• Korean journal of food and cookery science
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• v.11 no.5
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• pp.542-547
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• 1995

Pectinesterase was isolated from the culture medium of Aspergillus japonicus and partially purified by DEAE-Sephadex batchwise, Sephadex G-75 gel filtration and ion exchange chromatography. The purified enzyme solution was completely free from polygalacturonase which depolymerizes pectin molecule. The ability of the pectinesterase to demethylate high methoxyl pectin was investigated. On 20 minute of incubation methoxyl content of low methoxyl pectin decreased from 88％ to 6.93%. In general gel prepared with the pectin containing lower methoxyl content showed the lower value of percent sag, and showed the hieher Bel strength. Textural characteristics of pectin gel determined by Rheometer showed that as the methoxyl content was lowered, hardness and resilience of the gel were increased and cohesiveness was decreased. Apple juice containing HMP and organic acids can be converted into low methoxyl pectin apple jelly by the action of pectinesterase and addition of calcium ion. The strength of low methoxyl pectin apple jelly increased when it stored at room temperature.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1433-1436
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• 2000

The effect of addition of pectin on the stability of casein solution was studied to apply casein-pectin mixture to apple juice. The solubility of 0.1% casein solution was below 20% at pH 3-5. However, the solubility of 0.1% casein-0.1% pectin mixtures was over 70% at pH 2-10. The increase in the concentration of casein-pectin mixture showed adverse effect on the solubility. The apple juice (pH 3.4), containing 0.1-0.5% casein-pectin mixtures, remained stable without the precipitation of casein. The stability of apple juice including casein-pectin mixture was maintained upon heating at $100^{\circ}C$ for 10 minutes or refrigerating for a week. This study suggested the possibility of protein fortification to acidic beverages since casein-pectin mixture maintained stability in apple juice.

• Korean journal of food and cookery science
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• v.2 no.1
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• pp.65-70
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• 1986

Total pectin content of Korean apple varieties at optimum harvest time was deter-mined by carbazole reaction method and pectin fraction content in each variety was also determined. Properties of pectin extracted ty 2a Sodium hexa metaphesphate were compared with commercial pectin. Among apple varieties, pectin contents varied in the range of 0.26-0.48％ on fresh basis and 1.76-4. 0% on dry basis. Ball's was the highest and then high in order of Spur early blaze, Golden delicious, Fuji. , Jonathan. In each pectin fraction, soluble pectin fractions in Rall's was the lowest and in both Spur early blaze and Golden Delicious were highest but insoluble fractions in the latter were lowest. Thub the changes in poetic substances in Spur early blaze and Golden delicious seem to he occurred: during early ripening. In the analysis of properties of isolated pectin, ash, anhydrogalacturonic arid7(AUA) content and methoxyl content were different among apple varieties. Ash and methoxyl content in all isolated pectin were higher and AUA content lower than in commercial pectin. Degree of esterification (DE) in all apple varieties were above 70％.

• Korean Journal of Microbiology
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• v.5 no.2
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• pp.55-60
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• 1967

Studies on the changes of methanol content in the manufacturing process of apple wine and apple brandy. The results from the studies of transition and changes of methanol content in the fermentation of wine and brandy from Korean apple, Kugkwang and Iwai are as follows. 1) Pectin, the source of methanol, can be extracted as dregs more than 85% of its in the process of pressing to get juice. 2) In the process of fermenting wine, the occurence of methanol depends on the condition of the apple itself (i.e. species, freshness, change in quality, or corruption). It seems that the insoluble pectin in the fresh apples changes into the soluble pectin as time goes by. 3) The heating treatment of fresh apples produced more methanol compared with nonheating treatment. 4) The content of methanol in apple brandy can influence free methanol content in mash pulp.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.1
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• pp.63-68
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• 1988

The changes of methoxy content. compositional sugars. degree of esterification (DE) and pectic substances such as LMP (low methoxy pectin), HMP (high methoxy pectin) IAP (ionically associated pectin) and CBP (covalently bounded pectin) of Fuji apple were investigated during maturity. The contents of LMP+HMP and IAP+CBP in alcohol insoluble solid(AIS) were 70% and 20%. respectively. These pectic substances were increased slightly during maturity. The reductions of hexose and uronic acid were Iron 20-50% and from 2-4%, respectively, but the inclosed of pentose was from 1-9% in LMP, HMP, IAP and CBP during maturity of Fuji apple. The galactose was decreased significantly among hexose. Whereas the relative ratio of uronic acid in HMP and CBP was increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.700-705
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• 2003

Oriental pear was used as treatment of asthma, control of blood pressure tonic medicine vasoactio, diabetes in oriental medicine. In this study, it was investigated that pear pectin effects on cardiovascular system as blood pressure and renin and atrial natriuretic peptide (ANP) in plasma, cardiac hypertrophy. The experiments were performed on Sprague-Dawley rats, 2K1C hypertension model was prepared by constricting the left renal artery with a sliver clip. Animals were then divided into four groups, 5 mg/kg, 10 mg/kg, 15 mg/kg and the control, pear pectin and apple pectin solutions were supplied with them. The blood pressure was more decreased in pear pectin 10 mg/kg than in apple pectin. The plasma ANP was decreased in pear pectin 10 mg/kg, and renin was increased in same concentration of drug. Cardiac hypertrophy had a tendency to decrease in pear pectin 15 mg/kg, but was not statistically significant compared to control group.

