• Food Science and Preservation
• /
• v.6 no.4
• /
• pp.521-529
• /
• 1999

The high influx of imported fruits into Korea is threatening to price and quality competition of domestic fruits. This investigation was conducted to raise price and quality competition of domestic fruits and to develop new products. The scale of production and processing, amount of processing and new processing technology were discussed. The area of cultivation land as well as the rate of processing is decreasing annually, an item of processing is limited to several kinds. Accordingly in this study, the status of production and manufacturing of some fruits and the new processing technologies such as high voltage pulsed electric fields, high hydrostatic pressure, ohmic heating, membrane separation and microwave treatment have investigated to fruit processing. Consequently, the minimal processing technology has to take advantage of various agricultural products in the food industry.

• Food Science and Preservation
• /
• v.5 no.3
• /
• pp.270-274
• /
• 1998

In order to enhance the availability of Korean loquat fruit, loquat juice was manufactured and its physicochemical characteristics are measured. The juice of raw fruit and pressed juice after blanching with steam that the pH, sugars, total acids and yields were 3.4, 3.6, and 8.5, 8.0 $^{\circ}$ Brix, and 0.36, 0.34%, and 53.2, 57.4% respectively. Four groups of juices were processed as followed. A ; juice of clarified after filteration, B ; pressed and filtered juice of raw fruit in refrigerated for 50 days, C ; clarified juice of heated at 90$^{\circ}C$ for 2 min., D ; clarified juice of blanched and pressed with raw fruit. Total acids, pH and sugars of A, B, C and D juices were 0.27, 0.35, 0.29 and 0.28%, and 3.80, 3.10, 3.68 and 3.71, and 7.5, 8.5, 8.0 and 8.2 $^{\circ}$Brix, respectively. Juice of B was higher total free sugar and organic acid than others. The chromaticity of D juice was stable than others. In the sensory test of loquat juice, that the product showed excellent result at 11 $^{\circ}$Brix and pH 3.78 when 4% of fructose and 0.05% of citric acid added.

• Korean Journal of Food Science and Technology
• /
• v.30 no.1
• /
• pp.125-131
• /
• 1998

The change of pectinesterase (PE) activity and pectin substances in fig fruit were investigated and low sugar jams prepared by various methods from fig fruit were compared. Fig fruit PE, which began to show the activity at the harvest time, was not inactivated and had slight activity during frozen storage at $-25^{\circ}C$. The amount of alcohol insoluble solid (AIS) and the degree of esterification (DE) of AIS were reduced by its own PE activity. However the intrinsic PE of fig fruit was not enough to make low-methoxyl pectin below 50% of DE. Fig pulp treated by its own PE and combination of fig PE and orange PE could make low-methoxyl pectin. After PE treatments, fig pulp adjusted below pH 4.0 by addition of citric acid kept red colour. Fig Jams processed by various methods had lower soluble solid $(31{\sim}49^{\circ}Brix)$ compared with conventional fig jam. Five kinds of fig jams out of those showed higher score than others in the sensory evaluation. For preparation of the five jams, the fig pulps with or without 1% pectin were treated at $50^{\circ}C$ for 25 minutes with addition of orange PE (200 units/400 g pulp). The treated pulps were added with 0.25% citric acid, 0.7% calcium and 20% cane sugar. The mixed pulps were prepared for jams containing low sugar by hot plate or microwave or refrigeration (excepting the mixed pulp without pectin).

• Food Science and Preservation
• /
• v.17 no.6
• /
• pp.881-888
• /
• 2010

We investigated the influence of carbonic maceration (CM) at different temperatures on the enological characteristics of Campbell Early grape must. Total acid levels decreased after 5 d, as CM temperature increased. All of pH; redness; and total anthocyanin, polyphenol, and tannin concentrations increased as CM temperature increased. Malic acid concentration fell at high CM temperatures, but lactic acid level increased under such conditions. Polyphenol levels and antioxidant activity were higher when CM was conducted at $35^{\circ}C$ than at other temperatures. The results show that the temperature of CM treatment greatly influences wine quality factors such as color, taste, and antioxidant capacity.

