Dicaffeoyl polyamine derivatives from bitter goji: Contribution to the bitter taste of fruit.

Although the bioactive compounds in goji have been thoroughly identified and quantified, little information is available on the bitter compounds in the berries, and no systematic works on the substances responsible for their bitterness have been performed. Herein, the substances contributing to the bitterness of berries were isolated and purified from bitter-tasting goji by the combined use of column chromatography and high-pressure liquid chromatography (HPLC). The bitterness of the isolated compounds was evaluated using a biosensor with immobilized rat taste-bud tissues. The structures were elucidated via comprehensive mass spectrometry (MS) and nuclear magnetic resonance (NMR) analyses. Seven spermine or spermidine alkaloids were identified, including four new compounds (lyciamarspermidines A and B and lyciamarspermines A and B). The intensities of the bitterness levels of the isolated compounds differed with the number of glucose substituents. These isolated compounds all contribute to the bitterness of goji. The results of this study provide opportunities for the further investigation of the bitterness of goji.

Metabolomic profiling delineate taste qualities of tea leaf pubescence.

The amount of pubescence on leaf epidermis is an important morphological marker for the quality of green tea, and the tea with plenty of pubescence is generally recognized as having a better taste. However, there is no systematic study on chemical compositions of tea leaf pubescence. The contributions of pubescence to taste properties are far from clear. In this research, 114 components were identified from the tea leaf pubescence of yunkang 10, a broad-leaf tea cultivar with plenty leaf pubescence, for the first time with a non-targeted metabolomics approach using ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF-MS). Compared to the tea leaf with the pubescence removed (non-pubescent leaf), the pubescence obtained from the same shoots had relatively higher contents of amino acids and lower contents of polyphenols. It was also found that the umami of pubescence was elevated, while the bitterness and astringency were significantly declined. Partial least-squares (PLS) analysis suggested that the polyphenols and amino acids accounted for the taste quality. To the best of our knowledge, this is the first time that the metabolites in tea leaf pubescence were profiled. The results offer the direct concrete evidence on the contributions of pubescence to the tea taste properties.

Investigating country-specific music preferences and music recommendation algorithms with the LFM-1b dataset.

Recently, the LFM-1b dataset has been proposed to foster research and evaluation in music retrieval and music recommender systems, Schedl (Proceedings of the ACM International Conference on Multimedia Retrieval (ICMR). New York, 2016). It contains more than one billion music listening events created by more than 120,000 users of Last.fm. Each listening event is characterized by artist, album, and track name, and further includes a timestamp. Basic demographic information and a selection of more elaborate listener-specific descriptors are included as well, for anonymized users. In this article, we reveal information about LFM-1b's acquisition and content and we compare it to existing datasets. We furthermore provide an extensive statistical analysis of the dataset, including basic properties of the item sets, demographic coverage, distribution of listening events (e.g., over artists and users), and aspects related to music preference and consumption behavior (e.g., temporal features and mainstreaminess of listeners). Exploiting country information of users and genre tags of artists, we also create taste profiles for populations and determine similar and dissimilar countries in terms of their populations' music preferences. Finally, we illustrate the dataset's usage in a simple artist recommendation task, whose results are intended to serve as baseline against which more elaborate techniques can be assessed.

Avaliação do potencial de cinco cultivares de videiras americanas para sucos de uva no sul de Minas Gerais / Potential evaluation of five american cultivars for grape juices in the south of Minas Gerais state

Objetivou-se, no presente trabalho realizar uma caracterização dos sucos de uva de cinco cultivares de videira americana Vitis labrusca (Folha de Figo, Alwood, Concord, BRS-Rúbea e Isabel) segundo suas características visuais, olfativas e gustativas, utilizando um método descritivo por um painel de degustadores da Embrapa Uva e Vinho (EMBRAPA/CNPUV) de Bento Gonçalves e da Associação Brasileira de Enologia (ABE), constituído por doze degustadores. De acordo com os resultados, os sucos das cultivares Isabel e Folha de Figo foram superiores aos demais, segundo a análise de componentes principais (ACP), principalmente pelas variáveis limpidez, equilíbrio olfativo, intensidade e corpo gustativo, persistência olfato-gustativa e julgamento geral (notas). O suco Folha de Figo foi superior ao Isabel quanto à tonalidade, sendo o primeiro caracterizado como vermelho-violáceo. A cultivar Folha de Figo é a mais utilizada na região para a produção de suco, podendo os produtores utilizarem também a cultivar Isabel, que mostrou potencial nas condições edafo-climáticas do sul de Minas Gerais.

The present work was designed to accomplish the characterization of the different grape juices of five grapevine cultivars of Vitis labrusca (Folha de Figo, Alwood, Concord, BRS-Rúbea e Isabel) according to their visual, smell and taste characteristics utilizing a descriptive method by a panel of tasters of Embrapa Grape and Wine (EMBRAPA/CNPUV) of Bento Gonçalves, and of the Brazilian Enology Association (ABE) consisting of 12 tasters. According to the results, the juices of the cultivars Isabel and Folha de Figo were higher than the others, analyzed statistically according to the Principal Component Analysis (PCA), mainly by the visual cleanliness variables, olfatory equilibrium, gustative body and quality, olfato-gustative persistence and general judgement (scores) and the juice of Folha de Figo was higher than Isabel according to visual shade, the former being characterized as violet-red. Folha de Figo is the most used cultivar for grape juices. Isabel would be also used, with a great potential in the environmental conditions of the south of Minas Gerais estate.