• Korean journal of food and cookery science
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• v.33 no.2
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• pp.181-189
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• 2017

Purpose: This study was conducted to examine the effects of the starch concentration of filled hydrogel and the addition of ${\alpha}-amylase$ and simulated mastication processing in an oral phase on lipid digestion and ${\beta}-carotene$ bioaccessibility of filled hydrogels. Methods: Lipid digestion and ${\beta}-carotene$ bioaccessibility of the filled hydrogels were measured after the samples were passed through an in vitro gastrointestinal tract model consisting of oral, gastric, and small intestinal phases. Results: The initial rate and final extent of lipid digestion were higher in the filled hydrogels than in the emulsion when the filled hydrogels were treated in an oral phase without simulated mastication processing and addition of ${\alpha}-amylase$, regardless of starch concentration. However, when the filled hydrogels were minced using mortar and pestle for 2 min and were exposed to ${\alpha}-amylase$, the filled hydrogel fabricated with 5% starch showed the lowest lipid digestion rate and extent compared to the emulsion and other filled hydrogels. Bioaccessibility of ${\beta}-carotene$ was higher in the filled hydrogels than in the emulsion, regardless of the digestion method performed in an oral phase and starch concentration. However, there were appreciable differences in bioaccessibility of the filled hydrogels depending on whether or not simulated mastication and addition of ${\alpha}-amylase$ were employed. Conclusion: These results suggested that the rheological properties of initial filled hydrogels and simulated mastication processing in an oral phase plays an important role in determining the lipid digestion and ${\beta}-carotene$ bioacccessibility entrapped within filled hydrogels.

• Preventive Nutrition and Food Science
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• v.15 no.4
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• pp.249-254
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• 2010

We examined the effect of extracts of meju prepared with traditional and standardized methods on pancreatic lipase and the absorption of dietary lipid. Aqueous methanolic (80%, v/v) extracts of meju dose-dependently inhibited the activities of porcine pancreatic lipase. The plasma triglyceride levels in Imprinting Control Region mice after a single oral administration of lipid emulsion containing aqueous methanolic extracts from meju made by the standardized methods were lower than that of the group given a lipid emulsion containing the extracts of meju made by traditional methods. The inhibitory activity of the meju extract on dietary lipid digestion appears to be more closely associated with aglycone forms of phenolic compounds such as free isoflavones than with glycosides, since meju samples with higher total phenolic or free isoflavone content showed the stronger inhibition against pancreatic lipase. Furthermore, the data suggest that meju made using the standardized method, which contains higher levels of total isoflavones relative to traditionally prepared meju, could effectively suppress digestion of dietary lipids and therefore have the potential to help ameliorate hyperlipidemia and obesity.

• Food Science of Animal Resources
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• v.34 no.3
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• pp.280-286
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• 2014

This study investigated the effects of cooking methods on the digestibility of lipids and formation of cholesterol oxidation products (COPs) in pork, during in vitro human digestion. Pork patties were cooked using four different methods (oven cooking, pan frying, boiling, and microwaving), to an internal temperature of approximately $85^{\circ}C$. The digestibility of pork patties were then evaluated, using the in vitro human digestion model that simulated the composition (pH, minerals, surfaceactive components, and enzymes) of digestive juices in the human mouth, stomach, and small intestine. The total lipid digestibility was higher after microwave cooking, whereas pan-frying resulted in lower in vitro digestibility, compared to the other cooking methods. The microwaving method followed by in vitro digestion also showed significantly higher content of free fatty acids and thiobarbituric acid reactive substances (TBARS), compared to the other cooking methods; whereas, the pan frying and boiling methods showed the lowest. Cholesterol content was not significantly different among the cooked samples before, and after in vitro human digestion. The formation of COPs was significantly higher in the microwave-treated pork samples, compared to those cooked by the other methods, which was consistent with the trend for lipid peroxidation (TBARS). We propose that from the point of view of COPs formation and lipid oxidation, the pan-frying or boiling methods would be useful.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.2
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• pp.176-181
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• 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
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• v.18 no.2
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• pp.282-295
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• 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.

• Applied Chemistry for Engineering
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• v.32 no.5
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• pp.487-496
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• 2021

Microalgae is one of the promising biodiesel feedstock with high growth rates compared to those of terrestrial oil crops. Despite its numerous advantages, biodiesel production from microalgae needs to reduce energy demand and material costs further to go to commercialization. During solvent extraction of microalgal lipids, lipid-extracted algae (LEA) cell residue is generated as an organic solid waste, about 80-85% of original algal biomass, and requires an appropriate recycling or economic disposal. The resulting LEA still contains significant amount of carbohydrates, proteins, N, P, and other micronutrients. This review will focus on recent advancement in the utilization of LEA as: (i) utilization as nutrients or carbon sources for microalgae and other organisms, (ii) anaerobic digestion to produce biogas or co-fermentation to produce CH₄ and H₂, and (iii) conversion to other forms of biofuel through thermochemical degradation processes. Possible mutual benefits in the integration of microalgae cultivation-biodiesel production-resulting LEA with anaerobic digestion and thermochemical conversion are also discussed.

