Physicochemical Properties and Volatile Organic Compounds of Dairy Beef Round Subjected to Various Cooking Methods.

To evaluate the effect of different cooking methods on the physicochemical quality and volatile organic compounds (VOC) of dairy beef round, twelve beef round pieces were divided into four groups: raw, boiling, microwave, and sous-vide. The sous-vide group had a higher pH than the boiling or microwave groups. The boiling group exhibited the highest shear force and CIE L*, followed by the microwave and sous-vide groups (p<0.05). The sous-vide group received higher taste and tenderness scores from panelists (p<0.05) and showed significantly higher levels of aspartic and glutamic acids than the other groups. The sous-vide and microwave groups had the highest oleic acid and polyunsaturated fatty acid levels, respectively. The sous-vide group had significantly higher hypoxanthine and inosine levels than the other groups. However, the microwave group had higher inosine monophosphate levels than the other groups. The sous-vide group had a higher alcohol content, including 1-octen-3-ol, than the other groups. Octanal and nonanal were the most abundant aldehydes in all groups. (R)-(-)-14-methyl-8-hexadecyn-1-ol, p-cresol, and 1-tridecyne were used to distinguish the VOC for each group in the multivariate analysis. Sous-vide could be effective in increasing meat tenderness as well as taste-related free amino acid (aspartic acid and glutamic acid) and fatty acid (oleic acid) levels. Furthermore, specific VOC, including 1-octen-3-ol, 2-ethylhexanal ethylene glycol acetal, and 2-octen-1-ol, (E)-, could be potential markers for distinguishing sous-vide from other cooking methods. Further studies are required to understand the mechanisms underlying the predominant association of these VOC with the sous-vide cooking method.

Microencapsulation of Caramel Flavor and Properties of Ready-to-drink Milk Beverages Supplemented with Coffee Containing These Microcapsules.

This study aimed to extend the retention of flavor in coffee-containing milk beverage by microencapsulation. The core material was caramel flavor, and the primary and secondary coating materials were medium-chain triglyceride and maltodextrin, respectively. Polyglycerol polyricinoleate was used as the primary emulsifier, and the secondary emulsifier was polyoxyethylene sorbitan monolaurate. Response surface methodology was employed to determine optimum microencapsulation conditions, and headspace solid-phase microextraction was used to detect the caramel flavor during storage. The microencapsulation yield of the caramel flavor increased as the ratio of primary to secondary coating material increased. The optimum ratio of core to primary coating material for the water-in-oil (W/O) phase was 1:9, and that of the W/O phase to the secondary coating material was also 1:9. Microencapsulation yield was observed to be approximately 93.43%. In case of in vitro release behavior, the release rate of the capsules in the simulated gastric environment was feeble; however, the release rate in the simulated intestinal environment rapidly increased within 30 min, and nearly 70% of the core material was released within 120 min. The caramel flavor-supplemented beverage sample exhibited an exponential degradation in its flavor components. However, microcapsules containing flavor samples showed sustained flavor release compared to caramel flavor-filled samples under higher storage temperatures. In conclusion, the addition of coffee flavor microcapsules to coffee-containing milk beverages effectively extended the retention of the coffee flavor during the storage period.

Antioxidant Activity of Yogurt Fermented at Low Temperature and Its Anti-inflammatory Effect on DSS-induced Colitis in Mice.

This study was performed to evaluate the antioxidant activity of yogurt fermented at low temperature and the anti-inflammatory effect it has on induced colitis with 2.5% dextran sodium sulfate (DSS) in Balb/c mice. Yogurt premix were fermented with a commercial starter culture containing Lactobacillus acidophilus, Bifidobacterium lactis, Streptococcus thermophilus, and Lactobacillus delbrueckii subsp. bulgaricus at different temperatures: 22°C (low fermentation temperature) for 27 h and 37°C (general fermentation temperature) for 12 h. To measure antioxidant activity of yogurt samples, DPPH, ABTS+ and ferric reducing antioxidant potential (FRAP) assays were conducted. For animal experiments, inflammation was induced with 2.5% DSS in Balb/c mice. Yogurt fermented at low temperature showed higher antioxidant activity than that of the yogurt fermented at general temperature. In the inflammatory study, IL-6 (interleukin 6) was decreased and IL-4 and IL-10 increased significantly in DSS group with yogurt fermented at general temperature (DYG) and that with yogurt fermented at low temperature (DYL) compared to that in DSS-induced colitic mice (DC), especially DYL had higher concentration of cytokines IL-4, and IL-10 than DYG. MPO (myeloperoxidase) tended to decrease more in treatments with yogurt than DC. Additionally, yogurt fermented at low temperature had anti-inflammatory activity, although there was no significant difference with general temperature-fermented yogurt (p>0.05).

