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关键词： Moringa oleifera seed   Protein   Structure   Physicochemical properties  

摘要： Effect of ultrasonic power on the structure and functional properties of water-soluble protein extracted from defatted Moringa oleifera seed were explored. The results showed that ultrasonic treatment could reduce beta-sheet and beta-turn content of water-soluble protein from Moringa oleifera seed (MOWP) and increase the content of random coil and alpha-helix. Changes in intrinsic fluorescence spectra, surface hydrophobicity (H-0) and thermal behaviors indicated that ultrasonic had significant effect on the tertiary structure of MOWP. The results of SEM and SDS-PAGE showed that the MOWP was aggregated but not significantly degraded by ultrasound. The solubility, foaming properties and emulsifying properties of MOWP increased firstly and then decreased with the increase of ultrasonic power. Ultrasonic treatment altered the functional properties of MOWP, which might be attributed to the exposure of hydrophilic group and the change of and secondary and tertiary structure.

关键词： Xanthoceras sorbifolium Bunge   Seed morphological traits   Seed oil   Crude fat   Soluble sugar   Mineral concentration   Fatty acid composition   Geographical-climatic factors  

摘要： The seed and seed oil of Xanthoceras sorbifolium Bunge has high value in multiple applications, but varies considerably in different populations. To provide a basis for seed selection, physicochemical traits of the seeds from 13 areas were determined and analyzed in relation to geographical-climatic factors. Most mineral elements and fatty acids exhibited positive correlations with longitude. Seeds from Mudanjiang had the highest concentrations of crude fat, soluble sugar, N, Ca, Zn, Mn, and saturated and monounsaturated fatty acids. Concentrations of K, Mg, and Cu were highest in Fuxin, and P and Fe were highest in Qingyang. The concentrations of the investigated components indicated that the seeds from the three areas (Mudanjiang, Fuxin, and Qingyang) were suitable for the production of cooking oil, biological products, and health food products. Seeds from Yonghe and Hunyuan had large size and may be suitable for food production and nursery stock. Based on the physicochemical traits of the seeds from the 13 areas, they were evaluated for their future development and utilization. The results indicated the seeds of X. sorbifolium as a natural source of nutrients and minerals for the human.

关键词： African lake   Aquatic vegetation   Nutrient   Redundancy analysis   Water transparency   Turbidity-tolerant macrophytes  

摘要： Between October 2014 to September 2016 we investigated the distribution of macrophyte assemblages in relation to water quality in the south western littoral zone of Lake Tana. in situ measurements of physicochemical parameters (DO, pH, EC, TDS, temperature and Secchi depth) were accompanied by nutrient analyses for NO3-N, soluble reactive phosphate (SRP) and total phosphorus (TP). Macrophytes were collected manually using a belt transect method. Thirty macrophyte species belonging to fifteen families were identified. Emergent and amphibious plants had the maximum percentage composition at 53 % and 30 %, respectively and attained the highest relative frequency and density, followed by floating species and other forms. Redundancy analysis (RDA) indicated that the density of Azolla pinnata subsp. africana, Ceratophyllum demersum, Cyperus alopecuroides, Digitaria milanjiana, Pycreus macrostachyos, Pycnostachys coerulea and Scirpus pallidus was positively and strongly associated with pH, Secchi depth, SRP and TP whereas that of Amaranthus hypochondriacus, Cyperus papyrus, Echinochloa stagnina, Ipomoea aquatic, Panicum maximum, Sacciolepis Africana and Stuckenia pectinata was negatively and strongly associated with these variables but positively with NO3-N. The density of Brachiaria sp., Vossia cuspidate and Leersia hexandra was negatively and strongly associated with pH, SRP and TP whereas the density of Typha latifolia was positively and strongly associated with TDS and EC. The highest diversity index (H' = 2.63) was recorded in Zegie Yiganda sampling site, which was better protected from anthropogenic impacts. In conclusion, Lake Tana is experiencing changes in physico-chemical parameters, which has favored a shift in species composition of macrophytes towards turbidity-tolerant emergent and amphibious species.

