Journal of the Science of Food and Agriculture

Published by Wiley
Online ISSN: 1097-0010
Print ISSN: 0022-5142
Fruit drinks containing probiotics are gaining interest in the global marketplace. For example, longan juice, containing carbohydrate and various bioactive components, is a potentially health-promoting beverage as well as probiotic carrier for human consumption. In this study, high-pressure and thermal processes were applied to eliminate competitive micro-organisms in longan juice prior to the addition of Lactobacillus acidophilus LA5 or Lactobacillus casei 01. The activities of these probiotics in a simulated gastrointestinal tract were also investigated. Encapsulated probiotics could survive in the acidic environment of the stomach and small intestine, while the free cells were completely eliminated. In the colon experiment, the influence of encapsulated L. casei 01 on colon lactobacilli was significantly greater than that of encapsulated L. acidophilus LA5. Both encapsulated probiotics suspended in processed longan juices led to extensive increases in the formation of lactic acid and short-chain fatty acids (SCFA). Acetate was the major SCFA produced by colon bacteria, followed by propionate and butyrate. The discernible clear zone suggested that L. casei 01 provided greater antibacterial activity than L. acidophilus LA5. Both encapsulated probiotics along with processed longan juice led to significant increases in colon lactobacilli, lactic acid and SCFA formation.
Change trends of zinc content and dry biomass. Data are presented as mean values (n = 3)
Elution curve of MZPS on DEAE-52 column.
UV scanning spectra of MZPS-1 and MZPS-2.
FTIR spectra of (A) MZPS-1 and (B) MZPS-2.
HPLC chromatograms of (A) MZPS, (B) MZPS-1, (C) MZPS-2 and (D) MZPS-3. Peaks: 1, mannose; 2, glucuronic acid; 3, galacturonic acid; 4, glucose; 5, galactose; 6, arabinose.
Edible fungi polysaccharides usually exhibited antioxidant activity, and zinc has been shown to have antioxidant properties. In the present work, Pholiota nameko SW-03 was used as a vector of zinc biotransformation in order to obtain mycelia zinc polysaccharide (MZPS), and the structural characterization and anti-ageing activity of MZPS were investigated. P. nameko SW-03 could accumulate zinc in the form of zinc-riched polysaccharide, and the zinc content in MZPS was 16.39 ± 0.72 mg g(-1) . Three fractions (MZPS-1, MZPS-2 and MZPS-3) were successfully isolated. The main fraction (MZPS-2) with the highest antioxidant activity in vitro was composed of glucose, mannose, glucuronic acid, galactose, galacturonic acid and arabinose in a molar ratio of 172.59:5.29:4.61:4.20:1.01:1.00, with the weight-average molecular weight of 13.63 kDa. The anti-ageing capability has been measured by building the D-galactose-induced ageing mice, and the results showed that MZPS could improve antioxidant status (SOD, T-AOC, MDA and LPO), indicating that MZPS had strong anti-ageing capability in vivo. This study suggested that organification of zinc through edible fungi liquid fermentation provided a novel method to produce mycelia zinc polysaccharide, which might be used as natural antioxidant to slow the progression of ageing. This article is protected by copyright. All rights reserved.
Clenbuterol (salbutamol), which increases muscle mass and decreases adipose tissue, is misused as a nutrient-repartitioning agent in livestock. In this paper a new sensitive method for determining clenbuterol in livestock is presented. The novelty of this approach is the separation and determination of salbutamol enantiomers with marked quantitative merits. Four proton di-ionisable Nano-baskets, namely 5,11,17,23-tetrakis(1,1-dimethylethyl)-25,26-bis(carboxy-methoxy)calix[4]arene-27,28-crown-3, -crown-4, -crown-5 and -crown-6 in the cone conformation, were synthesised and used to prepare bonded phases for high-performance liquid chromatography separation. The new synthesised bonded phases were characterised and optimised. The bonding interactions of solute/bonded phases were examined and the main interactions are reported. The clenbuterol levels in six samples of livestock meat (pork, pork casing, beef, beef casing, mutton and mutton casing) were analysed and the results revealed that for the best bonded phases the limits of detection and quantitation were 0.06 and 0.2 µg mL(-1) respectively. Copyright © 2012 Society of Chemical Industry.
The synergism of carbaryl (1-naphthyl-N-methyl carbamate) with 26 derivatives of 1,3-benzodioxole and naphtho-1,3-dioxole was examined by topical dosage of female houseflies, Musca domestica, which, though of a strain not selected with insecticides, were completely tolerant to carbaryl. The synergists also were non-toxic when applied alone. The doses of carbaryl and synergist in different combinations that gave 50 % mortality (LD50) were estimated. A simple form of graphical analysis revealed a common pattern in the results for 18 of the synergists. This indicated that if the mechanism that detoxifies carbaryl and that was depressed by these synergists was completely inhibited, the LD50 for carbaryl would be about 0.06 μg per fly. Moreover, the analysis enabled relative potencies for these synergists to be estimated on a simple and rational basis, and showed a 700-fold difference between the most and the least active. The significance of these and the remaining results is discussed in the light of the probable factors affecting the mode of action of the synergists.