Effect of Antioxidant Addition on Milk Beverage Supplemented with Coffee and Shelf-life Prediction.

This study aimed to extend the shelf-life of coffee-containing milk beverage by adding Theobroma cacao (cacao nibs) extract. To prepare the beverage sample containing cacao nibs extract, 0.8% cacao nibs hydrothermal extract was aseptically injected. Qualitative changes in the beverage samples, including antioxidant effect, peroxide value (POV), caffeine content, and sensory parameters were monitored regularly during storage at 10°C, 20°C, and 30°C for 4 wk. The inclusion of cacao nibs extract produced higher antioxidant activity compared to the control. As the storage temperature increased, the POV of all samples increased. Samples with cacao nibs extract generally displayed lower POV than the control. The caffeine content of all samples tended to decrease during storage, with the decrease accentuated by higher storage temperatures. In the shelf-life prediction using the Arrhenius model, the kinetic regressions of the cacao nibs extract-added sample and control were Y POV=1.2212X-2.1141 (r2=0.9713) and Y POV=1.8075X-2.0189 (r2=0.9883), respectively. Finally, the predicted shelf-life of cacao nibs-added group and control to reach the quality limit (20 meq/kg POV) were approximately 18.11 and 12.18 wk, respectively. The results collectively indicate that the addition of cacao nibs extract extends the shelf-life of the coffee-containing milk beverage and heightened the antioxidant effect.

Comparison of Allergic Parameters between Whey Protein Concentrate and Its Hydrolysate in Rat Basophilic Leukemia (RBL)-2H3 Cells.

This study was conducted to compare the anti-allergic effects of a whey protein concentrate (WPC) and WPC hydrolysate. WPC hydrolysate was prepared using enzymatic digestion for 8 h with trypsin and α-chymotrypsin, after which it was freeze-dried. The allergic parameters assessed in rat basophilic leukemia (RBL)-2H3 cells were degranulation and release of ß-hexosaminidase, release of tumor necrosis factor (TNF)-α, and changes in the expression of IL-1ß, IL-4, and IL-10 by real time polymerase chain reaction (PCR). During preparation of the WPC hydrolysate, hydrolysis increased rapidly from 0 to 10 min and then gradually increased slowly from 1 h onwards, achieving a final degree of hydrolysis of 78.50%. The SDS-PAGE analysis revealed a reduction in the intensity of several protein bands in the WPC hydrolysate compared to the WPC. IgE-induced ß-hexosaminidase release from RBL-2H3 cells was decreased to a higher degree following treatment with the hydrolysate compared to WPC treatment. W500 (500 µg/mL WPC) showed the least inhibition of ß-hexosaminidase release, but there was no significant difference between W500 and W1000 (1,000 µg/mL) (p<0.05). H1000 (1,000 µg/mL WPC hydrolysate) inhibited ß-hexosaminidase release by 39%. Compared to the control, treatment with H1000 decreased TNF-α secretion to 11.87 pg/mL. The gene expression levels of IL-1ß, IL-4, and IL-13 were all significantly decreased in hydrolysate (p<0.05). In the case of IL-1ß and IL-4, the expression levels in W1000 treated cells were decreased by 73.67% and 65%, respectively, and that of IL-13 was decreased by 66.43% compared to the control.

Qualitative Characteristics and Determining Shelf-Life of Milk Beverage Product Supplemented with Coffee Extracts.

