• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.4
• /
• pp.623-633
• /
• 2020

Objective: Substituting starch with digestible fiber (dF) can improve digestive health of rabbits and reduce costs. Therefore, it is necessary to develop a criterion for dF and starch supply. Effects of the dietary dF-to-starch ratio on pellet quality, growth and cecal microbiota of Angora rabbits were evaluated. Methods: Five isoenergetic and isoproteic diets with increasing dF/starch ratios (0.59, 0.66, 0.71, 1.05, and 1.44) were formulated. A total of 120 Angora rabbits with an average live weight of 2.19 kg were randomly divided into five groups with four replicates. At the end of 40 day feeding trial, cecal digesta were collected to analyse microbiota. Results: The results showed that the dF/starch ratio had linear effects on pellet variables (p<0.01). When the dF/starch ratio was 1.44, the pellets had the lowest powder and highest durability. The dF/starch ratio had unfavorable linear effects on growth variables (p<0.001). When analyzed by quadratic regression, the optimal dF/starch ratios for average weight gain and feed/gain were 0.59 and 0.74, respectively. There were differences in wool yield, fiber length and fiber diameter caused by the dF/starch ratio (p<0.05), and the dF/starch ratios that ranged from 0.66 to 1.06 were appropriate for good results. The cecal microbiota operational taxonomic unit (OTU) number index in the 1.05 dF/starch treatment was higher than that in the 0.66 and 0.71 dF/starch treatments. The higher dF/starch ratio resulted in a higher cecal microbiota OTU number index (p<0.05). The proportion of Ruminococcus in the 0.71 dF/starch treatment was higher than that in the 0.59 dF/starch treatment (p<0.05) Conclusion: The most suitable dF/starch ratio for feed pellet quality is 1.44, and for rabbit growth the optimal range of ratios is from 0.59 to 0.74. With combination of the wool growth, output cost, and cecal microbiota, we suggest that a dietary dF/starch ratio ranging from 0.74 to 1.06 is optimal.

• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.8
• /
• pp.1124-1130
• /
• 2014

The objective of this study was to determine the responses in the digestibility of dry matter (DM) and amino acid (AA) composition of ileal endogenous flow (IEF) of pigs (initial body weight, $69.1{\pm}6.46$ kg) fed N-free diets (NFD) formulated with different ratios of corn starch to dextrose. Fifteen pigs fitted with a T-cannula at the distal ileum were fed 5 diets according to a triplicated $5{\times}2$ incomplete Latin-square design. Each period consisted of a 5-d adjustment period and 2 d of ileal digesta collection for 12 h on each of d 6 and 7 and between each period, there was a 5-d recovery period to avoid abnormal weight loss. The ratios of corn starch to dextrose investigated were 0:879, 293:586, 586:293, 779:100, and 879:0 for diet numbers 1, 2, 3, 4 and 5, respectively, and chromic oxide (5 g/kg) was used as an indigestible index. Ileal DM digestibility was greater in Diet 1 than that in Diet 4 (89.5% vs 87.3%, p<0.01) but they were not different from Diet 2, 3, or 5. The IEF for most of indispensable AA were not different among diets with the exception of Met, in which a lack of corn starch or dextrose gave lower (p = 0.028) IEF of Met than diets containing corn starch and dextrose. Likewise, the dispensable AA and total AA in the IEF did not differ among diets. The respective IEF of AA (mg/kg of dry matter intake) in pigs fed Diets 1, 2, 3, 4, or 5 were 301, 434, 377, 477,or 365 for Lys, 61, 89, 71, 87, or 61 for Met, and 477, 590, 472, 520, or 436 for Thr. Proline was the most abundant AA in the IEF followed by Gly, Glu, and Asp and together accounted for approximately 50% of the total ileal AA flows of pigs fed NFD. In conclusion, the variation in proportion of corn starch and dextrose in a NFD does not largely affect estimates of IEF of N and AA for growing-finishing pigs.

