• Journal of Microbiology and Biotechnology
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• v.34 no.2
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• pp.330-339
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• 2024

Corn cobs were fermented with Aspergillus niger to produce soluble dietary fiber (SDF) of high quality and excellent food safety. In this work, the fermentation process was optimized by single-factor test and response surface methodology (RSM). The optimal fermentation conditions were determined to be a material-liquid ratio of 1:30, an inoculum concentration of 11%, a temperature of 32℃, a time of 6 days, and a shaking speed of 200 r/min. Under these conditions, the SDF yield of corn cob increased from 2.34% to 11.92%, and the ratio of soluble dietary fiber to total dietary fiber (SDF/TDF) reached 19.08%, meeting the requirements for high-quality dietary fiber (SDF/TDF of more than 10%). Scanning electron microscopy (SEM) and Fourier-transformed infrared spectroscopy (FT-IR) analysis revealed that the fermentation effectively degraded part of cellulose and hemicellulose, resulting in the formation of a loose and porous structure. After fermentation the water swelling capacity, water-holding capacity, and oil-holding capacity of the corn cob SDF were significantly improved and the adsorption capacity of glucose, cholesterol, and nitrite ions all increased by more than 20%. Moreover, the total phenolic content increased by 20.96%, which correlated with the higher antioxidant activity of SDF. Overall, the fermentation of corn cobs by A. niger increased the yield and enhanced the functional properties of dietary fiber (DF) as well.

• Korean journal of food and cookery science
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• v.17 no.5
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• pp.503-509
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• 2001

The effects of salting methods on textural properties of Kakdugi were evaluated during fermentation at 1$0^{\circ}C$ for up to 52 days. Kakdugi samples were prepared by 4 different salting methods at final salt concentration of 1.5%, which is appropriate for organoleptic quality. The salting methods for radish cubes(2 cm size) of Kakdugi were as follows; 1) Treatment S-1: spraying dry salt uniformly on to the radish cubes at 1.5%(w/w) and holding for 1 hr, 2) Treatment S-5: spraying dry salt uniformly on to the radish cubes at 1.2%(w/w) and holding for 5 hr, 3) Treatment B-1: brining radish cubes in a 8.5%(w/v) salt solution for 1 hr, 4) Treatment B-5: brining radish cubes in a 4.0%(w/v) salt solution for 5 hr. The contents of water soluble pectin, total soluble solid and PG activity were increased as the fermentation periods increased. A majority of total dietary fiber(TDF) consisted of soluble dietary fiber(SDF), and the amount of insoluble dietary fiber(IDF) was relatively small in Kakdugi during fermentation. Furthermore, an increase in SDF and a consequent decrease in IDF contents were observed with the fermentation time increased.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.3
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• pp.395-404
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• 2019

Objective: Wheat bran (WB) and rice bran (RB) are the agricultural by-products used as poultry feed in many developing countries. However, their use for poultry feed is limited due to high fiber and the presence of anti-nutritional substances (e.g. ${\beta}-glucans$). The objective of this study was to develop a method to improve the quality of those brans by reducing the fiber content. Methods: A two-step fermentation method was developed where the second fermentation of first fermented dry bran was carried out. Fermentation was performed at a controlled environment for 3 h and 6 h (n = 6). The composition of brans, buffer solution and rumen liquor was maintained in a ratio of 1:2:3, respectively. Brans were analyzed for dry matter, crude fiber (CF), acid detergent fiber (ADF), neutral detergent fiber (NDF), and acid detergent lignin (ADL) content. Celluloses and hemicelluloses were calculated from the difference of ADF-ADL and NDF-ADF, respectively. Samples were compared by two-factor analysis of variance followed by Tukey's multiple comparison tests (p<0.05). Results: CF %, ADF % and cellulose tended to decrease and NDF % and hemicellulose content was reduced significantly (p<0.05). After the 1st fermentation step, NDF decreased $10.7%{\pm}0.55%$ after 3 h vs $17.0%{\pm}0.78%$ after 6 h in case of WB. Whereas, these values were $2.3%{\pm}0.30%$ (3 h) and $7.5%{\pm}0.69%$ (6 h) in case of RB. However, after the 2nd fermentation step, the decrease in the NDF content amounted to $9.1%{\pm}0.72%$ (3 h), $17.4%{\pm}1.13%$ (6 h) and $9.3%{\pm}0.46%$ (3 h), $10.0%{\pm}0.68%$ (6 h) in WB and RB, respectively. Cellulose and hemicellulose content was reduced up to $15.6%{\pm}0.85%$ (WB), $15.8%{\pm}2.20%$ (RB) and $36.6%{\pm}2.42%$ (WB), $15.9%{\pm}3.53%$ (RB), respectively after 2nd fermentation of 6 h. Conclusion: Two-step fermentation process improved the quality of the brans for their use in poultry feed.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.7
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• pp.942-946
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• 2004

