• Korean Journal Plant Pathology
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• v.11 no.3
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• pp.217-223
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• 1995

Nature of graft transmissibility of pear abnormal leaf spot disease was examined by various grafting methods in the greenhouse and field. When the diseased and symptomless twigs were collected in winter and grafted in the next spring to the seed-originated healthy root stock, the abnormal leaf spot was developed only in the case of the diseased twigs. Double grafting on a seed-originated healthy root stock, where the diseased and the symptomless twigs were used as 1st and 2nd scions, respectively, developed abnormal leaf spot lesions without exception on the 2nd scions. Tongue-graft with the diseased and the symptomless trees also incited abnormal leaf spots on the both trees. Abnormal leaf spots of were also developed on HN-39, an indicator pear tree, used as a 2nd scion in a double graft test, where the diseased twig and a seed-originated healthy tree were used as the 1st scion and the root stock, respectively. When the diseased twig was top-grafted to the healthy root stock, lesion development of abnormal spot was limited to the grafted twig itself in the 1st year, but expanded to the main branches in the 2nd year, and spread over the whole tree in the 3rd year. This result indicates that the causal agent of abnormal leaf spot disease is transmitted by graft.

• The Korean Journal of Community Living Science
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• v.21 no.1
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• pp.71-79
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• 2010

This study was conducted to develop fresh-cut and processed pears. After treatment of citric acid (1%) or N-acetylcysteine (0.2 M), and co-treatment of citric acid (1%) and N-acetylcysteine (0.2 M) into the pears c.v. 'Wonhwang', the quality changes of pears during cold storage ($1^{\circ}C$) for 10 days were investigated respectively. Pear quality and the taste of pears increased much more in those treated with anti-browning agents than those in the control group at 10 days after anti-browning treatment and cold storage. Changes in Hunter b values of pears treated with 0.2 M N-acetylcysteine were insignificant. Those with Polyphenol oxidase (PPO) activity and ethylene production were had the most decreased effects and those with the phenolics compound contents were the most lowered. Firmness of fruits increased in treatment of 0.2 M N-acetylcysteine + 1% citric acid solution. The amount of respiration decreased in the application of 1% citric acid solution. Consequently, fruit freshness can be maintained more effectively by the treatment of the anti-browning agent compared to non-treatment, even if the effectiveness were different among different kinds of anti-browning agents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.63-69
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• 2011

To characterize the polysaccharides which exist as soluble forms in Korean traditional alcoholic beverages, the polysaccharides were isolated from Korean pear wine and their anti-complementary activities were examined. The main polysaccharide, PW-1 was purified to homogeneity from the crude polysaccharide (PW-0) in pear wine by size exclusion chromatography using Sephadex G-75. Molecular mass of PW-1 was estimated to be 150 kDa and it contained significant proportion of mannose (81.8%) and 5 different minor component sugars such as arabinose (1.2%), galactose (2.7%), glucose (8.5%), galacturonic acid (5.3%) and glucuronic acid (0.5%). These analyses indicated that the main polysaccharide in pear wine was mainly present as a mannan which had originated from the cell walls of fermenting yeasts. On the other hand, PW-1 showed potent anti-complementary activity in a dose-dependent fashion. Identification of C3 activation products by the crossed immunoelectrophoresis using anti-human C3 and anti-complementary activity of PW-1 in $Ca^{++}$-free condition suggested complement activations by PW-1 from Korean pear wine occur via both classical and alternative pathways.

• Korean Journal of Agricultural Science
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• v.38 no.1
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• pp.39-44
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• 2011

The changes in major moth populations were monitored by sex pheromone traps in pear orchards at Yuseong-Gu, Daejeon from 2008 to 2010. Among four major moths, Grapholita molesta and Caposina sasakii occurred most frequently. Their occurrences peaked 2 to 3 times during the growing season from May to September. G. molesta was exceptional, occurring until September. For the environmentally-friendly control of these moths, 9 control materials including insect pathogenic bacteria and environmentally-friendly agricultural materials, were examined on the larva of 4 kinds of moth and sprayed on pear leaves in the field. As the generalized results of bioassay, Bacillus thuringiensis subsp. kurstaki and Sophora flavescens extract were shown to have better control effects than any other control material.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.856-867
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• 2017

