• Horticultural Science & Technology
• /
• v.34 no.6
• /
• pp.807-817
• /
• 2016

Many onion growers and researchers assert that differences in soil type, agricultural practices, weather, and duration of prolonged onion cultivation in a particular field could affect onion bulb quality. This study evaluates the bulb quality of onions grown in different regions and determines the correlations between bulb characteristics and postharvest loss during cold and ambient storage. Soil and onion bulbs were collected from fields in six onion growing regions in Korea, during the growing season of 2011-2012. The fresh weight, dry matter content, and carbon (C), sulfur and magnesium contents of the onion bulbs were significantly affected by the location in which they were grown. Bulbs grown in Muan had the greatest number of scales, thinnest scale thickness, and the highest total soluble solids (TSS) and total flavonoids (TF). Bulbs originating from Jecheon had the lowest pyruvic acid (PA), total phenolics and TF. Storage loss of bulbs from the different regions was similar in refrigerated storage, but differed in ambient temperature storage. Bulb fresh weight was positively correlated with scale thickness (r = 0.617) and cold storage loss (CSL; r = 0.398). Dry matter content was positively correlated with C (r = 0.958) and TF (r = 0.256) contents, while it was negatively correlated with CSL (r = -0.424). CSL was primarily affected by the fresh weight, as well as the dry matter, C, and PA contents of the bulbs, while ambient storage loss was primarily influenced by the amount of TSS.

• Journal of Bio-Environment Control
• /
• v.9 no.4
• /
• pp.230-236
• /
• 2000

For extension of storability, onion bulbs produced in Cheju Island were exposed to ${\gamma}$-ray irradiation at a dosage of 0, 3, or 6Krad and stored in a natural cavern, or in low (2$^{\circ}C$) or ambient temperature storage condition. Sprouting began from approximately five months in storage, regardless of storage condition, and increased as the storage period increased. From early August, sprouting as high as 50% occurred in the natural storage cavern, and 20% in ambient temperature storage when bulbs were treated with 0 krad ${\gamma}$-ray. However, bulbs treated with 3 or 6krad ${\gamma}$-ray did not any sprouting until six months in storage. No significant weight loss was observed in all treatments until sprouting occurred from 40 days after the initiation of storage. Weight loss, however, increased remarkably after 40 days in storage, indicating that it was closely related to sprouting during storage. Bulbs stored at 2$^{\circ}C$ showed 5~10% rot, but were still edible. Percent rot reached to as high as 50% in bulbs unirradiated and stored at ambient temperatures after seven months, while it in irradiated bulbs reached to 5, 33, and 30% at 2$^{\circ}C$, in a natural cavern, and ambient temperatures, respectively. Sugar contents slightly increased in irradiated bulbs in the later storage period under ambient temperatures, while sugar contents in irradiated bulbs in the later storage period under ambient temperatures, while sugar contents in Allium vegetables generally decrease in later storage if unirradiated. Sulfur content slightly increased in irradiated bulbs in the early storage period and decreased gradually in all treatments in the later storage stage.

• Applied Biological Chemistry
• /
• v.24 no.4
• /
• pp.218-223
• /
• 1981

This study was conducted to investigate the effects of post-harvest drying method and subsquent storage condition on the quality of garlic bulbs for 10 months from July, 1980 to April, 1981. The 27% weight loss of garlic bulbs by HPHD (hot air post-harvest frying) for 12 days at $40^{\circ}C$ (8hrs/day) was equal to that by NPHD (conventional natural post-harvest drying) for 35 days. But the decay occured 5.5% only in NPHD. During the storage period of garlic bulbs by HPHD, their decay and weight ]oss were less 25.4% and 13.5% in ambient storage, and less 14.2% and 7.5% in low temperature storage than those of NPHD. When garlic bulbs were stored in low temperature, the weight loss and decay were less 20.0% and 22.4% in NPHD, and tess 14.0% and 9.9% in HPHD than those in ambient temperature storage. The Quality of garlic bulbs packed with 0.08mm polyethylene film stored at ambient temperature for 2 months was so poor as to be inedible because of the adverse effect of $CO_2$ and the growth of molds, but in low temperature storage for 10 months it was in good shape showing the weight loss, the decay and the sprouting 2.6%, 3.4% and 26.8%, respectively.