• Preventive Nutrition and Food Science
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• v.22 no.2
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• pp.107-117
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• 2017

The purpose of this study was to evaluate the antioxidant and anticholinesterase activities of yellow and white bitter yams from South Western Nigeria using methanolic extraction and simulated gastrointestinal digestion models. The phenolic compounds in the bitter yam varieties were evaluated by high performance liquid chromatography with a diode array detector (HPLC-DAD). The total phenolic content of the bitter yams was measured by the Folin-Ciocalteu method, reductive potential by assessing the ability of the bitter yam to reduce $FeCl_3$ solution, and the antioxidant activities were determined by the 2,2-diphenyl-1-picrylhydrazyl radical ($DPPH^{\cdot}$) scavenging activity, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation ($ABTS^{{\cdot}+}$) scavenging activity, nitric oxide radical ($NO^{\cdot}$) scavenging ability, hydroxyl radical scavenging ability, and ability to inhibit $Fe^{2+}$-induced lipid oxidation. The HPLC-DAD analysis revealed the presence of some phenolic compounds in the studied bitter yam varieties, with varying degree of quantitative changes after cooking. The antioxidant indices (total phenolic content, total flavonoid content, reducing power, $DPPH^{\cdot}$ scavenging activity, $ABTS^{{\cdot}+}$ scavenging activity, and $NO^{\cdot}$ scavenging activity) were higher in the simulated gastrointestinal digestion model compared to the methanolic extract, with the in vitro digested cooked white bitter yam ranking higher. Similarly, the in vitro digested yams had a higher inhibitory action against lipid oxidation compared to the methanolic extracts, with the cooked white bitter yam ranking high. The methanolic extracts and in vitro enzyme digests showed no acetylcholinesterase inhibitory abilities, while methanolic extracts and the in vitro enzyme digest displayed some level of butyrylcholinesterase inhibitory activities. Therefore the studied bitter yams could be considered as possible health supplements.

• Journal of the Korean Society of Food Science and Nutrition
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• v.3 no.1
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• pp.43-46
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• 1974

It was reported that the digestion ratio of chlorella was low because it had a low metabolic rate in body. Generally, the thickness of a cell membrane of it is $200-250\;{\AA}$, the weight of it is approximatly 13% of the total weight of a dry cell. And it is composed of protein, lipid, hemicellulose and ash etc. So, in order to elevate the digestion ratio of chlorella in body, we experimented the crude treatment methods of chlorella. The results obtained in this experiment are summarized as follows : 1. The digestion ratios calculated from ordinary N- balance method were 83.05% for 10% chl. (b) plus diastase group ; 81.25% for 10% chl. (b) plus amylase group, and 79.23% for 10% chl. (b), 58.55% for 10% chl. (a). 2. Biological values from this method were 80.25% for 10% chl. (b) plus diastase group, and 60% for 10% for chlorella(a).

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.533-541
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• 2016

Effect of polyphenols-rich cacao extract (CE) on lipid hydrolysis by pancreatic lipase was investigated by pH-stat digestion. Two types of substrate (oil vs. emulsion) prepared from soybean oil and CE were studied as types I and II. In the case of type I, addition of CE did not show retardation of lipid hydrolysis, showing that pancreatic lipase was not inhibited. Final digestibility rate (${\Phi}$ max, %) and initial rate (mM/s) of the 24-h aged control (52.31%, 0.03 mM/s) were similar to those of the CE-added sample (58.88%, 0.03 mM/s). However, in the case of typeII, the hydrolysis rates of the control and CE-added emulsion showed distinct differences as aging time increased to 43 days, showing lower digestion in the CE-added emulsion than the control. After 43 days, ${\Phi}$ max values of the control and CE-added emulsion were 92.13% and 77.68%, respectively.

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.179-186
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• 2010

In biological wastewater treatment, high lipid concentrations can inhibit the activity of microorganisms critical to the treatment process and cause undesirable biomass flotation. To reduce the inhibitory effects of high lipid concentrations, a two-phase anaerobic system, consisting of an anaerobic sequencing batch reactor (ASBR) and an upflow anaerobic sludge blanket (UASB) reactor in series, was applied to synthetic dairy wastewater treatment. During 153 days of operation, the two-phase system showed stable performance in lipid degradation. In the ASBR, a 13% lipid removal efficiency and 10% double-bond removal efficiency were maintained. In the UASB, the chemical oxygen demand (COD), lipid, and volatile fatty acid (VFA) removal efficiencies were greater than 80%, 70%, and 95%, respectively, up to an organic loading rate of 6.5 g COD/l/day. No serious operational problems, such as significant scum formation or sludge washout, were observed. Protein degradation was found to occur prior to degradation during acidogenesis.