• Applied Biological Chemistry
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• v.35 no.1
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• pp.23-29
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• 1992

Bromelain was purified from Korean pineapple, Ananas comosus, L. The enzyme was purified about 21 fold by DEAF-cellulose ion-exchange chromatography and gel filtration on Sephadex G-150. Purified enzyme was confirmed as active single band by polyacrylamide electrophoresis and the molecular weight was estimated to be about 22,000 by SDS-PAGE. The optimum pH and temperature were 6.0 and $60^{\circ}C$, respectively. The range of its stability to the pH and temperature were respectively 5.0 to 7.0 and below $50^{\circ}C$. It was found that $Mn^{2+}$ increased the enzyme activity, whereas $Mg^{2+}\;and\;Fe^{2+}$ decreased it abruptly. The purified enzyme was inhibited by p-chloromercuribenzoic acid, indicating that reactive SH groups are required for the enzyme activity. The reaction of the enzyme followed typical Michaelis-Menten kinetics with Km value of $5.747{\times}10^{-4}\;M\;and\;Vmax\;of\;131.58\;{\mu}g/min$ for casein. When meat was treated with the enzyme, free soluble nitrogen and amino acid nitrogen increased as enzyme concentration increased.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.219-219
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• 2005

• Food Science and Preservation
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• v.19 no.5
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• pp.712-719
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• 2012

In this study, the physicochemical and physiological activities of 10 different commercially available juices (apple juice-A: cloud type; apple juice-B: clear type; blueberry juice; grape juice-A; grape juice-B; orange juice-A; orange juice-B; pineapple juice; pomegranate juice; and tomato juice) were investigated. The average pH, titratable acidity, Brix, and reducing sugar were 3.57, 0.57%, $13.1^{\circ}Brix$, and 57.58%, respectively. The total polyphenol and flavonoid contents were within the ranges of 98.29-878.12 ug/mL and 23.82-156.63 ug/mL, respectively, and pomegranate juice showed the highest content, followed by blueberry juice and apple juice-A. In the DPPH radical scavenging assay, apple juice-A, grape juice-A, and pomegranate juice exhibited the highest activity (greater than 90%) while orange juice-B, pineapple juice and tomato juice showed the weakest. The tyrosinase inhibitory effect was highest in apple juice-A, followed by orange juice-A and blueberry juice. The reducing power was highest in pomegranate juice and lowest in pineapple juice and grape juice-A. The antioxidant activity by reducing power was highly correlated with the total polyphenol content.

• Journal of Life Science
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• v.20 no.11
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• pp.1718-1724
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• 2010

Bioactive and chemical properties of silkworm powder (SP) degradation by fruit extract containing the proteolytic enzymes of kiwifruit, papaya, pineapple and pear were investigated. Silkworm powder was incubated with extracts from each fruit at $60^{\circ}C$ for 24 hr. Protein content was slightly higher in the SP treated with fruit extract than that in the control SP. Major minerals were K, Ca, Mg, and Zn. Major fatty acids were linolenic acid, oleic acid, and palmitic acid. When total protein patterns were analyzed by SDS-polyacrylamide gel electrophoresis (PAGE), silkworm protein was strongly degraded by the treatment of fruit extract from pineapple, papaya, and pear, but little silkworm degradation was observed in kiwifruit extract treatment. Fibriolytic activity was only detected in the SP by the fruit extract treatments from papaya and pear. DPPH radical scavenging activity was slightly stronger in the SP treated with fruit extract than that in silkworm powder. However, all these samples exhibiteda relatively low activity compared with the butylated hydroxytoluene (BHT). These results may provide the basic data for understanding the biological activities and chemical characteristics of SP treated with fruit extract for development of functional foods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1461-1466
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• 2013

In this study, we ascertained the characteristics of crude protease extracted from fruits (fig, kiwifruit and pineapple) as well as traditional Korean fermentation starters (bio nuruk, traditional nuruk, meju and rice koji) to determine their suitability for industrial application. Crude protease extracted from traditional Korean fermentation starters was found to have a higher optimum temperature ($70^{\circ}C$) and salt concentration (1~3%) but a lower optimum pH (3~6) value compared to the corresponding values for the protease extracted from fruits. On comparison, the total activities of protease per gram unit follow the order: bio nuruk> rice koji> traditional nuruk> fig> pineapple> meju> kiwifruit. Based on our results, we conclude that protease extracted from traditional Korean fermentation starters has potential for application in food industry, for example, as a meat tenderizer for sausage manufacturing and as a protease for cheese production.

• Journal of Nutrition and Health
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• v.30 no.8
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• pp.995-1008
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• 1997

This study was performed to investigate the change in taste perception during aging and its effects on dietary intake in Korean elderly. The subjects were female aged 65 through 90 in the Anyang area, and college women were included as a comparison group . Dietary intake of the elderly(n=155) and young subjects (n=38) was measured by a 3 day diet record. The taste threshold and 'just right' concentrations(JRC) for sweet and salty tastes were assessed by sensory evaluation . Sucrose solution (0.0.,0.4,0.6,0.8,1.0, 1.2%) and salt solution(0, 0.02, 0.03,0.06,0.09,0.12,0.15%) were used to establish thresholds. for JRC assessment, four suprathreshold sucrose concentrations of 5, 8, 11 and 14% in orange-pineapple flavored juice and salt concentrations of 0.20, 0.34, 0.50and 0.75% in beef stock were prepared. Mean intakes of energy, protein , vitamin A, thiamin , riboflavin, niacin ,calcium and iron of the elderly were below the Korean Recommended Dietary allowances. The elderly showed higher taste thresholds than young subjects of both sweet and salty tastes consumed less calories. Needs to bespecified. The older subjects having high threshold or JRCs for sweet and salty tastes consumed fewer calories from protein and fat. Pearson correlation coefficients was between JRC for sweet and salty tastes 0.54(p<0.01). The correlation coefficients between tastes threshold and nutrient intakes were very low for both age groups. Unlike the college women, in the elderly the JRC of sweet taste of the orange-pineapple juice were negatively correlated with intakes of energy, protein, fats, thiamin , riboflavin , niacin ,vitamin C , iron and consumption of meat and egg food groups (p<0.01). In summation age-related alterations in sweet and salty taste perception were observed in the elderly and dietary intakes of the elderly see to be influenced by these taste perception changes.

