scholarly journals Effects of Moisture Content and Storage Temperatures on Germination of Quercus macrocarpa Acorns

1987 ◽  
Vol 5 (1) ◽  
pp. 22-24
Author(s):  
W.R. Schroeder ◽  
D.S. Walker

Viability of bur oak Quercus macrocarpa Michx. acorns was determined after 6 months storage at − 2°C (28°F), 1°C (34°F) and 5°C (41°F) and moisture contents of either 17%, 27%, 37% or 44%. Viability was significantly affected by moisture content with optimum germination occurring for acorns stored at 44% moisture. Optimum storage temperature was 1°C (34°F) although acorns tolerated subfreezing temperatures to − 2°C (28°F) with little loss in viability. Acorn moisture content had a greater effect on viability than storage temperature. Storage for up to 6 months had no detrimental effects on germination of bur oak acorns.

Author(s):  
Jaqueline Ferreira Vieira Bessa ◽  
Osvaldo Resende ◽  
Rayr Rodrigues Lima ◽  
Maria Aparecida Da Silva Lopes ◽  
Carolina De Freitas Fófano Garcia ◽  
...  

<p><span class="fontstyle0">The objective of this work was to evaluate, throughout the storage, the effect of temperature and moisture content on soybean grains with high damage caused by stink bug in the crop, through sanitary quality. Two moisture contents (11.75 and 13.84% wet base) were used and the grains were packed in high density polyethylene packages (HDPE), stored in four BOD’s, regulated at temperatures of 20, 25, 30 and 35 °C and evaluated every two months by analyzing the water activity, grain sanity and the occurrence index. The experiment was set up in a completely randomized design and in a 2 x 4 x 4 factorial scheme, with two moisture contents, four storage temperatures and four evaluation times. The moisture content and the temperatures throughout the storage influence the sanitary quality of the soybean grains damaged by stink bug. The higher the moisture content and the storage temperature, the higher the water activity of soybeans damaged by bedbug, and the increase in the occurrence of fungi</span> <br /><br /></p>


1985 ◽  
Vol 15 (6) ◽  
pp. 1074-1079 ◽  
Author(s):  
P. B. Tompsett

Seed of Shoreaalmon Foxw., Shorearobusta Gaertn. f., and Shorearoxburghii G. Don was subjected to desiccation treatments or retained at several different temperatures on 1% agar or in various containers; viability and moisture contents (wet-weight basis) were assessed periodically. Germination ability declined when moisture contents were reduced below approximately 35% for S. roxburghii, below a value exceeding 40% forS. almon, and below 40% for S. robusta; a straight-line relationship was observed between the probit of germination and moisture content percentage. When all three species were kept on agar at 2, 6, or 11 °C little or no germination resulted; on transfer to 26 °C after 153, 54, and 30 days for S. roxburghii, S. robusta, and S. almon, respectively, negligible further germination occurred. Similar chilling damage occurred in S. robusta and S. almon at 16 °C. Mean germination times were twice as long at all temperatures tested for S. roxburghii as they were for the other species. Storage at near 40% moisture content in ventilated containers at 16 °C enabled survival of S. roxburghii seed for 9 months with over 50% viability, whereas other species declined in viability to near 20% within 14 days. A sudden loss of viability within 24 h was observed for seed of S. robusta placed in 11 or 6 °C; in the subsequent few days, little further loss of viability occurred. With 40% moisture content, seeds of all species at 21 °C stored as well as or better than those at lower temperatures. Retention for short periods in closed containers quickly reduced germination for S. robusta and S. almon.


2016 ◽  
Vol 79 (1) ◽  
pp. 148-152 ◽  
Author(s):  
TIAN DING ◽  
YAN-YAN YU ◽  
CHENG-AN HWANG ◽  
QING-LI DONG ◽  
SHI-GUO CHEN ◽  
...  

ABSTRACT The objectives of this study were to develop a probability model of Staphylococcus aureus enterotoxin A (SEA) production as affected by water activity (aw), pH, and temperature in broth and assess its applicability for milk. The probability of SEA production was assessed in tryptic soy broth using 24 combinations of aw (0.86 to 0.99), pH (5.0 to 7.0), and storage temperature (10 to 30°C). The observed probabilities were fitted with a logistic regression to develop a probability model. The model had a concordant value of 97.5% and concordant index of 0.98, indicating that the model satisfactorily describes the probability of SEA production. The model showed that aw, pH, and temperature were significant factors affecting the probability of toxin production. The model predictions were in good agreement with the observed values obtained from milk. The model may help manufacturers in selecting product pH and aw and storage temperatures to prevent SEA production.


