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关键词： edible bird's nest   FTIR   glycopeptide   N-acetylneuraminic acid   recovery  

摘要： BACKGROUND Processing of edible bird's nest (EBN) requires extensive washing to remove impurities and produces huge amounts of EBN co-products, which contain mainly feathers with glycoproteins attached, which are usually discarded. This study was conducted to recover the valuable EBN glycoproteins from the waste material. Enzymatic hydrolysis was applied to recover EBN glycopeptides from EBN co-products (EBNcoP) and processed cleaned EBN (EBNclean) was used as control, which were then freeze-dried into EBN hydrolysates (EBNh(coP)and EBNh(clean), respectively). RESULTS The recovery yield for EBNh(clean)and EBNh(coP)were 89.09 +/- 0.01% and 47.64 +/- 0.26%, respectively, indicating nearly 50% of glycopeptide can be recovered from the waste material. Meanwhile,N-acetylneuraminic acid, a major acid sugar in EBN glycoproteins, of EBNh(coP)increased by 229% from 58.6 +/- 3.9 to 192.9 +/- 3.1 g kg(-1), indicating the enzymatic hydrolysis removed impurities and thus enhanced theN-acetylneuraminic acid content. Total soluble protein was more than 330 g kg(-1)for all the samples. Colour parameter showed that hydrolysate samples have greaterL* (lightness) values. Chroma result indicates the intensity of all the samples were low (< 11). Fourier-transform infrared (FTIR) spectrum displayed that the EBNh(coP)exhibited similar functional groups with EBNh(clean), indicating that the EBN(coP)has similar functionality as EBNclean. Significantly higher (P <= 0.05) 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) activities were reported in EBNh(coP)after the enzymatic reaction. CONCLUSION EBNh(coP)were successfully recovered from low value EBN(coP)with enhanced antioxidant activities. The findings of this work are beneficial for the EBN industry to reduce wastage and enhance economic values of EBN co-products, both economically and nutritionally. (c) 2020 Society of Chemical Industry

关键词： in vitrodigestion   maltodextrin   microcapsules   spray-dryer   stevia leaves   UHPLC-MS  

摘要： This work aimed to formulate and perform physicochemical and functional characterization of maltodextrin microcapsules containing ethanolic extract of stevia, rich in antioxidant compounds, encapsulated by a spray-drying process with two maltodextrins (DE10 and DE19). The powders were named M10 and M19, respectively. We analyzed the physicochemical parameters, antidiabetic activity, cytotoxicity, bioaccessibility of the compounds byin vitrodigestion, as well as the structure of the microcapsules by scanning electron microscopy. Microcapsules showed higher solubility (similar to 35%), lower moisture content (similar to 29%), and the maltodextrin DE10 had higher efficiency as an encapsulating agent (87%) when compared to DE19 (76%) and showed well-defined spherical structures. The microencapsulation preserved the content of phenolic compounds and antioxidant activity present in the extract (7.2% and 87.5%, respectively). The bioaccessibility of these microencapsulated compounds and antioxidant activity were higher under different conditions ofin vitrodigestion (mouth, gastric, and intestinal conditions) and showed no cytotoxic effects. We identified 41 compounds (by UHPLC-MS/MS-Qtof) related to the nutritional benefits offered by stevia and the microencapsulation technique can be recommended to preserve bioactive compounds. Practical Application Ethanol extract from stevia leaves contains antioxidant phytochemicals related to the nutritional benefits of stevia. However, this extract presents low solubility and consequently low bioaccessibility underin vitrodigestion. The microencapsulation process protects the bioactive compounds of the different pH from digestion and improves the physical-chemical parameters of the extract, increasing its applicability as a possible food additive.

关键词： Bamboo shoots   Dietary fiber   Modification   Subcritical water   High pressure homogenization   Physicochemical properties  

摘要： In presented study, the effects of subcritical water (SW) and high pressure homogenization (HPH) treatments on the physicochemical and structural characteristics of dietary fibers (DFs) from bamboo shoots (Phyllostachys praecoxf. Prevernalis) were investigated. The soluble dietary fiber (SDF) content was dramatically increased in SW and HPH treated DFs. Compared with HPH, SW modification enhanced higher physicochemical properties including water holding capacity (WHC), oil holding capacity (OHC) and swelling capacity (SC) of DFs. The abilities of DFs to absorb cholesterol and nitrite ions were both greatly increased after treatments. The results of Scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), and X-ray diffraction (XRD) showed that the structure of DFs were changed by SW and HPH. In conclusion, SW treatment showed better effects on improvement of physicochemical properties of bamboo shoot DFs than that of HPH, and the modified DFs could be a potential new functional foods or food additives.