This study was conducted to establish the shelf-life of a milk beverage product supplemented with coffee extracts. Qualitative changes including peroxide value (PV), microorganism content, caffeine content, and sensory evaluation were measured periodically in beverages kept at 10, 20, and 30°C for 8 wk. Lipid oxidation of the product was measured by peroxide value analysis, and apparent changes were observed during a 4 wk storage period. Caffeine analysis revealed that the changes in caffeine content were negligible during the storage period. Total aerobic bacteria, Escherichia coli, yeast, and mold were not detected in the products during an 8 wk storage period. Sensory evaluation revealed that after 4 wk of storage overall acceptance was less than 3 points on a 5-point scale. In this study, PV was used as an indicator of the shelf-life of the milk beverage product. PV analysis revealed that a value of 20 meq/kg was the end of the shelf-life using the Arrhenius equation and the accelerated shelf-life test (ASLT). Assuming that the beverages are kept at 4°C during distribution, calculation of when the PV reached the quality limit point (20 meq/kg) was done with the equation ln(PV) = 0.3644X - 2.21834 and, using that equation, PV = e0.3644X-2.21834 was calculated. Therefore, 14.3086 wk was determined to be the shelf-life of the milk beverage supplemented with coffee when stored at 4°C.

Optimization of Manufacturing Conditions for Improving Storage Stability of Coffee-Supplemented Milk Beverage Using Response Surface Methodology.

This study aimed at optimizing the manufacturing conditions of a milk beverage supplemented with coffee, and monitoring its physicochemical and sensory properties during storage. Raw milk, skim milk powder, coffee extract, and emulsifiers were used to manufacture the beverage. Two sucrose fatty acid esters, F110 and F160, were identified as suitable emulsifiers. The optimum conditions for the beverage manufacture, which can satisfy two conditions at the same time, determined by response surface methodology (RSM), were 5,000 rpm primary homogenization speed and 0.207% sucrose fatty acid emulsifier addition. The particle size and zeta-potential of the beverage under the optimum condition were 190.1 nm and - 25.94±0.06 mV, respectively. In comparison study between F110 added group (GF110) and F160 added group (GF160) during storage, all samples maintained its pH around 6.6 to 6.7, and there was no significant difference (p<0.05). In addition, GF110 showed significantly higher zeta-potential than GF160 (p<0.05). The particle size of GF110 and GF160 were approximately 190.1 and 223.1 nm, respectively at initial. However, size distribution of the GF160 tended to increase during storage. Moreover, increase of the particle size in GF160 was observed in microphotographs of it during storage. The L* values gradually decreased within all groups, whereas the a* and b* values did not show significant variations (p<0.05). Compared with GF160, bitterness, floating cream, and rancid flavor were more pronounced in the GF110. Based on the result obtained from the present study, it appears that the sucrose fatty acid ester F110 is more suitable emulsifier when it comes to manufacturing this beverage than the F160, and also contributes to extending product shelf-life.

Effects of Germinated Brown Rice Addition on the Flavor and Functionality of Yogurt.

This study aimed to investigate the functional and physicochemical properties of yogurt, supplemented with germinated brown rice (GBR) containing γ-aminobutyric acid (GABA), during storage. GBR was produced by soaking brown rice at 30℃, and saccharified germinated brown rice (SGBR) was produced by treating brown rice with α- and ß-amylase for 1 h, at 80℃ and 60℃, respectively. Yogurt was manufactured using a commercial starter (YC-X11, CHR. Hansen, Denmark) at 37℃ for 12 h. The fatty acids and GABA contents were analyzed using GC and HPLC, respectively. The fatty acids in the cereal samples consisted of oleic, linoleic, and palmitic acid. The portion of oleic acid was the highest, at 35.65% in GBR, and 32.16% in SGBR. During germination, the oleic acid content increased, whereas linolenic and palmitic acid contents from GBR tended to decrease. Although the portion of saturated fatty acids, such as stearic and myristic acid, decreased significantly (p<0.05), that of unsaturated fatty acids, such as oleic and linoleic acid, increased with an increase in supplementation of BR, GBR, or SGBR in the yogurt. The yogurt, supplemented with cereal samples, showed a tendency of an increase in the concentration of GABA with an increase in the supplementation of the cereal samples. However, yogurt supplemented with GBR showed the highest concentration of GABA, regardless of the supplementation of the cereal samples. These results indicated that yogurt supplemented with BR, GBR, or SGBR could be a promising dairy product.

