通讯机构:
[Xingbo Shi; Xingbo Shi Xingbo Shi Xingbo Shi] L;Laboratory of Micro & Nano Biosensing Technology in Food Safety, Hunan Provincial Key Laboratory of Food Science and Biotechnology, College of Food Science and Technology, Hunan Agricultural University, Changsha, 410128 China
关键词:
biosensing;catalyses;DNA;imaging;prussian blue nanoflowers
摘要:
DNA is use to precisely control the morphology of prussian blue nanoparticles (PBNPs) via electrostatic interaction‐mediated self‐assembly of inorganic ions and protonated DNA for the first time. The flower‐like PBNPs (PB nanoflowers) mediated by 30‐mer Oligo‐C exhibit excellent photothermal properties, mimetic peroxidase activity, biorecognition ability, photo‐fenton catalytic performance and light scattering, and is expected to be widely used in biosensing, catalysis and imaging. Abstract While shapes and surface properties of nanomaterials are known to play important roles in defining their properties, it remains challenging to fine‐tune the morphologies systematically and predictably. Considering the extraordinary performance, prussian blue nanoparticles (PBNPs) are selected as the proof‐of‐concept nanomaterials. Herein, a DNA‐dependence approach to fine‐control the morphology of PBNPs via electrostatic interaction‐mediated self‐assembly of inorganic ions and protonated DNA is developed. The regulation of different DNA on the morphology of PBNPs is systematically investigated. 30‐mer Oligo‐C or ‐T (C30/T30) mediates formation of flower‐like PBNPs (PB nanoflowers), whereas cubic structure with different sizes is observed in the presence of 10‐mer oligo‐G or 30‐mer Oligo‐A (G10/A30). Detailed mechanism studies indicate that the protonation of nucleobases is the key factor for the morphological evolution. C30‐dependent PB nanoflowers are superior to PB nanocubes in photothermal properties, peroxidase mimetic activity, photo‐Fenton catalytic performance, and light scattering property, which present 1.2‐, 3.78‐, 1.58‐, 1.93‐fold improvement, respectively. Furthermore, PB nanoflowers mediated by the diblock DNA (sDNA; comprising C30 and complementary strands of the target DNA) unexpectedly acquire biorecognition capabilities. This work opens a new avenue for the systematic and predictable synthesis of PB nanoflowers, which broadens the repertoire of PBNPs for catalysis, biosensing, and imaging.
摘要:
Abstract: Ganpu vine tea is a new type of health care citrus fruit tea made from citrus shell, Pu-er tea, and vine tea baked as raw materials. In this study, the in vitro uric acid synthase inhibition system and hyperuric acid cell model were constructed to appraise the uric acid lowering efficacy of Ganpu vine tea, traditional Ganpu tea, and vine tea. Results showed that in the uric acid synthase inhibition system, the aqueous extract can inhibite the puric metabolically related enzymes, such as adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), and xanthine oxidase (XOD). The ability of the aqueous extract to inhibit the above enzyme was as follows: vine tea > Ganpu vine tea > Ganpu tea; all teas had a strong effect on XOD inhibition. The hyperuric acid cell model test showed that the aqueous extract inhibited uric acid production through accumulating inosine and hypoxanthine and hindering xanthine synthesis. The uric acid reductive ability was as follows: Vine tea > Ganpu vine tea > Ganpu tea. The inhibition of enzymes related to uric acid synthesis and the inhibition of uric acid production were significantly enhanced through adding vine tea to Ganpu tea. It also shows that flavonoids are the main factor driving this ability because they are the main active ingredients in these botanical drinks. Keywords: Ganpu vine tea; xanthine oxidase; uric acid; in vitro enzyme inhibition model; cellular model
摘要:
Research of lactic acid bacteria and its metabolites on biological preservatives becomes a hot topic. Lactobacillus plantarum O(2), with good inhibition on Phytophthora capsici (P. capsici), was isolated from the pickle. In this study, the effects of L. plantarum O(2) fermentation supernatant (FS) on pepper postharvest preservation and its induced resistance to P. capsici were studied. Results showed that weight loss rate, rot index, respiration rate, relative electrical conductivity, loss of chlorophyll content and V(C) of pepper in FS treatment group were decreased by 18 %, 64 %, 15 %, 26 %, 33 % and 20 % compared with blank control (BC) after 20d storage. L* and b*-value of pepper in FS group were lower than those in the BC group. In addition, the damage-induced resistance test found that the infection rate in the FS group was reduced by 39 %, compared with CK2 after 12d storage. Moreover, phenylalanine ammonia-lyase activity, peroxidase activity, polyphenol oxidase activity, proline content, total phenol content and flavonoid content increased by 14 %, 9 %, 30 %, 8 %, 8 % and 9 %, respectively, while malondialdehyde content decreased by 13 %. These results indicated that FS treatment showed good fresh-keeping effects on postharvest pepper. It could enhance the tolerance of pepper under stress by improving defensive enzyme activities, slowing down the damage caused by P. capsici, and inducing pepper resistance to P. capsici. Therefore, FS can be used as a microbial source bio-preservative for postharvest pepper.
