Entity

Time filter

Source Type


Zhang Y.,South China University of Technology | Zhang Y.,Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center | Sun W.,South China University of Technology | Zhao M.,South China University of Technology | And 5 more authors.
International Journal of Food Science and Technology | Year: 2015

This study aimed to investigate the effect of pepsin pretreatment on the ACE-inhibitory and DPPH radical scavenging activities of soya protein hydrolysates prepared with alcalase and protamex. The protein recovery, TCA-soluble peptide content, surface hydrophobicity, particle size and zeta potential were evaluated. Results showed that the hydrolysates exhibited varying ACE-inhibitory (i.e. the highest value 72.6% by alcalase and 84.3% by protamex) and DPPH radical scavenging activities (i.e. the highest value 51.9% by alcalase and 51.7% by protamex). Pepsin pretreatment could make soya proteins more susceptible for hydrolysis, and the results showed that the ACE-inhibitory and DPPH radical scavenging activities of the resultant hydrolysates were improved. A highly significant positive correlation between ACE-inhibitory and DPPH radical scavenging activities was observed in the alcalase hydrolysates, while no significant correlation among other treatments. The physical properties of hydrolysates, that is surface hydrophobicity, particle size and zeta potential, could influence their ACE-inhibitory and DPPH radical scavenging activities. © 2015 Institute of Food Science and Technology. Source


Zhao M.-M.,South China University of Technology | Zhao M.-M.,Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center | Liu M.,South China University of Technology | Liu M.,Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center | And 4 more authors.
Modern Food Science and Technology | Year: 2015

A water-soluble polysaccharide (MOWP) and an alkali-soluble polysaccharide (MOAP) were isolated from Mallotus oblongifolius. The MOWP and MOAP yields were 6.00% and 3.07%, respectively. The molecular weights of the MOWP and MOAP were determined by a high performance gel permeation chromatography assay. The molecular weights of the MOWPs were 906 kDa and 49 kDa, and the molecular weight of the MOAP was 95 kDa. The monosaccharide composition was determined by a pre-column derivatization assay. Based on the monosaccharide composition analysis, the MOWP was mainly comprised of glucose, galactose, and xylose. MOAP was mainly comprised of mannose, galactose, and xylose. The glycosidic bonds of MOWPs and MOAPs were determined by a methylation assay. The branched MOWPs and MOAPs were composed mainly of →3)-Xylf-(1→, →3)-Galp-(1→ and →3)-Glcp-(1→ in different ratios. MOWPs and MOAPs exhibited moderate antioxidant capacities. MOWPs showed better DPPH scavenging activity than did MOAPs. MOAPs showed better reducing power and oxygen radical absorbance capacity than did MOWPs. ©, 2015, South China University of Technology. All right reserved. Source


Chen H.,South China University of Technology | Zhao M.,South China University of Technology | Zhao M.,Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center | Lin L.,South China University of Technology | And 7 more authors.
Food Research International | Year: 2015

Defatted walnut meal (DWM), a main byproduct of walnut oil production, is rich in proteins with a high essential amino acid content. Our research was focused on the functional activities of defatted walnut meal hydrolysate (DWMH). DWMH exhibited relatively strong hydroxyl scavenging and oxygen radical absorbance capacities, protective effect on H2O2-injured PC12 cells compared with GSH and cerebrolysin. Besides, DWMH could combat d-galactose induced learning and memory impairments in the Morris water maze test and in the Dark/light avoidance test of mice. Seventy-seven peptides were identified by UPLC-ESI-MS/MS in the most potent antioxidative fraction of DWMH. WSREEQEREE and ADIYTEEAGR were the peptides that most likely accounted for the suppression of H2O2-induced apoptosis in PC12 cells. The mixture of the commercially available amino acids did not offer any protection on H2O2-injured PC12 cells, suggesting that amino acid sequence rather than amino acid composition was the dominant influencing factor. DWMH could be recommended as natural antioxidants for the development of functional foods targeting memory impairments. © 2015 Elsevier Ltd. Source


Zhuang M.,South China University of Technology | Lin L.,South China University of Technology | Lin L.,Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center | Zhao M.,South China University of Technology | And 8 more authors.
Food Chemistry | Year: 2016

Five tasty peptides were separated from soy sauce, by sensory-guided fractionation, using macroporous resin, medium-pressure liquid chromatography and reverse phase-high performance liquid chromatography, and identified by ultra-performance liquid chromatography tandem mass-spectrometry as ALPEEV, LPEEV, AQALQAQA, EQQQQ and EAGIQ (which originated from glycinin A1bB2-445, glycinin A1bB2-445, cobyric acid synthase, leucine-tRNA ligase and glycoprotein glucosyltransferase, respectively). LPEEV, AQALQAQA and EQQQQ tasted umami with threshold values of 0.43, 1.25 and 0.76 mmol/l, respectively. ALPEEV and EAGIQ had minimal umami taste, but ALPEEV, EAGIQ and LPEEV showed umami-enhancement with a threshold estimated at 1.52, 1.94 and 3.41 mmol/l, respectively. In addition, the synthetic peptides showed much better sensory taste than mixtures of their constitutive amino acids. It indicated that peptides might play an important role in the umami taste of soy sauce. © 2016 Elsevier Ltd. All rights reserved. Source


Zheng L.,South China University of Technology | Zheng L.,Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center | Zhao Y.,South China University of Technology | Zhao Y.,Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center | And 6 more authors.
Journal of Functional Foods | Year: 2016

Antioxidant activities of amino acids and synthetic dipeptides were studied to elucidate the structure-activity relationship of antioxidant dipeptides. Results showed that Tyr- and Trp-containing dipeptides showed the highest radical scavenging activities in both ABTS and ORAC assays with Trolox equivalent (TE) values ranging from 0.69 to 4.97 μmol TE/μmol peptide, followed by Cys- and Met-containing dipeptides. With respect to their reducing power and Fe2+ chelating abilities, only Cys-containing dipeptides showed moderate reducing power, and none of them displayed Fe2+chelating ability. It indicated that antioxidant dipeptides mainly acted as radical scavengers and the presence of Tyr, Trp, Cys or Met residue with electron/hydrogen donating ability was the driving force for dipeptides to scavenge radicals. Additionally, Tyr- and Trp-containing dipeptides with Tyr/Trp residue at the N-terminus showed stronger antioxidant activities than that at the C-terminus, and the neighboring residue also affected their activities by steric effect, hydrophobicity and hydrogen bonding among others. © 2015 Elsevier Ltd. Source

Discover hidden collaborations