Mature berries of Pinot Noir grapevines were sampled across a latitudinal gradient in Europe, from southern Spain to central Germany. Our aim was to study the influence of latitude-dependent ...environmental factors on the metabolite composition (mainly phenolic compounds) of berry skins. Solar radiation variables were positively correlated with flavonols and flavanonols and, to a lesser extent, with stilbenes and cinnamic acids. The daily means of global and erythematic UV solar radiation over long periods (bud break-veraison, bud break-harvest, and veraison-harvest), and the doses and daily means in shorter development periods (5–10 days before veraison and harvest) were the variables best correlated with the phenolic profile. The ratio between trihydroxylated and monohydroxylated flavonols, which was positively correlated with antioxidant capacity, was the berry skin variable best correlated with those radiation variables. Total flavanols and total anthocyanins did not show any correlation with radiation variables. Air temperature, degree days, rainfall, and aridity indices showed fewer correlations with metabolite contents than radiation. Moreover, the latter correlations were restricted to the period veraison-harvest, where radiation, temperature, and water availability variables were correlated, making it difficult to separate the possible individual effects of each type of variable. The data show that managing environmental factors, in particular global and UV radiation, through cultural practices during specific development periods, can be useful to promote the synthesis of valuable nutraceuticals and metabolites that influence wine quality.
In the library environment, games and gamification can be used to improve various services and activities. Although many successful gamification projects have already been implemented, some ...librarians still lack knowledge and are sceptical about the use of games in libraries. This is also the case in Slovenia, where library gamification projects are rarely formalised and publicised. Moreover, not much is known about whether Slovenian librarians obtain any knowledge about these approaches during their formal education. For this purpose, interviews were conducted with ten main compulsory course holders at the Department of Library and Information Science and Book Studies at the Faculty of Arts, University of Ljubljana. The main objective of the study, which was carried out in January 2021, was to investigate the attitudes of Slovenian Library and Information Science (LIS) educators towards the inclusion of games and gamification in their courses and in academic library services. The results showed that they rarely cover games and gamification-related topics in their lectures, nor do they use them for knowledge transfer. They especially see the potential to design games and gamification activities that would promote departmental library, its services and activities, motivate students for independent research and support the educational process.
Cheese in a sack is a traditional cheese produced in Croatia. Types of cheese with similar production technology are made in other countries but chemical and microbiological composition varies ...between regions. Traditionally, cheese in a sack is produced without the addition of starter cultures. Addition of beneficial probiotic cultures to numerous dairy products has documented advantages. Effects that the addition of probiotic bacteria to traditional cheese have on aroma compounds and sensory properties have not been fully investigated. The aim of this study is to determine the sensory properties and differences in the aromatic profiles between cheese samples ripened in a lambskin sack, produced traditionally without the addition of any starter culture, or with the addition of probiotic bacteria.
In this study, cheese in a sack was produced with the addition of probiotic cultures
B and
ssp.
S1. During ripening volatile aroma compounds were analysed with a solid-phase microextraction gas chromatography-mass spectrometry. Sensory properties were evaluated by trained tasters who are familiar with the traditional taste of the cheese from a sack. The results of aroma composition and taste scores were then compared using factorial and principal component analyses.
Chromatography showed differences in the composition of aroma compounds and the sensory properties between the cheese produced with
starter cultures and the control cheese, traditionally produced without a starter culture. The addition of probiotic cultures
B and
ssp.
S1 resulted in products with better sensory properties and chemical profile of volatile aromatic compounds.
This study investigates the usage of naturally present probiotic cultures as starter cultures in cheese in a sack production. Their effects on aroma profiles and sensory characteristics have been compared for the first time using factorial and principal component analyses.
