Time filter

Source Type

Li J.,Beijing Technology and Business University | Zhu Y.,Beijing Technology and Business University | Teng C.,Beijing Technology and Business University | Teng C.,Beijing Key Laboratory of Flavor Chemistry | And 5 more authors.
Journal of Food Science and Technology | Year: 2017

The effect of bovine serum albumin (BSA), whey protein isolate (WPI), whey protein hydrolysate (WPH), sodium caseinate (SC), carboxymethylcellulose sodium (CMC), fish gelatin (FG), high methoxyl apple pectin (HMAP), low methoxyl apple pectin (LMAP), gum Arabic (GA), ι-carrageenan (CGN), and hydroxypropyl chitosan (HPCTS) on physical stability of internal or external aqueous phase of water-in-oil-in-water (W/O/W) emulsions was evaluated. WPI and CGN in the internal aqueous phase, and GA, HPCTS, and CMC in the external phase reduced the size of emulsion droplets. BSA, WPI, SC, FG, CGN, and HPCTS improved the dilution stability of W/O/W emulsions, but HMAP had a negative effect. BSA, WPI, SC, FG, LMAP, GA, CGN, HPCTS, or CMC significantly improved the thermal stability of W/O/W emulsions. Results also indicated that the addition of CGN (1.0%), HMAP (1.0%), WPH (1.0%), or HPCTS (1.0%) in internal aqueous phase significantly increased the viscosity of emulsions, however, addition to the external aqueous phase had insignificant effects. A protein-knockout experiment confirmed that proteins as biomacromolecules, were the key factor in improving physical stability of emulsions. © 2017, Association of Food Scientists & Technologists (India).


Yan Z.,Beijing Technology and Business University | Yang R.,Beijing Technology and Business University | Li X.,Beijing Technology and Business University | Li X.,Beijing Key Laboratory of Flavor Chemistry
Journal of Chinese Institute of Food Science and Technology | Year: 2013

In recent years, with the development of molecular biology and the deepening of study on cloning expression, the exogenous gene expression systems are being further researched. Microbial expression systems have many advantages, such as simple culture, short period and low cost. Up to now, several relatively mature expression systems have been set up. Such as Escherichia coli expression system, Bacillus subtilis expression system, yeast expression system and Filamentous fungal expression system. These expression systems are the important foundation for proteinic production and research. This paper reviews the characteristics of the above expression systems, the influencing factors on high level expression and their current application.


Li J.,Beijing Technology and Business University | Li J.,Beijing Higher Institution Engineering Research | Shi Y.,Northwest University, China | Zhu Y.,Beijing Technology and Business University | And 5 more authors.
Journal of Agricultural and Food Chemistry | Year: 2016

Water-in-oil-in-water (W/O/W) emulsions are effective vehicles for embedding application of active compounds but limited by their thermodynamic instability and rapid release properties. The present study added bovine serum albumin, whey protein isolate, whey protein hydrolysate, sodium caseinate, carboxymethylcellulose sodium, fish gelatin, apple pectin, gum arabic,-carrageenan, and hydroxypropyl chitosan separately to the internal or external aqueous phase to investigate their effects on the physical stabilities and controlled release properties of W/O/W emulsions. The effects of the natural macromolecules in the internal and external aqueous phases were different and depended upon the macromolecule structure and its mass fraction. The addition of the natural macromolecule strengthened the interfaces of emulsions, which improved the physical stability. The natural macromolecules that improved the stability often did not improve controlled release. Therefore, the balance between these properties needs to be considered when adding natural macromolecules to a W/O/W emulsion. © 2016 American Chemical Society.


Li J.,Beijing Technology and Business University | Zhu Y.,Beijing Technology and Business University | Zhu Y.,Beijing Key Laboratory of Flavor Chemistry | Teng C.,Beijing Technology and Business University | And 2 more authors.
Journal of Chinese Institute of Food Science and Technology | Year: 2016

The study used Bacillus amyloliquefaciensits 11568 that we screened before as the strain, then influence of factors such as nitrogen source, nitrogen source, pH, culture temperature, shake flask speed, metal ion types and concentration on the capacity of naringinase productivity was investigated. According to single-factor experiments and response surface methodology (RSM) experiments, the results indicated that the optimization cultivation conditions was as follows: maltose 15.1 g/L, yeast extract 5 g/L, (NH4)2HPO4 20 g/L, NaCl 10 g/L, tryptone 10 g/L, and the optimization fermentation conditions was as follows: culture temperature 40.9℃, initial pH 7.5, shake flask speed 180r/min, incubation time 48 h. Under such conditions, naringinase activity of 201.12 U/mL was reached, which was 2.4 folds than preoptimized. © 2016, Editorial Office of Journal of CIFST. All right reserved.


