scholarly journals How Pre-Harvest Inactivated Yeast Treatment May Influence the Norisoprenoid Aroma Potential in Wine Grapes

2020 ◽  
Vol 10 (10) ◽  
pp. 3369
Author(s):  
Pasquale Crupi ◽  
Marika Santamaria ◽  
Fernando Vallejo ◽  
Francisco A. Tomás-Barberán ◽  
Gianvito Masi ◽  
...  

Carotenoids are important secondary metabolites in wine grapes and play a key role as potential precursors of aroma compounds (i.e., C13-norisoprenoids), which have a high sensorial impact in wines. There is scarce information about the influence of pre-harvest inactivated yeast treatment on the norisoprenoid aroma potential of grapes. Thus, this work aimed to study the effect of the foliar application of yeast extracts (YE) to Negro Amaro and Primitivo grapevines on the carotenoid content during grape ripening and the difference between the resulting véraison and maturity (ΔC). The results showed that β-carotene and (allE)-lutein were the most abundant carotenoids in all samples, ranging from 60% to 70% of total compounds. Their levels, as well as those of violaxanthin, (9′Z)-neoxanthin, and 5,6-epoxylutein, decreased during ripening. This was especially observed in treated grapes, with ΔC values from 2.6 to 4.2-fold higher than in untreated grapes. Besides this, a principal components analysis (PCA) demonstrated that lutein, β-carotene, and violaxanthin and (9′Z)-neoxanthin derivatives principally characterized Negro Amaro and Primitivo, respectively. Thereby, the YE treatment has proved to be effective in improving the C13-norisoprenoid aroma potentiality of Negro Amaro and Primitivo, which are fundamental cultivars in the context of Italian wine production.


2012 ◽  
Vol 2 (3) ◽  
pp. 221-225 ◽  
Author(s):  
A. Ahmad ◽  
S. Quegan

Two methods of cloud masking tuned to tropical conditions have been developed, based on spectral analysis and Principal Components Analysis (PCA) of Moderate Resolution Imaging Spectroradiometer (MODIS) data. In the spectral approach, thresholds were applied to four reflective bands (1, 2, 3, and 4), three thermal bands (29, 31 and 32), the band 2/band 1 ratio, and the difference between band 29 and 31 in order to detect clouds. The PCA approach applied a threshold to the first principal component derived from the seven quantities used for spectral analysis. Cloud detections were compared with the standard MODIS cloud mask, and their accuracy was assessed using reference images and geographical information on the study area.



Author(s):  
Asger Christiansen ◽  
Jens Carstensen ◽  
Flemming Møller ◽  
Allan Nielsen

Currently, no objective method exists for estimating the rate of change in the colour of meat. Consequently, the purpose of this work is to develop a procedure capable of monitoring the change in colour of meat over time, environment and ingredients. This provides a useful tool to determine which storage environments and ingredients a manufacturer should add to meat to reduce the rate of change in colour. The procedure consists of taking multi-spectral images of a piece of meat as a function of time, clustering the pixels of these images into categories, including several types of meat, and extracting colour information from each category. The focus has primarily been on achieving an accurate categorisation since this is crucial to develop a useful method. The categorisation is done by applying an orthogonal transformation followed by k-means clustering. The purpose of the orthogonal transformation is to reduce the noise and amount of data while enhancing the difference between the categories. The orthogonal transformations principal components analysis, minimum noise fraction analysis and kernel-based versions of these have been applied to test which produce the most accurate categorisation.



Biomolecules ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 874 ◽  
Author(s):  
Min Hong ◽  
Zhuo-Heng Chi ◽  
Yong-Qing Wang ◽  
Yue-Ming Tang ◽  
Qun-Xian Deng ◽  
...  