• Korean journal of food and cookery science
• /
• v.5 no.1
• /
• pp.43-47
• /
• 1989

For identifying the cause of the difference from the texture of mealy potatoes-Namjak and soomi- and soggy Potatoes-Daeji and Dowon-, starch and pectic substances and their relating materials were analyzed, and polygalacturonase(PG) activity was measured. The shape and size of Namjak and soomi starch granules were circular and diameter ranged from 0.02 to 0.024 mm. In the meanwhile, Daeji and Dowon had two sizes of starch granules; larger one tend to be oval in shape and diameter of longer side ranged from 0.04 to 0.045 mm, that of narrower side ranged from 0.02 to 0.03 mm and smaller one was rather circular in shape and average deameter was below 0.005 mm. Oval shaped potato starch grancules under polarized light showed dark cross of V-shape, whereas circular granules showed cross shape. Total sharch contents of Namjak and soomi were higher than that of Daeji and Dowon. The changes of pectic substances were the decrease of the insoluble pectin and the increase of the soluble pectin, and the reduction of the total pectic substance content after cooking. This phenomena were more prominent in Namjak and Soomi than in Daeji and Sowon. PG activities of Namjak and Soomi were greater than Daeji and Dowon. Calcium contents of Namjak and Soomi were lower than Daeji and Dowon. Phytic acid contents of Namjak, Soomi, Daeji and Dowon were 0.093%, 0.096%, 0.078%, and 0.081%, respectively. Hardness of Namjak and Soomi were less than Daeji and Dowon. The mealy potatoes had higher starch contents, higher tendency to pectin solubilization, higher PG activities, lower calcium contents and less hardness than the soggy Potatoes.

• Microbiology and Biotechnology Letters
• /
• v.47 no.3
• /
• pp.412-422
• /
• 2019

The present study reports the morphological and molecular characterization of the fungal strain, CMSS06 and evaluates its raw starch hydrolyzing ability in four different agricultural substrates (rice bran, banana peel, cassava tubers, and coconut water). The potential use of each agricultural substrate to replace the expensive fermentation media was evaluated with six different fermentation media: rice bran (RB), banana peel (BP), cassava starch (CS), cassava in coconut water (CSCW), cassava in modified coconut water (CMCW), and pure Coconut water (CW). The fungal strain CMSS06 was identified as Thielaviopsis ethacetica by the analysis of the ITS sequences. The T. ethacetica alpha amylase enzyme exhibited maximum alpha amylase activity at 72 h, pH 7.0, and $40^{\circ}C$ on soluble starch. This species resulted in the highest enzyme activity (mU/ml) of 26.06, 10.89, 58.82, 14.2, and 54.67 with the RB, BP, CS, CSCW, and CMCW fermentation media, respectively. The results indicate that CS can be used as a carbon substrate and CMCW can be used to accelerate the fermentation by T. ethacetica. The enzyme was partially purified by 40-60% ammonium sulphate fraction, and it showed total enzyme activity, total protein content, specific activity, purification fold, and a recovery of 2400 mU, 30 mg, 80 mU/mg, 2.7, and 71.1%, respectively. The molecular mass of the T. ethacetica alpha amylase was estimated on SDS-PAGE, and two bands around 50 kDa and 70 kDa were identified. The present study implies that T. ethacetica can produce alpha amylase, and it can be used to hydrolyze raw starch during the fermentation processes.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.214-214
• /
• 2022