Pork meat rejected by consumers because of a nauseating taint was analysed by gas chromatography and mass spectrometry (g.c.-m.s.) and found to contain 5–20 mg kg−1 of 1,4-dichlorobenzene. Trace amounts (10–35 μg kg−1) of 1,4-dichlorobenzene were found in wood-shavings used as litter materials and in the feedstuffs, but were considered insufficient to be the main cause of contamination. Meat from the following batch of pigs from the same source contained only very small amounts, similar to those present in normal pork obtained elsewhere (<25 μg kg−1). Examination of data recorded by g.c.-m.s. in the previous 2 years showed that 1,4-dichlorobenzene was present in trace quantity (>10μg kg−1) in several samples of normal meat, and appeared to be widespread in its occurrence.
L(+)-Lactic acid is used in the pharmaceutical, textile and food industries as well as in the synthesis of biodegradable plastics. The aim of this study was to investigate the effects of different medium components added in cassava wastewater for the production of L(+)-lactic acid by Lactobacillus rhamnosus B 103. The use of cassava wastewater (50 g L(-1) of reducing sugar) with Tween 80 and corn steep liquor, at concentrations (v/v) of 1.27 mL L(-1) and 65.4 mL L(-1) respectively led to a lactic acid concentration of 41.65 g L(-1) after 48 h of fermentation. The maximum lactic acid concentration produced in the reactor after 36 h of fermentation was 39.00 g L(-1) using the same medium, but the pH was controlled by addition of 10 mol L(-1) NaOH. The use of cassava wastewater for cultivation of L. rhamnosus is feasible, with a considerable production of lactic acid. Furthermore, it is an innovative proposal, as no references were found in the scientific literature on the use of this substrate for lactic acid production.
Sheep perinephric fat has been found to contain 11-cyclohexylundecanoic acid to the extent of approximately 0.05% of the total weight of fatty acids.
Differences in the proportions (%) of milk fatty acids
Effects of the individual variation among dairy cows on the cis-9, trans-11 CLA synthesis are still not well characterized. Therefore, the protein expression profiles of isolated milk epithelial cells (MECs) were detected by 2-DE and their correlation with the various proportion of cis-9, trans-11 CLA were evaluated. Although animals were offered the same diet, the proportion of cis-9, trans-11 CLA in group High (1.02 ± 0.10 %) was twice as high as that in group Low (0.59 ± 0.14 %) (p < 0.05). MECs owned the characteristics of native epithelial cells were successfully isolated from the milk and these cells had no obvious RNA degradation or hardly contaminated with leucocytes or blood red cells. Moreover, the protein expression pattern of Cathelicidin 5 in isolated MECs was positively, whereas Annexin I (confirmed by real time PCR), ZW10 interactor and Kappa casein were negatively related to the cis-9, trans-11 CLA proportion in the milk fat. The varied individual content of cis-9, trans-11 CLA in cows may associate with Annexin I. These findings may provide some theoretical basements for the studies about effects of the individual variation among dairy cows on the cis-9, trans-11 CLA synthesis.
Xylanases have attracted much attention because of their potential applications. Unfortunately, the commercialization of xylanases was limited by their low catalytic activities. The purpose of this work was to improve the activity of a xylanase by optimization of the expression conditions, and investigate its characterization. The activity of recombinant AuXyn11A (reAuXyn11A), a family 11 xylanase from Aspergillus usamii E001 expressed in Pichia pastoris GS115, reached 912.6 U mL(-1) under the optimized conditions, which was 2.14 times as high as that expressed using the standard protocol. After the endogenous 18-aa propeptide was processed in P. pastoris, the reAuXyn11A (188-aa mature peptide) was secreted and purified with a specific activity of 22,714 U mg(-1) . It displayed the maximum activity at pH 5.0 and 50 °C, and was stable at a pH range of 4.0-8.0 and at a temperature of 46 °C or below. Its activity was not significantly affected by most of metal ions tested and EDTA. The xylooligosaccharides of xylobiose (X2) to xylohexaose (X6) were produced from insoluble corncob xylan by reAuXyn11A. The high specific activity and good enzymatic properties suggested that the reAuXyn11A was a potential candidate for applications in industrial processes.
BACKGROUND: γ-Glutamyltranspeptidase (GGT; EC is a widely distributed enzyme that is of interest in the food industry. In this study the effects of pH and dissolved oxygen (DO) on GGT synthesis from Bacillus subtilis SK 11.004 were investigated. RESULTS: GGT production increased to 0.5 U mL−1 when the pH value was controlled at 6.5. The control of a single DO level revealed that the highest specific growth rate (3.42 h−1) and GGT production rate (0.40 U g−1 mL−1) were obtained at DO levels of 40 and 10% respectively. To satisfy the different oxygen demands at different stages of cell growth and GGT synthesis, a stage DO level control strategy was designed as follows: 40% from 0 to 4 h, 30% from 4 to 6 h and 10% from 6 to 18 h. Furthermore, the maximum biomass (2.27 g L−1) and GGT production (3.05 U mL−1) could be obtained using a fermentation strategy combining a constant pH value with stage DO level control. CONCLUSION: The proposed fermentation strategy resulted in a 13.7-fold increase in GGT production. This finding should be of great importance for the industrial production of GGT. Copyright
D-Tagatose, as one of the rare sugars, has been found to be a natural and safe low-calorie sweetener in food products and is classified as a GRAS substance. L-Arabinose isomerase (L-AI, EC, catalysing the isomerisations of L-arabinose and D-galactose to L-ribulose and D-tagatose respectively, is considered to be the most promising enzyme for the production of D-tagatose. The araA gene encoding an L-AI from Bacillus stearothermophilus IAM 11001 was cloned, sequenced and overexpressed in Escherichia coli. The gene is composed of 1491 bp nucleotides and codes for a protein of 496 amino acid residues. The recombinant L-AI was purified to electrophoretical homogeneity by affinity chromatography. The purified enzyme was optimally active at 65 degrees C and pH 7.5 and had an absolute requirement for the divalent metal ion Mn(2+) for both catalytic activity and thermostability. The enzyme was relatively active and stable at acidic pH of 6. The bioconversion yield of D-galactose to D-tagatose by the purified L-AI after 12 h at 65 degrees C reached 36%. The purified L-AI from B. stearothermophilus IAM 11001 was characterised and shown to be a good candidate for potential application in D-tagatose production.