Zhu Y.P.,Beijing Technology and Business University | Teng C.,Beijing Technology and Business University | Sun B.G.,Beijing Technology and Business University | Sun B.G.,Beijing Key Laboratory of Flavor Chemistry
Food and Bioproducts Processing | Year: 2013

The strain Bacillus subtilis B2 isolated from a Chinese traditionally fermented food was capable of producing α-glucosidase inhibitor (AGI). On the basis of single-factor experiments, the optimum culture conditions using okara as the substrate were achieved by response surface methodology (RSM). The experimental results lead to the conclusion that the highest yield of AGI was reached at the fermentation time 65.6 h, fermentation temperature 39.0°C, Okara concentration 4.5% and pH 7.11. A second-order model developed for the production of AGI prediction exhibits a F-value of 15.8 and a high value for the coefficient of determination (R2 = 0.933). Under these conditions, the AGI activity of the broth reached 29.4. In comparison with the highest AGI activity (24.3) obtained at the one-factor-at-a-time fermentation condition, the AGI activity increased by 21%. The AGI in the fermentation broth of B. subtilis B2 was also partially purified and determined by HPLC-ELSD. One of effective AGI, deoxynojirimycin (DNJ) has been proved in the fermentation broth, which indicated that the fermented okara might be considered as one of the promising materials for producing the food-derived DNJ products. © 2012 The Institution of Chemical Engineers.


Liu Y.,Beijing Technology and Business University | Miao Z.,Beijing Technology and Business University | Guan W.,Beijing Technology and Business University | Sun B.,Beijing Key Laboratory of Flavor Chemistry
Molecules | Year: 2012

The organic volatile flavor compounds in fermented stinky tofu (FST) were studied using SPME-GC/MS. A total of 39 volatile compounds were identified, including nine esters, seven alcohols, five alkenes, four sulfides, three heterocycles, three carboxylic acids, three ketones, two aldehydes, one phenol, one amine and one ether. These compounds were determined by MS, and conformed by comparison of the retention times of the separated constituents with those of authentic samples and by comparison of retention indexes (RIs) of separated constituents with the RIs reported in the literature. The predominant volatile compound in FST was indole, followed by dimethyl trisulfide, phenol, dimethyl disulfide and dimethyl tetrasulfide. In order to find a better extraction time, the extraction times was optimized for each type of SPME fiber; the results show that the best extraction time for Carboxen/PDMS is 60 min, for PDMS/DVB 30 min, for DVB/CAR/PDMS 60 min and for PDMS 75 min. Of the four fibers used in this work, Carboxen/PDMS is found to be the most suitable to extract the organic volatile flavor compounds in fermented stinky tofu. © 2012 by the authors.


Zhang Y.,Beijing Technology and Business University | Zhang Y.,Beijing Key Laboratory of Flavor Chemistry | Huang M.,Beijing Technology and Business University | Huang M.,Beijing Key Laboratory of Flavor Chemistry | And 7 more authors.
Food Science and Biotechnology | Year: 2014

Volatile compounds in Chinese fermented flour paste were extracted using simultaneous distillation and extraction (SDE) and analyzed using gas chromatography-mass spectrometry (GC-MS) with DB-5 and DB-WAX capillary columns. A total of 84 volatile compounds were identified, including 8 aldehydes, 19 esters, 14 acids, 17 hydrocarbons, 7 heterocycles, and 19 other trace compounds. The major volatiles included furfural, 5-methyl-2-phenyl-2-hexenal, 4-ethylguaiacol, 2-phenylacetaldehyde, ethyl hexadecanoate, isovaleraldehyde, palmitic acid, and 5-methylfurfural. Aroma compounds were investigated using gas chromatography-olfactometry (GC-O) and aroma extract dilution analysis (AEDA). A total of 27 olfactory regions were exposed and 18 aroma extracts were located. Altogether, 6 aroma compounds identified using GC-O showed higher flavor dilution factors (FD≥32), including isovaleraldehyde, furfural, pentanoic acid, 2-acetylfuran, 1-octen-3-ol, and 2-phenylacetaldehyde. Compared with soybean sauce, fermented flour paste has more esters and aldehydes, which contribute to the desired fruity, caramel, sweet, and roasted odors. © 2014 The Korean Society of Food Science and Technology and Springer Science+Business Media Dordrecht.