This study aimed to examine the fermentation quality of a tropical Elephant grass (Pennisetum purpuereum) and temperate Italian ryegrass (Lolium multiflorum) forages ensiled additive of fermented juice of epiphytic lactic acid bacteria (LAB) and to determine what factor affects the fermentation characteristics of the crops. In both species cell walls neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents in silages were consistently decreased (p<0.05) with the addition of FJLB at ensiling more then Control treatment. The FJLB additive increased number of LAB (cfu) and lactate concentration in the silages in both species. The Control treatment without additive underwent a clostridial type of fermentation with traces of propionic, iso-butyric, n-butyric acids contents with higher (p<0.01) levels of volatile basic nitrogen (VBN %TN) and had appreciable decreased of nutrient in silages. FJLB treatment improved silage nutritive value with little contents of VBN %TN, ethanol and very small amount of dry matter (DM) and hemicellulose losses (p<0.05) between 2 to 5% and 7 to 3% respectively, in Elephant grass and Italian ryegrass species. The results in this study indicates that while among the factors affecting silage fermentation butyric type of fermentation was more pronounced in tropical elephant grass compared to the temperate Italian ryegrass, FJLB additive revealed a better silage fermentation products in both species.

• The Korean Journal of Food And Nutrition
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• v.8 no.2
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• pp.116-127
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• 1995

Recently, interests of dietary fiber associated with critical physiological effects have been rising in Korea physiological effect in the body. In the present study, the contents of fiber components in 15 kinds of vegetables being consumed commonly in Korea were investigated, and the effects of various treatments (cooking and Kimchi fermentation) on fiber were studied. The results are summarized as follows. Fiber contents of vegetables were 11.8∼31.9% of neutral detergent fiber(NDF), total insoluble dietary fiber, 10.9∼25.4% of acid detergent fiber(ADF), 8.8∼23.8% of cellulose, 0.6∼10.6% of hemicellulose and 1.0∼5.2% of lignin, on dry weight basis. Especially, peppers had higher contents of NDF than the other vegetables. In the vegetables used in the present study, it was found that a great portion of NDF, total insoluble dietary fiber, was composed of cellulose because cellulose covered 63% of NDF. 'Cooking increased the NDF, ADF and cellulose contents, and most change was due to the change of cellulose. The values of hemicellulose and lignin showed an Irregular pattern upon cooking. Fermentation slightly increased NDF, ADF and cellulose, while hemicellulose and lignin showed irregular pattern.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.45-51
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• 2007

A growth trial (Expt. 1) and an in vitro fermentation experiment (Expt. 2) were conducted to determine the response of growth performance, cecal fermentation characteristics and in vitro gas production to incremental levels of substitution of digestible fiber for lignified fiber in the diet of weaned rabbits. Three diets, formulated by substituting soyhulls (SH; used as digestible fiber source) for soybean straw (used as lignified fiber source) at substitution levels of 0, 25 and 50%, were used in a factorial design. In the growth trial (Expt. 1), increasing levels of SH substitution resulted in a quadratic increase in daily body weight gain rate (p<0.04) and feed conversion efficiency (p<0.02), but in a numerical decrease in dietary DM intake (p=0.15). When SH were included in the diet at 25% substitution level, rabbits had the highest rate of liveweight gain and feed conversion efficiency. As SH substitution level increased, pH values and ammonia-N of cecal contents linearly (p<0.001) decreased, but total VFA concentration linearly (p<0.03) increased. With incremental levels of SH substitution, the percentage of acetate and butyrate linearly (p<0.05) reduced, but the percentage of propionate and minor acids linearly (p<0.03) increased. Increasing the SH substitution levels tended to increase incidence of diarrhea. In the in vitro fermentation experiment (Expt. 2), regardless of origin of substrates fermented, increasing SH substitution level resulted in increased maximal gas production (p<0.001) and shortened gas production lag time, but had no effect on gas production rate (p>0.2). These observations suggest that incrementally feeding SH to rabbits could stimulate their cecal microbial activity, allowing cecal fermentation to shift towards favoring fiber digestion. In conclusion, digestible fiber from soyhulls may partially substitute for more lignified fiber, soybean straw, without having an adverse effect on cecal fermentative and microbial activity and growth performance. For growing rabbits, about 73% of total dietary NDF should be supplied by effective NDF, the remainder could come from digestible NDF, such as soyhulls.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1006-1012
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• 1997

To observe the food quality of Baik-kimchi which is known as a watery Chinese cabbage pickles without fish sauce and red pepper paste, the changes of dietary fibers and pectic substances during fermentation at 5$^{\circ}C$ and $25^{\circ}C$ were studied. Baik-kimchi fermented at $25^{\circ}C$ showed a greater changes in pH and acidity than those of 5$^{\circ}C$ during storage. Ripened Baik-kimchi products fermented at 5$^{\circ}C$ could be prepared on 9~12 days of fermentation, and those had a pH range from 4.25 to 4.40 and acidity of 0.34~0.53. But in the case of $25^{\circ}C$ fermentation, Baik-kimchi ripened for 3 days showed a pH of 4.02 and acidity of 0.54. The pH and acidity of the Baik-kimchi juice changed more rapidly than those of the Baik-kimchi solid regardless of fermentation temperatures. The content of soluble dietary fiber(SDF) was ranged from 3.06 to 4.87% at 5$^{\circ}C$ and a wide variation in SDF was observed in the sample fermented at $25^{\circ}C$(4.15~11.22%). Insoluble dietary fiber(IDF) were increased from 21.66% to 28.42% in solid of Baik-kimchi during fermentation at 5$^{\circ}C$ and ranged from 21.37% to 24.65% for sample fermented at $25^{\circ}C$. A notable amount of pectin had been dissolved in juice of Baik-kimchi till the best ripening time and showed the level of 223.2mg/100ml at 5$^{\circ}C$ on the day of 9 and 207.3mg/100ml at $25^{\circ}C$ on the day of 2. In contrast, the contents of pectin in solid Baik-kimchi decreased, whereas contents of sodium hexametaphosphate soluble pectin(HXSP) and HCl soluble pectin(HClSP) increased with fermentation period.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.4
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• pp.603-615
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• 2008

