Volatile Metabolism of Wine Grape Trincadeira: Impact of Infection with Botrytis cinerea

The aroma of grapes is cultivar dependent and is influenced by terroir, vineyard practices, and abiotic and biotic stresses. Trincadeira is a non-aromatic variety associated with low phenolic content and high sugar and organic acid levels. This cultivar, widely used in Portuguese wines, presents high susceptibility to Botrytis cinerea. This work aimed to characterise the volatile profile of Trincadeira grapes and how it changes under infection with B. cinerea. Thirty-six volatile organic compounds were identified, from different functional groups, namely alcohols, ester acetates, fatty acid esters, fatty acids, aldehydes, and products of the lipoxygenase pathway. Both free and glycosidic volatile organic compounds were analysed by Gas Chromatography and Gas Chromatography coupled to Mass Spectrometry for component quantification and identification, respectively. A multivariance analysis showed a clear discrimination between healthy and infected grapes with 2-trans-hexenal and isoamyl-acetate among the compounds identified as negative and positive markers of infection, respectively. Ester acetates such as 2-phenylethyl acetate, isoamyl acetate, and 2-methylbutyl acetate were present in higher contents in infected samples, whereas the contents of several fatty acid esters, such as ethyl decanoate and ethyl dodecanoate, decreased. These data were integrated with quantitative PCR data regarding genes involved in volatile metabolism and showed up-regulation of a gene coding for Hydroperoxide Lyase 2 in infected grapes. Altogether, these changes in volatile metabolism indicate an impact on the grape quality and may be related to defence against B. cinerea. The presence/absence of specific compounds might be used as infection biomarkers in the assessment of Trincadeira grapes’ quality.

Pour point depressants for fuels based on tall oil fatty acid esters

С целью расширения области применения жирных кислот таллового масла – побочного продукта сульфатной варки целлюлозы (которые преимущественно состоят из непредельных С18-кислот), в том числе за счет получения различных синтетических продуктов на их основе, синтезированы соответствующие этиленгликолевый и додециловый эфиры. Изучена возможность применения указанных сложных эфиров в качестве депрессорных присадок для марок универсального топливного мазута и судового экологического топлива. Жирные кислоты этерифицированы 1-додеканолом и этиленгликолем в присутствии катализатора п-толуолсульфокислоты. Температуру текучести топлив определяли ручным методом по стандарту ASTM D97. Температура текучести топлива судового экологического снизилась с +21 до 0 °С при использовании 2% додецилового эфира жирных кислот в качестве присадки. Установлено, что синтезированные эфиры жирных кислот таллового масла снижают температуру текучести остаточных топлив на уровне, сравнимом с применением промышленно производимой депрессорной присадки, что позволяет расширить сырьевую базу присадок этого типа и сократить закупки по импорту, а также более глубоко использовать жирные кислоты таллового масла в органическом синтезе. In order to expand the field of application of tall oil fatty acids, a by-product of sulfate pulping (which mainly consist of unsaturated C18 acids), including the production of various synthetic products based on them, the corresponding ethylene glycol and dodecyl esters have been synthesized. The possibility of application the esters as pour point depressants for grades of universal fuel oil and marine ecological fuel has been studied. Fatty acids were esterified with 1-dodecanol and ethylene glycol in the presence of a p-toluenesulfonic acid as catalyst. The pour point of the fuels was determined manually according to the ASTM D97 standard. The pour point of ecological marine fuel decreased from +21 to 0 °C when using 2% dodecyl ester of fatty acids as an additive. It was found that the synthesized esters of tall oil fatty acids reduce the pour point of residual fuels at a level comparable to the use of a commercially produced depressant additive, which makes it possible to expand the feedstock base of this type of additives and reduce import purchases, as well as to use more extensively tall oil fatty acids in organic synthesis.