2019 ◽  
Vol 62 (3) ◽  
pp. 661-671 ◽  
Author(s):  
Jia Wu ◽  
Xiangyang Lin ◽  
Shengnan Lin ◽  
Paul Chen ◽  
Guangwei Huang ◽  
...  

Abstract. The effects of packaging and storage conditions on the moisture content and instrumental and sensory textural properties of raw and salty light roasted (SLR) California almonds were studied under different storage conditions. The controlled combinations included low, medium, and high temperatures and low and high relative humidity (RH). Almond samples were packaged in cartons or polyethylene (PE) bags with and without vacuum. Both absorption and desorption of moisture by almonds were observed during storage and were dependent on the packaging and storage conditions. In general, gradual changes were observed for samples with PE and vacuum PE packaging in most of the storage conditions, while the samples packed in cartons showed more dramatic changes because these unprotected samples were more vulnerable to seasonal changes in humidity. The SLR almonds showed consistent moisture gains, while the raw almonds tended to lose moisture content in most of the storage conditions. This may be attributed to the low initial moisture content of the SLR samples. All raw samples packed in cartons became softer over time. The softening tended to be enhanced by high storage humidity and temperature. The raw almonds packaged in PE bags were firmer than those packed in cartons but also became softer over time. The firmness of the SLR samples was generally lower than that of raw samples, probably because roasting reduced the density and mechanical strength of the kernels. The firmness of PE packaged SLR samples increased in uncontrolled storage conditions and in higher storage temperature and humidity conditions but decreased slightly in lower temperature and humidity conditions. Vacuum packaging did not affect the firmness much. Using PE packaging and maintaining the RH below 50% and the temperature below 25°C are effective in stabilizing both raw and processed almonds. Keywords: Almond, Firmness, Nonpareil, Packaging, Relative humidity, Sensory, Storage, Temperature, Texture.


1994 ◽  
Vol 119 (3) ◽  
pp. 563-567 ◽  
Author(s):  
Chiam L. Liew ◽  
Robert K. Prange

Effects of ozone and storage temperature on carrots and two postharvest pathogens—Botrytis cinerea Pers. and Sclerotinia sclerotiorum de Bary—were investigated. Pathogen-inoculated and uninoculated whole carrots were exposed to an ozone concentration of 0 (control), 7.5, 15, 30, or 60 μl·liter-1. Treatment chambers were flushed with a total flow rate of 0.5 liters·min-1 (air and ozone) for 8 h daily for 28 days. The experiment was repeated twice at storage temperatures of 2, 8, and 16C. The residual ozone concentration (ozone supplied-exhausted and reacted ozone) increased with ozone supply concentration but was less at higher storage temperatures. A 50% reduction of daily growth rates of both fungi at the highest ozone concentration indicated that ozone was fungistatic. Carrot respiration rate, electrolyte leakage, and total color differences increased with ozone concentration. Ozone-treated carrots were lighter (higher L* values) and less intense (lower chroma values) in color than control carrots.


2017 ◽  
Vol 63 (No. 9) ◽  
pp. 417-424 ◽  
Author(s):  
Ahmadloo Fatemeh ◽  
Kouchaksaraei Masoud Tabari ◽  
Goodarzi Gholam Reza ◽  
Salehi Azadeh

This study investigated methods to overcome seed dormancy in Crataegus pseudoheterophylla Pojarkova seeds. Seeds with and without endocarps were treated with gibberellic acid (GA<sub>3</sub>) at different concentrations and four storage temperatures. Then they were stratified in an alternate temperature regime. The amount of absorbed water in seeds with endocarps was monitored by measuring the fresh weight of seeds for 0, 24, 48, 72, and 96 h of imbibition. The electrical conductivity (EC) and the percentage of water uptake by seeds stored for 12 months at laboratory temperature, in a refrigerator, in a freezer, and in freeze-thaw conditions were measured. The highest germination (59.7%) was recorded in seeds without endocarps treated with 3,000 mg·l<sup>–1</sup> GA<sub>3 </sub>and stored either in a laboratory or a refrigerator (32.7–35.3%). All treatments of seeds without endocarps where GA<sub>3</sub> was applied showed statistically higher percentages of germination than the control. Seeds with endocarps stored at refrigerator temperature imbibed water up to 44.3% with increasing imbibition periods, whereas the amount of seeds that absorbed water in freezer and freeze-thaw conditions was almost the same. The tests showed the highest EC during storage in the freezer, with the lowest water uptake and viability in seeds stored during the freeze-thaw process.