Supplement of dietary fibers (DF) is regarded as one of the most effective way to prevent and relieve chronic diseases caused by long-term intake of a high-fat diet in the current society. The health benefits of soluble dietary fibers (SDF) have been widely researched and applied, whereas the insoluble dietary fibers (IDF), which represent a higher proportion in plant food, were mistakenly thought to have effects only in fecal bulking. In this article, we proved the anti-obesity and glucose homeostasis improvement effects of IDF from pear pomace at first, and then the mechanisms responsible for these effects were analyzed. The preliminary study by real-time PCR and ELISA showed that this kind of IDF caused more changes in the gut microbiota compared with in satiety hormone or in hepatic metabolism. Further analysis of the gut microbiota by high-throughput amplicon sequencing showed IDF from pear pomace obviously improved the structure of the gut microbiota. Specifically, it promoted the growth of Bacteroidetes and inhibited the growth of Firmicutes. These results are coincident with previous hypothesis that the ratio of Bacteroidetes/Firmicutes is negatively related with obesity. In conclusion, our results demonstrated IDF from pear pomace could prevent high-fat diet-induced obesity in rats mainly by improving the structure of the gut microbiota.

• Horticultural Science & Technology
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• v.17 no.3
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• pp.341-343
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• 1999

Quality of 'Niitaka' pear fruit was evaluated by instrumental and sensory analysis in relation to storability. Fruits harvested at commercial maturity were stored in a common storage room or in a cold storage at $2^{\circ}C$. During storage, fruits were sorted by instrumental measurement of soluble solid content (SSC) and flesh firmness. Then, overall acceptability was evaluated by organoleptic test. Critical storage period was determined by sensory evaluation index for different storage methods. After 60 days of storage, eating quality was acceptable when flesh firmness was higher than $3.3kg/8mm{\emptyset}$. As for soluble solid contents, high eating quality was obtained when pear fruit contained soluble solids higher than $13.0^oBrix$. In 'Niitaka' pears, however, changes in soluble solid content seemed not to be an appropriate parameter to determine storability since SSC increased during both common and cold storage. Data of organoleptic test and postharvest changes in flesh firmness suggested that storability of 'Niitaka' pear fruit seemed to be 30 days in a common storage and 120 days in a refrigerated storage.

• Nutrition Research and Practice
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• v.11 no.3
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• pp.198-205
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• 2017

BACKGROUND/OBJECTIVES: The anti-diabetic activity of pear through inhibition of ${\alpha}-glucosidase$ has been demonstrated. However, little has been reported about the effect of pear on insulin signaling pathway in obesity. The aims of this study are to establish pear pomace 50% ethanol extract (PPE)-induced improvement of insulin sensitivity and characterize its action mechanism in 3T3-L1 cells and high-fat diet (HFD)-fed C57BL/6 mice. MATERIALS/METHODS: Lipid accumulation, monocyte chemoattractant protein-1 (MCP-1) secretion and glucose uptake were measure in 3T3-L1 cells. Mice were fed HFD (60% kcal from fat) and orally ingested PPE once daily for 8 weeks and body weight, homeostasis model assessment of insulin resistance (HOMA-IR), and serum lipids were measured. The expression of proteins involved in insulin signaling pathway was evaluated by western blot assay in 3T3-L1 cells and adipose tissue of mice. RESULTS: In 3T3-L1 cells, without affecting cell viability and lipid accumulation, PPE inhibited MCP-1 secretion, improved glucose uptake, and increased protein expression of phosphorylated insulin receptor substrate 1 [p-IRS-1, ($Tyr^{632})$)], p-Akt, and glucose transporter type 4 (GLUT4). Additionally, in HFD-fed mice, PPE reduced body weight, HOMA-IR, and serum lipids including triglyceride and LDL-cholesterol. Furthermore, in adipose tissue, PPE up-regulated GLUT4 expression and expression ratio of p-IRS-1 ($Tyr^{632})/IRS$, whereas, down-regulated p-IRS-1 ($Ser^{307})/IRS$. CONCLUSIONS: Our results collectively show that PPE improves glucose uptake in 3T3-L1 cells and insulin sensitivity in mice fed a HFD through stimulation of the insulin signaling pathway. Furthermore, PPE-induced improvement of insulin sensitivity was not accompanied with lipid accumulation.

