• Title/Summary/Keyword: Postharvest technology

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Fermentation Characteristics of Wine Yeast Strains for White Wine Making (백포도주 양조에 있어서 포도주 효모의 발효 특성)

  • Seoktae Jeong;Nami Goto;Park, Jonguck
    • Food Science and Preservation
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    • v.8 no.3
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    • pp.326-330
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    • 2001
  • The characteristics of used wine yeast strains were as follows, S6U showed low fermentation speed than those of other yeast strains, but this strain fermented completely later. The wine fermented by W-3 was very low contents of total acid, 0.75% and the ones fermented by UCD530 and AC- contained much extract, 3.26 mg/L and 3.22 mg/L respectively. The wine fermented by CEG and CS2 were predominant in yellowness, and EC1118 produced large amount of acetaldehyde, 49.9 mg/L than those of other strains. EC1118 and CY3079 displayed low methylene blue dyeing ratio, below 15%, meaning high alcohol tolerance yeast. UCD530 produced extremely high contents of glycerol, succinate and lactate compared with other strains. These properties revealed that UCD530 was a typical Saccharomyces bayanus species. The main organic acids produced by wine yeasts were pyruvate, lactate, succinate and acetate. The concentration of acetate in experimental wine could be divided into two parts, one group had concentration below 170 mg/L (UCD530, EC1118, AC-, CY3079, W-3), and the other had concentration up to 350 mg/L (S6U, CEG, CS2).

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Comparison of Packaging Methods to Prolong the Freshness and Quality of Korean Head Cabbage (Brassica rapa). (알배추 포장 방법에 따른 품질 및 선도 비교)

  • Lee, Jung-Soo
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.25 no.3
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    • pp.101-109
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    • 2019
  • The effect of packaging and storage methods in enhancing the shelf life and improving the postharvest quality of the Korean head cabbage (Brassica rapa) used for wrapping vegetables was studied at 10℃. The wrapping cabbage was packed using four types of packaging and storage materials: (A) Perforated PP film; (B) Non-perforated PP film; (C) PVC film for wrapping; and (D) non-packaged as control. The quality parameters, such as fresh appearance, weight loss, hue angle, moisture content, hardness, and SSC of wrapping cabbage were investigated. The weight loss of wrapping cabbage showed a significant difference between the one packaged with film and the non-packaged as control. The general appearance of Korean cabbage stored at 10℃ was not significantly affected by the packaging treatments. However, Korean head cabbage packaged with perforated film tend to show a better external appearance compared with those exposed to the other packaging during three weeks of storage at 10℃. The inside appearance, hue angle, moisture content, hardness, and SSC, gradually decreased during the storage period. No remarkable change in the measured items were observed in Korean cabbage packaging methods. In this experiment, the Korean cabbage packaged inside a PP film with holes, and stored at 10℃ temperature had the most desirable outcome of extending the head cabbage's shelf life and appearance quality. Results suggest that perforated packaging treatment combined with low storage temperature could be an effective method in prolonging the shelf life of Korean cabbage for wrapping vegetable.

Postharvest Changes in Quality and Biochemical Components of Perilla Leaves (들깻잎의 수확후 품질 및 성분변화)

  • Hong, Young-Pyo;Kim, Seung-Yeol;Choi, Woo-Young
    • Korean Journal of Food Science and Technology
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    • v.18 no.4
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    • pp.255-258
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    • 1986
  • This study was carried out to determine the shelf-life and quality changes of perilla leaves (Perilla ocimoides L.) in relation to changes in the concentration of biochemical components during storage. The shelf-life of perilla leaves was 2 to 3 days at room temperature and 6 days at $3^{\circ}C$. This was extended to 12 days at room temperature and 20 days at $3^{\circ}C$ by packaging in a 0.01 mm thick polyethylene film sack (PEFS). The ascorbic acid concentration of fresh perilla leaves was 23 mg per 100 g fresh weight. This declined to 16 mg per 100 g fresh weight on the 4th day of storage in all treatments. Ascorbic acid concentrations decreased further to 7 mg on the 8th day at room temperature and 8 mg per 100 g on the 16th day at $3^{\circ}C$ in PEFS. Total and reducing sugar concentrations in the controls were higher than those in the PEFS storage at room temperature. Protein and free amino acid concentrations gradually increased during storage. A higher protein level was maintained in the control than in the PEFS treatment. Changes in nucleic acid concentration and peroxidase and polyphenoloxidase activities during storage were also measured in relation to the changes in quality of perilla leaves.