Soluble starch synthases (SSs) elongate α-glucans from ADP-Glc to the glucan nonreducing ends and play a critical role in synthesizing resistant starch in the rice. A total of 10 SSs isoforms were reported in rice, including granules-bound starch synthase I (GBSSI), GBSSII, starch synthase I (SSI), SSIIa (SSII-3), SSIIb (SSII-2), SSIIc (SSII-1), SSIIIa (SSIII-2), SSIIIb (SSIII-1), SSIVa (SSIV-1), and SSIVb (SSIV-2). SSIII proteins are involved in forming the B chain and elongating cluster filling chains in amylopectin metabolism. The functions of SSIIIb (SSIII-1) are less clear as compared to SSs. Here, we sought to shed light on the genetic diversity profiling of the SSIII-1 gene in 374 rice accessions composed of 54 wild-type accessions and 320 bred cultivars (temperate japonica, indica, tropical japonica, aus, aromatic, and admixture). In total, 17 haplotypes were identified in the SSIII-1 coding region of 320 bred cultivars, while 44 haplotypes were detected from 54 wild-type accessions. The genetic diversity indices revealed the most negative Tajima's D value in the temperate-japonica, followed by the wild type, while Tajima's D values in other ecotypes were positive, indicating balancing selection. Nucleotide diversity in the SSIII-1 region was highest in the wild group (0.0047) while lowest in temperate-japonica. Lower nucleotide diversity in the temperate-japonica is evidenced by the negative Tajima's D and suggested purifying selection. The fixation index (F_ST) revealed a very high level of gene flow (low F_ST) between the tropical-japonica and admixture groups (F_ST=-0.21) followed by admixture and wild groups (-0.04), indica and admixture groups (0.02), while low gene flow with higher F_ST estimates between the temperate-japonica and aus groups (0.72), tropical-japonica and aromatic groups (0.71), and temperate-japonica and admixture groups (0.52). Taken together, our study offers insights into haplotype diversity and evolutionary fingerprints of SSIII-1. It provides genomic information to increase the resistant starch content of cooked rice.

• Microbiology and Biotechnology Letters
• /
• v.19 no.3
• /
• pp.290-295
• /
• 1991

Direct conversion of raw starch without liquefaction to maltose using maltose-forming fungal a-amylase (Fungamyl) was carried out in an agitated bead enzyme reactor (bioattritor). The reaction rate in bioattritor was comparable with conventional method which utilized liquefied soluble starch. Moreover the extent of maltose formation increased substantially compared with conventional method; from 150 g / I of raw starch, around 95 g/l of maltose was formed and 72% of maltose content in sugar mixture was achieved. Especially, pH influenced greatly not only on total sugar formation from raw starch in bioattritor but also on maltose content in sugar mixture. The optimal pH for maltose formation from raw starch was shifted into the weak alkaline pH, the optimal pH of 8.0~9.0 in bioattritor contrast to pH of 5.0~5.5 for liquefied starch. The maltose formation and content were also affected by the amounts of Fungamyl added and raw starch concentration. Consumption of maltose-forming Fungamyl can be substantially reduced by supplementary addition of starch liquefying a-amylase (Termamyl).

• Journal of Nutrition and Health
• /
• v.13 no.4
• /
• pp.167-176
• /
• 1980

This study was conducted to compare effects of various types of dietary carboh ydrates fed with different levels of protein on the protein utilization in weanling rats. Sixty male Sprague-Dawley rats weighing $60{\pm}1.3grams$ were adapted for 1 week with 77% starch-15% casein diet. Then the animals divided into 12 groups according to body weight and fed each experimental diet for two weeks. Carbodydrates used were glucose, starch, and sucrose and the amount of protein given were 0g, 1g, 3g, 5g casein/day. Protein portion of the diet was fed in two seperate feedings per day while nonprotein portion was fed ad libitum. It seemed that there was no significant difference in the protein utilization by using the different kinds of carbohydrate, but in P.E.R., N.P.U., weights of organs and protein and lipid in total carcass, glucose groups were tended to be slightly lower than starch and sucrose groups. The larger the amount of casein given, the higher were the value of body weight gain, F.E.R., weights of organs, total lipid in carcass and the amount of nitrogen retention. On the while, the larger the amount of casein given, the lower were the value of the intake of non-protein portion, P.E.R., N.P.U, and the percentage of nitrogen retention.

