• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.4
• /
• pp.559-567
• /
• 2015

Ex vivo digestion of proteins and fat in Red Chittagong Cattle milk from Bangladesh was carried out using human gastrointestinal enzymes. This was done to investigate the protein digestion in this bovine breed's milk with an especial focus on the degradation of the allergenic milk proteins; ${\alpha}_{s1}$-casein and ${\beta}$-lactoglobulin and also to record the generation of peptides. Lipolysis of the milk fat and release of fatty acids were also under consideration. After 40 min of gastric digestion, all the ${\alpha}_s$-caseins were digested completely while ${\beta}$-lactoglobulin remained intact. During 120 min of duodenal digestion ${\beta}$-lactoglobulin was reduced, however, still some intact ${\beta}$-lactoglobulin was observed. The highest number of peptides was identified from ${\beta}$-casein and almost all the peptides from ${\kappa}$-casein and ${\beta}$-lactoglobulin were identified from the gastric and duodenal samples, respectively. No lipolysis was observed in the gastric phase of digestion. After 120 min of duodenal digestion, milk fat showed 48% lipolysis. Medium (C10:0 to C16:0) and long (${\geq}C17:0$) chain fatty acids showed 6% to 19% less lipolysis than the short (C6:0 to C8:0) chain fatty acids. Among the unsaturated fatty acids $C18:1{\sum}others$ showed highest lipolysis (81%) which was more than three times of $C18:2{\sum}all$ and all other unsaturated fatty acids showed lipolysis ranging from 32% to 38%. The overall digestion of Bangladeshi Red Cattle milk was more or less similar to the digestion of Nordic bovine milk (Norwegian Red Cattle).

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.2
• /
• pp.176-181
• /
• 2000

In order to clarify the inhibitory effects of orchardgrass (Dactylis glomerata L.) lipids on ruminal fermentation and digestion, two experiments were carried out in vitro. Experiment 1 was carried out using residues of grass hay from which the lipid fraction was removed by ether extraction. To ground grass samples were added 0, 1.5, 3.0, 4.5 and 6.0% lipids and incubated anaerobically at $39^{\circ}C$ for 24 h, with the mixtures of artificial saliva and rumen fluid. Increasing grass lipid levels remarkably reduced DM and NDF disappearances. Volatile fatty acid concentration was significantly reduced at 3.0, 4.5 and 6.0% lipid levels. Microbial nitrogen proportion to total nitrogen tended to decrease by the addition of the lipids. These results indicated that grass lipids have a marked inhibitory effect on ruminal fermentation and digestion, especially when to the substrate was added 3% or more grass lipids as ether extracts. Experiment 2 was conducted to study the relationship between changes in the free fatty acids and changes in the fermentation traits. Samples were incubated for 3, 6, 9, 12, 15, 18, 21 and 24 h as a sole substrate. The polyunsaturated fatty acids steadily decreased during incubation, whereas the saturated fatty acid ($C_{18:0}$) increased. It was suggested that the hydrogenation was extended during the initial stage of incubation. The unsaturated fatty acids ($C_{18:2}$, $C_{18:3}$) produced at the initial stage of incubation were negatively correlated with the amount of microbial N and DM disappearance, indicating that polyunsaturated fatty acids had the possibility to show an inhibiting effect on ruminal fermentation and digestion.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.1
• /
• pp.23-30
• /
• 2000

The effects of grass lipids and long chain fatty acids (LCFA; palmitic, stearic and oleic acids), at low concentrations (0.001~0.02%), on the growth and enzyme activity of two strains of anaerobic fungi, monocentric strain Piromyces rhizinflata B157 and polycentric strain Orpinomyces joyonii SG4, were investigated. The addition of grass lipids to the medium significantly (p<0.05) decreased filter paper (FP) cellulose digestion, cellulase activity and fungal growth compared to control treatment. However, LCFA did not have any significant inhibitory effects on fungal growth and enzyme activity, which, however, were significantly (p<0.05) stimulated by the addition of oleic acid as have been observed in rumen bacteria and protozoa. This is the first report to our knowledge on the effects of LCFA on the rumen anaerobic fungi. Continued work is needed to identify the mode of action of LCFA in different fungal strains and to verify whether these microorganisms have ability to hydrogenate unsaturated fatty acids to saturated fatty acids.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.7
• /
• pp.941-946
• /
• 2001