Carotenoids are the principal pigments in the loquat. Although the metabolic pathway of plant carotenoids has been extensively investigated, few studies have been explored the regulatory mechanisms of loquat carotenoids because knowledge of the loquat genome is incomplete. The chromoplast-specific lycopene β-cyclase gene (CYC-B) could catalyze cyclization of lycopene to β-carotene. In this study, the differential accumulation patterns of loquat with different colors were analyzed and virus-induced gene silencing (VIGS) was utilized in order to verify CYC-B gene function. Using a cloning strategy of homologous genes, a CYC-B gene orthologue was successfully identified from the loquat. At a later stage of maturation, CYC-B gene expression and carotenoids concentrations in the ‘Dawuxing’ variety were higher than in ‘Chuannong 1-5-9′, possibly leading to the difference in pulp coloration of loquat. Interference of CYC-B gene expression in the loquat demonstrated clear visual changes. The green color in negative control fruits became yellow, while TRV2-CYC-B silenced fruits remained green. CYC-B gene expression and total carotenoid content in the pulp decreased by 32.5% and 44.1%, respectively. Furthermore, multiple key genes in the carotenoid metabolic pathway synergistically responded to downregulation of CYC-B gene expression. In summary, we provide direct evidences that CYC-B gene is involved in carotenoid accumulation and coloration in the loquat.



1969 ◽  
Vol 14 ◽  
Author(s):  
J. Thas

The  pigments or the plastids belong to two groups: the chlorophylls or green  pigments and the carotenoids or yellow pigments. The chlorophyll group can be  divided in chlorophyll a, chlorophyll b and protochlorophyll and the  carotenoid group in carotenes (principally β-carotene) and different  xanthophylls. In connection with other research work (light quality and  quantity measurements, photosynthesis, ...) it is important to determine the  chlorophyll a, chlorophyll b, carotene and xanthophyll content.    According to this method the chlorophyll a, chlorophyll b and carotenoid  content is determined by a spectrophotometric method after extraction with  acetone. The carotenes, after extraction with petroleumether and acetone and  after separating from other pigments by column chromatography, are determined  from preleminary quantitative spectrophotometric calibrations with synthetic  β-carotene. The difference between the carotenoid content and the β-carotene  content gives the amount of xanthophylls.



1980 ◽  
Vol 19 (04) ◽  
pp. 205-209
Author(s):  
L. A. Abbott ◽  
J. B. Mitton

Data taken from the blood of 262 patients diagnosed for malabsorption, elective cholecystectomy, acute cholecystitis, infectious hepatitis, liver cirrhosis, or chronic renal disease were analyzed with three numerical taxonomy (NT) methods : cluster analysis, principal components analysis, and discriminant function analysis. Principal components analysis revealed discrete clusters of patients suffering from chronic renal disease, liver cirrhosis, and infectious hepatitis, which could be displayed by NT clustering as well as by plotting, but other disease groups were poorly defined. Sharper resolution of the same disease groups was attained by discriminant function analysis.



2020 ◽  
pp. 809-823
Author(s):  
Nino Chkhartishvili ◽  
Londa Mamasakhlisashvili ◽  
Irma Tchanturia ◽  
Demetre Bakradze

Preserving rare grapes is not just a matter of variety. Recent dna research has shown that unusual and unknown grape varieties provide clues to wine history. During the centuries, 525 Georgian grape varieties had been known but most of them were degenerated. Nowadays, more than 437 rare Georgian vine varieties are preserved in the geo 038 collection of Agricultural Research-Scientific Center, established in 2014 under the Environment Protection and agriculture ministry. Study of the genetic pool of Georgian grape varieties determine the sustainability of the sector and enrichment of the modern wine market. For this reason the studies of the rare aboriginal grape varieties have begun by their ampelography, phenology, chemical, and oeno-caprological characterizes. The aim of this study is to investigate rare, Georgian, aboriginal wine-grapes by their ampelography, chemical and oenolo-caprological characterizes, and to offer different style and aroma wines to the market, enriching the modern wine assortment. The present study investigated firstly the rare Georgian aboriginal grape variety (Chvitiluri) by its characterizes. In this study grapes caprologycal indication, dynamic development of the sugar accumulation, TA and pH in berries, polyphenols extract in skin and seeds, and phenolic compounds were determined. The grape has been compared with Georgian and French wine-grapes and their products as well. The results show that the grape variety - Chvitiluri, and vinification technique (aging on lee) have the significant impact on the total phenol content in wine. White varietal wine contents high alcohol 13,2%, total phenols 733-500mg/l. Wine has specific, varietal characterizes color, taste, aroma. This study indicates that the rare local, aboriginal variety presents the perspective sort for wine production and can be returned in wine production.



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