Liu Y.,Beijing Technology and Business University | Guan W.,Beijing Technology and Business University | Miao Z.,Beijing Technology and Business University | Sun B.,Beijing Key Laboratory of Flavor Chemistry
Advanced Materials Research | Year: 2012

Benzyl 4-ethyloctanoate was synthesized by the reaction of 4-ethyloctanoyl chloride with benzyl alcohol, and its synthesis conditions were optimized. The yield of benzyl 4-ethyloctanoate was about 93%. Based on the synthesis of benzyl 4-ethyloctanoate, phenethyl 4-ethyloctanoate, phenylpropanol 4-ethyloctanoate and cinnamyl 4-ethyloctanoate were prepared. The odor evaluations indicate that these four new ester compounds have floral and sweet note. These ester compounds have relatively high molecular weights and can be used as fixing agent to prolong the fragrance compounds lifetime.


Liu Y.,Beijing Technology and Business University | Miao Z.,Beijing Technology and Business University | Yang J.,Beijing Technology and Business University | Guan W.,Beijing Key Laboratory of Flavor Chemistry | Sun B.,Beijing Key Laboratory of Flavor Chemistry
Applied Mechanics and Materials | Year: 2012

The volatile flavor compounds of Huizhou preserved vegetable were extracted by hydrodistillation (HD) and simultaneous distillation-extraction (SDE). The essential oils obtained were analyzed by gas chromatography-mass spectrometry, accompanying by comparison of the retention time of authentic samples and by calculation of retention index about the separated constituents. 50 volatile flavor compounds were identified in the essential oils of Huizhou preserved vegetable obtained by HD and SDE in all. 41 compounds were identified in the essential oil from HD and 36 compounds identified in the essential oil from SDE. The constituents which are very important to the odor of Huizhou preserved vegetable include 3-hydroxy-2-butanone, dimethyl disulfide, hexanal, furfural, 2-furanmethanol, 2-methylbutanoic acid, benzeneacetaldehyde, phenylethyl alcohol, 5-ethyldihydro-2(3H)-furanone, 5-pentyl-dihydro-2(3H)-furanone, etc. The exclusive compounds in the essential oil gained by HD consist of hexanol, heptanol, 1-(2-furanyl)-ethanone, 5-methyl-dihydro-2(3H)-furanone, benzaldehyde, phenol, benzyl alcohol, methyl benzoate, ethyl benzoate. The exclusive compounds obtained by SDE are 3-hydroxy-2-butanone, dimethyl trisulfide, trans-2-(2-pentenyl)-furan, camphor, vanillin, etc. The differences result in the two essential oils with a few distinctions on aroma characteristics.


Li X.,Beijing Technology and Business University | Li E.,Beijing Technology and Business University | Zhu Y.,Beijing Technology and Business University | Teng C.,Beijing Technology and Business University | And 4 more authors.
Carbohydrate Research | Year: 2012

The activity of the extracellular xylanase produced by Streptomyces rameus L2001 against different xylans and xylooligosaccharides (XOS) was investigated. The main products of hydrolysis of birchwood xylan and oat-spelt xylan by the S. rameus L2001 xylanase were xylobiose (X2) and xylotriose (X3), suggesting that this is an endo-acting xylanase. This was confirmed by analysis of XOS degradation products. The enzyme hardly hydrolyzed X2 and X3, but hydrolyzed xylotetraose (X4) and xylopentaose (X5) producing mainly X2 and X3 through transglycosylation. Depending on the substrate, different quantities of reducing sugars were produced by the xylanase: 150 mg/g from corncob, 105 mg/g from bean culms, and 133 mg/g from bagasse. With the bagasse substrate, the xylanase yielded 2.36, 2.76, 2.03, and 2.17 mg/mL of X2, X3, X4, and X5, respectively. The structure of xylobiose and xylotriose from the hydrolysis of corncob xylan was identified by MS and NMR. The production of XOS from various agricultural wastes has potential industrial applications. This is the first report of XOS production by S. rameus L2001. © 2012 Elsevier Ltd. All rights reserved.

Loading Beijing Key Laboratory of Flavor Chemistry collaborators
Loading Beijing Key Laboratory of Flavor Chemistry collaborators