Dietary fiber is an inevitable component in pig diets. In non-ruminants, it may influence many physiological processes in the gastrointestinal tract (GIT) such as transit time as well as nutrient digestion and absorption. Moreover, dietary fiber is also the main substrate of intestinal bacteria. The bacterial community structure is largely susceptible to changes in the fiber content of a pig's diet. Indeed, bacterial composition in the lower GIT will adapt to the supply of high levels of dietary fiber by increased growth of bacteria with cellulolytic, pectinolytic and hemicellulolytic activities such as Ruminococcus spp., Bacteroides spp. and Clostridium spp. Furthermore, there is growing evidence for growth promotion of beneficial bacteria, such as lactobacilli and bifidobacteria, by certain types of dietary fiber in the small intestine of pigs. Studies in rats have shown that both phosphorus (P) and calcium (Ca) play an important role in the fermentative activity and growth of the intestinal microbiota. This can be attributed to the significance of P for the bacterial cell metabolism and to the buffering functions of Ca-phosphate in intestinal digesta. Moreover, under P deficient conditions, ruminal NDF degradation as well as VFA and bacterial ATP production are reduced. Similar studies in pigs are scarce but there is some evidence that dietary fiber may influence the ileal and fecal P digestibility as well as P disappearance in the large intestine, probably due to microbial P requirement for fermentation. On the other hand, fermentation of dietary fiber may improve the availability of minerals such as P and Ca which can be subsequently absorbed and/or utilized by the microbiota of the pig's large intestine.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1230-1237
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• 2018

Objective: The present study was undertaken to determine an optimal balance between the amount of physically effective neutral detergent fiber (peNDF) to metabolizable glucose (MG) on rumen fermentation, blood metabolites and growth performance of 8 to 10-month-old heifers. Methods: A total of 15 healthy Holstein heifers weighing an average of 256 kg (8 month of age) were randomly assigned to three groups of five. Treatment diets consisted of the following three $peNDF_{8.0}/MG$ levels: 1.46 (Treatment A), 1.74 (Treatment B), and 2.08 (Treatment C). Results: The results showed that the ratio of $peNDF_{8.0}/MG$ affected rumen fermentation, blood metabolites and growth performance of heifers. The average daily gain of heifers tended to decrease as the ratio of $peNDF_{8.0}/MG$ increased (p = 0.07). The concentrations of blood urea nitrogen, triglyceride, and cholesterol increased significantly (p<0.05), while the high-density lipoprotein concentration decreased (p<0.05). After feeding 2 h and 4 h, insulin concentration in Treatment A was greater than Treatment C (p<0.05). Propionate concentration had decreasing trend (p = 0.07); acetate to propionate ratio and non-glucogenic to glucogenic volatile fatty acid (NGR) increased significantly (p<0.05). In addition, the digestibility of dry matter, crude protein, neutral detergent fiber, and acid detergent fiber decreased significantly (p<0.05). Conclusion: The present investigation indicated that dietary $peNDF_{8.0}/MG$ ratio can affect the growth and development, blood metabolites, rumen fermentation and apparent digestibility of heifers, and the optimal dietary $peNDF_{8.0}/MG$ ratio for 8 to 10-month-old heifers in the present study was 1.46.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.11
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• pp.1508-1513
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• 2000

The aim of this trial was to study the response of laboratory animals including omnivores (rats) and herbivores (rabbits, guinea pigs and hamsters) to the same level of dietary fiber on their digestive enzymes and hindgut fermentation. Ten weanling animals of each of four species, rabbits, guinea-pigs, rats and Syrian hamster, were fed a basal diet of 18% crude protein and 10% crude fiber for six weeks. The digesta and tissue of each intestinal segment were collected to measure the activity of digestive enzymes. Rabbits contained the highest secreted pepsin activity in the stomach, whereas rats contained the highest protease and ${\alpha}-amylase$ activity in the small intestine, and lower fibrous hydrolases in the hindgut than rabbits, guinea pigs and hamsters. The total VFA productions in the caecum and colon were highest in rats, followed by hamsters and rabbits, while the guinea pigs contained the lowest VFA and a different pattern of VFA molar ratio from the other laboratory animals. The degree of hindgut fermentation in these laboratory animals was in reverse to the trend for their fiber digestion.