scholarly journals Redistribution of chlorides in concrete specimens occurring during storage

2021 ◽  
Vol 54 (3) ◽  
Author(s):  
Elisabeth Helsing

AbstractIt has been observed that storage of specimens with chloride gradients before determining the chloride profile can lead to changes in the shape of the chloride profile. An experimental study to quantify the influence of the duration of the storage period and the storage temperature has been carried out. It comprised three storage periods (7, 28 and 91 days) and two storage temperatures (+ 5 °C and + 20 °C). The specimens had previously been immersed in a 15% NaCl solution for 56 days and were sealed in plastics during storage. The results show that a temperature of + 5 °C diminishes the rate of redistribution considerably, compared to a storage carried out at + 20 °C, and the longer the storage period is, the more redistribution will take place. It is also shown that it is of importance to assure that the sealing of the specimens during storage is capable of maintaining the relative humidity at the surface, so that local redistribution of chlorides close to the surface will not take place.

1984 ◽  
Vol 47 (4) ◽  
pp. 260-262 ◽  
Author(s):  
B. W. BERRY ◽  
K. F. LEDDY ◽  
C. A. ROTHENBERG

Beef livers from freshly slaughtered cattle were inoculated with coagulase-positive Staphylococcus aureus and then placed in frozen storage. After 14 d of frozen storage, one-half of the livers were subjected to 21°C for 24 h followed by a 15-d period of storage at −1°C. The other livers were kept in frozen storage (−29°C) during this 15-d period after which all livers were subjected to either 10 or 21°C temperatures. S. aureus counts did not change during the 15-d storage period at −1°C, whereas aerobic plate counts (APC) increased by over 3 log10 cycles. The low storage temperature plus the growth of competitor bacteria most likely prevented S. aureus from proliferating. When all livers were subjected to 24 to 144 h of storage at either 10 or 21°C, those that had been subjected to 15 d of slow surface thawing displayed a lower S. aureus count and higher APC than livers subjected to rapid thawing followed by holding at the high temperatures. This may mean that if livers become contaminated with substantial numbers of S. aureus before freezing, then rapid thawing coupled with high storage temperatures (more typical of meat merchandising in less developed countries) could allow for rapid S. aureus growth before competitor organisms increase in numbers.


Author(s):  
S. A. Henga ◽  
W. M. Thagana ◽  
Hunja Hurage ◽  
M. W. Githendu

Rice (Oryza sativa L.) is an annual grass with the third-highest world production after sugarcane and maize. However, due to losses in vigor caused by poor seed storage, global consumption has surpassed production. Preservation of germ plasma both in-situ and ex-situ is the key to the conservation of rich biodiversity. Seed vigor is a key element of seed quality and high vigor seeds give uniform plants stand and higher yields per area. Accelerated ageing tests enable testing the vigor of stored seeds by subjecting the seeds to a particular temperature and relative humidity over time and then performing standard germination tests. Viability of most seeds normally reduces with the storage period, storage temperature and relative humidity. There is limited information on the duration of storage for rice seeds. Accelerated ageing is considered an excellent option as a vigor test when compared to seedling emergence and index of emergence speed because of the shortest time of acquisition and efficient results. Accelerated ageing tests at 0, 24, 48 and 72 hours (45ºC and 98% RH) were carried out JKUAT post-harvest laboratory using eight rice varieties’ in four replications of 100 seeds each. Data were analyzed using GENSTAT statistical package. ANOVA and T-tests at 5% significant level. Results showed that there was significant variation in both coleorhiza and coleoptile formation among rice varieties (p<0.001), treatments (p<0.001) and interaction between rice varieties and treatment (p<0.001). The difference between all treatments was significant with 72 hours’ treatment having the highest number of days to coleorhiza and coleoptile formation. The present study has shown that prolonged duration of higher temperatures results in a reduction of seed viability. The earliest coleorhiza formation was observed on day 2 and the latest on day 6. Results from this study will guide farmers and seed processors on considerations regarding storage period and storage temperature to ensure high-quality seeds.


2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Folayan R Falayi ◽  
Ojo Benjamin

The aim of this study was to design, construct and evaluate the performance of solar aided crib for storage of freshly harvested maize (Zea mays) in a humid tropical climate. A crib with two drying chambers of size 600 mm x 685 mm x 1500 mm with moisture emission chamber of 600 mm x 115 mm x 1500 mm was designed, constructed and evaluated using appropriate design procedures at the department of Agricultural and Environmental Engineering, Federal University of Technology, Akure, Ondo State, Nigeria. The roof of the crib is made of perspex which transmits the sun's energy into stored maize in the crib for effective drying purpose. The crib was raised at 50 mm above the ground surface and wire netted against rodents. It has two doors for easy loading and off-loading. Freshly harvested Maize weighing 500 kg of 30.5% moisture content (wet basis) was stored for three months. Moisture content of the maize was taken on weekly basis while relative humidity and temperature were measured on daily basis. Readings were taken at three positions (top, middle and bottom) in apertures that were made in those positions but were immediately covered up at the end of every reading.  The ambient temperatures varied from 20.90C to 380C and also relative humidity varied from 41% to 91% throughout the period of the experiment. The moisture content at the point of storage was 30.5 % but was reduced to 4 % after three months. The final weight of maize in cobs was 362 kg which implied that the Perspex roof significantly aided in the drying process. The structure is structurally balanced and there was no grain deterioration either by fungal invasion or insects attack during the storage period. Keywords: Crib, Drying, Moisture content, Storage, Temperature


2020 ◽  
Vol 83 (6) ◽  
pp. 1057-1065
Author(s):  
YINGYING SUN ◽  
PEI GAO ◽  
YANSHUN XU ◽  
WENSHUI XIA ◽  
QIAN HUA ◽  
...  