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Postharvest Changes in Quality and Biochemical Components of Leaf Lettuce (상치의 수확후(收穫後) 품질(品質) 및 성분변화(成分變化))

  • Kim, Seong Yeol;Hong, Young Pyo;Choi, Woo Young
    • Korean Journal of Agricultural Science
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    • v.12 no.1
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    • pp.128-138
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    • 1985
  • This study was conducted to elucidate the shelf-life and quality changes in relation to biochemical components in leaf lettuce (Lactuca sativa L.). The shelf-life of leaf lettuce at room temperature was 2 to 3 days. But it was extended to 3 weeks by packaging in a 0.01 mm thick polyethylene film sack when stored at $3^{\circ}C$. The ascorbic acid contents of fresh leaf lettuce was 25 mg per 100 gram fresh weight. The acid at room temperature was almost destroyed after 4 days storage. But the contents of ascorbic acid at $3^{\circ}C$ maintained about 50 to 60% of the initial level in packaging of polyethylene film sack after 8 days storage. The content of chlorophyll was greatly decreased at room temperature but no significant changes were found at $3^{\circ}C$. The changes of total sugar and reducing sugar contents during storage were not very different between treatments. The contents of alkali soluble protein and free amino acid gradually increased in the treatments of polyethylene film sack packaging during storage in general, but the contents decreased after the increase in control treatment. Nucleic acid content, peroxidase and polyphenoloxidase activities were measured and discussed in relation to the leaf senescence.

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Effect of Maturity and Storage Temperature on Preservation of Fresh Jujube (숙도 및 저장온도가 생대추의 저장적성에 미치는 영향)

  • An, Duck-Soon;Lee, Dong-Sun
    • Korean Journal of Food Science and Technology
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    • v.29 no.4
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    • pp.758-763
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    • 1997
  • Fresh jujubes (Zizyphus jujuba Miller) of whitish green and red ripe maturities were stored at 5 different temperatures, and quality changes through the storage were measured to find an optimal storage condition. Respiration rates and their temperature dependences for both maturities were not different from each other, which suggested non-climacteric pattern of postharvest respiration. Red ripe fruits showed heavier weight and higher content in soluble solid and ascrobic acid compared with whitish green mature fruits. Through the storage of jujubes in perforated packages tissue softening and decay were main visual quality deteriorations with the former preceding the latter. The whitish green mature jujubes showed slower rate of quality changes in softening and decay than red ripe ones, and are thus more suitable for long term storage. In the storage, the whitish green fruits changed into red color, and showed increase in soluble solid and decrease in acidity and ascorbic acid content. Storing the jujubes at $-2^{\circ}C$ resulted in symptoms of chilling injury, and storing at higher temperatures above $0^{\circ}C$ accelerated the decay and softening. $0^{\circ}C$ was found to be optimal temperature for long term storage, where jujube had the lowest rate of quality changes without chilling injury. Even at optimal temperature of $0^{\circ}C$, however, storage life retaining freshness was only around 40 days which is not enough.

