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Characteristics and use of electrolyzed water in food industries 全文
2018
Campagnol, P. C. B. | Menezes, C. R. | Cichoski, A. J. | Genro, A. L. G. | Silva, M. S. | Flores, D. R. M. | Athayde, D. R. | Silva, J. S. | Wagner, R.
Electrolyzed water (EW) is a new technology that emerged in the last years with potential application in foods, mainly in microbiological aspects, with variation in application modes, dipping the food in solution, where variation of time can be changed and be apply in the form of spray. Because EW characteristics, its action in microorganisms are still been studied for mechanism elucidation and possible damages, as well its influence in the intrinsic characteristics of food, like color and oxidation. This unconventional or ‘green’ technology has the purpose to prove microbiological quality of food and decrease the use of natural resources like water with minimal generation of chemical/toxic residues. More studies are necessary in relation to this technology and its possible applications in food industry, as well characteristics and mechanisms.
显示更多 [+] 显示较少 [-]Destruction of representative submarine food waste using supercritical water oxidation 全文
2015
In this study, 13 types of organic materials were oxidized using H₂O₂in a continuous flow reactor under the condition of supercritical water. The effect of the operational parameters on the conversion of total organic carbon (TOC) and total nitrogen (TN) was investigated, and the resulting quality of treated water was analyzed. It was found that these materials were easily oxidized with a TOC conversion achieving 99 % at temperature of 460 °C and TN conversion reaching 94 % at temperature of 500 °C. Rice decomposition was rapid, with TOC and TN decomposition rates of 99 % obtained within residence of 100 s at temperature of 460 °C. At temperature of 460 °C, pressure of 24 MPa, residence time of 100 s, and excess oxygen of 100 %, the quality of treated water attained levels commensurate with China’s Standards for Drinking Water Quality. Reaction rate equation parameters were obtained by fitting the experimental data to the differential equation obtained using the Runge–Kutta algorithm. The decrease of the TOC in water samples exhibited reaction orders of 0.95 for the TOC concentration and 0.628 for the oxygen concentration. The activation energy was 83.018 kJ/mol.
显示更多 [+] 显示较少 [-]Molecular composition of water-soluble lignins separated from different non-food biomasses 全文
2015
Savy, Davide | Nebbioso, Antonio | Mazzei, Pierluigi | Drosos, Marios | Piccolo, Alessandro
Separation of water-soluble lignins from lignocellulosic biomass provides a new and still poorly exploited feedstock to increase the sustainability of biorefineries. We applied derivatization followed by a reductive cleavage (DFRC) method, 2D-HSQC-NMR, and ³¹PNMR after ³¹P-labeling, to investigate molecular composition in water-soluble lignins obtained by alkaline oxidation from three biomass materials for energy (miscanthus, giant reed and an industrially pre-treated giant reed). Chromatographic identification of lignin products cleaved by DFRC showed a large predominance of guaiacyl (G) units in all biomasses and a lesser abundance of syringyl (S) and p-coumaryl (P) monomers. Our S/G ratios disagree with those reported in literature by other lignin separation methods. Carboxyl functions (ferulic and pcoumaric acids) were revealed by heterocorrelated ¹H–¹³C HSQC-NMR, and confirmed by ³¹P-NMR spectra of ³¹ P-labeled lignin molecules. An understanding of molecular composition of water-soluble lignins from biomass sources for energy is essential for lignin most efficient exploitation in either industrial or agricultural applications.
显示更多 [+] 显示较少 [-]Non-thermal plasma-activated water inactivation of food-borne pathogen on fresh produce 全文
2015
Ma, Ruonan | Wang, Guomin | Tian, Ying | Wang, Kaile | Zhang, Jue | Fang, Jing
Non-thermal plasma has been widely considered to be an effective method for decontamination of foods. Recently, numerous studies report that plasma-activated water (PAW) also has outstanding antibacterial ability. This study presents the first report on the potential of PAW for the inactivation of Staphylococcus aureus (S. aureus) inoculated on strawberries. PAW treatments achieved a reduction of S. aureus ranging from 1.6 to 2.3 log at day-0 storage, while 1.7 to 3.4 log at day-4 storage. The inactivation efficiency depended on the plasma-activated time for PAW generation and PAW-treated time of strawberries inoculated with S. aureus. LIVE/DEAD staining and scanning electron microscopy results confirm that PAW could damage the bacterial cell wall. Moreover, optical emission spectra and oxidation reduction potential results demonstrate the inactivation is mainly attributed to oxidative stress induced by reactive oxygen species in PAW. In addition, no significant change was found in color, firmness and pH of the PAW treated strawberries. Thus, PAW can be a promising alternative to traditional sanitizers applied in the fresh produce industry.
显示更多 [+] 显示较少 [-]Antioxidant and pro-oxidant in vitro evaluation of water-soluble food-related botanical extracts 全文
2011
Damien Dorman, H.J. | Hiltunen, Raimo
The total phenol content, antioxidant and pro-oxidant activities of deodourised, water-soluble aniseed, basil, caraway, cardamon, fennel, ginger, juniper, laurel and parsley extracts were estimated using a number of in vitro assays. The laurel and basil extracts contained the highest phenol content of 107.3±1.3 GAE [mg gallic acid equivalents/g (dry wt.) extract] and 98.5±1.4 GAE, respectively, whilst the ginger extract contained the lowest content at 14.9±0.9 GAE. Juniper, laurel and basil extracts were consistently better than the other extracts in terms of iron(III) reducing activity, inhibition of β-carotene-linoleate thermal co-oxidation and N,N-dimethyl-p-phenylenediamine and hydroxyl radical scavenging assays. Potential pro-oxidant activities of the extracts were assessed using both DNA and bovine serum albumin (BSA) as substrates. None of the extracts were capable of stimulating hydroxyl-mediated DNA fragmentation; however, the extracts could be categorised in the protein oxidation assay as extracts with (i) no significant (p>0.05) effect, (ii) a significant (p<0.05) protective effect or (iii) a significant (p<0.05) pro-oxidant effect. The extracts from juniper, laurel and basil had a pro-oxidative effect upon BSA at a dose of 2mg/ml, as estimated from the degree of carbonylation measured.