ABSTRACT The present study was conducted to evaluate the effects of long-term storage at various temperatures (4, 25, and 35°C) on flavor and microbiological and physicochemical qualities of traditional Chinese low-salt fermented fish (Suanyu). Food spoilage and pathogenic bacteria (coliforms, Pseudomonas, and Salmonella) were inhibited during the 90 days of storage at all temperatures. Lactic acid bacteria, yeast, and total viable bacteria counts of samples stored at 35°C were reduced sharply, whereas other parameters were stable. Compared with refrigerated storage (4°C), higher storage temperatures (25 and 35°C) accelerated moisture migration, lipid oxidation, and proteolytic degradation. Storage time had a greater effect than storage temperature on the increase of volatile compounds in Suanyu. Refrigerated storage was better than higher storage temperatures (25 and 35°C) for maintaining the odor quality of Suanyu during the storage period. Total biogenic amine concentrations in all samples were ≪200 mg/kg. Suanyu can be consumed safely during 90 days of storage based on the levels of spoilage and pathogenic bacteria and concentrations of biogenic amines, but refrigerated storage effectively slows down the microbial and physicochemical changes, resulting in better organoleptic quality. The results of this study will be useful for processors controlling the safety and quality of fermented fish during transport and storage. HIGHLIGHTS


1973 ◽  
Vol 105 (7) ◽  
pp. 1005-1009 ◽  
Author(s):  
Arlene McMorran

AbstractAt a constant temperature of 1 °C, survival of diapausing second-instar larvae of C. fumiferana (Clem.) for any given period is, to a large extent, determined by pre-storage treatment. At a pre-storage temperature of 20 °C larval survival was 80% or higher following storage periods ranging from 169 to 290 days. Survival of larvae pre-stored at 24 °C was never as high as at 20 °C, and the survival began to decrease after 225 days storage. At 28 °C this decrease had occurred before 169 days of storage. Larvae held at high pre-storage temperatures had almost normal survival when the pre-storage period was shorter. Mean time for larvae to emerge from diapause was increased by longer diapause periods and by high pre-storage temperatures. There was a corresponding decrease in larval vigour.


HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1190-1193 ◽  
Author(s):  
William J. Carpenter ◽  
Eric R. Ostmark

The storage and germination environments were evaluated to determine the cause of low total germination percentages and highly irregular germination of Coreopsis lanceolata L. seed. Highest total germination and most rapid and uniform germination of seed occurred at constant 15C, other constant temperatures and all alternating temperature regimes caused lower total germination or delayed it. Seeds tolerated -20C during storage, but total germination was reduced below -5C. Recently harvested seeds had 44% total germination, but 54% to 81% germination was achieved after 6 hours of soaking seeds in 1000 ppm GA3, 1000 ppm ethephon, or 25 ppm kinetin alone or in combination. Growth regulators reduced the number of days to 50% of final germination (T50), and the span in days between 10% and 90% of germination (T90 - T10). Storing fresh seeds without chemical treatment for > 6 months at 5C and 10% to 20% relative humidity (RH), or 15C at 20% to 35% RH, increased total germination to 75% and 80%, respectively. Ten days were required to achieve T50 after 5 to 6 months of storage at 5C and 10% to 20% RH or 15C and 10% to 40% RH, with longer periods to T50 at other storage durations and RH levels. The germination spans (T90 - T10) were lengthened the higher the seed storage temperatures between 5 to 25C, with longer spans as seed storage durations and relative humidities increased. Total germination was similar after storing seeds at 5 or 15C and 10% to 30% RH and after soaking recently harvested seeds in GA3 + ethephon, but the days to T50 and T90 - T10 were shorter after growth regulator treatment. Chemical names used: (2-chloroethyl) phosphonic acid (ethephon); gibberellic acid (GA3); 6-furfurylaminopurine (kinetin).


