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Physical Properties of Dietary Fiber Sources from Peel of Asian Pear Fruit at Different Growth Stages

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Physical properties and compositions of dietary fiber sources (DFS) from peels of Asian pear fruit, Hosui, Niitaka and Chuwhangbae, were examined at different growth stages, young, unripe, and ripe fruits, to investigate their use as functional ingredients. Total dietary fiber (TDF) contents of DFS prepared from peels of three cultivars at three stages were high, 74.00-88.38%, with most being insoluble dietary fiber. Total phenolic compound contents of DFS were 1.64-4.46mg/g, with those of Niitaka and Chuwhangbae increasing with growth stages. Density of DFS from young fruit was significantly lower than those from unripe and ripe fruits (p
... Although a study has been conducted to isolate functional foodstuffs such as dietary fibers and pectins from pears (Zhang et al., 2005), the use of pear-derived products in the food and beverage industry is currently poor. Methods of fermenting pear puree, which can improve the flavor and functionality of pears, have neither been extensively studied nor adopted. ...
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A lactic acid bacterial strain showing fast growth and high acid production when cultured in Korean pear puree was isolated from Kimchi. This strain was analyzed by using the API 50 CHL kit and 16S rRNA sequencing and was thus identified as Leuconostoc mesenteroides 51-3. Korean pear puree was fermented with the L. mesenteroides 51-3 strain at 30°C for 12 h. The changes in pH, titratable acidity and viable cell count during fermentation were investigated. The pH and titratable acidity of the pear puree were 4.06 and 0.66%, respectively, after 12 h of fermentation. The viable cell count of L. mesenteroides 51-3 rapidly increased to 3.7 × 10 9 CFU/g after 12 h of cultivation. The content of lactic acid and acetic acid was determined to be 0.138 and 0.162%, respectively, after 12 h of fermentation. When the fermented pear puree was stored at 4°C, the pH, titratable acidity and viable cell count remained fairly constant for 14 days.
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The changes of dietary fiber content in cultivars of Asian pear (Pyrus pyrifolria) fruits were investigated during the growth. In peel and flesh, insoluble dietary fiber (IDF) decreased regardless of cultivars while soluble dietary fiber (SDF) increased during the growth. Total dietary fiber (TDF) content in peel of Pungsu, Shingo, and Chuhwang cultivars; decreased from 26.6%, 25.4% and 27.7% to 10.5%, 10.7% and 11.9%, respectively. They were higher than TDF content in the peel of Korean tangerine. The IDF contents of their peels were higher than SDF content of them, but reverse results were found in flesh near the maturation time. The ratio of SDF content to IDF content in the peel and flesh during the whole growing time increased continuously. Contents of neutral detergent and acid detergent fiber in peel and flesh decreased with the pear growth. Hemicellulose content of peel decreased from 11.3% to 1.3% in Pungsu, from 16.5% to 1.2% in Shingo and from 10.6% to 1.8% in Chuhwang, respectively. The cellulose content also showed the similar result. Lignin contents of the peel and flesh were decreased continuously during the whole growing period.
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