Effect of acetone extract from stem bark of Acacia species (A. dealbata, A. ferruginea and A. leucophloea) on antioxidant enzymes status in hydrogen peroxide-induced HepG2 cells.

Acacia species are multipurpose trees, widely used in the traditional systems of medicine to treat various ailments. The major objective of the present study was to determine the gene expression of enzymatic antioxidants by acetone extract from the stem bark of three Acacia species (Acacia dealbata, Acacia ferruginea and Acacia leucophloea) in hydrogen peroxide (H2O2)-induced human hepatoma (HepG2) cells. The expression of antioxidant enzymes such as superoxide dismutase containing copper-zinc (CuZnSOD)/manganese (MnSOD), catalase (CAT) and glutathione peroxidase (GPx) in HepG2 cells was evaluated by real-time PCR. The results of antioxidant enzyme expression in real-time PCR study revealed that the H2O2 (200 µM) challenged HepG2 cells reduced the expression of enzymes such as SOD, GPx and CAT. However, the cells pre-treated with acetone extracts of all the three Acacia species significantly (P > 0.05) up-regulated the expression of antioxidant enzymes in a concentration dependent manner (25, 50 and 75 µg/mL). In conclusion, the findings of our study demonstrated that the acetone extract of Acacia species effectively inhibited H2O2 mediated oxidative stress and may be useful as a therapeutic agent in preventing oxidative stress mediated diseases.

Effect of yogurt containing deep sea water on health-related serum parameters and intestinal microbiota in mice.

Deep sea water (DSW) has health benefits and is widely used as food supplement; however, its effect in fermented products has not been explored. Here, we investigated the effect of DSW-containing yogurt on health-related serum parameters and intestinal microbiota in mice. Animals were assigned to 3 feeding groups, which received water (control), normal yogurt (N-yogurt), or DSW-containing yogurt (DSW-yogurt) with a basal diet. Mice were killed at wk 4 or 8 of feeding and analyzed for serum parameters and microbial population in the small intestine. Both yogurt groups demonstrated increased populations of intestinal lactic acid bacteria compared with the control group. The activity of serum aspartate aminotransferase and alanine aminotransferase was markedly decreased in the DSW-yogurt and N-yogurt groups, and triglyceride level tended to be lower in the DSW-yogurt group compared with that in the control mice. Furthermore, the DSW-yogurt group showed a more significant decrease in the ratio of total cholesterol to high-density lipoprotein-cholesterol than did the N-yogurt group. These findings suggest that DSW supplementation of yogurt can increase its beneficial effects on lipid metabolism.

Antioxidant, inhibition of α-glucosidase and suppression of nitric oxide production in LPS-induced murine macrophages by different fractions of Actinidia arguta stem.

In traditional systems of medicine, fruits, leaves, and stems of Actinidia arguta (Sieb. et Zucc.) Planch. ex Miq. have been used to treat various inflammatory diseases. The present study determined the proximate composition, antioxidant, anti-inflammatory, and hypoglycemic potential of A. arguta stem. Phenolic composition of hot water extract and its sub-fractions was determined by Folin-Ciocalteu's reagent method. In vitro antioxidant activities of the samples were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging assays. Anti-inflammatory activity of different fractions was investigated through the inhibition of nitric oxide (NO) production in lipopolysaccharide (1 µg/ml) stimulated RAW 264.7 cells. In addition, inhibition of α-glucosidase activity of hot water extract was determined using p-nitrophenyl-α-d-glucopyranoside (pNPG) as a substrate. Ethyl acetate (557.23 mg GAE/g) fraction contains higher level of total phenolic content. The antioxidant activity evaluated by DPPH radical scavenging assay showed a strong activity for ethyl acetate (IC50 of 14.28 µg/ml) and n-butanol fractions (IC50 of 48.27 µg/ml). Further, ethyl acetate fraction effectively inhibited NO production in RAW 264.7 cells induced by lipopolysaccharide (LPS) than other fractions (nitrite level to 32.14 µM at 200 µg/ml). In addition, hot water extract of A. arguta stem exhibited appreciable inhibitory activity against α-glucosidase enzyme with IC50 of 1.71 mg/ml. The obtained results have important consequence of using A. arguta stem toward the development of effective anti-inflammatory drugs.