2020 ◽  
Vol 25 (1) ◽  
pp. 91-114
Author(s):  
Joyce Limbaga ◽  
Katherine Ann Castillo-Israel

The yacon tuber has gained interest due to its health-promoting components, such as high amounts of fructooligosaccharides (FOS) and phenolic compounds with strong antioxidant properties. However, the high water content and the soft, delicate internal tissues render it highly perishable, leading to significant losses during postharvest handling. The packaging and storage temperatures, two important factors in maintaining quality when storing fresh yacon tubers, were studied. The results showed that modified atmosphere packaging (MAP) combined with low temperature (10°C) had positive effects on the visual quality of yacon. Weight loss and shriveling were reduced in MAP compared to the unpacked yacon under room and 10°C storage temperatures. The use of MAP under room temperature for an extended storage period was limited by the development of disease and the occurrence of root sprouts and surface cracks in yacon, which reduced its visual quality. FOS hydrolysis by fructan exohydrolase occurred during storage, leading to higher amounts of fructose, glucose, and sucrose. The use of MAP regardless of storage temperature delayed the onset of rapid FOS decline. The total phenolic contents in the range of 4.84-5.98 mg Gallic acid equivalent per gram dry sample and antioxidant activity of yacon did not decrease relative to its initial content. Yacon could be stored at 10°C in conjunction with MAP to maintain quality and extend the shelf life of fresh yacon tubers.


2000 ◽  
Vol 67 (2) ◽  
pp. 225-231 ◽  
Author(s):  
SOLEDAD ALBALÁ-HURTADO ◽  
M. TERESA VECIANA-NOGUÉS ◽  
ENRIQUE RIERA-VALLS ◽  
ABEL MARINÉ-FONT ◽  
M. CARMEN VIDAL-CAROU

The stability of the water-soluble B vitamins and the fat-soluble vitamins A and E of three liquid infant milks was followed throughout 12 months of storage at 20, 30 and 37 °C. Two samples were ‘follow-on’ milks from two different manufacturers and the other a ‘junior’ milk from one of these. The levels of water-soluble vitamins and vitamin E remained constant during storage at the three temperatures. In contrast, vitamin A decreased in samples from one manufacturer at all storage temperatures, and in samples from the other only at 37 °C. A kinetic equation was derived that made it possible to predict the influence of storage temperature on the shelf life of these kinds of products, together with the storage period during which levels of vitamin A recommended as adequate would remain.


Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 99
Author(s):  
Gethmini Kodagoda ◽  
Michael E. Netzel ◽  
Yasmina Sultanbawa ◽  
Tim O’Hare ◽  
Hung T. Hong

The Queen Garnet Plum (QGP), a cultivar of Japanese plum (Prunus salicina Lindl.), was developed as a high anthocyanin plum in a Queensland Government breeding programme. Anthocyanins have been associated with various health attributes, including diabetes control, cardiovascular disease prevention and anti-inflammatory activity. This study was aimed at identifying the changes in physiochemical properties and important phytochemicals of QGP when stored under two storage temperatures. QGP from two growers were stored at 4 and 23 oC for 0, 4, 7, 10 and 14 days. At the end of each storage period the peel, outer flesh (up to 7 mm from the peel) and inner flesh were separated and analysed for chroma, total soluble solids (TSS) and titratable acidity (TA). The grower source had a significant effect on the measured parameters when considered as a covariate. Chroma values of the peel, inner and outer flesh were significantly (P < 0.05) different at 4 and 23 oC, after 14 days. There was no significant difference in the inner flesh TSS (IF-TSS) and outer flesh TSS (OF-TSS) between the different storage temperatures, but compared to day 0, after 14 days IF-TSS and OF-TSS were significantly (P < 0.05) lower. TA of the inner and outer flesh were significantly (P < 0.05) different at the two storage temperatures, but only the inner flesh TA was significantly (P < 0.05) different after 14 days. Further analysis is in progress for anthocyanins, total phenolics, carotenoids, folates and vitamin C. The current study indicates that QGP is climacteric and grower source, storage temperature and time as well as tissue can significantly affect the studied physicochemical parameters.


2021 ◽  
Vol 12 ◽  
Author(s):  
Dušica Ćalić ◽  
Jelena Milojević ◽  
Maja Belić ◽  
Rade Miletić ◽  
Snežana Zdravković-Korać

Globalization has drastically reduced the number of autochthon apple cultivars in the Serbian market and most of them have nearly disappeared; however, some of these cultivars, such as Petrovača, Budimka, Kolačara Pozna, and Kožara, have extraordinary quality, good pomological characteristics, and pest and disease resistance. The present study was conducted to develop a protocol for the storage of pollen for further use in the conservation and breeding of these cultivars. Viability and germination of the mature pollen were tested in vitro, at four storage temperatures (20, 4, −20, and −80°C), right after harvest or 1, 2, 3, 4, 5, and 6 months after storage. Differences in fresh pollen viability and germination between cultivars were statistically significant and ranged from 60 to 88% and 59 to 98%, respectively. Fresh pollen of cv. Budimka showed the highest viability and germination in comparison with other cultivars, especially cv. Kožara. Pollen viability and germination decreased over the storage period, and it was the lowest after 6 months of storage at room temperature in all tested cultivars. Storage at 4°C prolonged the pollen viability and germinability of 1–5 fold, depending on the cultivar and treatment duration; however, the pollen longevity of all cultivars was significantly extended when stored at −20 or −80°C. After 6 months, pollen of cv. Budimka stored at −20 and −80°C showed 14–15 fold higher germination rates in relation to pollen storage at room temperature for the same period. The results of the present study suggest that the pollen of these apple cultivars could be efficiently maintained at −20°C and could be further used for breeding purposes, e.g., for crossings between cultivars that flower at different times of the year.


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