关键词： antioxidant activity   oil   physicochemical properties   polyphenols   pomegranate seeds  

摘要： Pomegranate (Punica granatum L.) seeds oils (PSO) from three Tunisian varieties namely Jebali, Testouri, and Gabsi were extracted by ultrasonic-assisted extraction and analyzed for their physicochemical properties, fatty acids (FA) profile, and sterol composition. PSO of Gabsi and Testouri showed the best quality indexes in terms of peroxide and acid values and the highest oxidative stability index was observed for PSO of Gabsi ecotype (2.534 hr). Polyphenol content of PSO of Gabsi ecotype (886.909 mg/kg) was roughly 3 and 23 times higher than that of Jebali and Testouri ecotypes, respectively. Twelve FAs were identified by GC/FID. Punicic acid was the major compounds ranged from 81.53% (Testouri) to 86.41% (Gabsi). The unsaturated/saturated FA ratios of PSO were 14.53, 15.95, and 18.68, respectively for Gabsi, Testouri, and Jebali, respectively. Phytosterols were also identified and beta-sitosterol was the major compound in PSO. In addition, the phytochemical and antioxidant properties of phenolic extracts obtained from pomegranate seeds residues were investigated. Pomegranate seeds extract (PSE) of Gabsi cultivar showed the highest content of polyphenols (64.762 mg CAE/g) and flavonoids (7.127 mg RE/g). Antioxidant potential of extracts was performed using DPPH test and total antioxidant capacity (TAC). Results revealed that Gabsi cultivar was the most reactive extract with EC50 of 0.105 mg/mL for DPPH test and 40.622 mg AA/g for TAC. Phenolic profiles of PSE were also investigated. Results showed the importance of cultivar selection in the potential use of bioactive compounds of seeds as nutraceutical ingredients in food and chemical industries. Practical Application Three Tunisian pomegranate cultivars namely Jebali, Testouri, and Gabsi were investigated for their seeds oil and phenolic composition. Pomegranate seeds oil (PSO) are rich in bioactive polyunsaturated fatty acids and phytosterols that can be of interest in several food and chemical industrial applic

关键词： Cocoa powder   HPLC   TG-DTA-MS   Polyphenols   Microbiological analysis  

摘要： Four cocoa powder varieties processed in different European countries (Germany, Poland, Romania and Bulgaria) were subjected to physicochemical, phytochemical and microbiological analysis. The cocoa powders were extensively characterized by recording their pH and titratable acidity, respectively, the polyphenols and also the methylxantine derivatives content (theobromine and caffeine). The cocoa powders pH ranged between 5.37 and 8.23, while the titratable acidity was 3.2-4.3 miliequivalent (100 g)(-1) of cocoa powder. Their total polyphenols content ranged between 0.986 divided by 2.003 g GAE/(100 g)(-1). The methylxanthine derivatives (theobromine and caffeine) were analyzed by the HPLC method and ranges of 0.992-1.174% for theobromine and 0.096-0.369% for caffeine were obtained. Thermal analysis (TG-DTA) combined with mass spectrometry (MS) elucidated the decomposition processes and the volatile substances (CO, CO2, H2O, NO, theobromine, caffeine). The thermal analysis revealed transformations in the cocoa powders composition: drying and water loss;decomposition of pectic polysaccharides;lipids, amino acids and proteins, crystalline phase transformations and carbonizations. The microbiological analysis tested the degree of preservation of the cocoa powders across time, specifically immediately after unwrapping and after 14 days.

关键词： crystalline structure   flat‐   die extrusion   mechanical behavior   modified commercial starches   starch‐   based films  

摘要： Starch constitutes a promising resource for biodegradable packaging, but it presents several processing drawbacks when using conventional industrial equipment, such as flat-die extrusion. This work demonstrates that the replacement of native cassava starch (NS) with commercial hydrolyzed (HS) or carboxymethyl (CMS) starches diminishes the amount of energy required to process starch granules into thermoplastic films by extrusion. Homogeneous films with starch-glycerol interaction improvements are obtained when using HS or CMS instead of NS. HS films exhibit the lowest crystallinity and the highest susceptibility to water among the studied systems. Likewise, CMS films maximize V-h crystalline structure fraction and present higher Young's modulus and stress at break, and lower water vapor permeability values. In order to combine the positive properties and to overcome the limitations of each modified starch, blend films from HS:CMS (50:50 wt%) are also developed and investigated. Phase separation is observed in this system, and there are no improvements in the overall properties. The results of this investigation show that employing commercial CMS, even in very low carboxymethylation degree represents a successful strategy to improve mechanical and barrier properties of flat-die extruded films, while HS can be used to obtain water-soluble films for specific applications.