Medium chain fatty acids and fatty acid esters as potential markers of alcoholic fermentation of white wines

Aroma components of wines play an important role in the sensory quality of wines. In our paper we investigate the effect of commercially available yeast nutrients under different fermentation parameters. Caproic acid, caprylic acid, capric acid, and different fatty acid esters were used as markers of the alcoholic fermentation process. The optimal temperature for the fermentation of different white wines was at 15–16 °C, in the case of examined wines lower concentrations of fatty acids and fatty acid esters were found at this temperature. At 25–26 °C fermentation temperature very high concentrations of fatty acids and fatty acid esters were detected. Applying different nitrogen-containing wine additives we managed to achieve better aroma profiles for white wines even using musts of lower quality.

The Uptake of Ethinyl-Estradiol and Cortisol From Water by Mussels (Mytilus spp.)

Previous toxicokinetic studies have shown that mussels (Mytilus spp.) can readily absorb the three main mammalian sex steroids, estradiol (E2), testosterone (T) and progesterone (P) from water. They also have a strong ability to store E2 and the 5α-reduced metabolites of T and P in the form of fatty acid esters. These esters were shown to have half-lives that were measured in weeks (i.e. they were not subject to fast depuration). The present study looked at the toxicokinetic profile of two other common steroids that are found in water, the potent synthetic oestrogen, (ethinyl-estradiol) (EE2; one of the two components of ‘the pill’), and cortisol, a natural stress steroid in vertebrates. In the first three hours of uptake, tritiated EE2 was found to be taken up at a similar rate to tritiated E2. However, the levels in the water plateaued sooner than E2. The ability of the animals to both esterify and sulphate EE2 was found to be much lower than E2, but nevertheless did still take place. After 24 h of exposure, the majority of radiolabelled EE2 in the animals was present in the form of free steroid, contrary to E2, which was esterified. This metabolism was reflected in a much lower half-life (of only 15 h for EE2 in the mussels as opposed to 8 days for E2 and >10 days for T and P). Intriguingly, hardly any cortisol (in fact none at all in one of the experiments) was absorbed by the mussels. The implications of this finding in both toxicokinetic profiling and evolutionary significance (why cortisol might have evolved as a stress steroid in bony fishes) are discussed.

Chemical and sensorial characteristics of traditional fruit spirits from Southeast Europe

Spirits have proliferated and become an indispensable part of most gastronomic cultures around the world. The production and consumption of fruit brandies, especially plum and grape brandies as well as pear and apple brandies, have a long tradition in the countries of Southeast Europe. The aim of this study was to evaluate 47 fruit brandies produced in small distilleries and industrial plants from five countries. The content of the most common volatile compounds (methanol, higher alcohols and fatty acid esters) and the sensory quality of the fruit brandies were analysed. Principal component analysis (PCA) was performed using theconcentrations of the main volatile compounds in the spirit samples and sensory evaluation to identify similarities or differences between the spirit samples based on distillery size. The methanol concentration in all samples was below the EU legal limit. Methanol concentration was highest in Williams pear spiritsand lowest in grape pomace spirits. The PCA sample distribution confirms the good quality of samples from both small distilleries (SD) and industrial plants (IP), with some exceptions - samples with identified defects produced in some small distilleries. The results of the sensory evaluation show high sensory quality of fruit spirits from this part of Europe.

A Novel Approach of Bioesters Synthesis through Different Technologies by Highlighting the Lowest Energetic Consumption One

Fatty acids esters have a wide application as bioplasticizers and biolubricants in different industries, obtained mainly in classic batch reactors, through an equilibrium complex reaction, that involves high temperatures, long reaction times, vigorously stirring, and much energy consumption. To overcome these shortcomings, we synthesized a series of fatty acid esters (soybean oil fatty acids being the acid components with various hydroxyl compounds) through novel low energy consumption technologies using a bubble column reactor, a microwave field reactor and for comparison meaning, a classic batch reactor. The obtained bioesters physicochemical properties were similar to one another, a good concordance among their rheological properties was obtained, but the energetic consumption is lower when using the bubble column or the microwave reactors instead of the classical batch reactor.