• Korean Journal of Agricultural Science
• /
• v.40 no.3
• /
• pp.197-202
• /
• 2013

This study was aimed to find the storage potential of low temperature adapted shiitake mushroom under freezing temperature ($-3^{\circ}C$). Fresh shiitake mushroom was harvested at late Feb. and cooled to target temperature, $-3^{\circ}C$ in the cooling room for 24 hr. Cooled mushroom were then placed in plastic boxes, wrapped with plastic film ($30{\mu}m$), and stored at $-3^{\circ}C$ for 2 months. Weight loss of mushroom was ranged from 2.1 to 3.2%. Dry weight per unit fresh weight, however, was slightly increased because of moisture loss. Firmness of fruit body increased from $0.95kg/cm^{-2}$ (before storage) to $1.13kg/cm^{-2}$ (after 2 month storage). About half amount of starch was lost during 2 month storage. The amount of total and reducing sugars remained relatively constant. After storage, freshness of mushroom was recovered by thawing treatment. When recovered mushroom were packaged with styrofoam tray and PVC wrapping, and exposed to ambient and $10^{\circ}C$, respectively, brown spot on the gill of fruit body was found and slight decay symptom was also found at ambient temperature only but not at $10^{\circ}C$. Results indicated that low temperature adapted shiitake mushroom has a storage potential under freezing temperature ($-3^{\circ}C$). Freezing storage technology of fresh shiitake mushroom will contribute the increase of storability up to 2 months.

• Korean Journal of Agricultural Science
• /
• v.20 no.1
• /
• pp.9-17
• /
• 1993

Postharvest treatments such as polyethylene film wrapping, ethylene scrubber, and fruit coatings were compared to find a potential effect on the fruit quality in 'Fuji' apples during storage and simulated marketing. Polyethylene film wrapping appeared to be excellent in preventing weight loss during storage but fruits lost weight at a high rate when exposed to ambient temperature during simulated marketing. Also, surface cracking disorder was observed in parts of film-wrapped fruit under marketing condition after storage of 21 weeks. Ethylene scrubber effectively removed ethylene in polyetheylene bags but this effect reduced along with the increase of storage time. Although Prolong-treated fruits were good in appearance at 12-week storage, no beneficial effect was found on the inhibition of weight loss during storage as well as marketing. In addition, wax-like substances were accumulated on the surface after storage of 21 weeks, resulting in the reduction of marketability. Water soluble wax seemed highly effective on the inhibition of weight loss during storage and marketing. However, parts of fruit were severely injured probably due to the high concentration of wax. Undamaged fruit showed excellent appearance in shape and flesh quality even after 21 weeks of storage. Further study is required to find the proper concentration of wax.

• Journal of Biosystems Engineering
• /
• v.32 no.2 s.121
• /
• pp.102-108
• /
• 2007

Heat pump systems are recognized to be heating and cooing systems. In this study, to check the practical application possibility of heat pump systems as low temperature storage systems and get basic data, apples of a long term storage items were stored and performance of low temperature storage and quality changes of apples were evaluated. Cooling coefficient of performance of the system was from 1.1 to 1.3. Although ambient air temperature varied widely from $-13^{\circ}C$ to $29.6^{\circ}C$ during low temperature storage period from January to June, the average temperature of low temperature storage chamber was $1.1^{\circ}C$ at setting temperature of $1.5^{\circ}C$. Sucrose of apples stored by the heat pump decreased from initial sucrose of 15.4% (Brix number) to final sucrose of 14.3%. Weight loss ratio of apples was 9.7% and internal and external view of apples after low temperature storage were very satisfactory with the naked eye.

• Korean Journal of Food Science and Technology
• /
• v.15 no.3
• /
• pp.287-294
• /
• 1983

Change of color, browning index, soluble protein, reducing sugar content, and available lysine were monitored for raw and extruded barely powders during four months of ambient and accelerated storage temperatures with $A_w$ of 0.31 and 0.71, respectively. Loss of whiteness and soluble browning pigments increased with increased $A_w$ and temperature. The raw sample had an increased rate of browning intensity than the extruded samples. Among the extruded samples, the added sucrose sample had the lowest rate of browning during storage. Loss of reducing sugar content in all samples increased with increased $A_w$ and temperature. The loss of soluble protein and of the available lysine also increased with increased $A_w$ and temperature. The loss of reducing sugar and of the available lysine was at least partly due to the Maillard browning reaction. These results have important implications in teh processing and storage of raw and extruded burleys.

