• Horticultural Science & Technology
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• v.31 no.4
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• pp.429-436
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• 2013

Kimchi cabbage 'Choongwang' cultivar is mainly cultivated during summer in Gangneung area. 'Choongwang' cultivar was harvested in late July, applied with predrying, room cooling, and forced air cooling, and then packaged with/without 0.02 mm HDPE film to estimate the effect of postharvest treatment on quality characteristics (weight loss, trimming loss, firmness, SSC, color index, sensory evaluation) during 8 week storage at $2^{\circ}C$. Kimchi cabbage without 0.02 mm HDPE film showed high weight loss up to 13-20% while those of with liner were significantly lower. Also forced air cooling among the postharvest treatments was effective to reduce both weight loss and trimming loss. Appearance and freshness in sensory evaluation were the important factors in estimating good quality during storage. Liner treatment with forced air cooling showed highly significant for maintaining appearance and freshness ($P{\leq}0.01$). Color index was no differences between with/without 0.02 mm HDPE film and postharvest treatments. After 6 weeks storage in without 0.02 mm HDPE film with room cooling or control appearance was severely damaged and also internal browning was found. While in with 0.02 mm HDPE film internal browning was found after 8 weeks storage, just in room cooling or predrying treatment.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.655-665
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• 2014

The effect of modified atmosphere packaging (MAP) on kohlrabi (Brassica olerace L. gongulodes group)'s quality and antioxidant molecule during storage was examined to determine the optimal film package for maintaining freshness. To extend shelf life, MAP was tested using PE $50{\mu}m$ and oriented polypropylene (OPP) films with oxygen transmission rate (OTR) at 3,000, 10,000, $15,000mL/m^2/day/atm$. The OPP film packaging with modified oxygen transmission rate showed a delay in a weight loss and extended storage period. The package with OTR 3000 attained the desired gas composition of $O_2$ 3.2-6.7 kPa and $CO_2$ 13.1-19.8 kPa, in storage at room temperature. Kohlrabi stored in this package showed the lowest weight loss and the highest visual quality. Deterioration and off-odor were developed more rapidly in PE $50{\mu}m$ towards the end of the storage at room temperature. However, there are no differences among OTR films in visual quality and off-odor until 60 days at cold storage. Vitamin C content of kohlrabi was reduced rapidly in OTR 15000 with high transmission rate and showed less loss in PE $50{\mu}m$ and OTR 3000 in both room temperatures and cold storage. Results revealed that an OPP film with OTR 3000 extended the shelf life of kohlrabi in storage with maintained quality and vitamin C.

• Food Engineering Progress
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• v.21 no.4
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• pp.312-317
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• 2017

Weight loss that influences quality and farmer incomes is affected by the storage environment of agricultural products. The interior of storage should be maintained at high humidity to prevent the weight loss of products which contain a lot of moisture. The research had constantly proceeded with change in the heat exchanger surface areas, humidity systems, and weight loss forecast to maintain high humidity within storage. Relative humidity that exerts an effect weight loss of crop is influenced by storage temperature, leak state, and volume of product. When weight loss is predicted, different conditions of these factors are derived. In case of CA storage, ways of forecasting the weight loss become easier compared to cold storage due to sealed storage with external environment during storage period. In this study, apples were stored in purge-type CA storage and weight loss has been predicted by using operating characteristics and environmental conditions. As a result, humidity variation in the storage fluctuates with the operation of the unit-cooler. Furthermore, unit-cooler operation factor is influenced by outside temperature and respiration heat. Prediction value of weight loss according to temperature and humidity has been most accurately predicted. Prediction value through defrosting water measured shows unit-cooler work quality. K-value needs verification to calculate the VPD method.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2002.08a
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• pp.180.1-180
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• 2002

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2002.08a
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• pp.180.2-180
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• 2002

• Korean Journal of Agricultural Science
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• v.29 no.1
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• pp.24-31
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• 2002

This experiment was conducted to improve the market quality of fresh strawberries through postharvest treatment of $CO_2$ at commercial level. Postharvest application of $CO_2$ increased flesh firmness regardless of ripeness of strawberries. Firmness further increased in berries of full maturity but the actual firmness was higher in less mature berries. The optimal condition of $CO_2$ treatment was above 15% of $CO_2$ for 4 hours during cooling of harvested fruit. Residual effect of firmness increase was remained until simulated shipment as well as retail condition for 1 days at ambient temperature. Market quality of full ripe fruit at harvest significantly reduced due turning skin color to dark red and dryness of physically injured surface. Result indicated that a short term application of $CO_2$ during cooling has a benefit for keeping freshness of strawberries during export and local marketing.