Inhibition of nitric oxide production in LPS-stimulated RAW 264.7 cells by stem bark of Ulmus pumila L.

This study was designed to isolate and identify a potent inhibitory compound against nitric oxide (NO) production from the stem bark of Ulmus pumila L. Ethyl acetate fraction of hot water extract registered a higher level of total phenolics (756.93 mg GAE/g) and also showed strong DPPH (IC50 at 5.6 µg/mL) and ABTS (TEAC value 0.9703) radical scavenging activities than other fractions. Crude extract and its fractions significantly decreased nitrite accumulation in LPS-stimulated RAW 264.7 cells indicating that they potentially inhibited the NO production in a concentration dependent manner. Based on higher inhibitory activity, the ethyl acetate fraction was subjected to Sephadex LH-20 column chromatography and yielded seven fractions and all these fractions registered appreciable levels of inhibitory activity on NO production. The most effective fraction F1 was further purified and subjected to (1)H, (13)C-NMR and mass spectrometry analysis and the compound was identified as icariside E4. The results suggest that the U. pumila extract and the isolated compound icariside E4 effectively inhibited the NO production and may be useful in preventing inflammatory diseases mediated by excessive production of NO.

In vitro cytotoxicity of nonpolar constituents from different parts of kava plant (Piper methysticum).

Kava (Piper methysticum), a perennial shrub native to the South Pacific islands, has been used to relieve anxiety. Recently, several cases of severe hepatotoxicity have been reported from the consumption of dietary supplements containing kava. It is unclear whether the kava constituents, kavalactones, are responsible for the associated hepatotoxicity. To investigate the key components responsible for the liver toxicity, bioassay-guided fractionation was carried out in this study. Kava roots, leaves, and stem peelings were extracted with methanol, and the resulting residues were subjected to partition with a different polarity of solvents (hexane, ethyl acetate, n-butanol, and water) for evaluation of their cytotoxicity on HepG2 cells based on the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and lactate dehydrogenase and aspartate aminotransferase enzyme leakage assays. Organic solvent fractions displayed a much stronger cytotoxicity than water fractions for all parts of kava. The hexane fraction of the root exhibited stronger cytotoxic effects than fractions of root extracted with other solvents or extracts from the other parts of kava. Further investigations using bioassay-directed isolation and analysis of the hexane fraction indicated that the compound responsible for the cytotoxicity was flavokavain B. The identity of the compound was confirmed by (1)H and (13) C NMR and MS techniques.

Molecular cloning and expression of genes encoding a novel dioxygenase involved in low- and high-molecular-weight polycyclic aromatic hydrocarbon degradation in Mycobacterium vanbaalenii PYR-1.

Mycobacterium vanbaalenii PYR-1 is able to metabolize a wide range of low- and high-molecular-weight (HMW) polycyclic aromatic hydrocarbons (PAHs). A 20-kDa protein was upregulated in PAH-metabolizing M. vanbaalenii PYR-1 cells compared to control cultures. The differentially expressed protein was identified as a beta subunit of the terminal dioxygenase using mass spectrometry. PCR with degenerate primers designed based on de novo sequenced peptides and a series of plaque hybridizations were done to screen the M. vanbaalenii PYR-1 genomic library. The genes, designated nidA3B3, encoding the alpha and beta subunits of terminal dioxygenase, were subsequently cloned and sequenced. The deduced enzyme revealed close similarities to the corresponding PAH ring-hydroxylating dioxygenases from Mycobacterium and Rhodococcus spp. but had the highest similarity, 61.9%, to the alpha subunit from Nocardioides sp. strain KP7. The alpha subunit also showed 52% sequence homology with the previously reported NidA from M. vanbaalenii PYR-1. The genes nidA3B3 were subcloned into the expression vector pET-17b, and the enzyme activity in Escherichia coli cells was reconstituted through coexpression with the ferredoxin (PhdC) and ferredoxin reductase (PhdD) genes of the phenanthrene dioxygenase from Nocardioides sp. strain KP7. The recombinant PAH dioxygenase appeared to favor the HMW PAH substrates fluoranthene, pyrene, and phenanthrene. Several other PAHs, including naphthalene, anthracene, and benz[a]anthracene, were also converted to their corresponding cis-dihydrodiols. The recombinant E. coli, however, did not show any dioxygenation activity for phthalate and biphenyl. The upregulation of nidA3B3 in M. vanbaalenii PYR-1 induced by PAHs was confirmed by reverse transcription-PCR analysis.

