• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.47-51
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• 2006

Microorganisms involved in decaying Fuji apples during storage were investigated. Seven pathogens were isolated from the rotted fruits. Penicillium spp. was derived from 65-75% of decayed apples with P. expansum being dominant species. Effects of mild heat treatment on microbial reduction, respiration, and texture characteristics in Fuji apples were examined through hot water dipping at $40-65^{\circ}C$ for varied timε periods. Initial counts of total microorganisms and moulds in fresh fruits s showed 4.75 and 4.66 log CFU/g in a stem, as well as 5.35 and 4.32 log CFU/g in a calyx, respectively. The heat treatment at $40^{\circ}C$ for 180 min significantly reduced the population of total microorganisms and moulds in the fruits. Respiration rate of the apple fruits increased immediately after heat treatment and then returned to the normal level during storage. The rates of ethylene production in the fruits treated at $40-50^{\circ}C$ were maintained lower than that of the untreated control. The fruits treated at $40^{\circ}C$ showed slightly greater flesh firmness than the other apple samples during storage.

• Journal of Food Hygiene and Safety
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• v.34 no.1
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• pp.1-12
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• 2019

The health benefits associated with consumption of fresh produce have been clearly demonstrated and encouraged by international nutrition and health authorities. However, since fresh produce is usually minimally processed, increased consumption of fresh fruits and vegetables has also led to a simultaneous escalation of foodborne illness cases. According to the report by the World Health Organization (WHO), 1 in 10 people suffer from foodborne diseases and 420,000 die every year globally. In comparison to other processed foods, fresh produce can be easily contaminated by various routes at different points in the supply chain from farm to fork. This review is focused on the identification and characterization of possible sources of foodborne illnesses from chemical, biological, and physical hazards and the applicable methodologies to detect potential contaminants. Agro-chemicals (pesticides, fungicides and herbicides), natural toxins (mycotoxins and plant toxins), and heavy metals (mercury and cadmium) are the main sources of chemical hazards, which can be detected by several methods including chromatography and nano-techniques based on nanostructured materials such as noble metal nanoparticles (NMPs), quantum dots (QDs) and magnetic nanoparticles or nanotube. However, the diversity of chemical structures complicates the establishment of one standard method to differentiate the variety of chemical compounds. In addition, fresh fruits and vegetables contain high nutrient contents and moisture, which promote the growth of unwanted microorganisms including bacterial pathogens (Salmonella, E. coli O157: H7, Shigella, Listeria monocytogenes, and Bacillus cereus) and non-bacterial pathogens (norovirus and parasites). In order to detect specific pathogens in fresh produce, methods based on molecular biology such as PCR and immunology are commonly used. Finally, physical hazards including contamination by glass, metal, and gravel in food can cause serious injuries to customers. In order to decrease physical hazards, vision systems such as X-ray inspection have been adopted to detect physical contaminants in food, while exceptional handling skills by food production employees are required to prevent additional contamination.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.452-457
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• 2013

To obtain the useful data related to optimum nutrient management technique for pesticides-free jujube cultivation, nutrient contents of jujube leaves and fruits and the selected chemical properties of jujube orchard soils were investigated at 9 different orchards with pesticides-free cultivation in Boeun, Chungbuk, Korea. Soil and jujube leaf samples were collected from the different orchards in July and October, and jujube fruit samples were taken in October, 2012. Soil available $P_2O_5$ contents in the optimum level for jujube cultivation were 11% and 33% of total samples in July and October, respectively, but 56% of total samples was higher than the optimum level in both July and October. Exchangeable K and Ca ion contents were 44% and 67% of total samples, respectively, in both July and October, whereas exchangeable Mg ion content was 100% and 56% of total samples in July and October, respectively. Nutrient contents in jujube leaves were higher than those in fresh fruits. In addition, total nitrate, potassium and magnesium contents in the jujube leaves were higher in the samples collected in July than in October.

• Applied Biological Chemistry
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• v.13 no.2
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• pp.131-151
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• 1970

A new method of plastic film coating has been investigated to extend storage life of apples. The film coating was effected by dipping fresh apples in a plastic emulsion. The effect of plastic film coating on the preservation of freshness, respiratory activities and chemical components during storage, has been investigated on four leading varieties of apples. The results are summarized as follows: 1. The effect of film coating on storage life of apples was apparent, resulting in delay of after-ripening, shriveling, softening or physiological impediment as well as reducing consumption of reserve materials and waste fruits. 2. Change in the partial pressure of gas, i.e., increase in carbon dioxide and decrease in oxygen in apple tissue was resulted by the plastic film coating, suggesting that the film deposited on the fruit interfered with the diffusion of gases formed therein. 3. The effects of plastic film coating on the fruit storage varied with the type of plastic emulsions, coating temperature, varieties of apples and degree of fruit ripening. As regard to apple varieties, good results were obtained with PVA 217 for both American Summer Pearmain and Jonathan, and PVC 443 for McIntosh. 4. Reduction in the diminution rates of L-malic acid, ascorbic acid and soluble pectin etc. during storage of apples may account for the improved storage life of the fruits treated with plastic films.