The effects of various concentrations of saturated fatty acids (SFA; caprylic, capric and stearic acids) on the growth of the anaerobic fungus, Neocallimastix frontalis C5-1 isolated from the rumen of a Korean native goat were investigated. At higher concentrations of fatty acids (0.1%, w/v), the addition of SFA strongly decreased filter paper (FP) cellulose digestion and polysaccharide-degrading enzyme activity. The sensitivity of the rumen anaerobic fungus to the added fatty acids increased in the following order: caprylic ($C_{8:0}$)>capric($C_{10:0}$)>stearic($C_{18:0}$) acid, although stearic acid had no significant (p<0.05) inhibitory effects at any of the concentrations tested. However, the addition of SFA at lower concentrations (0.01 and 0.001% levels), did not inhibit FP cellulose degradation and enzyme activity. Furthermore, although these parameters were slightly stimulated by the addition of SFA, they were not statistically different from control values. This is the first report examining the effects of fatty acids on anaerobic gut fungi. We found that the lower levels of fatty acids used in this experiment were able to stimulate the growth and specific enzyme activities of rumen anaerobic fungi, whereas the higher levels of fatty acids were inhibitory with respect to fungal cellulolysis.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.8
• /
• pp.1222-1228
• /
• 2007

The aim of this experiment was to compare the characterization of fatty acid digestion of Beijing Fatty (BF) and Arbor Acres (AA) chickens. One-day-old male AA and BF chickens were raised in the same house, and fed with the same diet. We first evaluated utilization of dietary fatty acids in chickens by the total collection procedure, and chickens were then killed to compare the abundance of intestinal mRNA expression of liver-fatty acid binding protein (L-FABP) and intestinal-fatty acid binding protein (I-FABP) by Real-time PCR, and also the pH of intestinal mucosa at 3 and 6 weeks of age. Another group of chickens were sampled at 6 weeks of age to compare the total bile acid concentration in serum, and lipase activity in contents of the small intestine. Results showed that compared to AA chickens, BF chickens had higher lipase activity in the content of the small intestine (p<0.05), greater total bile acid content in portal vein blood (p<0.05) at 6 weeks of age, lower intestinal mucosal pH at both 3 weeks (p<0.05) and 6 weeks (p<0.05) of age, and higher abundance of liver-fatty acid binding protein (L-FABP) mRNA expression in intestine tissues at 6 weeks of age (p<0.05), and higher digestibility of fatty acids at both 3 and 6 weeks (p<0.05) of age. There was no difference in I-FABP mRNA expression between AA and BF chickens at either age. Thus, BF chickens had greater fatty acids utilization than AA chickens that was associated with L-FABP, lipase activity, bile acid content and intestinal mucosal pH.

• Asian-Australasian Journal of Animal Sciences
• /
• v.3 no.1
• /
• pp.27-31
• /
• 1990

Influences of plant phenolic acids and their possible metabolites(non-phenolic aromatic acids involved) in the rumen on the cellulolytic activity of mixed rumen populations were examined by a simple in vitro culture technique. Initial concentrations of aromatic acids were 1, 5, 10 and 20 mM/l. All the tested aromatic acids reduced microbial cellulose digestion especially at the higher initial concentration. P-Coumaric acid, ferulic acid and cinnamic acid, those having unhydrogenated propenoic side chain were more inhibitory than were 3-phenylpropinic acid and phloretic acid, those having hydrogenated propanoic side chain. Lag-time for cellulose digestion was prolonged by former three acids by 16 h. Apparent reduction in p-coumaric acid concentration was observed at 24 h when cellulose digestion began. Volatile fatty acid productions from cellulose fermentation were shifted by former three aromatic acids to produce more acetate and less propionate. This suggests that the selection of celluloytic organisms was induced by these aromatic acids.