显示更多 [+] 显示较少 [-]Ultrasound assisted extraction and spectrophotometric determination of trace selenium in water, food and vegetable samples 全文
2016
Altunay, Nail | Gürkan, Ramazan | Güneş, Murat
In the present study, a new ultrasound assisted extraction (UAE) method was developed for preconcentration of selenite, Se(iv), from sample matrices prior to analysis. The method is based on complex formation between phenoxazine dye, resazurin, and triiodide, I₃⁻, which is produced by oxidation of iodide with Se(iv) in the presence of cetylpyridinium chloride (CPC) at pH 5.0, and then the extraction of the complex into the micellar phase of the extracting agent. The proposed process offers good sensitivity, ease of use and short analysis time. The variables affecting complex formation and extraction efficiency were studied and optimized in detail. Under optimal conditions, a good linear relationship was obtained in the range of 2.5–120 μg L⁻¹ with a detection limit of 0.76 μg L⁻¹. The precision was found to be 3.5% (n: 5, 10 and 40 μg L⁻¹). After preconcentration of a 15 mL sample, a sensitivity enhancement factor of 34.1 was obtained. The method offers good sensitivity, ease of use and short analysis time. Total inorganic Se was determined after the reduction of Se(vi) to Se(iv) using hydrochloric acid. The validation was evaluated by analysis of two standard reference materials (SRMs) and the recovery test. Finally, the method was successfully applied to the determination of inorganic Se in selected samples, and recoveries higher than 93.7% to 103% were obtained.
显示更多 [+] 显示较少 [-]Optimization of the Emulsifying Properties of Food Protein Hydrolysates for the Production of Fish Oil-in-Water Emulsions 全文
2020
Padial-Domínguez, Marta | Espejo-Carpio, F Javier | Pérez Gálvez, Raúl | Guadix, Antonio | Guadix, Emilia M.
The incorporation of lipid ingredients into food matrices presents a main drawback—their susceptibility to oxidation—which is associated with the loss of nutritional properties and the generation of undesirable flavors and odors. Oil-in-water emulsions are able to stabilize and protect lipid compounds from oxidation. Driven by consumers’ demand, the search for natural emulsifiers, such as proteins, is gaining much interest in food industries. This paper evaluates the in vitro emulsifying properties of protein hydrolysates from animal (whey protein concentrate) and vegetal origin (a soy protein isolate). By means of statistical modelling and bi-objective optimization, the experimental variables, namely, the protein source, enzyme (i.e., subtilisin, trypsin), degree of hydrolysis (2–14%) and emulsion pH (2–8), were optimized to obtain their maximal in vitro emulsifying properties. This procedure concluded that the emulsion prepared from the soy protein hydrolysate (degree of hydrolysis (DH) 6.5%, trypsin) at pH 8 presented an optimal combination of emulsifying properties (i.e., the emulsifying activity index and emulsifying stability index). For validation purposes, a fish oil-in-water emulsion was prepared under optimal conditions, evaluating its physical and oxidative stability for ten days of storage. This study confirmed that the use of soy protein hydrolysate as an emulsifier stabilized the droplet size distribution and retarded lipid oxidation within the storage period, compared to the use of a non-hydrolyzed soy protein isolate.
显示更多 [+] 显示较少 [-]Lipid oxidation in oil-in-water emulsions: impact of molecular environment on chemical reactions in heterogeneous food systems 全文
2000
McClements, D.J. | Decker, E.A.
The susceptibility of lipids to oxidation is a major cause of quality deterioration in food emulsions. The reaction mechanism and factors that influence oxidation are appreciably different for emulsified lipids than for bulk lipids. This article reviews the current understanding of the lipid oxidation mechanism in oil-in-water emulsions. It also discusses the major factors that influence the rate of lipid oxidation in emulsions, such as antioxidants, chelating agents, ingredient purity, ingredient partitioning, interfacial characteristics, droplet characteristics, and ingredient interactions. This knowledge is then used to define effective strategies for controlling lipid oxidation in food emulsions.
显示更多 [+] 显示较少 [-]Oxidation mechanisms in real food emulsions: oil-water partition coefficients of selected volatile off-flavor compounds in mayonnaise
1999
Jacobsen, C. | Meyer, A.S. | Adler-Nissen, A.
Effects of composition and processing variables on the oxidative stability of protein-based and oil-in-water food emulsions 全文
2017
Kiokias, Sotirios | Gordon, Michael H. | Oreopoulou, Vassiliki
Because many common foods are emulsions (mayonnaise, coffee creamers, salad dressing, etc.), a better understanding of lipid oxidation mechanisms in these systems is crucial for the formulation, production, and storage of the relevant consumer products. A research body has focused on the microstructural and oxidative stability of protein-stabilized oil-in-water emulsions that are structurally similar to innovative products that have been recently developed by the food industry (e.g., non-dairy creams, vegetable fat spreads, etc.) This review presents recent findings about the factors that determine the development of lipid oxidation in emulsions where proteins constitute the stabilizing interface. Emphasis is given to “endogenous” factors, such as those of compositional (e.g., protein/lipid phases, pH, presence of transition metals) or processing (e.g., temperature, droplet size) nature. Improved knowledge of the conditions that favor the oxidative protection of protein in emulsions can lead to their optimized use as food ingredients and thereby improve the organoleptic and nutritional value of the related products.
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