40 research outputs found

    Effect of triticale grain characteristics, scouring, and extrusion conditions on physico-chemical properties, antioxidant activity, and volatile compounds of flat bread

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    The objective of the study was to determine the effect of grain preparation technology, extrusion cooking conditions, and triticale cultivars on physico-chemical properties of crisp bread. Triticale cultivars used in the experiments differed in protein content, starch content, amylolytic activity, and viscosimetric properties. The type of the twinscrew extruder used has an effect on starch degradation, phenolic contents, and antioxidant activity of the product, but a greater effect on those characteristics is found for grain scouring prior to extrusion. All factors had an effect on volatile compound amounts in crisp bread, but the direction and range of these changes were random in character. Results of this study show that triticale grain can be useful raw material for the production of flat bread

    Use of the SAW sensor electronic nose for detecting the adulteration of virgin coconut oil with RBD palm kernel olein.

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    An electronic nose (zNose™) was applied to the detection of adulteration of virgin coconut oil. The system, which is based on a surface acoustic wave sensor was used to generate a pattern of volatile compounds present in the samples. Virgin coconut oil was mixed with refined, bleached and deodorized palm kernel olein at a level of adulteration from 1 to 20% (wt/wt). Adulterant peaks were identified from the chromatogram profile and fitted to a curve using linear regression. The best relationship (R 2 = 0.91) was obtained between the peak tentatively identified as methyl dodecanoate and the percentage of palm kernel olein added. Pearson’s correlation coefficients (r) of 0.92 and 0.89 were obtained between adulterant peak methyl dodecanoate and of the iodine and peroxide values, respectively. Principal component analysis (PCA) was used to differentiate between pure and adulterated samples. The PCA provided good differentiation of samples with 74% of the variation accounted for by PC 1 and 17% accounted for by PC 2. Pure samples formed a separate cluster from all of the adulterated samples

    Discrimination of n-3 Rich Oils by Gas Chromatography

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    Exploring the capabilities of instrumental techniques for discriminating n-3 rich oils derived from animals is a very important though much neglected area that was emphasized more than 100 years ago. In this study the potential of gas chromatography (GC) for discriminating full fatty acid methyl ester (FAME) profiles from fish (cod liver and salmon) and marine mammal (seal and whale) oils is evaluated by means of principal component analysis (PCA). The FAME profiles from plant oils such as rapeseed, linseed and soy oils and seven different brands of n-3 supplements are also used in the discrimination process. The results from the PCA plots can reliably distinguish between plant, n-3 supplements, fish and marine mammal oils. By removing the contribution of the n-3 supplements and plant oils it is possible to discriminate between types of fish and marine animal oils. GC offers a rapid, simple and convenient means of discriminating oils from different species, brands and grades

    Effect of Skin Wine Pomace and Sulfite on Protein Oxidation in Beef Patties During High Oxygen Atmosphere Storage

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    Meat storage in high oxygen atmosphere has been reported to induce protein oxidation reactions decreasing meat quality. The incorporation of antioxidants has been proposed to reduce the extent of these reactions. In this study, the ability of red and white skin wine pomaces as well as sulfites to inhibit protein oxidation were tested in beef patties stored for up to 15 days at 4 °C in a high oxygen atmosphere (70 % O2 and 30 % CO2). SO2 (300 ppm) effectively protected against protein oxidation measured as radical formation by electron spin resonance (ESR) spectroscopy, as thiol loss by the DTNB assay and as myosin heavy chain (MHC) disulfide crosslinking by SDS-PAGE. Pomace from red wine production with a total phenol of 9.9 mg gallic acid equivalent/g protected against protein radical formation and against MHC crosslinking, but not against thiol loss by addition of 2.0 % (w/w) to the beef patties. Pomace from white wine production with a total phenol of 4.0 mg gallic acid equivalent/g only protected against MHC cross-linking. For both types of wine pomace, protein modifications not seen for sulfite addition were observed and were proposed to involve covalent phenol addition to proteins. Red wine pomace may be an alternative to sulfite as a meat additive for protection of beef patties against protein oxidation.Autonomous Government of Castilla y León through the research projects (BU268A11-2 and BU282U13) and the Danish Council for Independent Research |Technology and Production within the Danish Agency for Science Technology and Innovation for granting the project entitled: BAntioxidant mechanisms of natural phenolic compounds against protein cross-link formation in meat and meat systems^ (11-117033)

    The application of selected strains of lactic acid bacteria to improved the quality of rye-wheat bread

