213 research outputs found

    Recovery of Natural Antioxidants from Fruit Juice Industry Residuals by Ultrasound-Assisted Extraction and Response Surface Methodology

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    Fruit processing industries produce by-products that are good sources of natural antioxidants. These residuals are non-toxic and available in large quantities. A central composite design (CCD) and response surface methodology (RSM) were used to optimize experimental conditions. The processing variables were solvent type, solvent to solid ratio, ethanol concentration, temperature, and time. The responses were total phenolic content (TPC), scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, and yield. The optimal conditions were 70% ethanol— water mixture as a food grade solvent, temperature of 35 °C and extraction time 60 min for obtaining extracts with maximum of total phenolic content. Predicted values for total phenolic content in pear, apricot, and peach were 24.7, 19.3, and 10.4 mg gallic acid equivalents per 100 g fruit residual, respectively

    Extraction, purification and analysis of conotoxin of Conus textile captured from Persian Gulf and the investigation of analgesic effects of conotoxins in an animal model

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    Identification of venomous species of Persian Gulf cone snails and characterization of venom composition and their features is so important from the point of medical importance. Marine cone snails from the genus Conus are estimated to consist of up to 700 species. The venom of cone snails has yielded a rich source of novel neuroactive peptides or conotoxins. The present study was aimed to study the analgesic effect of Persian Gulf Conus textile and its comparison with morphine in mouse model. The specimens of Conus textile were collected of Larak Island from depth of 7 m. The collected samples were transferred to laboratory alive and were stored at -700 c. he veno s ducts were separated and ho ogenized with deionized water he ixture centrifuged at rp for inutes upernatant was considered as extracted veno and stored at - C after lyophylization. The protein profile of venom determined by using SDS-PAGE and HPLC used to investigate the extracted venom and to evaluate the analgesic activity, formalin test was carried out. SDS-PAGE indicated several bands ranged between 6 and 250 kDa. Chromatogram of the venom demonstrated more than 44 large and small fractions. The amount of 10 ng of Conus crude venom and analgesic peptide showed the best anti-pain activity in formalin test. No death observed up to 100 mg/kg, which is 250,000 times higher than the effective dose.Venom characterization of Persian Gulf Conus textile may be of medical importance and potential for new pharmaceutical drugs as well

    Green ultrasound-assisted extraction of anthocyanin and phenolic compounds from purple sweet potato using response surface methodology

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    Response surface methodology was used to optimize experimental conditions for ultrasound-assisted extraction of valuable components (anthocyanins and phenolics) from purple sweet potatoes using water as a solvent. The Box-Behnken design was used for optimizing extraction responses of anthocyanin extraction yield, phenolic extraction yield, and specific energy consumption. Conditions to obtain maximal anthocyanin extraction yield, maximal phenolic extraction yield, and minimal specific energy consumption were different; an overall desirability function was used to search for overall optimal conditions: extraction temperature of 68C, ultrasonic treatment time of 52 min, and a liquid/solid ratio of 20. The optimized anthocyanin extraction yield, phenolic extraction yield, and specific energy consumption were 4.91 mg 100 g-1 fresh weight, 3.24 mg g-1 fresh weight, and 2.07 kWh g-1, respectively, with a desirability of 0.99. This study indicates that ultrasound-assisted extraction should contribute to a green process for valorization of purple sweet potatoes

    Comparative study of extraction methods for pistachio hull antioxidants by multiple assays

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    In recent years, the use of natural antioxidants extracted from agricultural and industrial by-products has been increased because of sustainability, high and stable antioxidant activity, absence of toxicity. These extracts can be used as substitute of synthetic antioxidants for food products, color and oxidative stabilization. In this study, experimental design and response surface methodology (RSM) were used to optimize experimental variables such as sample weight (g), irradiation power and time (s) in microwave-assisted extraction (MAE) of antioxidants from pistachio hull. Effect of sample weight was found to be significant on total phenolic content (TPC), ferric reducing antioxidant power (FRAP), scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and extraction yields. The optimal conditions were water as solvent, particle size of 0.25 mm, microwave power 600 W, sample weight 0.2 g, irradiation time of 150 s. Finally, comparison of extraction methods was shown that MAE method gave better results than ultrasonic-assisted extraction (UAE) and conventional methods with the optimum operating conditions like time and energy consumption