摘要:
The effect of alkaline microcrystalline cellulose (AMC) deacidification and alkali refining on the physicochemical properties, fatty acid profile, active phytochemicals, antioxidant capacity, and volatile flavor components of crude camellia oil (CO) were investigated comparatively. The results showed that the acid value of AMC deacidification camellia oil (ADO) was effectively decreased from 1.50 & PLUSMN; 0.00 mg KOH/g to 0.30 & PLUSMN; 0.01 mg KOH/g. AMC deacidification more effectively retained 60.22% of the polyphenols (12.34 & PLUSMN; 0.38 mg GAE/100g), 74.60% of & alpha;-tocopherol (2.82 & PLUSMN; 0.00 mg/kg) and 93.25% of & beta;-Sitosterol (5.30 & PLUSMN; 0.05 mg/100g) in camellia oil compared to alkali refining and showed a stronger overall antioxidant capacity of the oil (P < 0.05). In addition, the volatile flavors of camellia oil were dominated by acids, aldehydes, and alcohols, and AMC deacidification better preserved the acidic flavors than alkali refining. Principal component analysis (PCA) revealed that ADO and CO were positively correlated with PC1 due to the highly in relation to the higher content of 9C, 11 TRConjugated linoleic acid and the stronger antioxidant capacity. Overall, AMC deacidification was moderate reaction conditions and zero wastewater production, making it a potentially effective alternative method in camellia oil deacidification.
摘要:
Protein-bound N(ε)-(carboxymethyl)lysine (CML), an advanced glycation end product within meat products, poses a potential health risk to humans. The objective of this study was to explore the impact of various edible oils on the formation of protein-bound CML in roasted pork patties. Eleven commercially edible oils including lard oil, corn oil, palm oil, olive oil, flaxseed oil, blended oil, camellia oil, walnut oil, soybean oil, peanut oil, and colza oil were added to pork tenderloin mince, respectively, at a proportion of 4% to prepare raw pork patties. The protein-bound CML contents in the pork patties were determined by HPLC-MS/MS before and after roasting at 200°C for 20min. The results indicated that walnut oil, flaxseed oil, colza oil, olive oil, lard oil, corn oil, blended oil, and palm oil significantly reduced the accumulation of protein-bound CML in pork patties, of which the inhibition rate was in the 24.43%-37.96% range. Moreover, the addition of edible oil contributed to a marginal reduction in the loss of lysine. Meanwhile, glyoxal contents in pork patties were reduced by 16.72%-43.21% after roasting. Other than blend oil, all the other edible oils restrained protein oxidation in pork patties to varying degrees (between 20.16% and 61.26%). In addition, camellia oil, walnut oil, and flaxseed oil increased TBARS values of pork patties by 2.2-8.6 times when compared to the CON group. After analyzing the fatty acid compositions of eleven edible oils, five main fatty acids (palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid) were selected to establish Myofibrillar protein-Glucose-fatty acids systems to simulate the roasting process. The results showed that palmitic acid, oleic acid, linoleic acid, and linolenic acid obviously mitigated the formation of myofibrillar protein-bound CML, exhibiting suppression rates ranging from 10.38% to 40.32%. In conclusion, the addition of specific edible oil may curb protein-bound CML production in roasted pork patty by restraining protein or lipid oxidation, reducing lysine loss, and suppressing glyoxal production, which may be attributed to the fatty acid compositions of edible oils. This finding provides valuable guidance for the selection of healthy roasting oils in the thermal processing of meat products.
摘要:
In this study, Rhizopus oryzae HC-1, a food-grade fungal isolated from sufu, was utilized for solid-state fermentation (SSF) of soybeans, to investigate its effect on metabolites composition and antioxidant activity. Results revealed that SSF notably enhanced the total phenolics content (TPC), total flavonoids content (TFC), aglycone isoflavones, and antioxidant capacity of soybeans. The increase in aglycone isoflavones was attributed to the action of secreted beta-glucosidase. The fermented soybean (FSB) with strongest antioxidant activity was further investigated by UPLC-MS/MS-based untargeted metabolomics analysis and in vitro human gut microbiota modulation effect by colonic fermentation. A total of 176 and 114 metabolites differed significantly between non-fermented soybean (NSB) and FSB in positive-and negative-ion modes, respectively. FSB and NSB had a beneficial modulation effect on the microbiota community structure. Additionally, colonic fermentation of both FSB and NSB for 24 h resulted in a higher relative abundance of beneficial bacteria Bacteroides compared to the control group, and FSB showed a greater modulation effect. Thus, SSF with R. oryzae HC-1 was found to significantly improve the metabolite profile, antioxidant activity and human intestinal microbiota modulation effect of soybeans, potentially offering novel functional or nutraceutical ingredients for the food and pharmaceutical industry.