retention indexes
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2021 ◽  
pp. 004051752110242
Author(s):  
Qianhui Tang ◽  
Lei Wang ◽  
Weidong Gao ◽  
Ruru Pan

Fabric shape retention is a crucial property that impacts the durability and usability of fabric and which needs a convenient and accurate evaluation method. In the previous research, the automated crease recovery testing method was used to obtain fabric crease recovery information and evaluate the property of shape retention. Based on the previous research, an orthogonal test method was adopted to investigate the effect of different test parameters on the stability of shape retention detection in this paper. First, three factors, that of sample size, pressure, and pressure time, and three different levels of each factor were determined by the L9(34) orthogonal test table. Next, the fabric shape retention indexes were detected by nine different test schemes, and the comprehensive score of shape retention index standard deviation was obtained as the evaluation criterion of the orthogonal test results. Finally, the optimal test scheme was determined by visual analysis and variance analysis. The results show that the sample size has a certain effect on the stability of shape retention indexes, while the pressure time and the pressure have no significant influence. The optimal test scheme is that the sample size is 30 cm × 30 cm, the pressure time is 60 s, and the pressure is 40 N. The test result measured by the optimal test parameters reveals excellent stability when the vertex angle standard deviation is 2.0°, the height standard deviation is 0.06 cm, and the shape retention area standard deviation is 0.16 cm2. This paper provides an experimental basis for improving the accuracy of fabric shape retention evaluation method.


Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1892
Author(s):  
Arancha de-la-Fuente-Blanco ◽  
Vicente Ferreira

This review discusses the different approaches developed by researchers in the last 40 years for the qualitative and semi-quantitative screening of odorants, with special emphasis in wine aroma profiling. In the first part, the aims and possibilities of Gas chromatography-olfactometry (GC-O) as odour-screening and aroma profiling technique are discussed. The critical difference between approaches is whether the ranking of odorants is carried out on an extract containing all the odorants present in the product, or on an extract representative of the odorants contained in the vapour phases that cause the odour and flavour. While the second alternative is more direct and can be more efficient, it requires a good understanding of the factors affecting orthonasal olfaction, handling volatiles (purging, trapping, eluting, and separating) and about the sensory assessment of GC effluents. The review also includes an updated list compiling all the odorants detected in wine by GC-O, including retention indexes and odour descriptions with a general guideline for the identification of odorants.


Foods ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 87 ◽  
Author(s):  
Shiqing Song ◽  
Li Fan ◽  
Xiaodong Xu ◽  
Rui Xu ◽  
Qian Jia ◽  
...  

Two types of braised pork were prepared from self-made braised sauce added to Maillard reaction intermediate (MRI) and white granulated sugar, respectively. Descriptive sensory analysis and gas chromatography-mass spectrometry (GC-MS) were conducted to investigate their differences in sensory and aroma compounds. The results showed that the effect of self-made braised sauce in braised pork was comparable to white granulated sugar. One-hundred-and-nine volatile flavor compounds were identified by GC-MS using headspace-solid phase microextraction (HS-SPME) and simultaneous distillation and extraction (SDE). Thirty-six odor active compounds with retention indexes ranging from 935–2465 were identified by aroma extract dilution analysis (AEDA). Additionally, their odor activity values (OAV) were calculated. It was found that 17 aroma compounds showed an OAV greater than 1. Among them, pentanal (almond, pungent), nonanal (fat, green), (E, E)-2,4-decadienal (fat, roast), phenylacetaldehyde (hawthorn, honey, sweet), dodecanal (lily, fat, citrus) and linalool (floral, lavender) reached the highest OAV values (>200), indicating a significant contribution to the aroma of two types of braised pork. These results indicated that the self-made braised sauce added with MRI could be used for cooking braised pork with good sensory characteristics.


2015 ◽  
Vol 10 (9) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Miroslav Ločárek ◽  
Jitka Nováková ◽  
Pavel Klouček ◽  
Anna Hošt'álková ◽  
Ladislav Kokoška ◽  
...  

Alkaloidal extracts of six selected species of Amaryllidaceae were studied with respect to their antibacterial and anti-yeast activity and their alkaloidal fingerprint. Twenty-five alkaloids were determined by GC/MS, and sixteen of them identified from their mass spectra, retention times and retention indexes. In the antimicrobial assay, Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus were used, along with isolates of the human pathogenic yeasts Candida albicans, C. glabrata, C. dubliniensis and Lodderomyces elongiosporus. The six extracts, together with 19 Amaryllidaceae alkaloids isolated in our laboratory, showed almost no inhibitory activity against the bacteria tested. However, promising anti-yeast properties were detected; the most potent activity was shown by lycorine, which inhibited C. dubliniensis with a MIC of 32 μg/mL, C. albicans and L. elongiosporus, both with MICs of 64 μg/mL, followed by caranine inhibiting C. dubliniensis with a MIC of 128 μg/mL. Among the alkaloidal extracts, Narcissus jonquilla cv. Baby Moon showed the most potent anti-yeast activity, with minimal and average MIC values of 128 and 192 μg/mL, respectively, followed by Leucojum aestivum, Narcissus poeticus var. recurvus and N. canaliculatus (average MICs 256, 267 and 299 μg/mL, respectively). The lowest MIC value among extracts was obtained for N. canaliculatus against L. elongiosporus (MIC 64 μg/mL).