• Applied Biological Chemistry
• /
• v.51 no.1
• /
• pp.11-16
• /
• 2008

The extraction conditions for resveratrol production from grape fruit stem, which is a by-product of grape processing, were optimized to develop high-functional grape-based products. Additionally, the bioefficacy of grape fruit stem extract (GFSE) as an antioxidant agent was evaluated. Resveratrol was extracted using various experimental conditions such as extractant type, extractant concentration, raw material-extractant ratio, extraction time and temperature, and the results were analyzed using a statistical program (SPSS). The resveratrol yield was the highest when 80% ethanol with a raw-material-extractant ratio of 1:10 (w/v) was used. In addition, the optimal temperature and time were selected as $60^{\circ}C$ and 90 min, respectively. When the antioxidant activity was analyzed and expressed as DPPH radical scavenging activity and SOD-like activity, the antioxidant activity of GFSE was higher than that of BHT, BHA and L-ascorbic acid. Finally, it was found that GFSE could be used as a raw material for the production of high antioxidant agents.

• Journal of Bio-Environment Control
• /
• v.31 no.4
• /
• pp.384-392
• /
• 2022

The objective of this study was to estimated nitrogen content and chlorophyll using RGB, Hyperspectral sensors to diagnose of nitrogen nutrition in apple tree leaves. Spectral data were acquired through image processing after shooting with high resolution RGB and hyperspectral sensor for two-year-old 'Hongro/M.9' apple. Growth data measured chlorophyll and leaf nitrogen content (LNC) immediately after shooting. The growth model was developed by using regression analysis (simple, multi, partial least squared) with growth data (chlorophyll, LNC) and spectral data (SPAD meter, color vegetation index, wavelength). As a result, chlorophyll and LNC showed a statistically significant difference according to nitrogen fertilizer level regardless of date. Leaf color became pale as the nutrients in the leaf were transferred to the fruit as over time. RGB sensor showed a statistically significant difference at the red wavelength regardless of the date. Also hyperspectral sensor showed a spectral difference depend on nitrogen fertilizer level for non-visible wavelength than visible wavelength at June 10th and July 14th. The estimation model performance of chlorophyll, LNC showed Partial least squared regression using hyperspectral data better than Simple and multiple linear regression using RGB data (Chlorophyll R²: 81%, LNC: 81%). The reason is that hyperspectral sensor has a narrow Full Half at Width Maximum (FWHM) and broad wavelength range (400-1,000 nm), so it is thought that the spectral analysis of crop was possible due to stress cause by nitrogen deficiency. In future study, it is thought that it will contribute to development of high quality and stable fruit production technology by diagnosis model of physiology and pest for all growth stage of tree using hyperspectral imagery.

• The Korean Journal of Community Living Science
• /
• v.20 no.1
• /
• pp.61-69
• /
• 2009

This study was conducted to examine the chemical composition of kiwifruit skin, and to est its anti-microbial activities and cytotoxicities, thus, exploring ways for the economic utilization of kiwifruit skin. Four varieties of kiwifruit were examined: Daeheung, Bidan, Haegeum No.1 and Hayward. Vitamin C content in the fruit skins of Bidan, Daeheung, Haegeum No.1 and Hayward were 72.44, 67.22, 62.51 and 61.44mg/100g, respectively. Total amino acids content in the fruit skins of Bidan, Haegeum No.1, Hayward and Daeheung ere 808.31, 706.02, 629.07 and 464.83mg/100g dry weight, respectively. K and Ca content ere $17.20-45.70{\mu}g/mL$ and $4.58-10.15{\mu}g/mL$. While, other inorganic matter contents were below $4.89{\mu}g/mL$. Anti-microbial activity of kiwifruit skin extracts, in terms of the diameter of inhibition zone when tested against five gram positive and three gram negative microbial trains (even in the concentration of 2,000mg/L), was less than 14.1mm. The hyperplasia inhibition of lung cancer cells by methanol extracts from Bidan and Haegeum No.1 using concentrations of 800mg/L were 27.7% and 14.5%, however, those from Daeheung and Hayward were below 3% Consequently, it will be useful to know that kiwifruit skin can be added to processed goods which demand for higher concentrations of vitamin C, amino acids, K and Ca.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.4
• /
• pp.641-645
• /
• 2001