Propolis is a complex resinous sticky substance that honeybees collect from buds and exudates of various plants. Owing to its versatile biological and pharmacological activities, propolis is widely used in medicines, cosmetics and foods. The aim of this study was to evaluate the cytotoxic and antioxidative effects of various ethanolic extracts of propolis (EEPs) on human colon cancer cell line HCT-116 and compare them with their composition determined by HPLC-DAD. The most abundant flavonoids in all samples were chrysin, pinocembrin and galangin (12.697–40.811 µg mg−1), while the main phenolic acids were caffeic acid, ferulic acid and isoferulic acid. Dose- and time-dependent inhibition of growth of HCT-116 cells was observed for all propolis samples, with IC50 values ranging from 26.33 to 143.09 µg mL−1. Differences in cytotoxic activity of propolis samples were associated with differences in their composition. All EEP samples reduced both superoxide anion radical and nitrite levels and also had strong DPPH-scavenging activity. All tested propolis samples had pronounced cytotoxic and antioxidative activities.
The 7S and 11S fractions from soybean proteins have interesting high nutritional and excellent functional properties. The aim of this research was to improve the functional properties of soy proteins by studying the effect of bis(2-ethylhexyl) sodium sulfosuccinate (AOT) reverse micelles on the conformation of the 7S and 11S globulins using Fourier transform infrared and X-ray diffraction spectroscopy. Fourier transform infrared revealed that the intensity of the 7S and 11S globulin bands from AOT reverse micelle extraction at 1600–1700, 1480–1575, 1220–1300, 3330, 1448 and 1395 cm−1 was higher than from aqueous buffer. X-ray diffraction data showed that the intensities of 7S globulin using two extraction methods at 2θ about 10° were significantly different (P < 0.05), about 22° slightly increased. The intensities of 11S globulin at 2θ about 10° and 22° were similar. The average distance between particles (dhkl) for 7S globulin with aqueous buffer extraction at 2θ about 10° was greater than AOT reverse micelle extraction. This study showed the potential of reverse micelles as a protocol for extracting the 7S and 11S globulins for analytical purposes. The results represent a new avenue for determining the structures of the 7S and 11S globulins.
The production of rapidly acidifying laboratory silage provides support for the hypothesis that rate of fall of pH in the early stages is the vital factor in the preservation of free arginine and lysine produced in ensilage, inhibiting the extensive decarboxylation which occurs under conditions of more gradual production of acid and of high pH.
BACKGROUND Herbhoneys, relatively new bee products, are expected to have interesting medicinal properties. However, there is still a lack of data concerning their composition and antioxidant properties. H-1 and C-13 NMR spectroscopy coupled with chemometric analysis (PCA and PLS-DA) and antioxidant assays (DPPH-ESR and ORAC-FL) were used to study 25 samples of Polish herbhoneys and honeys. RESULTSAntioxidant activity varied among the samples. The best properties were exhibited by cocoa and instant coffee herbhoneys. The contents of total polyphenols and total carotenoids in the studied samples were found to be 70-1340mg GAE kg(-1) and 0-28.05mgkg(-1) respectively. No significant differences between herbhoney and honey samples were found in their sugar profiles. The PCA of C-13 NMR spectra of the samples in DMSO-d(6) resulted in sample clustering due to sucrose content. CONCLUSION Herbhoneys have similar antioxidant properties to traditional honeys, being therefore of equal nutritional value. There was a noticeable influence of the extract concentration on the observed antioxidant effect. For samples with high antioxidant activity, polyphenols were responsible for the observed effect. Sample clustering due to sucrose content in the NMR-PCA study allowed effortless detection of adulteration. (c) 2013 Society of Chemical Industry
BACKGROUND: Lignification-associated phenolic acids are widely distributed in graminaceous plant cell walls. This study developed a rapid and sensitive reversed-phase method for the simultaneous quantification of protocatechuic (PRA), vanillic (VA), ferulic (FA) and p-coumaric (PCA) acids and investigated the relationship between these compounds and lignin contents in 13 fibrous feeds. RESULTS: The phenolic acids were identified at a column temperature of 15 °C in a single run, in which the wavelength was programmed at 260 nm for PRA and VA, then switched to 310 nm for FA and PCA determinations. Satisfactory precision, recovery, and linearity were obtained with this method. Among 13 feeds, PCA was most abundant, followed by FA, VA and PRA. Great variations in phenolic acid and lignin contents were found. FA content was much richer than PCA content in maize and wheat brans, and the highest PCA content occurred in maize stalks. Lignin content was correlated with proportions of FA (r = − 0.95) and PCA (r = 0.90) in the summed phenolic acids and the PCA:FA ratio (r = 0.91). CONCLUSION: The improved method appears to be useful for simultaneous quantification of target phenolic compounds. Both FA and PCA may be good indicators for plant cell wall lignification associated with feed digestibility. Copyright