• Mycobiology
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• v.42 no.3
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• pp.262-268
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• 2014

Several postharvest diseases of table grapes (Vitis vinifera) occur during storage, and gray mold rot is a particularly severe disease because the causal agent, Botrytis cinerea, grows at temperatures as low as $0^{\circ}C$. Other postharvest diseases, such as those caused by Penicillium spp. and Aspergillus spp., also often lead to deterioration in the quality of table grapes after harvest. The use of plant essential oils such as thymol and linalool, to reduce postharvest diseases in several kinds of fruits, including table grapes and oranges, has received much attention in European countries. However, to the best of our knowledge there has been no report of the use of thymol fumigation to control gray mold in table grapes in Korea. Thymol ($30{\mu}g/mL$) and linalool ($120{\mu}g/mL$) significantly inhibited mycelial growth and conidia germination of B. cinerea. The occurrence rate of gray mold rot of B. cinerea and other unknown fungi was significantly reduced by fumigation with $30{\mu}g/mL$ thymol in several table grape cultivars, such as Campbell early, Muscat Bailey A, Sheridan, and Geobong. In this study, fumigation with $30{\mu}g/mL$ thymol, had no influence on the sugar content and hardness of grapes, but reduced fungal infection significantly. This suggests that $30{\mu}g/mL$ thymol could be utilized to reduce deterioration of grapes due to gray mold and other fungal infections during long-term storage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.5
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• pp.410-414
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• 2004

To understand the postharvest characteristics of soybean sprouts, 5-day-old sprouts were harvested, packed in PE film, and stored at 4, 12, and $20^{\circ}C$ for up to 4 days. In addition, the sprout respiration rate was measured after storage at 4, 8, 12, 16, 20, and $24^{\circ}C$ for up to 20h. During the first day of storage at $20^{\circ}C$, the sprouts maintained temperature-dependent longitudinal growth, especially of hypocotyl length; hypocotyl and root grew 0.8cm and 0.2cm, respectively. The hypocotyl thickness decreased by 11, 13, and $18\%$ after 4 days of storage at 4, 12, and $20^{\circ}C$, respectively. No temperature-dependent differences in fresh weight, dry weight, or water content were found, despite decreases of $3\%$ over the 4 days of storage. A significant postharvest decrease of $50\%$ in vitamin C content was observed in the sprouts stored at $20^{\circ}C$ for 3days. Based on the $CO_2$ production rate, the soybean sprouts exhibited an increase in respiration in proportion to the storage temperature; sprouts stored at 8, 12, 16, 20 and $24^{\circ}C$ showed approximately 2, 5, 6, 11, and 17 times, respectively, than the respiration rate of sprouts stored at $4^{\circ}C$. These results indicate the importance of low temperature storage during market circulation for minimizing the postharvest morphological and nutritional degradation of soybean sprouts.

• Journal of Biosystems Engineering
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• v.43 no.4
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• pp.379-385
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• 2018

Purpose: Postharvest handling of onions (harvesting, cleaning, grading, cooling, storing, and transport) should be performed continually to reduce costs and improve quality. The purpose of this study is to a) determine the design parameters and operating conditions of anion auto-dumping that constitutes a key component of the postharvest bulk handling machinery system, and b) to perform a performance test with the auto-dump prototype system. Methods: Kinematic analyses and computer simulations of the auto-dump mechanism were applied to analyze the operating conditions and design parameters. Results: The optimum working condition for the auto-dump was determined from kinetic analyses. In addition, the interaction between the velocity of the hydraulic cylinder and the angular velocity of the auto-dump were analyzed in order to control the bulk handling machinery system. The acting forces and optimum operating conditions of the hydraulic cylinder were determined by analyzing the forces related to the mass of inertia of the auto-dump assembly during rotation. The method of controlling the feeding rate of onions in terms of the uniformity of the stacking pattern and the control of the entire system was better than the two-stage method of controlling the rotational speed of the auto-dump. Based on the performance test with the prototype for the auto-dump, the stacking pattern and rigidity of the system were analyzed. Conclusions: These results would be of great importance in the postharvest bulk handling machinery system for onions.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.577-582
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• 2011

Greenhouse satsuma mandarins (Citrus unshiu Marc., cv. Gungchun) of an early harvesting cultivar were treated by hot water showering at 65$^{\circ}C$ for 10 s at a commercial scale in a packing house and then stored at 5$^{\circ}C$ for 3 weeks and subsequently at 18$^{\circ}C$ for 1 week (simulated shelf-life) to examine the potential use of hot water treatment (HWT) as an environmentally benign method to maintain mandarin quality characteristics during postharvest storage and sale. The respiration rate just after heat treatment or during storage was at a similar level in both the treated and untreated fruit. HWT also had no detrimental effects on quality attributes including pH, titratable acidity, soluble solids content, weight loss, firmness, and peel color. The development of stem-end rot, mold decay, and black rot was lower in the heat-treated fruit compared to those in the untreated control. A sensory evaluation showed that HWT markedly improved fruit appearance, making the fruit cleaner and glossier. The results suggested that HWT can be applied to satsuma mandarin as an effective pretreatment to maintain postharvest quality during storage and marketing.