To utilize the by-products from whelk processing, whelk internal organ jeotgal was manufactured by adding pineapple and kiwifruit juices containing bromelain and actinidin, respectively. The protease activities of pineapple and kiwifruit juices were 52 and 248 unit/mL, respectively. 1 kg ground whelk internal organ was immersed to 12.5% salt concentration and then the 20, 50, or 100 mL of fruit juice were added in it. the quality of products fermented for up to 70 day at 1$0^{\circ}C$ was observed. Jeotgal wit pineapple juice showed lower pH and higher amino nitrogen content than with kiwifruit juice on 70 day of fermentation. the total nitrogen contents was the highest on 30 day of fermentation and stable thereafter. Although total numbers of microorganism were increased as fermentation progressed, there were no correlations among the juices or its adding amounts. It was thought that interactions between kinds of natural microflora and the proteases from fruit juices, and other constituents in jeotgal affected total nitrogen content of jeotgal and the growth rate of natural microorganisms. Of the all jeotgals in this study, no coliform was found It is suggested that the preparation of jeotgal with pineapple or kiwifruit juice is effective aspect of safety and quality.

• Food Science and Preservation
• /
• v.18 no.4
• /
• pp.527-534
• /
• 2011

The purpose of this studies was analyzed moisture content, rheology and sensual test of jujube jungkwa by addition of water, sugar, fructose at processing of jujube jungkwa for development the optimization for processing of jujube jungkwa. The changes of moisture contents at process condition of jujube jungkwa were increased by increasing of sugar and water quantity. And moisture contents of jujube jungkwa were increased by high fructose quantity and low sugar quantity, but were decreased by high sugar and fructose quantity. The 'b' values of jujube jungkwa at low sugar quantity were decreased by the increasing of water quantity, but increased at high sugar quantity. The cohesiveness of jujube jungkwa at 0.03 kg of fructose were high by the increasing of sugar quantity, but those at 0.065 kg of fructose were high by the decreasing of sugar quantity. And those at 0.050 kg of fructose were similar without the quantity of sugar. The sweet taste of jujube jungkwa were increased by the increasing of water and fructose quantity. The characteristics of jungkwa at conditions of processing for the best quality of jujube jungkwa were 18-20% of moisture content, 2.0-3.0 of 'b' values, 3.0-3.2 of color scores, and 3.3-3.4 of sweet taste scores. The conditions of processing for the best quality of jujube jungkwa were determined to 0.95-1.04 L of water, 0.052-0.060 kg of fructose at 0.95 kg of sugar.

• Applied Biological Chemistry
• /
• v.22 no.1
• /
• pp.28-32
• /
• 1979

Experiments were carried out for finding out a reasonable background of inferior processing quality of Korean citrus fruits of unshiu varieties. The results obtained were as follows. 1. It is considered that the essence of fruit tastes were sweetness and acidity. Their contents were $9.0-10.0^{\circ}Bx$ and 5.3-6.6% (as citric acid) respectively. These indicates that Korean native citrus fruits were inferior in quality. 2. The hesperidin contents were 58mg% in early ripe unshiu varieties, but were low comparatively as 45mg% in late varieties. 3. The portions of fruit peel were high as 25% in Im and Sukcheon unshiu. Therefore these varieties are favorable for long-time storage. The juice extraction rate were 50% on the average with not much difference between varieties. 4. Specific gravity of the extracted juice were 1.040. Vit. C and hesperidin contents of the juice were $25{\sim}30mg%$ on the average in all varieties.