Ochratoxin A (OTA) is a mycotoxin produced by some Aspergillus and Penicillium species. In this study, a strain of Bacillus subtilis was studied for its action against OTA-producing Aspergillus and degradation. At the same time, the mechanisms were investigated. A strain of Bacillus spp. isolated from fresh elk droppings was screened out using the methods described by Guan Shun(1) . The 16S rRNA gene sequence suggested that it was Bacillus subtilis (CW 14). It could inhibit the growth of the OTA-producing species, Aspergillus ochraceus 3.4412 and Aspergillus carbonarius , with inhibition rates of 33.0% and 33.3%, respectively. At 6 µg mL(-1) of OTA, both viable and autoclaved (121 °C, 20 min) cells of CW 14 bound more than 60% of OTA. In addition, OTA was degraded by the cell-free supernatant of CW 14. By high performance liquid chromatography (HPLC), the cell-free supernatant degraded 97.6% of OTA after 24 h incubation at 30 °C, and no degradation products were produced. The fastest degradation occurred during the first 2 h. In 3-grams samples of contaminated maize, 47.1% of OTA was degraded by 50-mL inocula of overnight cultures of CW 14. These findings indicated that B. subtilis CW 14 could both prevent OTA contamination and degrade OTA in crops.
Sensory analysis is a crucial tool for evaluating the quality of extra virgin olive oils. One aim of such an investigation is to verify if the sensory attributes themselves - which are strictly related to volatile and phenolic compounds - may permit to discriminate high-quality products obtained by olives of different cultivar and/or grown in various regions. Moreover, a crucial topic is to investigate the interdependency between relevant parameters determining consumer acceptance and objective sensory characteristics evaluated by Panel test. By statistically analyzing the sensory results, a grouping - but not discriminatory - effect was evidenced for some cultivars and some producing areas. The preference map shows that the most appreciated samples by consumers were situated in the direction of the "ripe fruity" and "sweet" axis and opposite to the "bitter" and "other attributes" (pungent, green fruity, freshly cut grass, green tomato, harmony, persistency) axis. Extra virgin olive oils produced from olives of the same cultivars and grown in the same areas shared similar sensorial attributes. Some differences in terms of expectation and interpretation of sensory characteristics of EVOOs might be present for consumers and panellists: most of the consumers appear unfamiliar with positive sensorial attributes, like bitterness and pungency.
Turnover rate constant and turnover time of 14 C-labeled MBC in the three soils under experimental conditions and under field conditions
Release ratio of inorganic carbon in SOC mineralization by adding calcium carbonate to the three soils
Priming effect PE(t)% in the three soils
Organic substrates and calcium are important factors controlling organic matter turnover in Karst soils. To understand their effects on soil organic carbon (SOC) mineralization, an incubation experiment was conducted involving a control treatment (CK), the addition of a (14)C-labeled rice straw (T1), CaCO(3) (T2), and both (14)C-labeled rice straw and CaCO(3) (T3) to two types of Karst soils (terra fusca and rendzina) and a red soil from southwestern China. Cumulative mineralization of the rice straw over 100 days in rendzina (22.96 mg kg(-1)) and terra fusca (23.19 mg kg(-1)) was higher than in the red soil (15.48 mg kg(-1); P < 0.05). Cumulative mineralization of native SOC decreased following addition of (14)C-labeled rice straw in the rendzina and terra fusca but increased in the red soil (negative and positive priming effects on native SOC). The turnover times of (14)C-labeled microbial biomass C (MBC) in the red soil, terra fusca and rendzina were 71 ± 2, 243 ± 20 and 254 ± 45 days, respectively. By adding CaCO(3), the accumulation of SOC was greater in the Karst soils than in the red soil. Although the interactions between rice straw decomposition and priming effects on native SOC are not yet understood, there was considerable variation between Karst and red soils. Soil calcium was a positive factor in maintaining SOC stability. MBC from rice straws was stable in terra fusca and rendzina, whereas it was active in the red soil. The Karst soils (terra fusca and rendzina) used in this study benefited SOC accumulation.
The aim of this study was to ascertain the effect of the N form (NO(3) (-) , NH(4) (+) and organic N) and N concentration on plant isotopic fractionation and on the contribution of the different N sources to the plant N budget, in order to evaluate the feasibility of using plant δ(15) N values for discriminating between conventional and organic crops. To this end, different N concentrations (applied as NO(3) (-) ), N forms (NO(3) (-) versus NH(4) (+) ), and increasing NO(3) (-) applications to an organic N-based fertilization regime were studied. When using NO(3) (-) as N source, intra-plant fractionation was significant and tended to increase when NO(3) (-) concentration increased in the root medium. However, negligible net isotopic fractionation was observed when comparing theoretical and measured plant δ(15) N values. On the other hand, when plants are fertilized with a mixture of NO(3) (-) and NH(4) (+) , differences in uptake patterns for both salts could result in variation in plant δ(15) N regarding to the expected value. Finally, the application of NO(3) (-) to plants was detected when it was combined with high levels of organic N sources, from 99:1 organic:inorganic N ratio. Under certain conditions and following some considerations concerning sampling, δ(15) N values can be considered to be a potential tool to guarantee the authenticity of organic products.