• Korean Journal of Food Science and Technology
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• v.33 no.4
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• pp.423-426
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• 2001

Electron spin resonance (ESR) spectroscopy was used to investigate the effect of irradiation dose on irradiated dried fruits. Dried banana, pineapple and pistachio were irradiated with doses of 0, 0.5, 1, 2 and 5 kGy at room temperature using a Co-60 irradiator. Multiplet ESR signals were observed in irradiated dried banana and pineapple, and singlet ESR signal was observed in irradiated pistachio, while these characteristic signals were not detected in non-irradiated samples. Since the amount of free radicals linearly increased with the applied doses $(0.5{\sim}5\;kGy)$, highly positive correlation coefficients $(R^2=0.9874{\sim}0.9974)$ were obtained between the irradiation doses and the corresponding free radical concentrations. The characteristic ESR signals were observed in irradiated samples even after 40 days of storage at room temperature.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.275-275
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• 2017

Dressing is a seasoned mixture usually used as a stuffing in food. Quality characteristics and antioxidant activity of fruit dressing using lentil legume were investigated. The four groups were divided into D-1(fruit dressing purchased from the local market in Deagu, Korea), D-2 (grapefruit-sugaring dressing prepared with grapefruit sugaring and lentil legume paste), D-3 (vinegar dressing purchased from the local market in Deagu, Korea), D-4 (pineapple-vinegar dressing prepared with pineapple vinegar and lentil legume paste), and then they were analyzed with regard to general compositions, Hunter's color value, mineral and free amino acid content and antioxidant activities. The pH and titratable acidity in all samples ranged from 2.9 to 4.6 and from 0.6 to 1.2%, respectively. The crude protein content were 2.29% for D-2 dressing and 4.03 for D-4 sample, while were not detected D-1 and D-3 samples. In case of Hunter's value, The ' L'and 'a' values of all samples ranged from 45.98 to 56.54 and from -1.59 to 3.30, respectively. The D-4 sample exhibited the higher levels of Ca (215.40 mg/kg), K (1,105.83 mg/kg), Mg (233.63 mg/kg) and Fe (13.78 mg/kg). The levels of heavy metals (As, Pb, Cd and Hg) in all samples were not detected. The contents of total amino acid in D-3 and D-4 samples were 8.269 and 3.419 mg/mL, respectively. The highest contents of total phenols($191.13{\mu}g\;GAE/mL$) and DPPH radical scavenging activity(93.69%, Inhibition) were observed in D-4 sample.

• Applied Biological Chemistry
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• v.35 no.4
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• pp.300-307
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• 1992

Bromelains (EC 3.4.4.24) isolated from pineapple fruit and stem have been purified about 18 and 46-folds to homogenity in the same yield of 23%. Molecular weights of fruit and stem-bromelain were estimated to be 32.5 KDa and 37 KDa by Sephadex G-200, respectively. The enzymes were composed of one subunit. The fruit and stem-bromelain had their maximum activity at pH 8.0, $70^{\circ}C$ and at pH 7.0, $60^{\circ}C$. Especially the enzymes catalyzed hydrolysis of plant proteins such as ISP (Isolated soybean protein) and wheat gluten with high molecular activity compared to animal proteins. The enzymes were competitively inhibited by sulfhydryl reagent; $K_i$ values of fruit and stem-bromelain for pCMB(p-chloromercuribenzoate) were 0.18 mM and 0.10 mM. Activities of the enzymes inhibited by pCMB were reversibly restored with increasing concentration of cysteine.

• Food Science of Animal Resources
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• v.42 no.1
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• pp.61-72
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• 2022

Antioxidants present in fruits and vegetables have a potential to reduce disease risk, and increase the shelf life of food products by reducing lipid oxidation. The effect of marination with antioxidants-rich fruit juices on quality characteristics of vacuum-packed chicken wings were examined during frozen storage. Chicken wings were mixed separately with marinades containing pineapple juice, June plum juice, and mango juice and kept for 12 h and 24 h. Three best marination conditions were selected based on a sensory evaluation. Antioxidant activity and total phenolic content of fruit juices, and marinade uptake, and marinade loss of marinated chicken wings were determined. In addition, vacuum packed marinated chicken wings were tested for pH, water holding capacity (WHC), 2-thiobarbituric acid reactive substances (TBARS) value and antioxidant activity over a 4-wk frozen storage. The best sensory properties were reported from chicken wings marinated with pineapple juice for 24 h, mango juice for 24 h, and June plum juice for 12 h (p<0.05) compared to other marinade-time combinations. Mango juice showed the highest antioxidant activity (92.2%) and total phenolic content (38.45 ㎍/mL; p<0.05) compared to other fruit juices. The pH and WHC of vacuumpacked chicken wings were slightly decreased over the frozen storage (p<0.05). Moreover, chicken wings marinated with mango juice had the lowest TBARS values and the highest 2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical scavenging activity. In conclusion, mango juice was selected among tested as the most effective marinade for enhancing the oxidative stability of lipid while maintaining the other meat quality traits of vacuum-packed chicken wings.