• Journal of Nutrition and Health
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• v.27 no.1
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• pp.59-69
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• 1994

Dietary fiber(DF) intakes of Korean during 1969∼1990 were estimated and the major food sources of fiber were analyzed using the data from the Annual Reports of Korean National Nutrition Survey. The estimated daily DF intake of Korean has gradually decreased during the 22 years, from 24.46g in 1969 to 17.31g in 1990 with a remarkable decline in 1987. The average DF intakes of the rural population were higher than those fo urban's until 1980, but the situation was reversed until 1987 and the regional difference in DF consumption disappeared thereafter. Vegetables, cereals, grain and legumes were the major sources of fiber for Korean in recent 5 years(1986∼1990), providing 32%, 16% and 19% of DF intake respectively. Throughout the 22years, the intakes of DF from cereals and fresh vegetables have been reduced and those from processed vegetables, seaweeds and fruits has been increased. Df intake from legumes continuously increased until 1986, and it decreased thereafter. Rural population consumed more fiber from cereals than the urban's during the 1970s, but thereafter regional difference in cereal fiber intakes became insignificant. Urban population consumed more fiber from legumes and fruits than the rural's through the entire period. The results of this study indicate that the present DF intake of Korean is considerably lower than generally anticipated and is below the tentative recommended DF intake and thus higher DF intake than the present level is needed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.5
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• pp.611-616
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• 1993

This study was carried out to investigate change in the polygalacturonase and ${\beta}-galactosidase$ activities, pectins, cell wall structure of persimmon fruit during ripening and softening. Polygalacturonase and ${\beta}-galactosidase$ activities were not detected at turning stage. However polygalacturonase activities of mature and soft persimmon fruits were 55.01 and 206.70units/100g-fresh weight(fr. wt.), respectively. ${\beta}-Galactosidase$ activities of mature and soft persimmon fruits were 21.79 and 380.23unit/100g-fr. wt. respectively. The contents of total and insoluble pectins increased during maturation but decreased during softening. The content of water-soluble pectin increased during maturation and softening. The intercellular space was in larged during ripening, and middle lamella was degraded in mature persimmon fruit, and the cells of soft persimmon fruit were separated each other.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.3
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• pp.216-220
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• 2002

In this study, edible coatings for ‘Niikata’ pears have been applied in order to provide an alternative way to control and extend market quality and shelf life during cold storage. Fruit treated with edible coatings had better effects on maintaining some quality features such as fresh weight, firmness and SSC content than non-coated fruits. However, non-coated fruits in terms of overall quality were better evaluated than fruit with edible film. It may be caused by various factors such as film thickness effect oil emulsion on fruit skin, unknown reactions between the fruit skin and functional groups in the chitosan structure and so on.

• Korean Journal of Food Science and Technology
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• v.15 no.4
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• pp.409-413
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• 1983

Vitamin and mineral composition of ethephon treated tomatoes were studied, and the results are summarized as follow: 1. Ascorbic acid, carotene (total and beta-carotene), thiamin and riboflavin contents in tomato fruits were not adversely affected by ethephon treatment 1 week before harvest, and these results were consistent for two consecutive years. Riboflavin content of tomatoes in 1979 was significantly higher than that in 1978, and this difference could be due to enviornmental factors. 2. Mineral content in tomato fruits were not significantly affected by ethephon treatment 1 week before harvest. Calcium and manganese contents in treated tomatoes significantly varied from year to year.

• Korean Journal of Food Science and Technology
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• v.4 no.1
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• pp.13-17
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• 1972

This experiment was conducted to observe the changes of composition of atmosphere in storage room by controlled ventilation under normal and sub-atmospheric conditions, and the biochemical changes in apple texture under these conditions. The results were as follows; 1) By controlled ventilation, concentration of carbon dioxide in storage room was optionally regulated and constantly maintained. 2) Among compositions of internal atmosphere of apple, especially, concentration of ethylene was much decreased at apple stored under sub-atmospheric condition than that stored under normal atmospheric condition. 3) Acidity of apple stored under sub-atmospheric condition was much greater than that of apple stored under normal atmospheric condition. 4) Respiratory quotients of apple, which was stored under normal and sub-atmospheric conditions, were shown to be high. But decarboxylation of added pyruvate was found more active in slices prepared from apple stored under sub-atmospheric condition.

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.738-742
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• 1990

Cell wall components were decreased during maturation and postharvest of persimmon fruits. Contents of pectin and alkali-soluble hemicellulose were increased during maturity, but those of acid-soluble hemicellulose were decreased. Contents of pectin and alkali-soluble hemicellulose were decrease in soft persimmon, whereas acid-soluble hemicellulose was increased remarkably. Cellulose contents were increased during maturation and this tend was notable in soft persimmon. Contents of cell wall polysaccharides per 100g-fresh weight were decreased. Contents of total pectin and insoluble pectin were increased during maturation but decreased in soft persimmon. Content of water-soluble pectin was increased during maturation and postharvest.