• Food Science and Preservation
• /
• v.5 no.1
• /
• pp.7-12
• /
• 1998

Chestnuts(Castanea cretana, Eunki) were used for quality evaluations from the physiological and physicochemical points of view during storage under different temperatures and relative humidities for 8 months. Quality criteria included spouting, rotting, weight loss, and the changes in moisture, total sugar, reducing sugar, and total vitamin C of the stored sample. Sprouts(roots) were developed in about 2 months in all stored samples which had been mixed with sawdust(50% moisture) and stored under the conditions of 2∼25$^{\circ}C$ and 62∼95% RH. The sprout development was more significant in the storage temperature of Pit(9${\pm}$6$^{\circ}C$, 80${\pm}$5% RH, PT)and room(16${\pm}$7$^{\circ}C$, 85${\pm}$10% RH, RT) than low(3${\pm}$1%, 80${\pm}$5% RH, LT)and ambient(14${\pm}$11$^{\circ}C$, 67${\pm}$5% RH, AT). The rates of rotting and weight loss were appreciable in the order of PT, AT, RT and LT, and those of LT were 1∼2%. The use of wet sawdusts resulted in the increase of moisture contents in stored samples, thereby causing the rotting phenomena. Some chemical components of stored samples were found liable to the changes according to storage conditions, that is; total sugars showed a decreasing tendency along with a temporary increase during storage, and both reducing sugar and vitamin C were similarly accumulated in the samples stored at low temperature conditions. The results indicated that long-term storage of chestnuts will be possible in either cases of the application of low temperature following sprout-inhibition treatment or the use of lower temperature than 0$^{\circ}C$ to suppress its sprouting during storage.

• Food Science and Preservation
• /
• v.2 no.2
• /
• pp.243-249
• /
• 1995

Potatoes, Irish cobbler, were subject to quality evaluation from the physiological and physicochemical points of view during storage under different temperatures and relative humidities for 11 months. Quality criteria were sprouting, rotting, weight changes, moisture, total sugar, reducing sugar and vitamin C. Low temperature condition(LT, 2∼4$^{\circ}C$, 80% RH) was enough to preserve Potatoes for 11 months, but it was indicated to be limitations that the increase in reducig sugar as well as sprouting by about 3.3 to 6.7% occurred from the 3rd month of storage. Meanwhile, pit temperature(PT, 3∼15$^{\circ}C$, 75∼85% RH), room temperature(RT, 7∼17$^{\circ}C$, 80∼95% RH) and ambient temperature(AT, 2∼25$^{\circ}C$, 62∼72 RH) were shown infeasible conditions for the storage of potatoes mainly due to the increase In sprouting-rate and subsequent quality-loss after 3 months of storage. Based on the results, it proposed that more economical conditions, ranging 10 to 15$^{\circ}C$ and about 80% RH following sprout inhibition treatment should be used for the long-term storage of potatoes.

• Tunnel and Underground Space
• /
• v.21 no.4
• /
• pp.297-306
• /
• 2011

In this paper, we performed thermodynamic energy balance analysis of the underground lined rock cavern for compressed air energy storage (CAES) using the results of multi-phase heat flow analysis to simulate complex groundwater-compressed air flow around the cavern as well as heat transfer to concrete linings and surrounding rock mass. Our energy balance analysis demonstrated that the energy loss for a daily compression and decompression cycle predominantly depends on the energy loss by heat conduction to the concrete linings and surrounding rock mass for a sufficiently air-tight system with low permeability of the concrete linings. Overall energy efficiency of the underground lined rock caverns for CAES was sensitive to air injection temperature, and the energy loss by heat conduction can be minimized by keeping the air injection temperature closer to the ambient temperature of the surroundings. In such a case, almost all the heat loss during compression phase was gained back in a subsequent decompression phase. Meanwhile, the influence of heat conductivity of the concrete linings to energy efficiency was negligible.