• Nutrition Research and Practice
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• v.8 no.1
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• pp.33-39
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• 2014

Obesity occurs when a person's calorie intake exceeds the amount of energy burns, which may lead to pathologic growth of adipocytes and the accumulation of fat in the tissues. In this study, the effect and mechanism of pear pomace extracts on 3T3-L1 adipocyte differentiation and apoptosis of mature adipocytes were investigated. The effects of pear pomace extract on cell viability and the anti-adipogenic and proapoptotic effects were investigated via MTT assay, Oil red O staining, western blot analysis and apoptosis assay. 3T3-L1 preadipocytes were stimulated with DMEM containing 10% FBS, 0.5 mM 3-isobutyl-1-methylxanthine (IBMX), $5{\mu}g/ml$ insulin and $1{\mu}M$ dexamethasone for differentiation to adipocytes. 3T3-L1 cells were cultured with PBS or water extract of pear pomace. Water extract of pear pomace effectively inhibited lipid accumulations and expressions of PPAR-${\gamma}$ and $C/EBP{\alpha}$ in 3T3-L1 cells. It also increased expression of p-AMPK and decreased the expression of SREBP-1c and FAS in 3T3-L1 cells. The induction of apoptosis was observed in 3T3-L1 cells treated with pear pomace. These results indicate that pear pomace water extract inhibits adipogenesis and induces apoptosis of adipocytes and thus can be used as a potential therapeutic substance as part of prevention or treatment strategy for obesity.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.971-976
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• 1999

Exo-polygalacturonase (EPG) from Rhizopus sp. was applied to the extraction of pectin from pear pomace because EPG produces pectin by solubilizing protopectin. The content of total galacturonic acid in water-alcohol insoluble pectin (WAIP) was determined as 34.6%. Pear pomace was solubilized by using EPG, with regarding reaction pH, temperature, time and ratio of enzyme to substrate in order to find optimum condition. While the yield by an acidic treatment was 6.2%, the maximum yield by an enzymatic treatment was 23.4% under the extraction condition of pH 7.8, $60^{\circ}C$, 36 hr and 1/10 of enzyme/substrate. At this condition, the purity and methoxyl content of enzyme-extracted pectin were, respectively, 34.7% and 0.7%, while those of acid-extracted pectin were, respectively, 71.1% and 5.0%. Meanwhile, the average molecular weight of pectin extracted by the enzymatic method was $2.5{\times}10^{3}$ while that of acid-solubilized pectin was $8.4{\times}10^{3}$.