1948 ◽  
Vol 26f (3) ◽  
pp. 160-167
Author(s):  
D. MacDougall

Irish moss (Chondrus crispus) from Canada's east coast was used to study possible improvements in the production and storage of gelose. The optimum pH for the extraction of gelose from Irish moss was between 6 and 7. Fine leaf particles, which prevent rapid filtration, were readily removed by supercentrifuging. Comparison of drum drying and drying from the frozen state showed that the former caused a marked lowering of viscosity but had little effect on suspending power or jelly strength. The logarithm of the viscosity determined by means of a MacMichael viscosimeter was related directly to the concentration; therefore, viscosity measurements can be corrected for the moisture content of the samples. The effect of storage temperature on deterioration was greater than the effect of relative humidity. Samples stored at 0° and 40° F. for 12 weeks showed no significant changes in viscosity or suspending power, whereas those stored at 80° and 120° F. deteriorated very rapidly. Material was vacuum ice-dried to 2% moisture without damage but the quality decreased when the extracts were stored at high temperatures.


2009 ◽  
Vol 134 (1) ◽  
pp. 156-163 ◽  
Author(s):  
Chae Shin Lim ◽  
Seong Mo Kang ◽  
Jeoung Lai Cho ◽  
Kenneth C. Gross

To study ripening-related chilling injury in pepper (Capsicum annuum L.), chilling-tolerant ‘Buchon’ and chilling-sensitive ‘Nockgwang’ fruit were harvested at mature green (MG), breaker (BR), and red-ripe (RR) stages and stored at 1, 5, and 10 °C for 21 d. ‘Buchon’ did not show surface pitting (SP) regardless of ripeness stage and storage temperature, whereas ‘Nockgwang’ at MG and BR exhibited SP at 1 and 5 °C. After 14 days of storage at 1 °C, chilling-sensitive ‘Nockgwang’ did not show SP when fruit were at the RR stage. Compared with ‘Buchon’, ‘Nockgwang’ at MG and BR had more electrolyte leakage increase during storage at 1 and 5 °C. ‘Buchon’ at all ripeness stages showed significantly higher ethylene production during storage regardless of storage temperatures. Contents of β-carotene and lycopene increased in both cultivars as ripening progressed. The contents of β-carotene and lycopene were similar between the two cultivars regardless of storage temperatures and ripeness stages. Susceptibility of pepper fruit to chilling appeared to be related to superoxide dismutase (SOD) and catalase (CAT). Activities of SOD and CAT were much higher in ‘Buchon’ than ‘Nockgwang’, more apparently at MG and BR. The results suggest that chilling-tolerant ‘Buchon’ and fruit at RR could have been equipped with a more efficient antioxidizing system, even if it was not clear whether oxidative stress is a cause or an effect of the CI in pepper.


1992 ◽  
Vol 2 (3) ◽  
pp. 378-381 ◽  
Author(s):  
Luis Hernández-Rivera ◽  
Robert Mullen ◽  
Marita Cantwell

Asparagus (Asparagus officinalis L.) spears (cv. UC 157) trimmed to 20 cm were cooled 0, 4, 8, 12, 16, and 20 hours after harvest and evaluated for resistance to shear at 5 and 10 cm above the cut end immediately after cooling and during storage at 0.5, 2.5, and 5C. Resistance to shear increased during cooling delays and with time in storage. Initial cooling delays and simulated marketing conditions (transfer to 15C for 1 day) were the principal causes of increased resistance to shear. A 4-hour cooling delay resulted in an average 40% increase in resistance to shear. Transfer to 15C for 1 day resulted in a greater increase in shear force in the rapidly cooled than in the delayed-cooled spears. Increases in resistance to shear during storage varied from 0% to 50% and depended on the storage temperature, time, and the initial cooling delay. Spears trimmed to a green base showed less increase in shear force after storage than did spears trimmed to a white base. The visual quality of asparagus stored for 14 days was similar (excellent) among spears from different storage temperatures and between green- and white-base spears. Storage quality after 24 days had decreased more in spears stored at 5C than at 2.5 or 0.5C, and more in the green-base than the white-base spears.


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