Liver and serum metabolites of obese and lean mice fed on high fat or normal diets were analyzed using ultraperformance liquid chromatography-quadrupole-time-of-flight mass spectrometry, gas chromatography-mass spectrometry, and partial least-squares-discriminant analysis (PLS-DA). Obese and lean groups were clearly discriminated from each other on PLS-DA score plot and major metabolites contributing to the discrimination were assigned as lipid metabolites (fatty acids, phosphatidylcholines (PCs), and lysophosphatidylcholines (lysoPCs)), lipid metabolism intermediates (betaine, carnitine, and acylcarnitines), amino acids, acidic compounds, monosaccharides, and serotonin. A high-fat diet increased lipid metabolites but decreased lipid metabolism intermediates and the NAD/NADH ratio, indicating that abnormal lipid and energy metabolism induced by a high-fat diet resulted in fat accumulation via decreased β-oxidation. In addition, this study revealed that the levels of many metabolites, including serotonin, betaine, pipecolic acid, and uric acid, were positively or negatively related to obesity-associated diseases. On the basis of these metabolites, we proposed a metabolic pathway related to high-fat diet-induced obesity. These metabolites can be used to better understand obesity and related diseases induced by a hyperlipidic diet. Furthermore, the level changes of these metabolites can be used to assess the risk of obesity and the therapeutic effect of obesity management.

The processes of degumming, alkali refining, bleaching and deodorization removed 99.8% phospholipids, 90.7% iron, 100% chlorophyll, 97.3% free fatty acids and 31.8% tocopherols from crude soybean oil. The correlation coefficient between the removals of phosphorus and iron in soybean oil during processing was r = 0.99. The relative ratios of α‐, β ‐, γ‐ and δ‐tocopherols in crude oil, degummed oil, refined oil, bleached oil and deodorized soybean oil were almost constant, γ‐ and δ ‐tocopherols represented more than 94% of tocopherols in soybean oil. The order of oxidation stability of oil is crude > deodorized > degummed > refined > bleached oil.

A reduced life span is an outcome associated with many prevalent diseases, including diabetes, obesity, and high blood pressure. In seeking to prevent these diseases, many researchers have looked into potential therapeutic benefits of naturally occurring compounds. AMP-activated protein kinase (AMPK) is a major metabolic-sensing protein implicated in the prevention of metabolic disorders, or in minimizing the effects thereof, via the regulation of both upstream and downstream target molecules. In the field of food and nutrition, the current focus lies in the finding of components that activate AMPK. AMPK is a serine/threonine protein kinase and is activated by several natural compounds, including resveratrol, epigallocatechin gallate, berberine, and quercetin. AMPK activation can induce ATP (adenosine triphosphate) generation through pathways such as glycolysis and beta-oxidation. By contrast, ATP-consuming pathways, including fatty acid and cholesterol syntheses, and gluconeogenesis, are suppressed by AMPK activation. In this review, we will discuss how the activation of AMPK by naturally occurring compounds could help to prevent the development of numerous diseases; the potential mechanism underlying these effects will also be addressed.

The light-induced off-flavor and dimethyl disulfide increased as fluorescent light exposure increased from 0, 2, 4, 6, to 8h (PϽ0.05). Sensory evaluation and identified compounds suggest that dimethyl disulfide was mainly responsible for the light-induced off-flavor in skim milk. Dimethyl disulfide was formed by the singlet oxygen oxidation of methionine in milk. Gas chromatographic analysis and sensory evaluation showed that 200, 500, and 1000 ppm ascorbic acid, which is a singlet oxygen quencher, lowered the formation of dimethyl disulfide and off-flavor in skim milk (PϽ0.05).