    Evaluation of Nitrite Exposure from Meat Products Supplied in Tehran, Iran

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    Nowadays, due to the increased consumption of meat products, investigation of their additives such as nitrite seems necessary. Nitrate in combination with salt has a synergistic characteristic against pathogenic microorganisms. Nitrite combines with protein, fats, and volatile and non-volatile compounds in meat and plays an important role in flavoring meat products. Excessive use of this substance leads to a more dangerous compound called nitrosamine. The present study aimed to investigate the nitrate content of meat products with different levels of meat. Health risk assessment toward nitrite was also calculated. A total of 108 samples of meat products in various commercial brands were collected and analyzed from retail markets of Tehran to detect the amount of nitrite in them. Meat products in terms of their meat percentage were divided into three categories under 50%, 50% to 70%, and more than 70%. Estimated daily intake (EDI), based on per capita consumption rate and hazard quotient (HQ) for adults and children were also estimated. The mean concentration of nitrite in meat products with >70% meat, 50-70%, and <50% were 28.04, 30.07, and 27.02 mg kg-1, respectively that did not resemble any significant difference (p>0.05). The results indicated that the levels of nitrite were lower than permissible levels. The calculated HQ was less than 1 for meat products. However, this value was more for children. So is necessary to take precautions any over-consumption of this type of product in children

    Ultrasound-assisted extraction of polyphenols from potato peels: profiling and kinetic modelling

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    peer-reviewedUltrasound‐assisted extraction (UAE) at 33 and 42 kHz has been investigated in the extraction of polyphenols from peels of two potato varieties, cream‐skinned Lady Claire (LC) and pink‐skinned Lady Rosetta (LR), commonly used in snack food production. Extraction efficacy between the UAE‐untreated (control) and the UAE‐treated extracts was assessed on the total phenolic content and antioxidant capacities (DPPH and FRAP). Application of UAE showed significantly higher recovery of phenolic compounds compared to solid–liquid extraction process alone. Lower ultrasonic frequency (33 kHz) was more effective in recovering polyphenols compared to 42 kHz ultrasonic treatment. The liquid chromatography‐tandem mass spectrometry revealed that chlorogenic acid and caffeic acid were the most prevalent phenolics in LR peels, whereas caffeic acid was dominant in LC peels. Peleg's equation showed a good correlation (R2 > 0.92) between the experimental values and the predicted values on the kinetics of UAE of phenolic compounds.The authors acknowledge financial support from the ‘NovTechIng’ project funded under the Food Institutional Research Measure (Project No. FIRM/11/F/050) by the Irish Department of Agriculture, Food and Marine

    Crude oil yield and properties of rice bran oil from different varieties as affected by extraction conditions using soxhterm method

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    The current study was employed to investigate the effect of solvent type, extraction time and bran ratio on the rice bran oil (RBO) properties from three varieties of rice bran namely Bario, lowland and upland rice. RBO was extracted by using soxtherm extraction method using methanol solvent at different extraction time (3, 4 and 5 h) and bran ratio (10, 20 and 30 g). Free fatty acid (FFA), total phenolic content (TPC) and antioxidant properties were assessed. Solvent that has low polarity exhibited the attraction of polar component of oil with the highest yield by ethanol (16.16%), followed by methanol (15.38%). FFA contents occurred higher in lowland types of rice bran in all types of solvents at P<0.05 with ethanol (12.73%), methanol (11.96%) and hexane (11.13%), while the total phenolic content and antioxidant properties were influenced by the types of rice bran and solvents used for extracting components out of the bran. The highest phenolic content in the crude oil was extracted using ethanol in lowland (0.509 mg/ml), and the lowest was extracted by hexane in Bario (0.061 mg/ml). The highest antioxidant activity was observed in RBO extracted using methanol of lowland (73.74%) and RBO extracted using ethanol of upland (73.65%), while the lowest were observed in RBO extracted using hexane. The different types of solvent have the significant impact on the crude oil yield and properties of crude oil extracted

    The influence of solid state information and descriptor selection on statistical models of temperature dependent aqueous solubility.

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    Predicting the equilibrium solubility of organic, crystalline materials at all relevant temperatures is crucial to the digital design of manufacturing unit operations in the chemical industries. The work reported in our current publication builds upon the limited number of recently published quantitative structure-property relationship studies which modelled the temperature dependence of aqueous solubility. One set of models was built to directly predict temperature dependent solubility, including for materials with no solubility data at any temperature. We propose that a modified cross-validation protocol is required to evaluate these models. Another set of models was built to predict the related enthalpy of solution term, which can be used to estimate solubility at one temperature based upon solubility data for the same material at another temperature. We investigated whether various kinds of solid state descriptors improved the models obtained with a variety of molecular descriptor combinations: lattice energies or 3D descriptors calculated from crystal structures or melting point data. We found that none of these greatly improved the best direct predictions of temperature dependent solubility or the related enthalpy of solution endpoint. This finding is surprising because the importance of the solid state contribution to both endpoints is clear. We suggest our findings may, in part, reflect limitations in the descriptors calculated from crystal structures and, more generally, the limited availability of polymorph specific data. We present curated temperature dependent solubility and enthalpy of solution datasets, integrated with molecular and crystal structures, for future investigations
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