A 2‐year study explored metabolic and phenotypic plasticity of sun‐acclimated Vitis vinifera cv. Pinot noir leaves collected from 12 locations across a 36.69–49.98°N latitudinal gradient. Leaf ...morphological and biochemical parameters were analysed in the context of meteorological parameters and the latitudinal gradient. We found that leaf fresh weight and area were negatively correlated with both global and ultraviolet (UV) radiation, cumulated global radiation being a stronger correlator. Cumulative UV radiation (sumUVR) was the strongest correlator with most leaf metabolites and pigments. Leaf UV‐absorbing pigments, total antioxidant capacities, and phenolic compounds increased with increasing sumUVR, whereas total carotenoids and xanthophylls decreased. Despite of this reallocation of metabolic resources from carotenoids to phenolics, an increase in xanthophyll‐cycle pigments (the sum of the amounts of three xanthophylls: violaxanthin, antheraxanthin, and zeaxanthin) with increasing sumUVR indicates active, dynamic protection for the photosynthetic apparatus. In addition, increased amounts of flavonoids (quercetin glycosides) and constitutive β‐carotene and α‐tocopherol pools provide antioxidant protection against reactive oxygen species. However, rather than a continuum of plant acclimation responses, principal component analysis indicates clusters of metabolic states across the explored 1,500‐km‐long latitudinal gradient. This study emphasizes the physiological component of plant responses to latitudinal gradients and reveals the physiological plasticity that may act to complement genetic adaptations.
In this paper, morphological and biochemical parameters (flavonoid and carotenoid composition, non‐enzymatic leaf total antioxidant capacity and ultraviolet (UV)‐absorbing pigment content) of Pinot noir grapevine leaves were measured at different vineyards across a 1,500‐km latitude gradient in Europe.
We identified cumulative UV radiation as the strongest correlator with most leaf metabolites and pigments and also found that leaf fresh weight and area were negatively correlated with both global and UV radiation.
The acquired data set also allowed the analysis of complex interactions between various classes of metabolites in responding to environmental conditions. The study emphasizes the physiological component of plant responses to latitudinal gradients and reveals the physiological plasticity that may act to complement genetic adaptations.
Introduction. Online customer reviews present one of the most important factors in book purchasing or borrowing decisions. Given that only well-organized reviews are useful, Amazon has already ...started linking multiple formats and editions of the same book. Nevertheless, this method is not suitable for books that have appeared in many formats and editions as some attributes do not apply to all versions.Research questions. In our study we were interested in the aspects of a book users perceive as important and the extent to which these attributes match FRBR entities. We were also interested in the relation between specific attributes in the reviews and the numeric rating of the book.Methods. We used content analysis on two random samples of Amazon customer reviews. The sample included a total of 600 reviews of three well-known fiction book titles that have many formats and editions that accommodate the different preferences of readers.Results. The results show that readers take into consideration book information at various abstraction levels that match those in the FRBR model. Most reviewers comment on the book content while review readers consider reviews that comment on different aspects of a book as more helpful.Conclusions. Given that subjective opinion is an important factor in the users’ book selection decision, it would be reasonable to rethink the presentation and organisation of online book reviews.
Phenolic compounds are key components of wine, since they contribute to wine characteristics such as colour, astringency and bitterness. They also act like antioxidants, with mechanisms involving ...free-radical scavenging that could prevent cardiovascular diseases and cancer. The aim of the present work was to compare the obtained results of total polyphenols content and antioxidant potential (AOP) of several white wines (welschriesling and sauvignon blanc) during ageing on fine lees. The total polyphenols content decreased in average for 16.1 % in welschriesling wines and for 18.7 % in sauvignon blanc wines in the period of three months of wine ageing on lees. In the same period AOP of wines decreased in average for 16.0 % in welschriesling wines and for 8.0 % in sauvignon blanc wines. Expectedly, the samples with added oak chips in grape must had higher antioxidant potential than others.
