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关键词： Aroma profile   Soaking process   Quality   Peleg model  

摘要： The aim of this study was to investigate the effects of different type of leavening agents (ammonium bicarbonate-A, cream of tartar-B, grape-based leavening agent-C, baking powder-D) on the structural (also after soaking), physico-chemical and other quality characteristics of biscuits made with the same formulation. The major changes observed between samples were related to their textural properties, volatile profile and sensory characteristics. The presence of ammonium bicarbonate in sample A, gave arise to a biscuit with the most homogeneous surface appearance, the less hard structure and highest fracturability and spread, that promoted their greater milk uptake during soaking. The B and C biscuits, made with baking powder having tartaric acid, were characterized by a crisper texture and lower sensory overall acceptability. The presence in formulation of baking powders made with cream of tartar (B) and ammonium bicarbonate (A) mostly influenced the biscuit volatile profiles. Biscuit sample obtained with the most common baking powder (diphosphates powder) showed in general intermediate characteristics between A and B-C samples. Results obtained in this study demonstrate that a lot of final properties of biscuits can be strongly influenced by the type of leavening agents used in formulation.

关键词： Cranberries   Ultrasound   Microwave-vacuum treatment   Freezing   Hybrid drying   Quality attributes  

摘要： The aim of the study was to evaluate the effect of sonication (S), microwave-vacuum (MWV), convective freezing (F), cryogenic freezing (N), and their combinations, as well as pulsed vacuum osmotic dehydration (PVOD) on the drying kinetics, bioactive compounds, texture and color of whole cranberries during combined hot air convective drying, and microwave-vacuum drying (HACD+MWVD). Drying of berries took from 20 to 493 min. Drying rate was enhanced by 23% and drying time of non-osmotically dehydrated fruits was shortened by 33% using F treatment, while MWV decreased moisture content before drying by 68% and shortened the drying time of PVOD berries by 96%. Generally, total phenolic (TP) content increased during processing, total flavonoids (TF), and total monomeric anthocyanins (TMA) contents decreased, while the values of ferric reducing antioxidant power (FRAP) of dried fruits depended on the initial pretreatment. F and HACD+MWVD yielded fruits of the highestL*(33.8 +/- 0.7),a*(25.2 +/- 1.0), andb*(7.3 +/- 0.6), inflated oval shape, and a small amount of wrinkles on the surface. PVOD and HACD+MWVD resulted in flat and wrinkled fruits.

关键词： Conjugated polymers   layer-by-layer polymerization   nanocomposites   conducting network   physicochemical characteristics  

摘要： Nanocomposites of conjugated polymers polypyrrole (PPy) and polyvinyl chloride (PVC) as matrices and 1,4-phenylenediamine (PDA) as a linker with amine functional graphite (FG-NH2) as filler have been efficiently fabricated using in situ oxidative polymerization, and the effect of various mass ratios on physicochemical characteristics of prepared nanocomposite was investigated. The layer-by-layer oxidative polymerization of various matrices on host filler surface is confirmed by Fourier transform infrared, energy dispersive X-ray, and X-ray photoelectron spectroscopy examinations. Field emission scanning electron microscopy revealed fibrillary morphology of obtained nanocomposites. Thermal stability, glass transition temperature, and melting and crystallization temperature of the nanocomposites were increased with the incorporation of modified graphite. Brunauer-Emmett-Teller analysis explored the improved adsorption capacity (128 cm(3)g(-1)) of the nanocomposite with higher feeding ratio of pyrrole. The influence of FG-NH(2)and pyrrole on electrical conductivity performance of composites was also investigated. Functionalized graphite in the resultant PPy/PVC/PDA@FG-NH(2)nanocomposites played an important role in forming conducting network in PPy matrix indicating synergistic effect between PPy and FG-NH2.

关键词： Natural additive   Hydrolysis   Non-digestible starch   Sensory attribute   Edible quality  

摘要： Chitosan is a natural additive widely used in food processing due to its functional properties, but few messages are available about the direct effects of chitosan on the quality of purple highland barley noodles (PHBN). Samples with 0.25%-2% (w/w) of chitosan addition were assessed in this study. Results indicated that the texture and water-holding capacity (WHC) of PHBN were significantly increased by chitosan. The in vitro starch hydrolysis of PHBN was significantly inhibited by chitosan via converting digestible starch into non-digestible starch, thus resulting in a significant decrease in the glycemic index (GI) of PHBN. This effect of chitosan on starch hydrolysis showed in a dose-dependent manner. Moreover, the antimicrobial potentials, antioxidant activities, and sensory attributes of PHBN were also significantly enhanced by chitosan. Our findings strongly demonstrated that chitosan could not only significantly enhance the antimicrobial potentials of PHBN but also improve its edible quality.