Fermented rice flour (khao-khab, a non-glutinous rice) and related products are Thai traditional products. The types of acetic acid bacteria (AAB) microflora in khao-khab have not been reported. In this study, Acetobacter strains were isolated and identified based on the phenotypic and chemotaxonomic characteristics and molecular aspects. Twenty-five acetic acid bacteria isolated from fermented rice products and a starter for sweetened rice in Thailand by an enrichment culture approach, were assigned to the genus Acetobacter by phenotypic and chemotaxonomic characterisations. On the basis of the 16S rRNA gene sequence and 16S-23S rRNA gene ITS restriction analyses, 25 isolates were divided into six groups and identified at the specific level: (1) Group 1 included five isolates, which were identified as A. indonesiensis; (2) Group 2 included two isolates, which were identified as A. lovaniensis; (3) Group 3 included one isolate, which was identified as A. orientalis; (4) Group 4 included eleven isolates, which were identified as A. pasteurianus; (5) Group 5 included three isolates, which were identified as A. syzygii and (6) Group 6 included three isolates, which were unidentified and considered to constitute a new species. Results revealed that various Acetobacter species were distributed in Thai fermented rice flour and related products. A novel Acetobacter species was isolated from the product.
Kona coffee cherries were demucilaged by either mechanical, enzymic or chemical methods, by the action of bacterial pure cultures, or by natural fermentation. Thirteen volatile components were detected by gas chromatography in all samples of green coffee tested, and these included methanethiol, acetaldehyde, dimethyl sulphide, propionaldehyde, acetone, isobutyraldehyde, butyraldehyde, ethanol, and isovaleraldehyde. Probably, methanol and/or methyl ethyl ketone also were present among the volatile components detected. The relative concentrations of several volatile components did not vary appreciably among the different lots of coffee demucilaged experimentally. However, acetaldehyde concentration increased as the duration of natural fermentation was prolonged, being markedly higher in grossly over-fermented (spoiled) coffee beans. All samples of coffee demucilaged experimentally had similar cup-testing quality (Kona grade No. 1), indicating that none of the demucilaging methods enhanced or diminished coffee flavour or aroma. Over-fermented beans, however, were poor in cup-testing quality.
High-performance liquid chromatography of flavonoids in onion extracts. The compounds quantified were quercetin-3,4′-O-diglucoside (QDG), quercetin-4′-O-monoglucoside (QMG), isorhamnetin-3-glucoside (IMG) and quercetin aglycone (Q).
Correlation analysis for total phenolics, total flavonoids, FRAP and DPPH methanol extracts and 75% ethanol extracts
Onion is undoubtedly one of the major sources of flavonoids. However, there exists a varietals difference in composition, concentration and beneficial activities of onion, on the basis of cultivars, Day length sensitivity/ripening and types. To characterize such differences, 18 onion cultivars from Korean were evaluated for their total phenolics, flavonoids and antioxidant activity. Simultaneous quantification of quercetin, quercetin-3,4'-O-diglucoside (QDG), quercetin-4'-O-monoglucoside (QMG) and isorhamnetin-3-glucoside (IMG) was made in methanol and 75% ethanol. Total phenolic content was examined spectrophotometrically with Folin-Ciocalteau's phenol reagent and total antioxidant activity were studied by FRAP and DPPH methods. The cultivar Sunpower showed highest level of total phenolics (5016 ± 30.0 µg GAE g(-1) DW) and flavonoids (2873.95 ± 60.01 µg Q g(-1) DW) among the 18 cultivars in methanol. However, there was little less value of total phenolics and flavonoids in ethanol extracts. The antioxidant activity for cultivar Sunpower was highest in ethanol extracts 24.12 ± 1.00 and 16.13 ± 0.35 μM TE g(-1) DW with FRAP and DPPH, respectively. Among the 18 cultivars, Sunpower is the most promising cultivar in terms of total phenolics, total flavonoids and antioxidant activity. Our results suggest that the day length sensitivity/ripening among the cultivar do not play any significant role for high values of total phenolics, flavonoids and antioxidant activity.
Background: The ammonia and oxygen levels of water are physicochemical parameters that affect fish physiology. Thus, we hypothesized that in vivo exposure to stressful ammonia and oxygen levels will affect the post-mortem quality of the fish. Therefore, in this study, the effects of in vivo exposure to stressful ammonia and oxygen levels on the composition and content of thiobarbituric acid reactive substances in fillets from dourado (Salminus brasiliensis) and on the lipid oxidation of these fillets during frozen storage were evaluated. Results: Short-term exposure (12 h) to stressful environmental conditions (low oxygen and high ammonia levels) did not change the composition of the flesh. However, longer exposure (15 days) to these stressful conditions caused significant changes in the composition of the flesh. Exposure to a stressful ammonia level before slaughtering increased the susceptibility of the fish fillets to lipid oxidation during frozen storage. In contrast, exposure to low oxygen levels did not increase the lipid oxidation rate of the fillets. Conclusion: These results indicate that the in vivo exposure to high ammonia levels may reduce the quality and stability of dourado fillets.