关键词： Surfactants   Macromolecules   Biological systems   Molecular interactions  

摘要： Macromolecules are essential cellular components in biological systems responsible for performing a large number of functions that are necessary for growth and perseverance of living organisms. Proteins, lipids and carbohydrates are three major classes of biological macromolecules. To predict the structure, function, and behaviour of any cluster of macromolecules, it is necessary to understand the interaction between them and other components through basic principles of chemistry and physics. An important number of macromolecules are present in mixtures with surfactants, where a combination of hydrophobic and electrostatic interactions is responsible for the specific properties of any solution. It has been demonstrated that surfactants can help the formation of helices in some proteins thereby promoting protein structure formation. On the other hand, there is extensive research towards the use of surfactants to solubilize drugs and pharmaceuticals;therefore, it is evident that the interaction between surfactants with macromolecules is important for many applications which includes environmental processes and the pharmaceutical industry. In this review, we describe the properties of different types of surfactants that are relevant for their physicochemical interactions with biological macromolecules, from macromolecules-surfactant complexes to hydrophobic and electrostatic interactions.

关键词： Nanostructured lipid carriers   Compritol (R) 888 ATO   Squalene   Quercetin   Piperine  

摘要： Active plant constituents obtained from edible sources have manifested their pharmacological potential as a therapy against several diseases. But the lack of their desired physicochemical properties such as solubility, permeability ultimately leads to poor bioavailability. Two potent active plant constituents namely, quercetin and piperine having a problem with either solubility or permeability or both, and hence require an advanced lipid-mediated separate formulation system to improve their aforementioned concerns. Concerning advancement in nanoformulations, lipid-based nano-carriers systems have created their mark as a novel drug delivery system. Therefore, an advanced formulation like nanostructured lipid carriers (NLCs) has been formulated individually for both the active plant constituents/drugs through the solvent evaporation technique using high shear homogenization method followed by sonication. Compritol (R) 888 ATO, a solid lipid, and squalene as liquid lipid was used in their optimized ratios to formulate individual NLCs. Blank and individual drugs loaded NLCs were further characterized for their in vitro physicochemical properties. NLCs showed a negative surface charge with an average particle size below 200 nm. Electron microscopy images showed an anomalous structure of both the formulated NLCs with higher % drug encapsulation efficiency (DEE) with the desired in vitro drug release profile. In the case of quercetin-NLCs, 93.18 +/- 5.5 % DEE was observed followed by drug release up to 45.0 +/- 1.3 % within 12 h, while piperine-NLCs showed 91.80 +/- 2.51 % DEE and drug release up to 38 +/- 5.2 % at the same time. XRD and DSC plots showed the conversion of both the drugs into an amorphous structure encapsulated in a lyophilized NLCs matrix. Finally, the safety profile for formulated NLCs was confirmed by haemolysis assay. Hence, the developed active plant constituents enriched NLCs can further be delivered separately and/or in combination, and also may fur

关键词： Extrusion   Gelatinization   Modified starch   Texture   Noodle quality  

摘要： Noodle products are widely consumed worldwide. The acceptance and preference of these functional products by consumers can be promoted through the exploration of new knowledge to enhance their formulation and quality. Starch and its modified forms are important auxiliary materials or additives for modern food processing. They are considered safe processing auxiliary materials or efficient quality improvers widely used in noodle products. In this review, the physicochemical properties and structural characteristics of native starch and its modified forms used in noodle products are introduced. The applications of native starch, chemically, physically, and enzymatically modified starches in noodle products are reviewed. The application prospects and challenges in starch and its modified forms in noodle products are presented.

关键词： grain modification   infrared radiation   mechanical properties   physicochemical properties   structural changes  

摘要： Infrared (IR) is a highly efficient and energy-saving technology known for uniform heating, less heating time, and high energy transfer rate to improve food product quality and safety. IR technology has many applications, including drying and dehydration, enzyme inactivation, pathogen inactivation, and other miscellaneous uses such as roasting, frying, and broiling. However, the effect of IR radiation on the overall behavior of the grain and its components has not received much attention. This review focuses on the changes in the properties of grain starch when exposed to IR radiation. The effects of alteration in structural characteristics of starch on the mechanical and functional properties and on starch digestibility patterns have been discussed. An attempt has been made to present the theoretical basis for the interaction of IR radiation with the grain and its components. IR radiations interact with food molecules to vibrate the bonds to cause stretching in them. The vibration energy causes rearrangement of starch molecules resulting in the modification of mechanical and functional properties as well as the starch digestibility pattern of the grain. These may bring about changes in the outlook of the grain and hence the IR technology may find application in the grain processing industry.