关键词： Palm olein   Biodegradable   Biomaterials   Biopolymers   Ring-opening polymerisation  

摘要： The utilisation of palm oil-based polymers as biomaterials has received considerable interest to support further expansion in the biomedical field as they pose the potential capability of competing with synthetic polymers per their physicochemical, thermal, and crystallinity properties. In this study, the synthesis of a new green biopolymer, namely acrylated palm olein (APO) from a palm oil-based precursor, was developed. The APO was synthesised via the ring-opening process of the epoxidised palm olein (EPOo) with acrylic acid and triethylamine. The acrylation process produced an APO of a high yield (86.64%) with a molecular weight of 1750 Da. The ester group representing the APO was confirmed through the proton nuclear magnetic resonance (H-1-NMR), carbon-13 nuclear magnetic resonance (C-13-NMR) and Fourier transform infrared (FTIR), which revealed the promising biodegradable point of the APO molecular structure. Meanwhile, thermal and crystallisation profiles of the APO showed a single-stage decomposition pattern and its triglycerides (TAGs) crystal formation and melting behaviour. As a result, the desired APO polymer was obtained, which possessed potential biodegradable chemical functional group, amorphous, and low molecular weight properties.

关键词： Hog plum bagasse   Dietary fiber   Alkaline treatment   Microwave   Delignification  

摘要： In the present study, the use of microwave-assisted alkaline treatment (MAAT) to characterize hog plum (Spondias mombin L) bagasse (HPB) was investigated. HPB treated with sodium hydroxide (0.015, 0.025 and 0.03 M), and assisted with microwave treatment (600 W, 2400 MHz) for 5 min was analyzed for proximate (moisture, protein, fat, ash, fiber and carbohydrate content), lignocellulosic component (cellulose, hemicellulose and lignin), color parameters, functional (bulk density, water-WAC and, oil absorption capacity-OAC, swelling power and solubility index), structural (XRD) and morphological (SEM) properties with an untreated sample as the control. MAAT significantly (p < 0.05) showed a varied influence on proximate composition, but notably reduced crude fiber. Similarly, treatment reduced hemicellulose and lignin component, but increased cellulose content. Furthermore, treatment reduced color, but varied in functional properties of loose (0.065-0.137 g/cm3) and pack (0.113-0.167 g/cm3) bulk density, WAC (5.63-6.20 g/g) and OAC (7.10-4.97 g/g). An increase in swelling power (10.46-12.37 g/g) and solubility index (1.03-2.57%) was observed with treatment. Crystallinity pattern increased with treatment with peaks showing type I cellulose, while the morphological structure of delignified fiber showed increased porosity or pitched region with increasing treatment. The potential use of hog plum bagasse after MAAT for food application is technically feasible.

关键词： enzymatic hydrolysis   FTIR   lyophilized protein hydrolysate   polypeptides   structural properties   thermal stability  

摘要： The structural and physicochemical characteristics of protein hydrolysates prepared from Chinese sturgeon through the enzymatic hydrolysis process were evaluated. Two different enzymes including papain and alcalase 2.4L were used in the hydrolysis process. The papain enzyme significantly increased the degree of hydrolysis (20.62%) and decreased the zeta-potential (12.4 +/- 1.31 mV) as compared to the alcalase enzyme, which represented 15.55% and 15.53 +/- 0.77 mV, respectively. Alcalase 2.4L hydrolysate exhibited smaller particle size (822.047 +/- 61.26 nm) than papain hydrolysate (1425.39 +/- 44.82 nm). Hydrolysis by papain and alcalase 2.4L enzymes decreased the molecular weights (MW <= 1,000 Da) to 98.27% and 86.84%, respectively. The surface hydrophobicity and turbidity of the hydrolysates significantly affected by enzyme type and protein concentrations. By using the X-ray diffraction analysis, the papain hydrolysate showed a higher relative crystallinity degree (30.33%) than alcalase 2.4L hydrolysate (29.40%), whereas the Fourier transform infrared spectroscopy showed more clearly peaks for the amide bands of alcalase hydrolysate. The thermal properties also affected by enzymatic hydrolysis conditions, since the melting temperatures were 159.17 and 149.58 degrees C, whereas the rate of mass loss was 67.04% and 62.8%, for papain and alcalase hydrolysates, respectively. Practical Application The enzymatic hydrolysis process of proteins is employed to obtain the nutritionally and functionality important peptides that result during the preparation of fish protein hydrolysate. The objective of this study was to investigate the structural and physicochemical characteristics of protein hydrolysate prepared from Chinese sturgeon. This study showed that these characteristics were affected by enzymatic hydrolysis conditions especially enzyme type. The finding of this study may be useful in terms of providing new information on the properties of the protein hydrolysate an