Stability of black tea polyphenol, theaflavin, and identification of theanaphthoquinone as its major radical reaction product.

In the current study, we have focused on isolation and detection of major radical oxidation products from theaflavin in order to better understand antioxidation mechanisms of this compound. Theanaphthoquinone was identified as a major oxidation product of theaflavin from two different oxidant model systems: DPPH and peroxidase/hydrogen peroxide. This result indicated that the benzotropolone moiety in theaflavin may play an important role in its antioxidant properties. The stability of theaflavin was studied in varying pH solutions: simulated gastric juice and buffer solutions of pH 5.5, pH 7.4, and pH 8.5. The results indicated that theaflavin is unstable in alkaline conditions, while it was stable in acidic conditions. Theanaphthoquinone was identified as an autoxidation product of theaflavin during its stability study in alkaline conditions.

Determination of six kavalactones in dietary supplements and selected functional foods containing Piper methysticum by isocratic liquid chromatography with internal standard.

Kava (Piper methysticum) dietary products have been sold worldwide for treatment of nervous anxiety, tension, and restlessness. Recent reports showed potential association of kava usage and liver injuries. This study was conducted to develop simple and reliable methodologies for the extraction and determination of 6 major kavalactones: (+)-methysticin, (+)-dihydromethysticin, (+)-kavain, (+)-dihydrokavain, yangonin, and desmethoxyyangonin. Ultrasonic extraction techniques and isocratic reversed-phase liquid chromatography (LC) were optimized for different types of samples, including capsules containing kava root extract or root powder, raw root material, tea bags, and snack bar. A suitable internal standard, 5,7-dihydroxyflavone, was used for LC calibration. Kavalactones were completely separated in 30 min using a Luna C18-2 column at 60 degrees C with an isocratic mobile phase consisting of 2-propanol-acetonitrile-water-acetic acid (16 + 16 + 68 + 0.1, v/v/v/v). Within-laboratory, intraday, and interday method variation (% relative standard deviation) for most samples extracted by methanol or methanol-water mixture were <5%. Lower levels of kavalactone contents and higher variations were observed for tea bags from water extraction or infusion as compared to methanol extraction. Labeling information of tea bags based on methanol extraction could be misleading to consumers. Analytical recoveries of snack bar fortified at 10 and 20 microg/g were >84% with RSD values <8%. Methods developed in this study offer a simple and reproducible means for analysis of kavalactones in various matrixes of dietary products.

Characterization of 2-methyl-4-amino-5-(2-methyl-3-furylthiomethyl)pyrimidine from thermal degradation of thiamin.

Thiamin hydrochloride was thermally degraded in phosphate buffer (pH 6.5) at 110 degrees C for 2 h. A major decomposition product was isolated by column chromatography and structurally identified by spectrometric techniques ((1)H NMR, (13)C NMR, 2D NMR, and MS) as 2-methyl-4-amino-5-(2-methyl-3-furylthiomethyl)pyrimidine (MAMP). The possible formation pathway of MAMP was studied using two model systems. It is proposed that MAMP is formed by nucleophilic attack of 2-methyl-3-furanthiol on the thiamin.

Triterpene saponins from debittered quinoa (Chenopodium quinoa) seeds.

Twelve triterpene saponins have been isolated from the debittered seeds of quinoa (Chenopodium quinoa), and their structures were characterized on the basis of hydrolysis and spectral data, especially NMR evidence. Among them, three compounds, including 3-O-beta-D-glucuropyranosyl oleanolic acid (1), 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl hederagenin (2), and the new compound 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl-30-O-methyl spergulagenate 28-O-beta-D-glucopyranosyl ester (3), are identified for the first time from quinoa seeds. The other isolated saponins have been previously reported in quinoa.