Black scabbard fish (Aphanopus carbo Lowe, 1839) is a deep-water fish resource that is highly appreciated in southern European countries and can accumulate high levels of mercury in the muscle. Currently, European legislation establishes limits for the presence of toxic contaminants in raw seafood, despite these products are generally cooked before consumption. In addition, there is still a lack of information concerning the nutritional quality and contaminants available in cooked products. Therefore, the aim of this study was to assess the effect of sex, maturation stages and three common cooking practices (steaming, grilling and frying) on the toxic elements (Hg, As, Cd and Pb) and nutritional value (chemical, elemental and fatty acid composition) of black scabbard fish. Few variations occurred between sexes and maturation stages, particularly in fatty acid and elemental content. Concerning cooked black scabbard fish, the greatest differences occurred in fried and grilled samples, attaining higher Hg levels, whereas steamed fish composition was closer to raw black scabbard fish. Raw and cooked black scabbard fish can be considered as a very good source of essential nutrients such as n-3 PUFA, proteins, macro and trace elements. Yet, when the fish is grilled, the Hg content may be above the limits set by EU. Considering the alterations occurred during the cooking processes, steaming seems the best procedure to cook this species.
Fish wastes has been used for many years as an alternative in feeds for aquaculture. In the present study weight gain of juvenile white shrimp Litopenaeus vannamei fed diets including fish waste silage (WS), fish waste silage with soybean meal SBM (WS + S) or fish waste meal (WM) was compared. A conventional acidic silage process was applied to obtain from wastes (skin, heads, bones and viscera) of snapper (Lutjanus spp.), grunt (Haemulon plumieri), and grouper (Epinephelus spp.) an ingredient rich in protein. After 3 days ensilage more than 90% protein was hydrolysed. Waste material processed at pH 3.8 lost about 24% tryptophan. Butylated hydroxytoluene (BHT) prevented lipid oxidation, as shown after 45 days with malonaldehyde production. Shrimp fed WS + S diet gained 0.7 g per week higher than those fed WS and WM diets with 0.3 g per week (P < 0.05). WS processed with formic acid under conditions of low pH is beneficial for the white shrimp L. vannamei. It sustained reasonable weight gain combined with soybean meal in practical diets. On the other hand, BHT addition was beneficial in preventing oxidative action during silage preparation.
The British Government's Voluntary Flour Sampling Scheme was designed in 1957 to replace the National Flour Survey which had operated from the War years. With the cooperation of the milling industry, representative samples of wheat flours milled in the United Kingdom for human consumption were obtained by the Ministry of Agriculture, Fisheries and Food for nutritional analysis at the Laboratory of the Government Chemist. The Scheme has operated continuously since then and the results show that each type of flour has remained almost constant in nutritional composition with year-to-year variations 5% or less from the mean for almost all nutrients. As flour and flour-based cereal products are consumed in large amounts, the data obtained have significant nutritional implications which are discussed in the context of the national average dietary intakes.
Details are given of the methods of analysis used for the determination of the Organochlorine pesticide residues in each of the food groups into which the total diet samples were divided. the results obtained for each food group and the calculated result for the total diet are given and comparison is made between the observed daily intakes and the acceptable daily intakes recommended by F.A.O. and W.H.O.
Negative climate impacts on crop yield increase pressures on food security in China. In this study, climatic impacts on cereal yields (rice, wheat and maize) were investigated by analyzing climate-yield relationships from 1980 to 2008. Results indicated that warming was significant, but trends in precipitation and solar radiation were not statistically significant in most of China. In general, maize is particularly sensitive to warming. However, increase in temperature was correlated with both lower and higher yield of rice and wheat, which is inconsistent with the current view that warming results in decline in yields. Of the three cereal crops, further analysis suggested that reduction in yields with higher temperature is accompanied by lower precipitation, which mainly occurred in northern parts of China, suggesting droughts reduced yield due to lack of water resources. Similarly, a positive correlation between temperature and yield can be alternatively explained by the effect of solar radiation, mainly in the southern part of China where water resources are abundant. Overall, our study suggests that it is inter-annual variations in precipitation and solar radiation that have driven change in cereal yields in China over the last three decades.
The transfer of transgenes from 'model' wheat genotypes into elite wheat cultivars using conventional plant breeding is an alternative strategy for improving the dough quality of wheat. Thus a cross was made between a popular Chinese elite wheat cultivar of the Yangzi River down-central area that expresses high-molecular-weight glutenin subunit (HMW-GS): 1Bx7 + 1By8 plus 1Dx2 + 1Dy12, and a model transgenic wheat line B102-1-2 which over-expresses HMW-GS 1Ax1 in an L88-31 genetic background that includes HMW-GS 1Bx17 + By18. F(1) to F(6) generations of crosses between B102-1-2 (paternal) and Emai (maternal) were analysed for their HMW-GS compositions, allowing the selection of pure F(6) lines over-expressing HMS-GS 1Ax1 in the presence of the endogenous HMW-GS: 1Bx7 + 1By8 with 1Dx2 + 1Dy12, and 1Bx17 + 1By18 with 1Dx2 + 1Dy12. Analysis of the F(6) lines showed changes in the extensograph parameters, with increases in peak area, resistance to extension, and extensibility and peak resistance to extension, similar to those observed in the transgenic paternal line B102-1-2. This work showed that the expression levels of the 1Ax1 transgene and the effects on dough properties were similar in the transgenic parental line B102-1-2 and the F(6) progeny generated from a cross with an elite Chinese cultivar Emai. The feasibility of using transgenic lines expressing HMW-GS subunits in conventional breeding programmes was demonstrated.
