The phenolic composition of juice derived from fruits of sea buckthorn (Hippophae rhamnoides) was investigated by high-performance liquid chromatography (HPLC) with diode array and electrochemical detection. Flavonols were found to be the predominating polyphenols while phenolic acids and catechins represent minor components. Of the seven flavonols identified, isorhamnetin 3-O-glycosides were the most important representatives quantitatively. However, because of their structural properties, they were poor radical scavengers as shown by electron spin resonance spectroscopy. Phenolic compounds such as quercetin 3-O-glycosides, catechins, and hydroxybenzoic acids with a catechol structure exhibited good antioxidant capacities, but their concentration in sea buckthorn juice was small. These phenolic compounds, determined by HPLC, accounted for less than 5% of the total antioxidant activity of the filtered juice. Ascorbic acid was shown to be the major antioxidant in sea buckthorn juice. Because of its high concentration of 1.22 g/L, it contributes approximately 75% to total antioxidant activity. The remaining difference can be attributed to higher molecular weight flavan-3-ols (proanthocyanidins), which were determined photometrically after acid depolymerization to colored anthocyanidins.

With the aid of several different measuring methods it is possible to obtain an idea of the numerous possible generating mechanisms for the rolling noise of tyres. The knowledge of these noise generating processes leads to a broad spectrum of possibilities for reducing tyre noise, with each of these possibilities effecting just a small amount of noise reduction.

Craft breweries that tend to convince consumers with new interpretations of (ancient) beer styles increasingly influence the traditional beer market. Thereby, also ingredients not directly compliant with German beer purity laws come into use. Official food control currently faces the general problem of verifying food authenticity based on instrumental analytical methods. Related tasks in this field are the detection of non-labelled ingredients and the verification of product claims such as special food processing methods. For that purpose, chemometric analysis of high-resolution 1 H NMR spectra was applied for the differentiation of related beer styles including also special beers. It could be shown that pilsner style beers, wheat beers, India pale ales, sour beers, and special beers can be easily differentiated applying consecutive principal component analysis. Thereby, it turned out that crafted pilsner style beers are distinguishable from industrial pilsner style beers based on their organic acid profiles. Furthermore, three conspicuous compounds present in two different batches of only one of the beer samples were identified as allyl alcohol, 1,3-propanediol, and 3-hydroxypropionic acid directly from the NMR spectra without any further analytical efforts. Finally, the present paper serves as a proof of concept that NMR-based quantification is also possible using chemical shift information instead of signal intensities/integrals-at least in special cases.

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