摘要：
This paper reports the preparation and characterization of gelatin-cassava starch microspheres using the water-in-water emulsion technique. The effects of different weight ratios (10: 0, 9: 1, 8: 2, 7: 3, 6: 4, 5: 5) of starch to gelatin on the morphology, structure, thermal properties, and stability of microspheres were investigated. The morphology results showed that most microspheres had spherical shapes and smooth surfaces. When the weight ratio of starch to gelatin was 5: 5, the prepared microspheres formed a stable yolk-shell structure. The swelling capacity of the microspheres increased with the proportion of gelatin, up to 682.3%. The gelatin and starch in the microspheres were compatible but not miscible. Compared with the native starch, the crystalline structure of microspheres changed from A-type to a mixture of B-type and V-type, and the relative crystallinity decreased. Differential scanning calorimetry results showed that the melting of microspheres involved both gelatin dissolution and starch gelatinization. Due to the formation of composite microspheres, the starch content decreased, and the release of reducing sugars from the microspheres upon hydrolysis was reduced. The gelatin-cassava starch microspheres are simple to prepare, biocompatible, and can be used as a potential material for microencapsulation.
期刊：
International Journal of Biological Macromolecules,2024年264(Pt 1):130479 ISSN：0141-8130
通讯作者：
Zhao, Lingyan;Shi, Xingbo;Zhao, Qian
作者机构：
[Lu, Dai; Pan, Jun; Zhang, Tianyu; Jiang, Hao] 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;[Lu, Dai] TCM and Ethnomedicine Innovation & Development International Laboratory, School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, PR China;[Zhao, Lingyan] 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. Electronic address: LYzhaohnau@hunau.edu.cn;[Shi, Xingbo] 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. Electronic address: shixingbo123@hunau.edu.cn;[Zhao, Qian] 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. Electronic address: zhaoqian@hunau.edu.cn
通讯机构：
[Zhao, Lingyan; Shi, Xingbo; Zhao, Qian] 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. Electronic address:
关键词：
EDTA•2Na;Extinction coefficient;Improved ELISA;Photothermal effect;Prussian blue nanoparticles
摘要：
This work reports an improved enzyme-linked immunosorbent assay (ELISA) via the interaction between prussian blue nanoparticles (PBNPs) and amines for aflatoxin B1 (AFB1) detection. The effect of different amines on the structure and properties of PBNPs was systematically investigated. Amines with pK(b)<7, like ethylenediamine (EDA), can decompose structure of PBNPs, leading to the reduction of extinction coefficient and photothermal effect. Whereas, amines with large pK(b)>7, such as o-phenylenediamine (OPD), could undergo catalytic oxidation by PBNPs, resulting in the production of fluorescent and colored oxidation products. Accordingly, EDA and OPD were used to construct improved ELISA. Specifically, silica nanoparticles, on which AFB1 aptamer and amino binding agent (ethylenediaminetetraacetic acid disodium salt, EDTA•2Na) were previously assembled via carboxyl-amino linkage, are anchored to microplates by AFB1 and antibody. EDA concentration can be regulated by EDTA•2Na to affect extinction coefficient and photothermal effect of PBNPs, thereby achieving visual colorimetric and portable photothermal signal readout (Model 1). OPD concentration can also be controlled by EDTA•2Na, thus generating colorimetric and ultrasensitive fluorescent signals through PBNPs catalysis (Model 2). The proposed strategy not only opens new avenue for signal readout mode of biosensing, but also provides universal technique for hazards.
作者机构：
[Cheng, Yunhui; Xing, Yunhao; Wang, Xufeng; Wang, Xiongshi] School of Food Science and Bioengineering, Changsha University of Science and Technology, Changsha, Hunan, China;[Wang, Shaoyun; Wang, Yuqi] College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, China;[Luo, Kaiyun; Kuang, Chuyu] College of Food Science and Technology, Hunan Agricultural University, Changsha, Hunan, China
关键词：
Aggregation;Crosslinking;Gel;Soy protein isolate;Transglutaminase
摘要：
Transglutaminase (TGase) induced-crosslinking of soy protein isolate (SPI) was markedly influenced by the substrate aggregation state. Results showed that appropriate heating significantly accelerated the TGase crosslinking, and the 7S and 11S acidic subunits were more susceptible to the enzyme than the 11S basic proteins. The content of ε-(γ-glutamyl)-lysine isopeptide bonds increased from 4.74 to 8.61μmol/g protein when the heating intensity was increased from 75°C for 15min to 95°C for 30min, due to sufficient unfolding of the protein structure. Rheological data indicated that the gel formed from the SPI heated at 95°C for 30min exhibited the best properties, with a 60% increase in the storage modulus compared with the unheated sample. However, excessive heating (95°C, 60-120min) caused severe aggregation of SPI and formation of insoluble aggregates, resulting in poor crosslinking efficiency and weaker gel properties.