关键词： Fatty acids  

摘要： The effects of thermosonication of cream on physicochemical, microbiological, thermal, oxidation properties and fatty acid composition of butter were determined. Butter samples were produced from cream thermosonicated (TS) for 5, 10, or 15 min and from raw (R) and pasteurised (P) cream as controls. Thermosonication decreased moisture content, water activity, and pH of samples when compared with control groups. Mean particle size (D [3.2]) values of TS samples were lower than the R and P samples. Thermosonication improved spreadability compared with that of butter from pasteurised cream. Oxidative stability (induction time) of TS samples was lower than R, but higher than P. Two melting peaks were determined;in all samples, the T-onset of the first peak ranged from 11.39 to 11.93 degrees C, and the Tpeak was between 14.01 and 14.14 degrees C. Thermosonication significantly reduced total bacteria count and can improve spreadability, oxidative stability, and microbial safety of butter samples. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Acoustic cavitation   Milk homogenization   Milk thermal treatment   Dairy product  

摘要： The aim of this study was to evaluate the effects of non-thermal and thermal high-intensity ultrasound (HIUS) treatment on the microbial and enzymatic inactivation, physicochemical properties, and kinetic stability of the raw milk by applying different energy densities (1, 3, 5, and 7 kJ/mL). Two HIUS treatments were evaluated based on different nominal powers, named HIUS-A and HIUS-B, using 100 W and 475 W, respectively. HIUS-A treatment was non-thermal processing while HIUS-B was a thermal treatment only for the energy densities of 5 and 7 kJ/mL since the final temperature was above 70 degrees C. The HIUS-B treatment showed to be more efficient. Log reductions up to 3.9 cycles of aerobic mesophilic heterotrophic bacteria (AMHB) were achieved. Significant reductions of the fat globule size, with diameters lower than 1 mu m, better color parameters, and kinetic stability during the storage were observed. Also, HIUS-B treatment inactivated the alkaline phosphatase and lactoperoxidase. The HIUS-B treatment at 3 kJ/mL worked below 57 degrees C being considered a border temperature since it did not cause unwanted physicochemical effects. Furthermore, a microbial inactivation of 1.8 +/- 0.1 log cycles of AMHB was observed. A proper inactivation of only the Alkaline phosphatase and a significant reduction of the fat globules sizes, which kept the milk kinetically stable during storage was achieved.

关键词： Coupled ultrasound remediation   Activated persulfate   Synergism   EPR spin trapping  

摘要： Coupling ultrasound with other remediation technologies has potential to result in synergistic degradation of contaminants. In this work, we evaluated synergisms from adding high-power ultrasound (20 kHz;250 W) to activated persulfate over a range of bulk temperatures (20-60 degrees C). We studied the aqueous degradation kinetics of three polycyclic aromatic hydrocarbons (PAHs: naphthalene, phenanthrene, and fluoranthene) treated by ultrasound-alone, heat-activated persulfate, and combined ultrasonically-activated persulfate (US-PS). At 20 degrees C, observed US-PS rate constants strongly correlated with Wilke-Chang diffusion coefficients. This correlation indicates PAH molecules diffuse to the bubble-water interface prior to reaction with sulfate radicals (SO4 center dot-) generated at the interface. At higher temperatures, observed US-PS rate constants appear to be a more complicated function of temperature and diffusion coefficients. Synergy indexes for PAHs with fast diffusion coefficients were greatest at 20 degrees C. Fluoranthene, the largest and most hydrophobic PAH, had a maximum synergy index at 30 degrees C;it benefited from additional thermal persulfate activation in bulk solution. Fluoranthene synergy indexes, however, decreased above 30 degrees C and became antagonistic at 60 degrees C. Electron paramagnetic resonance (EPR) spin trapping was used to quantify hydroxyl radical ((OH)-O-center dot) produced from acoustic cavitation in the absence of persulfate. These data showed consistent (OH)-O-center dot production from 20 to 60 degrees C, indicating PAH antagonisms at 60 degrees C were not due to lower bubble collapse temperatures. Instead, the results suggest that PAH antagonisms are caused by increased radical-radical recombination as bulk temperature increases. In effort to develop an efficient, combined remediation technology, this work suggests bulk temperatures between 20 and 40 degrees C maximize US-PS synergisms.