• Journal of Nutrition and Health
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• v.28 no.9
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• pp.834-845
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• 1995

This study was conducted in order to establish an in vitro method simulating the physiological function of fibers along the large intestine of humans. Commercial fibers including guar gum, apple pectin, citrus pectin, CM-cellulose, alginic acid and $\alpha$-cellulose, and dietary fiber residues obtained from rice bran, barley, soybean, Korea cabbage, apple, tangerine and sea mustard were employed to determine the water-holding capacity, weight of hydrated residue and fiber content after anaerobic fermentation using human fecal inoculum for 24 hours, followed by dialysis under osmotic suction pressure. The weight of hydrated residue in commercial fibers was in the decreasing order of CM-cellulose > alginic acid, $\alpha$-cellulose > apple pectin, citrus pectin > guar gum and that in food fiber residues was in the decreasing order of rice bran, sea mustard > soybean > tangerine, Korean cabbage > barley > apple. It was demonstrated that the larger the weight of hydrated residue was, the more the weight of human stool increased. Consequently this in vitro method can be used as a preceeding test before undertaking animal or human experiment to predict the physiological effects of fiber residues from diverse food samples as well as commercially refined fibers.

• The Korean Journal of Mycology
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• v.19 no.2
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• pp.143-147
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• 1991

Botryosphaeria dothidea causing apple fruit rot was cultured in pectin-polypectate mine­raI salts or apple mediumss, to investigate pectolytic enzyme production and activity. Exo-polygalactu­ronase(PG) and exo-polymethylgalacturonase (PMG) in apple medium showed maximum of activity to 6.4 and 7.2 units at six days of culture, respectively. Their maximum activity in pectin-polypectate mineral salts medium was 5.9 and 5.3 units at eight days of culture lower than in apple medium respectively. Endo-PG and endo-PMG in pecin-polypectate mineral salts medium were maximum of activity to 4.4 and 16.2 units at six and eight days of culture, respectively, but activities in apple medium were 3.2 and 6.7 units at eight days of culture. Activity of polygalacturonate-trans-­eliminase(PGTE) and pectinmethyl-trans-eliminase(PMTE) was higher in pectin-polypectate mineral salts medium than in apple medium. Fungal growth was maximum at six and eight days of culture in pectin-polypectate mineral salts and apple medium, respectively.

• Applied Biological Chemistry
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• v.42 no.1
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• pp.1-5
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• 1999

For effective utilization of apple pomace, protopectinase(PPase) produced from Bacillus subtilis IFO 12113 was used for pectin extraction from apple pomace. Optimal conditions for enzyme treatment were found at $60^{\circ}$, pH 7.8, 48 hours with 20 : 1 ratio of substrate to enzyme. The yield of extracted pectin from water-alcohol insoluble pectin by enzyme at optimal condition was 34.3%. The purity and methoxyl content of extracted pectin by PPase at optimal condition were measured as 52.9% and 2.75%, respectively. Intrinsic viscosity and average molecular weight of extracted pectin by enzymatic method were 0.178 ml/g and $4.9{\times}10^3$, respectively.

• The Korean Journal of Mycology
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• v.21 no.2
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• pp.106-111
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• 1993

Pectolytic enzymes were extracted in apple fruits rotted by Botryosphaeria dothidea, and their activities and change of pectic substances were investigated. Exo-polygalacturonase(exo-PG), exo-polymethylgalacturonase(exe-PMG), polygalacturonate-trans-eliminase(PGTE) and pectin-methyl-trans-eliminase(PMTE) were produced by the pathogen. Activities of exo-PG and exe-PMG extracted from rotten apple fruits were high to 21.15 and 24.65 units/mg protein in specific activity at seven days after inoculation, respectively. Activities of PGTE and PMTE showed 5.60 and 7.90 units/mg protein, respectively, but they were lower than those of the exo-type enzymes. Water-soluble and versene-soluble pectins were 11.50 mg/100 mg-AIS and 7.31 mg/100 mg-AIS at 14 days after inoculation, namely, they were increased by 4.23 and 2.16 mg/100 mg-AIS over those of sound apples, respectively. Total soluble pectic substances of rotten apple were 72.4% of total pectic substances and it was higher by 24.8% than sound apple. Insoluble pectic substance was notably decreased from 15.32 to 7.16 mg/100 mg-AIS according to progress of decay while total pectic substances were not changed remarkably.