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Current Status and Recent Subjects of Rice Products Development in Korea (국내 쌀 가공식품의 개발현황과 당면과제)

  • 금준석
    • 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.109-119
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    • 2002
  • Rice production in Korea began to rise significantly after 1970. Rice is the dominant food in Korea and most of the rice production (about 95%) is consumed as cooked rice. it provides over 4,000Kj of energy per capita per day. Apparent rice availability in 2000, 93.6Kg of milled rice per person annually. The non-allergenic character of rice offers a sound basis for development of products for markets for all age groups. Whole grains are washed rice, coated rice, enriched rice in Korea. Utilization of rice as food can be categorized three categories in Korea; direct food use, processed foods, and brewing. Rice for direct consumption include regular whole grain, precooked rice, brown rice and specialty products such as aseptic cooked rice, retort cooked rice and rice burger. Rice used for processed foods includes that for cereal, soup, baby food, snack, cake, noodle, brown rice tea, and minor unclassified uses. Rice use for brewing is for the production of fermented rice wine. The use of rice for direct food is by for the greatest of the three uses. Although direct food accounts for the largest domestic consumption, a significant quantity of rice is used in processed products. The use of rice by-products as human food should not be over looked. Utilization of by products(rice germ, rice bran) requires a specialized technology. Typical type of rice is black rice. When cooked, black rice gives a black color to cooked rice. Glutinous rice performs specific functions in several commercial products such as dessert, gravis, cake and snack. Rice starch production is quite limited because of the high cost of making of starch. Rice processed products in Korea are occupied small parts of total rice production compared to Japan. Rice cake (Garadog) is the principal from of rice product consumed in Korea. Rice cake and snack is usually prepared from non-glutinous milled by washing, grinding, steaming, cooling and packaging. Rice cake will be continued to be a major rice product in Korea. Rice products represent a means to study variety differences in rice grain quality, since the processing magnifies differences not normally detected from more boiling. Recently, rice processing companies in Korea are about 400 ones which uses rice about 160,000tons. New rice processed products and modified traditional products must be developed and diversified with high quality and processing properties of rice processed products are improved.

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Effect of Cultivation Method on Growth and Storage Characteristics of Kimchi Cabbage Cultivar 'Chun Gwang' Grown on Semi-highland in Summer ('춘광' 배추의 준고랭지 여름철 재배 방법에 따른 생육과 저장 특성)

  • Lee, Jung-Soo
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.27 no.1
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    • pp.25-33
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    • 2021
  • This experiment was conducted to determine the effects of the pre- and post-harvest variable factors on the processed product of kimchi cabbage cultivated in semi-highland at summer time. Kimchi cabbage cultivar 'Chun Gwang' was grown in an open field and/or under a plastic greenhouse condition; it was stored at 0? after harvesting with low-density polyethylene (LDPE) film packaging. The pre-harvest characteristics growth parameters, fresh weight, head weight, no of leaves, leaf thickness, firmness, moisture content etc. were evaluated. The evaluated postharvest characteristics were fresh weight loss, appearance, trimming loss, SPAD value, moisture content and hue angle. The results show that the fresh weight and leaf thickness were higher in 'Chun Gwang' kimchi cabbages grown in the greenhouse than those in the field. However, the other evaluated factors were not affected by the type of cultural method. During the storage, the cabbage continued to decrease in fresh weight loss, trimming loss and moisture content. When compared to the kimchi cabbage showed significant difference in the fresh weight loss, trimming loss and moisture content during storage. It was confirmed that both cultural methods indoor- and outdoor did not show head growth parameters of 'Chun Gwang' kimchi cabbages on semi-high land at summer time. Although no difference in the growth before storage was observed, the evaluated characteristics like fresh weight loss etc. were influenced by cultural method as a pre-harvest factor. This study suggests that there were to be affected by pre-harvest factor during storage after harvest. In this study, an integrated management system combining relationship between processed agricultural products and their pre- and post-harvest factors.