• Journal of Biosystems Engineering
• /
• v.43 no.1
• /
• pp.37-44
• /
• 2018

Purpose: The objective of this study was to investigate the high-efficiency anaerobic digestion of organic wastes with high fat content. Specifically, the analysis focused on biogas production performance with a focus on carbon number and the double bond count of the long-chain fatty acids (LCFAs), which are hydrolysis products of triglycerides. Methods: Experiments were performed under mesophilic anaerobic conditions with a feed-to-microorganism ratio (F/M) of 1.0. Biogas production performance was analyzed through biogas production patterns, lag-phase, and the time required for 90% biogas production (T90). Results: Biogas production increased when the content of unsaturated LCFAs (containing relatively large numbers of carbon atoms) increased. In substrate containing LCFAs with four or more double bonds, although the initial lag-phase in biogas production was shortened, development of a three-step lag-phase resulted in decreased biogas production. These results suggest that high rates of anaerobic digestion are possible when the LCFAs have high unsaturated fatty acid content with three or fewer double bonds. Conclusions: When various types of LCFAs are digested anaerobically, biogas production performance can be improved if the unsaturated fatty acid content and number of double bonds are optimized for maximum production.

• The Korean Journal of Food And Nutrition
• /
• v.36 no.5
• /
• pp.368-378
• /
• 2023

Changes in contents of free sugars, amino acids, and fatty acids of legumes were analyzed for each phase of in vitro digestion. In addition, contents of resistant starch in raw and digested pulses were compared. Soybeans, kidney beans, cowpeas, and chickpeas were analyzed. An in vitro digestion model was used to analyze contents of nutrients using LC-MS and GC-MS. Stachyose in kidneybean, cowpea, and chickpea increased as the digestion phase progressed. In four types of legumes, raffinose slightly decreased or showed no significant difference between the Oral phase and the BBMV phase. Content of glucose, a monosaccharide, increased during the BBMV phase. During the digestion phase, levels of free amino acids and free fatty acids also increased. Content of resistant starch was reduced compared to that in the raw material. It was 0.01g/100 g food in soybean, 1.06 g/100 g food in red kidney bean, 0.77g/ 100g food in cowpea, and 0.76 g/100 g food in chickpea. It was confirmed that nutrients in the in vitro digestion model were liberated at each digestion phase with changes in the content of resistant starch. These results are expected to be used as fundamental data for obtaining bioavailability of nutrients.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.2
• /
• pp.282-295
• /
• 2005

The processing of dietary lipids can be distinguished in several sequential steps, including their emulsification, hydrolysis and micellization, before they are absorbed by the enterocytes. Emulsification of lipids starts in the stomach and is mediated by physical forces and favoured by the partial lipolysis of the dietary lipids due to the activity of gastric lipase. The process of lipid digestion continues in the duodenum where pancreatic triacylglycerol lipase (PTL) releases 50 to 70% of dietary fatty acids. Bile salts at low concentrations stimulate PTL activity, but higher concentrations inhibit PTL activity. Pancreatic triacylglycerol lipase activity is regulated by colipase, that interacts with bile salts and PTL and can release bile salt mediated PTL inhibition. Without colipase, PTL is unable to hydrolyse fatty acids from dietary triacylglycerols, resulting in fat malabsorption with severe consequences on bioavailability of dietary lipids and fat-soluble vitamins. Furthermore, carboxyl ester lipase, a pancreatic enzyme that is bile salt-stimulated and displays wide substrate reactivities, is involved in lipid digestion. The products of lipolysis are removed from the water-oil interface by incorporation into mixed micelles that are formed spontaneously by the interaction of bile salts. Monoacylglycerols and phospholipids enhance the ability of bile salts to form mixed micelles. Formation of mixed micelles is necessary to move the non-polar lipids across the unstirred water layer adjacent to the mucosal cells, thereby facilitating absorption.

• Transactions of the Korean hydrogen and new energy society
• /
• v.27 no.5
• /
• pp.533-539
• /
• 2016

This study was performed to evaluate the characteristics of start-up of anaerobic digestion from food waste with different inoculum ratios. The hydrogen yield was similar with different inoculum ratios. The hydrogen production rate increased with increasing inoculum ratio. But the specific hydrogen production rate decreased with increasing inoculum ratio. Total volatile fatty acids composition analysis showed that butyrate and acetate were the prevalent products in all reactors, followed by lactate and propionate. The acetate was most prevalent product in reactors at $X_0/S_0=0.080$ and 0.159. But in reactors at $X_0/S_0=0.239$ and 0.318, butyrate accounted for greater than 50% of the total volatile fatty acids.