2015 ◽  
Vol 10 (2) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Radosław Bonikowski ◽  
Konrad Celiński ◽  
Aleksandra Wojnicka-Półtorak ◽  
Tomasz Maliński

The compositions of mountain pine (Pinus uncinata) and peat-bog pine (P. uliginosa) needle essential oils were investigated. Enantiomeric compositions of selected monoterpene hydrocarbons were also examined. Respectively, fifty-three and seventy-six components of the essential oils were identified using GC-MS and retention indexes. The main group of essential oil components of mountain pine needles were monoterpenes, and bornyl acetate constituted approximately 30% (46.3g/100g) of the oil. In peat-bog pine essential oil, monoterpenes and sesquiterpenes exhibited a similar content (ca. 40%). Bornyl acetate and a-pinene were the main constituents of both essential oils. In the essential oil of P. uncinata needles, limonene, camphene, myrcene and ( E)-β-caryophyllene were also noticeable, while in the essential oil of P. uliginosa needles, Δ-car-3-ene, ( E)-β-caryophyllene, germacrene D, δ-cadinene, germacrene D 4-ol and α-cadinol were present in notable quantities. In both essential oils, borneol propionate, isobutyrate, 2-methylbutyrate and isovalerate were detected. Their presence was confirmed by synthesis and analysis of the standards; retention indexes on a non-polar column are published herein.


2014 ◽  
Vol 9 (12) ◽  
pp. 1934578X1400901 ◽  
Author(s):  
Lubomír Opletal ◽  
Miroslav Ločárek ◽  
Adéla Fraňková ◽  
Jakub Chlebek ◽  
Jakub Šmíd2 ◽  
...  

Alkaloidal extracts of seven selected plants of the family Papaveraceae were studied with respect to their activity against six strains of pathogenic bacteria and their alkaloidal fingerprint. Twenty-four alkaloids were determined by GC/MS, and twenty of them identified from their mass spectra, retention times and retention indexes. In the antibacterial assay, three Gram-positive ( Enterorococcus faecalis, Staphylococcus aureus and S. hyicus), and three Gram-negative ( Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa) strains were used. The most promising antimicrobial activity was shown by the alkaloidal extract of Macleaya cordata with MIC values of 16 μg/mL for Staphylococcus aureus, 32 μg/mL for Enterococcus faecalis and 64 μg/mL for Staphylococcus hyicus and Escherichia coli. All the tested pure isoquinoline alkaloids were considered inactive within the tested concentrations.


2014 ◽  
Vol 9 (8) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Jana Havlasová ◽  
Marcela Šafratová ◽  
Tomáš Siatka ◽  
Šárka Štěpánková ◽  
Zdeněk Novák ◽  
...  

Alkaloid extracts of eight Narcissus (Amaryllidaceae) species and varieties were studied with respect to their acetylcholinesterase (HuAChE) and butyrylcholinesterase (HuBuChE) inhibitory activity and alkaloid patterns. Thirty alkaloids were determined by GC/MS, and twenty-five of them identified from their mass spectra, retention times and retention indexes. Promising HuAChE inhibition activity was demonstrated by six Narcissus taxa and HuBuChE inhibition by N. jonquila cv. Double Campernelle and N. nanus cv. Elka with IC50 values of 24.1 ± 1.9 μg/mL and 25.1 ± 1.8 μg/mL, respectively. Two alkaloids were isolated in pure form using preparative TLC and identified as the galanthamine type alkaloid narwedine and the lycorine type alkaloid incartine. Both compounds were tested for their biological activity. They were considered inactive in HuAChE/HuBuChE assays, but showed promising prolyl oligopeptidase inhibition activities with IC50 values of 0.95 ± 0.12 mM and 0.91 ± 0.09 mM, respectively.


2013 ◽  
Vol 8 (6) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Lucie Cahlíková ◽  
Miroslav Ločárek ◽  
Nina Benešová ◽  
Radim Kučera ◽  
Jakub Chlebek ◽  
...  

Alkaloid extracts of eleven Narcissus (Amaryllidaceae) species and varieties were studied with respect to their acetylcholinesterase (HuAChE) and butyrylcholinesterase (HuBuChE) inhibitory activity and alkaloid patterns. Forty-two alkaloids were determined by GC/MS, and thirty of them identified from their mass spectra, retention times and retention indexes. Promising HuAChE inhibition activity was demonstrated by nine Narcissus taxa and HuBuChE inhibition by Narcissus poeticus cv. Pink Parasol with an IC50 value of 3.3 ± 0.5 μg/mL. The alkaloid identified as (11C- S)-homolycorine was isolated in pure form from Narcissus Sir W. Churchill using preparative TLC and was tested for its biological activity. Homolycorine inhibited HuAChE and HuBuChE in a dose-dependent manner with IC50 values of 63.7±4.3 μM and 151.0±15.2 μM, respectively.


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