Freshness Comparison of 'Mats-Kyeong-chae' in Accordance with Packaging Treatments and Storage Temperatures ('맛경채'의 포장방법과 저장온도에 따른 선도 비교)

  • Lee, KwanHo;Jang, Suk-Woo;Park, Suhyoung;Ahn, Yul Kyun;Lee, Jung-Soo
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.24 no.3
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    • pp.121-130
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    • 2018
  • 'Mats-kyeong-chae (Brassica lee ssp. namai cv. Tongssamchoo)', a new type of sweet Korean cabbage for fresh wrapping and soup cooking, was released by the Korea National College of Agriculture and Fisheries. The shelf-life and quality changes of this new cultivar was evaluated by packaging with PP (polypropylene) film bag and storing at three temperatures ($5^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$). As control, the cabbage was packaged in a corrugated paper box and stored at $25^{\circ}C$. At the storage temperature of $5^{\circ}C$, the degree of freshness, weight loss, hue angle and SPAD on cabbage packaged with PP film bag maintained its good quality and exhibited a longer period of marketable life compared to the samples stored in other treatments. Results showed that the use of PP film packaging and storing at $5^{\circ}C$ could be the optimum condition for commercial storage of 'Mats-kyeong-chae'. Further investigation on other quality parameters according to different packaging methods would be useful in maintaining the quality of 'Mats-kyeong-chae' at postharvest stages.

A Quality Prediction Model for Ginseng Sprouts based on CNN (CNN을 활용한 새싹삼의 품질 예측 모델 개발)

  • Lee, Chung-Gu;Jeong, Seok-Bong
    • Journal of the Korea Society for Simulation
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    • v.30 no.2
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    • pp.41-48
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    • 2021
  • As the rural population continues to decline and aging, the improvement of agricultural productivity is becoming more important. Early prediction of crop quality can play an important role in improving agricultural productivity and profitability. Although many researches have been conducted recently to classify diseases and predict crop yield using CNN based deep learning and transfer learning technology, there are few studies which predict postharvest crop quality early in the planting stage. In this study, a early quality prediction model is proposed for sprout ginseng, which is drawing attention as a healthy functional foods. For this end, we took pictures of ginseng seedlings in the planting stage and cultivated them through hydroponic cultivation. After harvest, quality data were labeled by classifying the quality of ginseng sprout. With this data, we build early quality prediction models using several pre-trained CNN models through transfer learning technology. And we compare the prediction performance such as learning period and accuracy between each model. The results show more than 80% prediction accuracy in all proposed models, especially ResNet152V2 based model shows the highest accuracy. Through this study, it is expected that it will be able to contribute to production and profitability by automating the existing seedling screening works, which primarily rely on manpower.

Regulation of Acid Contents in Kiwifruit Irradiated by Various Wavelength of Light Emitting Diode during Postharvest Storage (다양한 파장의 LED 조사를 통한 참다래 과실의 산 함량 조절)

  • Baek, Kwang-Hyun;Jang, Myung-Hwan;Kwack, Yong-Bum;Lee, Se-Weon;Yun, Hae-Keun
    • Clean Technology
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    • v.16 no.2
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    • pp.88-94
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    • 2010
  • The physiological roles of various wavelength of light emitting diode (LED) on ‘Hayward’ kiwifruit experiencing after-ripening were investigated. Various wavelengths from LED light source were irradiated on kiwifruits kept in plastic bags or under open air at $25^{\circ}C$. During two weeks of storage, firmness of Hayward kiwifruits was decreased by $25^{\circ}C$ treatment than by $4^{\circ}C$ treatment. In the $25^{\circ}C$ storage condition, the firmness of kiwifruits was decreased by the treatment of 380 nm UV and 470nm white LED light source. Sweetness of kiwifruits treated with 380 nm UV LED and dark condition at $25^{\circ}C$ increased higher than $15^{\circ}$Brix. The acidity of kiwifruits under open air was decreased 52% by incubating at $25^{\circ}C$ with 660 nm red LED treatment. The acidity of kiwifruits in plastic bags was decreased 52.6, 55.6, 52.8% by the treatment of 440 nm blue, 470 nm white and 660 nm red LED light source, respectively, compared to that of kiwifruits incubated in darkness at $25^{\circ}C$. Decreased acidity irradiated by 660 nm red LED light source can be applied for regulating periods of the kiwifruit after-ripening process. LED light sources emit very narrow wavelength with a power-saving mode, therefore, the usage of these LED light source for regulating the after-ripening process can be classified as a clean biotechnology producing safe and environment-friendly kiwifruits.