关键词： Proteins  

摘要： The presence or absence of prawn shell impacts the cooked muscle quality. Here, we evaluated the effect of different cooking temperatures and times during water bath treatment on the quality attributes of peeled and unpeeled prawns. Several factors, including heat penetration, moisture content, color distribution, microstructure, and texture changes were tested. Thermal protein denaturation was assessed to clarify differences in quality attributes between both samples. Heat penetration was slightly slower in unpeeled prawns compared to peeled prawns, which correlated with the lower denaturation rate for each protein (myosin, sarcoplasmic-collagen, and actin). The tissue connection between the shell and muscle protects the prawn meat from shrinkage, resulting in reduced water release. Maximum stress at 50, 65, and 75 degrees C was significantly higher in unpeeled prawns than in peeled prawns. However, the absence of shell resulted in a denser microstructure and slightly higher color profile in peeled prawns. These findings may be applied for the thermal processing of prawns. Practical Applications The applications of the findings of this study include but are not limited to: (a) predicting the thermal protein denaturation conditions for both peeled and unpeeled prawn muscles, which can facilitate the selection of the applied thermal process degree in order to reduce cooking losses, (b) direct mapping of color distribution at the surface and internal sections of both samples, which contribute to the acceptability of cooked prawn products and easy detection of overcooked areas, and (c) helping in the sensitization of consumers and also processors of the quality attribute retention of processed prawns, since prawns are processed with or without peeling as desired by the target customer

关键词： Chaenomeles   Osmotic dehydration   Combined drying   UPLC-PDA-FL   alpha-Amylase   alpha-Glucosidase   Antioxidant capacity  

摘要： The aim of this study was to determine the effect of osmotic dehydration (OD) using fruit concentrates (apple, pear, pineapple, sour cherry, blackcurrant, and chokeberry), before combined drying involving convective drying and vacuum-microwave finish drying, on the drying kinetics and physiochemical parameters (dry weight, water activity, content ofl-ascorbic acid, sugars, organic acids, and phenolic compounds). Moreover, biological activities, including antioxidant, antidiabetic, and anticholinergic activities, of the dried Japanese quince fruit and osmotic fluids before and after osmotic dehydration have been assessed. The chokeberry concentrate reduced the final moisture ratio by half compared with the non-OD Japanese quince fruit, and the pineapple and sour cherry concentrates hindered the dehydration process during vacuum-microwave drying. OD significantly shortened the combined drying time compared with non-OD samples. The OD Japanese quince fruit was characterized by an increased content of sugars (up to 20 times more) and a significant reduction in the content of organic acids (even 77% reduction compared with non-OD fruit). Total phenolic content and antioxidant capacity of OD fruits decreased, but increased inhibition potential of alpha-amylase, acetylcholinesterase, and butyrylcholinesterase was observed. Osmotic fluids were also analyzed before and after the OD, and the following changes were found: reduction of sugars and increase of organic acid content, increase in phenolic content, antioxidant and antidiabetic potential, regardless of the concentrate used. To sum up, the osmotic dehydration process has the potential to modulate the chemical composition and biological properties of the Japanese quince fruit.

关键词： Soybean 7S globulin   Reverse micelle extraction   Alkali extraction-acid precipitation   Thermodynamic property   Rheological property   Physicochemical properties  

摘要： In this paper, the structural, thermodynamic, and rheological properties of soybean 7S globulins extracted by bis (2-ethylhexyl) sulfosuccinate sodium salt (AOT)/isooctane reverse micelle method and alkali extraction-acid precipitation method were studied. Amino acid composition results showed that the 7S globulin produced by reverse micelle had more hydrophobic and sulfur-containing amino acids. Fourier transform infrared spectroscopy results demonstrated that the 7S globulin extracted by reverse micelle had more beta-sheets but less turn structure, and formed a more compact conformation. However, lower surface hydrophobicity was observed in the 7S globulin extracted by reverse micelle, indicating that the reverse micelle environment could protect the native folded structure of protein. Thermal stability tests showed that the 7S globulin extracted by reverse micelle had poorer thermostability with lower denaturation temperature, which was in accordance with the results of initial gelling temperature. Final storage modulus (G') and frequency sweep results revealed that the 7S globulin obtained by reverse micelle produced a harder textured gel.

关键词： Gum Arabic   Functionalization   Ferulic acid   Surface tension   Rheological behavior   Thermal behavior   Antioxidant  

摘要： Gum Arabic is a natural polysaccharide with valuable properties that enable its use in many industrial fields. Nevertheless, its application field may be enlarged to new properties. One way consists of the modification of the polysaccharide through an enzymatic process based on the oxidation of a phenolic compound. This work aims then to study the impact of the presence of ferulic acid oxidation products onto gum Arabic on its properties as its color, thermal properties, rheological and interfacial behaviors. For instance, modified gum Arabic powder underwent a change of color from white to orange and a glass transition was reported contrary to native gum. Though its rheological behavior did not change, its solubility decreased from 42.5 +/- 2.6 to 10.6 +/- 0.1% w/v. However, the amphiphilic behavior of functionalized gum Arabic seemed to be different from the one of native gum Arabic. For a given concentration, the surface tension of the modified polymer was lower (31.2 +/- 0.8 mN m(-1) for native gum Arabic against 52.5 +/- 2.4 mN m(-1) for the modified gum at 1% w/v). Finally, modified gum Arabic presented important antioxidant properties. The modification of gum Arabic with phenolic compounds appeared then as a promising way to produce a polysaccharide with new properties that could enlarge the field of its potential applications and could make it an interesting food ingredient.