Lactobacillus plantarum, isolate No. 13a, reduces (−)-quinate, shikimate and (−)-dihydroshikimate to a new metabolite identified as (−)-3t, 4t-dihydroxycyclohexane 1c-carboxylate. The absolute stereochemistry of the product is given and is shown to resemble that of (−)-quinic and (−)-dihydroshikimic acids.
Applicability of magnetic resonance imaging (MRI) to quantitative analysis of sodium in salted fish products is usually impaired by the partial (23)Na MRI 'invisibility' phenomena as well as high investment costs of the MRI equipment. Salmon and cod fillet pieces, unsalted and brine salted (50, 100, 150, 200 and 250 g kg(-1) NaCl) for 48 h, were studied using (1)H and (23)Na MRI. Based on MRI results, T(1) and T(2) relaxation times were calculated for (1)H and the T(2) time for (23)Na nuclei. In addition, water diffusion images for all fillet samples and reference brine solutions were obtained. Variation of the nuclear magnetic resonance relaxation times and water diffusion constants with brine concentration is discussed in terms of the muscle structural changes. Sodium MRI visibility factors for the MRI method used were determined for all fish samples. Observed changes in proton and sodium NMR relaxation times with the salt content reflect complex counteraction of several factors related to the muscle structural changes. Sodium MRI visibility factors appear to be dependent on a number of experimental factors in a complex matter, making quantitative sodium analysis by the MRI technique used non-trivial. Copyright © 2007 Society of Chemical Industry.
2,3-butanediol was identified in silage extracts using gas chromatography and mass spectrometry. It was present in stacks of untreated and formaldehyde-treated silage in concentrations of 2.4% of the dry matter.
Butanediol is first oxidised to acetoin by butane-2,3-diol dehydrogenase from a strain of Sarcina, in the presence of NAD+ and an excess amount of 2,6-dichloro-phenol-indophenol at an alkaline pH. Then the acetoin formed is reduced back to butane-2,3-diol by the same enzyme in an acidic condition, and NADH thereby oxidised is measured spectrophotometrically. Direct measurement of NADH formation in the first reaction, oxidation of butane-2,3-diol, has not yet been successful. Colorimetric measurement of the reduction of 2,6-dichlorophenol-indophenol was also unsuccessful. Ethanol in sample solutions should have been removed by evaporation before the enzymatic oxidation. Presence of acetoin caused no difficulty in the oxidation of butane-2,3-diol, but made it necessary to correct the measured values for the original acetoin contents. The isomers of butane-2,3-diol present in wines have been reported to be D(-) and meso, on both of which the butane-2,3-diol dehydrogenase from Sarcina appears to be able to act. The butane-2,3-diol contents of some Japanese commercial wines were determined by this enzymatic method. Concentrations ranged from 324 to 768 mg/litre.
A method has been developed for the analysis of 2,3,4,6-tetrachloro- and pentachloroanisoles and the corresponding chlorophenols in biological extracts. Ethylation followed by separation of the preformed anisoles from the corresponding phenetoles (ethyl phenyl ethers) by gas chromatography using an electron capture detector provides a sensitive method of analysis. The extraction method of Likens and Nickerson, whilst satisfactory for the chloroanisoles in all the samples investigated, was not adequate for quantitative recovery of chlorophenols from muscle or fatty tissue. An alternative extraction method, not applicable to chloroanisoles, was satisfactory for muscle but was not suitable for skin or fatty tissue.
BACKGROUND Heat-induced protein aggregation is important for the texture of various food products. Many types of food proteins have been found to assemble into fibrillar structures under certain conditions. We studied fibril formation of cottonseed 7S storage protein upon heating (for 0-720 min) at 90°C and pH 2.0, investigated the conversion rate, and determined the extent of thermal aggregation.RESULTSThioflavin-T fluorescence and Congo-red analysis indicated the formation of amyloid-like fibrils upon heating. Centrifugal filtration indicated that the conversion was very low (<10%) until congossypin concentration up to 2 mg mL−1, and the conversion increases with increasing heating time, but levels off after longer heating times. Dynamic light scattering and atomic force microscopy showed that the extent of thermal aggregation at pH 2.0, or contour length of the worm-like and fine-stranded aggregates, progressively increased with increasing heating time. Furthermore, reducing electrophoresis analyses indicated that progressive polypeptide hydrolysis occurred upon heating. Experiments indicate that congossypin can form heat-induced amyloid-like aggregates and the conversion of congossypin monomers into fibrils increased with heating time and protein concentration.CONCLUSION The results would be of vital importance for the utilisation of cottonseed proteins to produce thermally induced fibrillar gels with excellent properties. © 2013 Society of Chemical Industry
Background: The citric acid (CA) industry is currently struggling to develop a sustainable and economical process owing to high substrate and energy costs. Increasing interest in the replacement of costly synthetic substrates by renewable waste biomass has fostered research on agro-industrial wastes and screening of raw materials for economical CA production. The food-processing industry generates substantial quantities of waste biomass that could be used as a valuable low-cost fermentation substrate. The present study evaluated the potential of different agro-industrial wastes, namely apple pomace (AP), brewer's spent grain, citrus waste and sphagnum peat moss, as substrates for solid state CA production using Aspergillus niger NRRL 2001. Results: Among the four substrates, AP resulted in highest CA production of 61.06 ± 1.9 g kg(-1) dry substrate (DS) after a 72 h incubation period. Based on the screening studies, AP was selected for optimisation studies through response surface methodology (RSM). Maximum CA production of 312.32 g kg(-1) DS was achieved at 75% (v/w) moisture and 3% (v/w) methanol after a 144 h incubation period. The validation of RSM-optimised parameters in plastic trays resulted in maximum CA production of 364.4 ± 4.50 g kg(-1) DS after a 120 h incubation period. Conclusion: The study demonstrated the potential of AP as a cheap substrate for higher CA production. This study contributes to knowledge about the future application of carbon rich agro-industrial wastes for their value addition to CA. It also offers economic and environmental benefits over traditional ways used to dispose off agro-industrial wastes.