关键词：
Aggregation of gold nanoparticles;Aptamer-initiator stand;Dual-modality;Functional DNA;Hybridization chain reaction
摘要：
Aflatoxin B1 (AFB1) is one of the most toxic mycotoxins, which is frequently detected in agricultural products. Herein, a novel functional DNA -linked immunosorbent assay (DLISA) with dual-modality based on hybrid chain reaction (HCR) has been successfully developed for ultrasensitive detection of AFB1. The strategy relies on AFB1 immune-bridged occurrence of HCR and the salt-induced aggregation of gold nanoparticles (AuNPs). An aptamer-initiator stand (Apt-Ini stand) is designed for the AFB1 recognition and the activation of HCR, which can recognize the matched hairpins and cause the crossing-opening of H1 and H2, producing a long double-stranded DNA polymer. The addition of SYBR Green I achieves the fluorescent signal output. Remaining less DNA hairpins were added and stuck on the surface of AuNPs, which were insufficient to protect the AuNPs, resulting in the salt-induced aggregation with the color change from red to blue. The dual-modality provides limits of detections of 1.333×10(-14) g/mL and 2.471×10(-15) g/mL, respectively. This DLISA with dual-modality provides not only a colorimetry that can meet the needs of on-the-spot preliminary inspection, but also a fluorescence assay that can acquire the precise results.
通讯机构：
[Liu, XD ; Zhang, Y ] H;Hunan Agr Univ, Coll Food Sci & Technol, Changsha 410128, Peoples R China.;Hunan Acad Forestry, State Key Lab Utilizat Woody Oil Resource, Changsha 410004, Peoples R China.
关键词：
Camellia oleifera shell;Acidic deep eutectic solvents;Microwave-assisted;Lignin;Lignin nanoparticles
摘要：
Camellia oleifera shell (COS) is a waste biomass resource and abundant in lignin. Effective fractionation and valorization of lignin is of great significance. In this work, choline chloride (ChCl) and allyl trimethylammonium chloride (ATMAC) as hydrogen bond acceptors, and lactic acid (LA), acetic acid (AA) and oxalic acid (OA) as hydrogen bond donors were used to prepare six different acidic deep eutectic solvents (DES). The lignin was fractionated from COS by microwave -assisted method using acidic deep eutectic solvents, and lignin nanoparticles (LNPs) were further fabricated by self -assembly strategy. The structural characteristics of lignin and LNPs were analyzed and compared. The results demonstrated that ATMAC-LA pretreatment exhibited the highest delignification of 81.41% and cellulose retention of 95.1%. The molecular weight of lignin extracted from ChClbased DES was lower than those obtained by ATMAC-based DES when using identical hydrogen bond donors. The smallest average particle size (203.07 nm) of LNPs was obtained by ATMAC-AA pretreatment. In addition, ATMAC-LA exhibited the highest interaction energy of 56.1 kcal/mol and stronger electrostatic potential (- 46.72-54.58 kcal/mol), which elucidated its high delignification efficiency. ATMAC-LA DES exhibited high selectivity for lignin dissolution, and LNPs with smaller particle size and excellent stability could be fabricated. This work provides an efficient method to fractionate lignin from COS at 150 celcius for 15 min, and contributing to extend the opportunities of lignin valorization into bio-based materials.
摘要：
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.
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：
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.
通讯机构：
[Tiean Zhou; Yanyang Wu] A;Authors to whom correspondence should be addressed.<&wdkj&>College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Hunan Provincial Engineering Technology Research Center for Cell Mechanics and Function Analysis, Changsha 410128, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>College of Food Science and Technology, Hunan Agricultural University, Changsha 410128, China