• Preventive Nutrition and Food Science
• /
• v.20 no.4
• /
• pp.276-283
• /
• 2015

Hydrocolloids have many applications in foods including their use in dysphagia diets. We aimed to evaluate whether hydrocolloids in foods affect the digestibility of starch and protein, and their effects on antioxidant capacity. The thickening hydrocolloids: locust bean gum and carboxymethyl cellulose, and the gel-forming agents: agar agar, konjacglucomannan, and Hot & Soft Plus were blended with corn starch and soy protein, skim milk, or grape juice and were examined for their in vitro-digestability by comparing the reducing sugar and trichloroacetic acid (TCA)-soluble peptide, for antioxidant capacity by total polyphenol contents and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity. The hydrocolloids resulted in a decrease in starch digestibility with the gel-forming agents. Hydrocolloids diminished TCA-soluble peptides in skim milk compared to soy protein with the exception of locust bean gum and decreased free radical scavenging capacities and total phenolic contents in grape juice. Our findings may provide evidence for the use of hydrocolloids for people at risk of nutritional deficiencies such as dysphagia patients.

• Membrane Journal
• /
• v.8 no.3
• /
• pp.170-176
• /
• 1998

A study on the bioconversion of soluble starch to cyclodextrin(CD) homologue by CGTase was performed in the membrane-enzyme reactor equipped with a dead-end type membrane module. in the batch reactor, the total conversion of soluble starch to CD homologue was decreased rapidly from a maximum value of 45 % with increasing reaction time due to the product inhibition and breakdown of CD homologue to the reducing sugars. However, in the membrane-enzyme reactor, the total conversion of soluble starch was maintained at a constant value of 35 % throughout the reaction, since the membrane(MWCO = 10,000) promptly separated CD homologue from the reaction mixture. After the macdon for 24 hr in the membrane-enzyme reactor using a 10 % soluble starch solution, the cumulative production amount of CD homologue was about 3.7 kg/m$^2$ at the operating pressure of 2 atm.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.2
• /
• pp.230-236
• /
• 2018

Objective: Two ex vivo experiments were conducted to verify the effect of barley grain (Nusrat cultivar) treated with alkaline compounds (AC) including alum, ammonium, and sodium hydroxide or cation-exchanged organic extracts (OE) prepared from alfalfa hay, sugar beet pulp and Ulva Fasciata, on extent and digestion of starch. Methods: In the first study, the in vitro first order disappearance kinetic parameters of dry matter (DM), crude protein (CP) and starch were estimated using a non-linear model ($D_{(t)}=D_{(i)}{\cdot}e^{(-k_d{\cdot}time)}+I$, where: $D_{(t)}$ = potentially digestible residues at any time, $D_{(i)}$ = potentially digestible fraction at any time, $k_d$ = fractional rate constant of digestion (/h), I = indigestible fraction at any time). In the second experiment, the ruminal and post-ruminal disappearance of DM, CP, and starch were determined using in situ mobile nylon bag. Results: Barley grains treated with alum and alfalfa extract had a higher constant rate of starch digestion (0.11 and 0.09/h) than others. Barley grain treated with OE had a higher constant rate of CP digestion and that of treated with AC had a higher constant rate of starch digestion (0.08 and 0.11/h) compared with those of the other treatments. The indigestible fraction of starch treated with alum and sugar beet pulp extract was higher than that of the control group (0.24 and 0.25 vs 0.21). Barley grain treated with AC and OE had significant CP disappearance in the rumen, post-rumen and total tract, and also starch disappearance for post-rumen and total tract compared with the untreated (p<0.001). Conclusion: This study demonstrated that AC and OE might have positive effects on the starch degradation of the barley grain. In addition, treating barley grain with alum and sugar beet pulp extract could change the site and extend digestion of protein and starch.