Characteristics of moisture migration and volatile compounds of rice stored under various storage conditions

2021 ◽  
Vol 102 ◽  
pp. 103323
Author(s):  
Jinguang Liu ◽  
Yuqian Liu ◽  
Anqi Wang ◽  
Zhen Dai ◽  
Rui Wang ◽  
...  
Molecules ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 232
Author(s):  
María Consuelo Díaz-Maroto ◽  
Manuel López Viñas ◽  
Lourdes Marchante ◽  
María Elena Alañón ◽  
Ignacio Javier Díaz-Maroto ◽  
...  

The effects of different storage conditions, light exposure, temperature and different commercially available cork stoppers on the phenolic, volatile and sensorial profile of Verdejo wines were studied. Two natural corks of different visual quality and a microgranulated cork stopper were investigated over one year at two different storage conditions. One simulating light exposure and temperature in retail outlets and the other simulating optimal cellar conditions (darkness and 12 °C). The wines stored under commercial conditions showed greater losses of total and free SO2 and higher levels of brown-yellowish tones, related to the oxidation of flavan-3-ols. Although these wines underwent a decrease in the total content of stilbenes, a significant increase in trans-piceid was observed. In addition, these wines suffered important changes in their volatile and sensory profile. Volatile compounds with fruity and floral aromas decreased significantly, while volatile compounds related to aged-type characters, as linalool oxides, vitispirane, TDN or furan derivatives increased. Wines stored in darkness at 12 °C underwent minor changes and their sensory profiles were similar to wine before bottling. The high-quality natural corks and microgranulated corks better preserved the quality of the white wines from a sensory point of view. These results showed that temperature and light exposure conditions (diffuse white LEDs and 24 ± 2 °C) in retail outlets considerably decrease the quality of bottled white wines and, consequently, their shelf life, due to the premature development of aged-type characters.


2015 ◽  
Vol 4 (3) ◽  
pp. 56 ◽  
Author(s):  
Alexandr Ya Yashin ◽  
Boris V. Nemzer ◽  
Emilie Combet ◽  
Yakov I. Yashin

<p>Despite the fact that mankind has been drinking tea for more than 5000 years, its chemical composition has been studied only in recent decades. These studies are primarily carried out using chromatographic methods. This review summarizes the latest information regarding the chemical composition of different tea grades by different chromatographic methods, which has not previously been reviewed in the same scope. Over the last 40 years, the qualitative and quantitative analyses of high volatile compounds were determined by GC and GC/MS. The main components responsible for aroma of green and black tea were revealed, and the low volatile compounds basically were determined by HPLC and LC/MS methods. Most studies focusing on the determination of catechins and caffeine in various teas (green, oolong, black and pu-erh) involved HPLC analysis.</p> <p>Knowledge of tea chemical composition helps in assessing its quality on the one hand, and helps to monitor and manage its growing, processing, and storage conditions on the other. In particular, this knowledge has enabled to establish the relationships between the chemical composition of tea and its properties by identifying the tea constituents which determine its aroma and taste. Therefore, assessment of tea quality does not only rely on subjective organoleptic evaluation, but also on objective physical and chemical methods, with extra determination of tea components most beneficial to human health. With this knowledge, the nutritional value of tea may be increased, and tea quality improved by providing via optimization of the growing, processing, and storage conditions.</p>


2011 ◽  
Vol 34 (2) ◽  
pp. 100-110 ◽  
Author(s):  
ANGELES F. RECAMALES ◽  
VALERIA GALLO ◽  
DOLORES HERNANZ ◽  
MARIA LOURDES GONZÁLEZ-MIRET ◽  
FRANCISCO J. HEREDIA

1998 ◽  
Vol 61 (10) ◽  
pp. 1352-1357 ◽  
Author(s):  
G. NTIRAMPEMBA ◽  
B. E. LANGLOIS ◽  
D. D. ARCHBOLD ◽  
T. R. HAMILTON-KEMP ◽  
M. M. BARTH

Aerobic, microaerophilic, coliform, and mold populations of Botrytis cinerea -inoculated strawberry fruit not exposed (control) or exposed to low and high quantities of four volatile compounds during storage at 2°C were determined after storage for 7 days and after removal of the volatile and transfer to 22°C for 3 days. Fruit harvested at the ripe stage were inoculated with 106 conidia B. cinerea per ml and were placed in plastic containers containing no volatile compound (control) or two quantities of (E)-2-hexenal (10 or 100 μl), (E)-2-hexenal diethyl acetal (30 or 300 μl), benzaldehyde (30 or 300 μl), or methyl benzoate (12 or 60 μl). The fruit containers were overwrapped with a low-density polyethylene film, sealed, stored at 2°C for 7 days, and then transferred to 22°C for 3 days. Aerobic, microaerophilic, and coliform populations of fruit exposed to volatile compounds tended to be lower than the Controls after storage at 2°C for 7 days and, depending on the volatile compound, similar, lower, or higher than the Controls after transfer and storage at 22°C. However, due to variability in initial aerobic, microaerophilic, and coliform populations of the fruit used in the different trials (P &lt; 0.05), none of the differences between control and treatment and between treatments within a sample time were significant (P &gt; 0.05). Strawberry fruit exposed to 100 μl of (E)-2-hexenal was the only treatment that did not show a significant increase in mold populations after transfer and storage at 22°C for 3 days. Additional studies are needed to determine if (E)-2-hexenal can be used in combination with other postharvest storage conditions, such as low temperature and controlled/modified atmosphere, to delay mold spoilage and extend the shelf life of the strawberry.


HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 526D-526 ◽  
Author(s):  
Ming Zhang ◽  
Eric E. Roos

All kinds of plant seeds evolve volatile compounds during storage. However, a reliable deterioration forecast method is still not established using volatile evolution, even though some preliminary work indicated a relationship between volatile evolution and seed deterioration (Fielding and Goldsworthy, 1982; Hailstones and Smith, 1989; Zhang et al., 1993). Here we review some of the previous work concerning seed volatiles and present some more recent research on the effects of seed moisture content on deterioration. We found that volatile evolution from seeds was controlled by seed moisture level. Generally, seeds tended to evolve more hexanal and pentanal under extremely dry conditions (below 25% equilibrium RH). The production of hexanal and pentanal decreased with increasing seed moisture level. On the other hand, methanol and ethanol increased with increasing seed moisture. All of the volatile compounds accumulated in the headspace of the seed storage container during storage. Therefore, it should be possible to use different volatiles to indicate the deterioration of seeds stored under different moisture levels. We suggest that hexanal may be used for seed assessing deterioration under dry storage conditions (below 25% equilibrium RH), while ethanol may be used for seeds stored under higher moisture conditions (above 25% equilibrium RH). [References: Fielding, J.L. and Goldsworthy, A. (1982) Seed Sci. Technol. 10: 277–282. Hailstones, M.D. and Smith, M.T. (1989) Seed Sci. Technol. 17: 649–658. Zhang et al. (1993) Seed Sci. Technol. 21:359–373.]


2019 ◽  
Vol 125 ◽  
pp. 108625 ◽  
Author(s):  
Jossiê Zamperetti Donadel ◽  
Fabio Rodrigo Thewes ◽  
Rogerio de Oliveira Anese ◽  
Erani Eliseu Schultz ◽  
Magno Roberto Pasquetti Berghetti ◽  
...  

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