Co-products from bioethanol processing include wheat dried distillers grains with solubles (DDGS), corn DDGS, blend DDGS (e.g. wheat/corn at 70:30, 60:40 or 50:50 w/w), triticale DDGS, barley DDGS and pea DDGS. The objective of this study was to compare two systems, the DVE/OEB system versus the NRC 2001 model, in modelling the metabolic characteristics of proteins in dairy cattle from different types of co-products (DDGS) from different bioethanol processing plants. The predicted values from the NRC 2001 model were 10% higher (P < 0.05) in truly absorbable rumen-synthesised microbial protein in the small intestine, 10% lower (P < 0.05) in truly absorbed rumen-undegraded feed protein in the small intestine, 30% lower (P < 0.05) in endogenous protein and 2% lower (P < 0.05) in total truly absorbed protein in the small intestine than the predicted values from the DVE/OEB system. However, no significant difference was detected in terms of the degraded protein balance between the two models (P > 0.05). The sensitivity of the two models in detecting differences among DDGS types and between bioethanol plants was similar. The two models coincided in the superior protein value of blend DDGS as well as in the more optimal degraded protein balance (DPB) for corn DDGS. Although the differences between the DVE/OEB system and the NRC 2001 model were significant (P < 0.05) for most outputs owing to differences in some of the concepts and factors used in modelling, the correlations between total truly absorbed protein (DVE) and metabolisable protein (MP) values and between degraded protein balances (DPB(OEB) vs DPB(NRC) ) were also significant (P < 0.05).
The first genetically modified (GM) maize lines were approved for trading in Brazil after December 2007 and they were T25, MON810, Bt11, NK603 and GA21. The polymerase chain reaction (PCR) method was employed to monitor the presence of Bt11 and nested PCR was used to detect the presence of Bt176 in 81 maize-derived products (maize flour, corn meal, maize flour flakes and polenta) that were sold in Brazilian market from 2005 to 2007, before the release of GM maize in Brazil. The PCR detection limit for Bt11 was 10 g kg(-1) and for nested PCR of Bt176 it was 1 g kg(-1). All Brazilian samples analyzed showed no positive signal for these GM maize events. Bt11 and Bt176 GM maize lines were not detected by specific PCR in 81 maize-derived food samples sold in Brazil from 2005 to 2007, before the commercial release of GM maize in Brazil. These Brazilian food industries were in compliance with the rules stipulated by the current legislation with respect to consumer requirements about GMO labeling.
Deoxynivalenol (DON, vomitoxin), one of the most important mycotoxins produced by many Fusarium species, is found as a common contaminant of crops worldwide. Recent studies have described the presence of conjugated forms of DON (glycosides and fatty acid). The aim of the current study was therefore to investigate the natural occurrence of free and conjugated DON in Canadian corn. Free and conjugated DON was determined by gas chromatography-mass spectrometry (GC-MS) and enzyme-linked immunosorbent assay (ELISA) in 86 corn samples collected from the 2008 crop in Ontario, Canada. Free DON concentrations determined by ELISA were similar to values determined in most samples using GC-MS. Conjugated DON was detected in 72 samples. Levels of free DON ranged from 0.17 to 14.00 µg g(-1) using GC-MS. The highest levels of free DON were found in corn samples from the southern and southwestern regions of Ontario, while samples from eastern regions were less contaminated. Conjugated DON was found mainly in corn from the east-central region, with five of six samples showing high levels of conjugated DON (up to 43% increase in DON following acid hydrolysis). Low levels of conjugated DON (≤ 10% increase in DON following acid hydrolysis) were detected in the majority of corn samples from the southwestern region (nine of 19 samples) and from the central region (16 of 36 samples). The current survey emphasizes the frequency of conjugated DON in Ontario grown corn and the potential challenges in understanding the hazard posed by DON-contaminated foodstuffs and feedstuffs.
Top-cited authors
Michael N Clifford
  • University of Surrey
Francisco A Tomás-Barberán
  • Spanish National Research Council
Harinder Makkar
  • Univ. Hohenheim/Univ. Nanjing/Univ. Gansu/Univ. Ulanbator
Augustin Scalbert
  • International Agency for Research on Cancer
Celestino Santos Buelga
  • Universidad de Salamanca