关键词： Lime   Soil structure   Arable land   Marshland soils   Physical parameters   Cation exchange capacity   Aeration parameters  

摘要： Liming is a well-established practice to ameliorate acidic soils worldwide. However, 42 % of the arable soils in Germany are classified in a low pH-range (A/B). We hypothesize that the surface application and incorporation of lime will affect the structure and thus the physicochemical and hydraulic properties of two marshland soils with different clay content. Water holding capacity, total porosity, bulk density, hydraulic conductivity, and aeration parameters were quantified in the topsoil of two study sites located in the marshlands of Schleswig-Holstein, Germany. The soil at the first study site is a Haplic Gleysol, the most representative soil type in the region, with a clay content of 28 %, and the second is a Haplic Gleysol with a clay content of 40 %. The field experiments were arranged in a randomized block design with three different treatments: a control with no lime application (Lime0), lime application according to the soil-specific recommendations by VDLUFA (2000) to achieve an optimized soil pH (Lime1), and soil-specific recommendations x 1.5 (Lime1.5). Liming significantly increased the pH, cation exchange capacity, plant available water capacity, and aeration parameters, decreased bulk density in the soils already 12 months after application, and the effects remained stable during the surveyed three years after lime application. The results underline the importance of sufficient lime supply and the potentials of elevated lime doses to ameliorate soil structure, plant water supply and yields in undersupplied, clay-rich soils.

关键词： antioxidant activity   inlet temperature   physicochemical properties   seed-watermelon seed   spray drying  

摘要： Here, we studied the effects of inlet temperature on the physicochemical properties of the hydrolyzed protein (seed-watermelon seed hydrolyzed protein [SWSP]) powder in seed-watermelon seeds. The inlet temperature of the study was in the range of 150 to 180 degrees C, and the remaining experimental parameters remained constant, that is, the feed flow rate was 0.2 L/hr, the concentration of maltodextrin was 30%, and the outlet temperature was 80 degrees C. We studied the water activity and moisture content, bulk density, flowability (Carr index and Hausner ratio), angle of repose, solubility, color, hygroscopicity, powder morphology, particle size, crystallinity, and odor of the sample. Inlet temperature of 170 to 180 degrees C reduced the moisture content and increased the particle size. It was found that the value of measured water activity was less than 0.5, which helped in maintaining stability of the sample. Powders produced at the temperatures showed smoother particle surfaces, whereas higher inlet temperature showed spherical particles with some shrinkage as analyzed by scanning electron microscope. The inlet temperature affected the color of the sample, thus at high temperature, the sample had a brighter color. The sample was approximately 18% crystalline. At a preparation temperature of 160 degrees C, the sample showed significant antioxidant activity (P< 0.05).

关键词： Water treatment   Contaminant remediation   Stimulant drug   Carbonized materials  

摘要： The present study aimed to envisage the effect of physicochemical properties on the performance of Gliricidia sepium biochar (GBC) pyrolyzed at 300, 500, and 700 degrees C in the removal caffeine (CFN);a pharmaceutical and personal care product, from water. The physicochemical properties of GBC were characterized by proximate and ultimate analysis, BET, SEM, FTIR, and Raman spectroscopy. The adsorption batch experiment was carried out at various pH values (pH 3-10), mixing times (up to 24 h), and initial CFN concentration (10-500 mg/L). The FTIR analysis revealed the loss of polar functional groups on the surface of GBC derived at high temperatures. The redshifted and blue-shifted Raman peaks indicate the condensation of small molecules on GBC. The GBC derived at 700 degrees C demonstrated high CFN adsorption capacity (16.26 mg/g) due to its high surface area and aromaticity. The highest adsorption of CFN was occurred at acidic pH range from 3.5 to 4.5 due to the existence of nonspecific attraction between CFN and GBC. The kinetics and isotherm experimental data were fitted with Elovich and fractional power kinetic regression, Freundlich, and Temkin isotherm models, which suggested the adsorption of CFN on the GBC by mixed mechanisms;physisorption and chemisorption including pi-pi interactions, hydrogen bonding, n-pi interactions, electrostatic attraction, and electron donor-acceptor attraction. Moreover, both surface area and ammaticity index have demonstrated a high positive correlation for CFN adsorption, signifying the importance of controlling physicochemical properties based on the end-user purpose of biochar.