The influence of three different commercial yeasts (BDX, BM4X4 and ICV D21) and two different lactic acid bacteria (LAB), on glycerol content in Montenegrin wines Vranac and Kratošija were studied ...during 2012 vintage. Basic quality parameters of grape must (sugar content, total acidity, pH, tartaric and malic acid) were determined, as well as glycerol content after alcoholic and malolactic fermentation. It was found that within both wines, the highest content of glycerol was reached when BDX yeast was used. There were no significant differences within glycerol content when different LAB was used. In Kratošija wine glycerol content for BDX treatment varied between 9.02 – 9.09 g L-1, while in Vranac wine varied from 8.88 – 8.95 g L-1. Slightly higher glycerol content in wines with BM4X4 and ICV D21 commercial yeast were achieved also in Kratošija wine.
The aromatic profile of volatiles in dried figs varieties
Bružetka Bijela
and
Zimnica
were characterised by headspace solid-phase (HS-SPME) procedure with gas chromatography–mass spectrometry ...analysis (GC-MS). The volatile compounds were distributed by distinct chemical classes, including alcohols, aldehydes, esters, terpenic compounds, and other compounds. The figs were dried in a pilot plant cabinet dryer. Prior to drying process, figs were pre-treated by sulphur dioxide, immersed in solution of citric acid and ascorbic acid, respectively. Several mathematical thin-layer drying models, available in the literature, were fitted to experimental data of figs, implementing non-linear regression analysis techniques. The results showed that pre-treatments of figs decrease significantly the drying time. The best thin-layer drying model in terms of fitting performance was Wang and Singh model. The major volatile compound in dried figs was benzaldehyde. After benzaldehyde, the most abundant aldehyde in dried figs was hexanal. The comparison among dried figs showed the highest abundance of aldehydes, in general, in non-treated (control) dried figs compared to pre-treated samples. Furthermore, ascorbic acid was the most efficient in preserving esters and alcohols in case of
Bružetka Bijela
, whereas in case of
Zimnica
, sulphur dioxide was in advance compared to ascorbic acid. Ethyl acetate was the most abundant ester found in dried figs. Among other compounds, 2-butanone,3-hydroxy was the most abundant identified volatiles. Linalool, as the only identified terpen, was in case of both dried fig varieties, preserved by immersion into ascorbic acid. The immersion into citric acid has not been so successful in volatiles conservation.
Peaches are consumed worldwide and have great market demand. Compared to apricots, the volatiles defining the typical peach aroma are still poorly analytically characterized. The aim of our study was ...to determine the impact of the stage of ripening, sample storage conditions, and type of fiber coating and extraction glassware on peach aroma compounds. The peach aroma components were extracted by headspace solid-phase microextraction (HS-SPME) and with the application of a specific fiber (DVB/CAR/PDMS fiber) that retained the main group of volatiles present in peaches. Artisan-made glassware that enabled bigger sample loads was used. It was found that its application provided a 3-fold higher extraction of aromatic compounds on average. Significant differences were also found when the same peach pulp was analyzed fresh or frozen (in liquid nitrogen or in the freezer at -16 °C). In fresh peaches, a higher amount of some alcohols and important esters was determined. Liquid nitrogen had a positive impact on hexanal and (E)-2-hexenal, whereas the storage of samples in the freezer had a major impact on most other aldehydes, as well as limonene. The study revealed the importance of sample preparation and storage on the overall aromatic profile of peaches.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Volatile compounds (VCs) analysis was performed by solid-phase microextraction-gas chromatography-mass spectrometry. Main groups that define typical cheese flavour formed as a result of the addition ...of a starter culture (SC). The cheesemaking environment, the type of milk (cow, ewe, goat), and the heat treatment of milk were observed. The SC had influenced the total amount of some fatty acids and ketones. Compared to cow and ewe cheeses, goat cheese had higher values of hexanoic and octanoic acids, however, two alcohols, 1-hexanol, 2-ethyl- and hexanol, were only present in cow cheeses. We confirmed that the cheesemaking environment is also an important parameter influencing VC profiles of cheese. Higher amount of esters and the absence of 2-phenylethanol were observed in raw milk cheese, compared to thermised milk cheese where δ-octalactone was present.
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