calculated based on reference standards. NMR spectra were recorded on a Bruker Advance 400 MHz spectrometer, operating at 9.4 Tesla corresponding to the resonance frequency of 400.13 MHz for the 1H nucleus. The NMR spectra was recorded directly on the oil without any sample preparation. The difference between the mean values of the fatty acids content determined by GC-MS and NMR was not more than ± 15% for sunflower oil and lard, and ± 6% for palm oil.

Open access
Valorification of Jerusalem Artichoke Tubers (Helianthus Tuberosus) for Achieving of Functional Ingredient with High Nutritional Value

Abstract

Jerusalem artichoke tubers (Helianthus tuberosus) are distinguished by their protein, minerals (potassium, calcium, magnesium, iron, etc.) and inulin content. Inulin can be used in the diet of diabetics as a substitute of sugar, without having an impact on blood glucose. At the same time, an international study had shown that due to their inulin content, regular consumption of Jerusalem artichoke tubers can help to prevent type 2 diabetes. In this paper are presented the results of the researches performed to achieve a functional ingredient (powder) with high nutritional value by processing of Jerusalem artichoke tubers. Thus, the Jerusalem artichoke tubers (Red Jerusalem artichoke and White Jerusalem artichoke varieties) were subjected to a convective drying process at 50°C, to protect bioactive components (vitamins, phenolic compounds, etc.) to a moisture content that allow their milling and turning them into powder and, at the same time, their stability in terms of quality. The achieved functional ingredient was evaluated sensory, physicchemically and microbiologically. The powder obtained from Jerusalem artichoke tubers is characterized by their inulin-type fructans (51.60... 57.45%), crude fiber (6.85...8.27%), total polyphenols (18.51... 44.03 mg GAE/g), proteins (8.75...9.26%), iron (12.45...13.88 mg/100g), potassium (1905.44...2100.35 mg/100g), calcium (50.21...57.45mg/100g), magnesium (84.55...89.95mg/100g) and phosphorus content (300.12...345.35 mg/100g). At the same time, powder achieved from Jerusalem artichoke tubers has antioxidant potential. Due to its complex biochemical composition, the functional ingredient achieved from Jerusalem artichoke tubers can be used to fortify food and also as a sweetening agent for products destined to diabetics.

Open access