• Korean Journal of Plant Resources
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• v.28 no.6
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• pp.690-696
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• 2015

We micropropagated pear (Pyrus species) using shoot tips and nodal explants from three pear genotypes. The ability to establish shoot tip cultures, proliferate shoots, induce rooting, and acclimatize the resulting plantlets are all elements of in vitro micropropagation. Shoots were induced from shoot tips on Murashige and Skoog medium (MS) with five different plant growth regulator combinations. The highest shoot formation rates were achieved for the three genotypes using MS supplemented with 1.0 mg/L N⁶-benzyladenine (BA) and 0.1 mg/L gibberellic acid (GA₃). The maximum shoot number and shoot length for the three cultivars were recorded with 2.0 mg/L BA and 0.2 mg/L indole-3-butyric acid (IBA) in multiplication medium using nodal explants produced from microshoots. Nodal explants with one or two axillary buds cultured for three weeks initiated roots on medium supplemented with various concentrations of 1-naphthaleneacetic acid (NAA) or/and IBA in half-strength MS medium for adventitious rooting. The highest rooting response was with the combination of 0.2 mg/L NAA and 0.2 mg/L IBA. A combination of NAA and IBA resulted in a significant increase in the rooting ratio over NAA or IBA alone. In this medium, the root formation rate according to ranged from 68.9% for the BaeYun No. 3 genotype to 51.8% for the Hwanggeum genotype. We also investigated the influence of the concentration the polyamine phloroglucinol in rooting medium. For all three genotypes, the highest rooting ratio, longest root length, and greatest root number were observed in the treatments with 75-150 mg/L phloroglucinol. Most rooted plants were acclimatized successfully.

• Journal of Pharmacopuncture
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• v.25 no.2
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• pp.121-129
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• 2022

Objectives: The chemical composition of cactus pear seed oil (Opuntia ficus-indica [L.] Mill.) was analyzed in terms of its fatty acid composition, tocopherol content, phenolic identification, and the oil's phenolic-rich fraction antioxidant power was determined. Methods: Fatty acid profiling was performed by gas chromatography coupled to an FI detector. Tocopherols and phenolic compounds were analyzed by LC-FLD/UV, and the oil's phenolic-rich fraction antioxidant power was determined by phosphomolybdenum, DPPH assay and β-carotene bleaching test. Results: Fatty acid composition was marked by a high unsaturation level (83.22 ± 0.34%). The predominant fatty acid was linoleic acid (66.79 ± 0.78%), followed by oleic acid (15.16 ± 0.42%) and palmitic acid (12.70 ± 0.03%). The main tocopherol was γ-tocopherol (172.59 ± 7.59 mg/kg. In addition, Tyrosol, vanillic acid, vanillin, ferulic acid, pinoresinol, and cinnamic acid were identified as phenolic compounds in the analyzed seed oil. Moreover, the oil's phenolics-rich fraction showed a significant total antioxidant activity, scavenged DPPH up to 97.85%, and effectively protected β-carotene against bleaching (97.56%). Conclusion: The results support the potential use of cactus pear seed oil as a functional food.

• Nutrition Research and Practice
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• v.16 no.5
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• pp.577-588
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• 2022

BACKGROUND/OBJECTIVES: Poorly regulated inflammation is believed to be the most predominant factor that can result in a wide scope of diseases including atopic dermatitis (AD). Despite many studies on the effect of pear pomace in obesity-related disorders including dysregulated gut microbiota, the protective effect of pear pomace in AD is still unknown. This study aimed to evaluate the effect of pear pomace ethanol extract (PPE) on AD by inhibiting inflammation. MATERIALS/METHODS: In the in vivo experiment, 2, 4-dinitrochlorobenzene (DNCB) was applied to NC/Nga mice to induce AD-like skin lesions. After the induction, PPE was administered daily by oral gavage for 4 weeks. The clinical severity score, serum IgE levels, spleen weight, histological changes in dorsal skin, and inflammation-related proteins were measured. In the cell study, RAW 264.7 cells were pretreated with PPE before stimulation with lipopolysaccharide (LPS). Nitrite oxide (NO) production and nuclear factor kappa B (NF-𝛋B) protein expression were detected. RESULTS: Compared to the AD control (AD-C) group, IgE levels were dramatically decreased via PPE treatment. PPE significantly reduced scratching behavior, improved skin symptoms, and decreased ear thickness compared to the AD-C group. In addition, PPE inhibited the DNCB-induced expression of inducible nitrite oxide synthase (iNOS), the receptor for advanced glycation end products, extracellular signal-regulated kinase (ERK) 1/2, and NF-𝛋B. PPE inhibited the LPS-induced overproduction of NO and the enhanced expression of iNOS and cyclooxygenase-2. Moreover, the phosphorylation of ERK1/2 and NF-𝛋B in RAW 264.7 cells was suppressed by PPE. CONCLUSIONS: These results suggest that PPE could be explored as a therapeutic agent to prevent AD.