The characterization and quantification of anthocyanins in grape cultivars of Oll‐Meoru (Vitis coignetiae×Vitis labrusca), Neut‐Meoru (Vitis coignetiae×Vitis labrusca), Muscal Bailey A. (Vitis labruscana), and Campbell Early (Vitis labrusca×V. vinifera) cultivated in Korea were carried out by partial purification through XAD‐7 column chromatography followed by C‐18 HPLC/diode array detector (DAD), HPLC/MS, and HPLC/MS/MS analyses. The column oven temperature during the reverse phase C‐18 HPLC greatly affected the separation of individual anthocyanins. The result showed that the optimum column oven temperature was 35 °C. Sixteen different anthocyanins (11 nonacylated and 5 acylated anthocyanins) were identified in the grape juices. Oll‐Meoru, Neut‐Meoru, and Muscat Bailey A (MBA) grape juices contained only nonacylated anthocyanins. Oll‐Meoru and Neut‐Meoru grape juices had same anthocyanins, but their proportions were considerably different. Peonidin 3,5‐diglucoside and malvidin 3,5‐diglucoside were the major anthocyanins in Oll‐Meoru grape juice. Delphinidin 3‐glucoside was, however, the major anthocyanin in Neut‐Meoru grape juice. Peonidin 3‐glucoside and malvidin 3‐glucoside were the most abundant anthocyanins in Muscal Bailey A grape juice. Campbell Early grape juice contained both nonacylated and acylated anthocyanins. Cyanidin 3‐(p‐coumaroyl)glucoside‐5‐glucoside and peonidin 3‐(p‐coumaroyl)glucoside‐5‐glucoside were the most abundant anthocyanins in Campbell Early grape juice. Total anthocyanin contents were greatly different in different grape jucies, with the highest in Neut‐Meoru juice (1043.5 μg/mL), followed by Oll‐Meoru (997.7 μg/mL), MBA (390.2 μg/mL), and Campbell Early (183.9 μg/mL) juices. The total anthocyanin content in Neut‐Meoru grape juice was 5.67 times higher than that in Campbell Early grape juice. This represents the 1st report on the systematic characterization and quantification of anthocyanins in the juices of these grapes cultivated in Korea.

Manipulating the surface characteristics of metal oxide electrodes allows the properties of the interface between electrodes and the electrolyte to be controlled and can lead to improvements in both efficiency and reliability of the electrodes.

Soybean oil purified by silicic acid column chromatography did not contain peroxides, free fatty acids, phospholipids or oxidized polar compounds. The purified soybean oil was thermally oxidized at 180°C for 96 hr in the presence of air. The thermally oxidized compounds (31.3%) were separated from the purified soybean oil by gradient elution silicic acid chromatography. Thermally oxidized compounds contained hydroxyl groups, carbonyl groups andtrans double bonds according to the infrared spectrum. Thermally oxidized compounds were added to soybean oil and purified soybean oil at 0, 0.5, 1.0, 1.5 and 2.0% to study the effects of these compounds on the oxidative stability of oil. The oxidative stabilities of oils were determined by gas chromatographic analysis of volatile compound formation and molecular oxygen disappearance in the headspace of oil bottles. The thermally oxidized compounds showed prooxidant effects on the oxidative stabilities of both refined, bleached and deodorized soybean oil and purified soybean oil. Duncan's Multiple Range Test showed that thermally oxidized compounds had a significant effect on the volatile compound formatiion and oxygen disappearance in the headspace of oil at α=0.05.

The effects of hydrogen temperature and agitation rate on the formation of total conjugated linoleic acids (CLA) and CLA isomers were studied during hydrogenation with a selective Ni catalyst. The CLA isomers were identified by using a 100-m cyano-capillary column gas chromatograph and a silver ion-impregnated HPLC. Reaction temperature and agitation rate greatly affected the quantities of total CLA and individual CLA isomers, and the time to reach the maximum quantity of CLA in the partially hydrogenated soybean oil. As the hydrogenation temperature increased, the maximum quantity of CLA in soybean oil increased, but the time to reach the maximum CLA content decreased. By increasing the hydrogenation temperature from 170 to 210 degrees C, the quantity of CLA obtained was about 2.6 times higher. As the agitation rate decreased, the CLA formation in soybean oil increased, and the time to reach the maximum CLA content also increased. The maximum CLA contents in soybean oil obtained during hydrogenation at 210 degrees C with agitation rates of 300, 500, and 700 rpm were 162.82, 108.62, and 66.15 mg total CLA/g oil, respectively. The present data showed that it is possible to produce high-CLA-content soybean oil without major modification of fatty acid composition by short-time (10 min) selective hydrogenation under high temperature and low agitation rate conditions.