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    Celem pracy była ocena jakości pieczywa żytnio-pszennego otrzymanego na zakwasach fermentowanych z zastosowaniem szczepów L brevis i L plantarum. Oceniono wpływ czasu fermentacji zakwasu (6-20 h) oraz zastosowanego szczepu bakterii mlekowej (L brevis, L plantarum) na podstawowe wyróżniki jakości pieczywa. Wydłużenie czasu fermentacji zakwasu do 20 h w istotny sposób poprawia teksturę pieczywa. Badając wzrost zawartości związków fenolowych w funkcji czasu fermentacji zakwasu zaobserwowano statystycznie istotny wzrost ich zawartości. Odnotowano również statystycznie istotny wzrost aktywności antyoksydacyjnej badanych prób pieczywa mierzonej metodą FRAP i DPPH. Czas fermentacji oraz zastosowany szczep bakterii mlekowych nie wpływają istotnie na zawartość białka i popiołu w pieczywie. Analizując zmiany zawartości błonnika pokarmowego zaobserwowano istotny spadek zawartości nierozpuszczalnej frakcji błonnika pokarmowego (IDF), natomiast zawartość rozpuszczalnej frakcji (SDF) nie uległa zmianie pod wpływem dłuższego procesu fermentacji.The main objective of this study was to evaluate the quality of sourdough rye-wheat breads fermented with L brevis and L plantarum. Influence of fermentation time (6-20 h), and strains of lactic acid bacteria (L brevis, L. plantarum) were considered as independent factors and their effects on technological and chemical quality of bread were studied. Longer fermentation time (20 h) statistically improved the bread texture. During fermentation the levels of phenolic compounds significantly increased. Statistically increases of antioxidant activity of samples measured by DPPH and FRAP methods were observed. Fermentation time and the type of lactic acid bacteria used had non-significant effect on protein and ash contents. The insoluble fibre content (IDF) was found to decrease after fermentation, while the soluble fibre (SDF) in the bread samples was apparently not affected by fermentation

    May rye bread enriched with green tea extract be useful in the prevention of obesity in rats?

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    We examined the hypothesis that rye bread enriched with green tea extract (GTE) (at two different doses) can prevent obesity as a component of a hypercaloric diet by decreasing the absorption of energy providing nutrients and regulating lipid metabolism-related hormones, in comparison with normal caloric diet used in the Wistar rats. Adult male Wistar rats were divided into 4 groups: group ND received a normal caloric diet, group HRB received a hypercaloric diet with control rye bread, groups HRB0.8% and HRB1.1% received a hypercaloric diet with rye bread enriched with 0.8% and 1.1% GTE, respectively. Higher food intake in the ND group compared with the other groups of rats was noted; however, there was no statistical difference in the energy intake among any of the groups. Consumption of the hypercaloric diet increased the body weight of the rats (in comparison with ND), but rats from HRB1.1% group showed a tendency towards smaller gains in body weight (∼4.0%) when compared to the HRB group. The addition of 1.1% GTE to rye bread resulted in an increase in the energy content of faeces, compared to both HRB and ND groups. No differences were observed in plasma leptin concentrations between the four groups. The insulin level in rats fed a hypercaloric diet was higher in comparison to rats from the ND group. The consumption of rye bread enriched with 1.1% GTE may increase faeces energy excretion, but without significantly suppressing body weight gain, visceral fat accumulation, or changing biochemical parameters related to lipid metabolism

    Chromatografia gazowa, analiza sensoryczna i nos elektroniczny w ocenie aromatu czarnuszki (Nigella sativa L.)

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    Essential oil composition of Nigella sativa L., the enantiomeric ratio of its chiral compounds as well as sensory characteristics were the subject of the study. The evaluation of several samples of N. sativa seeds purchased in retail was performed by gas chromatography, chiral gas chromatography, olfactometry, sensory profile analysis and the electronic nose. Eleven components were identified. Olfactometry revealed p-cymene, thymoquinone and carvacrol as the most important odorants. P-cymene occurred in all of the samples at highest amounts. Six pairs of enantiomers were isolated. All the components showed variability in their enantiomeric ratios, with exception of carvone, which was found with a stable optical purity of the (-)-isomer, not lower than 85%. The dominating attributes in the sensory profile were cardboard, herbal and spicy. Results of sensory profile analysis and the electronic nose, both interpreted by the Principal Component Analysis, gave similar, although not identical differentiation of the samples.Przedmiotem badań był skład związków zapachowych olejku eterycznego z nasion Nigella sativa L., stosunki enancjomerów związków chiralnych oraz charakterystyka sensoryczna. Ocenę kilku prób nasion czarnuszki pozyskanych na rynku wykonano z zastosowaniem chromatografii gazowej, spektrometrii mas, chiralnej chromatografii gazowej, olfaktometrii, profilowej analizy sensorycznej oraz nosa elektronicznego. Zidentyfikowano jedenaście składników aromatu. Analiza olfaktometryczna wykazała, że głównymi odorantami były p-cymen, tymochinon i karwakrol. Najwyższą zawartość we wszystkich próbach stwierdzono dla p-cymenu. Rozdzielono sześć par enancjomerów. Wszystkie te związki wykazywały zróżnicowanie stosunku enancjomerów w poszczególnych próbach, za wyjątkiem karwonu, który występował zawsze w formie lewoskrętnej (-)-karwon, o czystości optycznej nie mniejszej niż 85%. Dominującymi atrybutami w ocenie sensorycznej były zapachy kartonowy, ziołowy i korzenny. Sensoryczna analiza profilowa i nos elektroniczny wykazały podobne zróżnicowanie między próbami. Wyniki otrzymane obiema metodami były interpretowane z zastosowaniem Analizy Składowych Głównych (PCA)
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