• Preventive Nutrition and Food Science
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• v.14 no.4
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• pp.362-366
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• 2009

To determine the effect of electron-beam irradiation on the contents of polymethoxylated flavones (PMFs) extracts from citrus pomaces (CP), CP was irradiated at 0, 1, 2, or 5 kGy. Methanol extract of the irradiated CP were prepared and the PMF (nobiletin, sinensetin, and tangeretin) content of the extract was determined. Nobiletin and sinensetin of CP extract significantly increased with irradiation dose-dependent. However, electron-beam irradiation decreased the amount of tangeretin in the CP extract. These data suggest that irradiation can liberate phenolic compounds such as nobiletin or sinensetin, but tangeretin might have different pathway of conversion by irradiation. Therefore, irradiation can be a tool to change the composition of PMFs in CP.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.732-738
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• 2009

An acidic polygalacturonase (PG) from Aspergillus kawachii was produced by solid state fermentation employing a polyurethane foam support. The conditions used for the production of acidic PG were particle size of support (0.6 or 500 $mm^3$) and fermentation time. From the factors studied, the particle size had important influence on enzyme production. The best conditions for acidic PG production were $0.6\;mm^3$ particle size, 18 hr at $30^{\circ}C$ and initial pH of 5.0. In addition, pectin was extracted from citrus pomaces (grapefruit, lime, and tangerine) by acidic PG at $50^{\circ}C$ for 24 hr with citric acid solution. Infrared spectroscopy showed that lime pomace had more high-methoxylated (65%) endogenous pectin than was obtained than from grapefruit or tangerine pomaces. The enzymatically extracted pectin yield in dry basis (d.b.) for grapefruit and lime pectins were 6.95 and 4.25%, respectively. The citric acid solution alone also contributed to pectin extraction from citrus pomaces (7-9%, d.b.). Limited pectin extraction by acidic PG from tangerine pomace was most likely due to the presence of low-methoxylated endogenous pectin. The enzymatic method for pectin extraction using acidic PG from A. kawachii is a promising technique for releasing highly polymerized pectic substances from high-methoxylated lime or grapefruit pomaces.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.4
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• pp.322-331
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• 2017

This study was conducted to evaluate the changes of pH, dry matter digestibility (DMD), $NH_3-N$ concentrate, gas production and volatile fatty acid (VFA) through in vitro fermentation by adding horse feces to various juice pomaces fermented with Bacillus, yeast and lactic acid bacteria. The pH range of fermented fluid with juice pomaces was 6.4-7.1, indicating that the digestion by microbial fermentation was normal. Juice pomaces adopted will be helpfully used to assist with digestion by microbes in intestines because approximately $10^9CFU/m{\ell}$ microbes were grown after 48 hours in fermented fluid. DMD rate gradually increased from 12 hours. It was 39.19% in pomaces of apple, 38.22% in grape, 37.02% in carrot, 36.2% in citrus and 34.35% in mixture respectively after 48 hours. $NH_3-N$ concentrate was not changed significantly as it was maintained at $1.5mg/100m{\ell}$ level in the entire treatment group from beginning of fermentation until 12 hours, but increased rapidly from 24 hours. Amount of gas produced was lowest in the mixture and increased rapidly after 12 hours. Total VFA increased from 24 hours and was highest at 48 hours. It was suggested that dry matter digestion was processed while fermented juice pomaces kept proper pH during in vitro digestion, and cellulose degrading microorganisms could act actively in the caecum and colon of horses.

• Applied Biological Chemistry
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• v.49 no.1
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• pp.60-64
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• 2006

The effect of far-infrared (FIR) irradiation and heat treatment on the antioxidant activity of extracts from citrus pomaces (CP) was evaluated. CP were placed in pyrex petri dishes (8.0 cm diameter) and irradiated at $100^{\circ}C$ and $150^{\circ}C$ for 5, 10, 15, 20, 40 or 60 min with a FIR heater or simple heater, respectively. After FIR irradiation or simple heat treatment, 70% ethanol extracts (EE) and water extracts (WE) of CP were prepared and radical scavenging activity (RSA) and reducing power of the extracts were determined. The antioxidant activities of the extracts increased as the time of heating or FIR-irradiation increased. When CP were FIR-irradiated at $100^{\circ}C$ far 30min, the values of RSA and reducing power of EE increased from 14.9% to 44.2%, and 0.290 to 0.886, respectively, compared to the untreated control. Simple heat treatment of CP at $100^{\circ}C$ for 60 min also increased RSA and reducing power of EE to 44.7%, and 1.045, respectively. FIR irradiation and heat treatment increased RSA and reducing power of WE from CP, too. These results indicated the antioxidant activity of CP extracts was significantly affected by FIR irradiation and heating temperature and duration on CP, and that the FIR irradiation and heat treatment process can be used as a tool for increasing the antioxidant activity of CP.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.4
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• pp.290-300
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• 2017

In vitro fermentation was conducted to figure out alternative fiber sources for horse feed. For the development of value-added products as a horse feed resource, the pomaces from apple, carrot, grape, and citrus were fermented under solid-state conditions in the presence of 60% soybean meal with 40% of each fruit pomace at 60% of moisture content. Lactobacillus plantarum SK3873, Lactobacillus plantarum SK3893, Weissella cibaria SK3880, and Bacillus subtilis SK3889 were isolated from the fermented fruit pomace by inoculation of horse feces. For the growth of Bacillus subtilis, Saccharomyces cerevisiae, and Lactobacillus plantarum, they were inoculated in 3-step order at 0, 12, and 24 h, respectively. The fruit pomace was fermented for 48 h at $35^{\circ}C$. The pH of the apple, carrot, grape, citrus and all mixed pomaces decreased from 5.45~6.25 to 4.40~4.77. Microbial growth was maintained at $10^8{\sim}10^9cfu/g$. After 12 and 24 h incubation, dry matter of carrot pomace were highest at 54.84 and 56.66%, respectively (P<0.05) and that of grape pomace was lower than others during fermentation (P<0.05). Dry matter was generally reduced by about 20%. NDF decreased gradually or maintained after 24 h, indicating the fiber degradation. Ash content tended to decrease during fermentation. After 48 hours fermentation, Bacillus, yeast and Lactobacillus showed an excellent growth by using juice by-products. These results suggest that fermented juice pomace has a potential as horse feedstuff with probiotics to maintain beneficial microflora in horse gut.