查看更多>>摘要：This study aims to investigate the inhibitory effects of free and bound bioactive extracts from naked oat on amylase and glucosidase activity. The free compound extract mainly included kaempferol-3-O-galactoside-6 ''-rhamnoside-3'''-rha, hesperetin-7-O-neohesperidoside, ginsenoside Re and soyasaponin Ba. Ten substances were detected in the bound compound extract, including ferulic acid, oxyacanthine, and trans-4-coumaric acid. The free and bound compound extracts showed dose-dependent inhibitory effects on alpha-amylase and alpha-glucosidase; the inhibition of alpha-amylase was reversible anti-competitive inhibition, and the inhibition of alpha-glucosidase was reversible linear mixed inhibition. The saponin ginsenoside Re had poor inhibitory effects on alpha-amylase and alpha-glucosidase; the saponin soyasaponin Ba had a poor inhibitory effect on alpha-amylase but a good inhibitory effect on alpha-glucosidase. After adding the extracts to the different starches, the hydrolysis rates all decreased significantly (p < 0.05). This study elucidates the low digestibility of naked oats and will help facilitate the development of low-glycemic foods using naked oats.
查看更多>>摘要：In this study, acid soluble collagens (ASCs) from different by-products of loach including skin, head, fins and bone were isolated, characterized and compared. As a result, the highest yield (on wet weight basis) was obtained for ASC from skin (ASC-S, 9.73%) compared with those from fins (ASC-F, 2.01%), head (ASC-H, 1.12%) and bone (ASC-B, 0.84%). By SDS-PAGE, these collagens were classified as type I collagens with slight difference of molecular weight. Glycine was the major amino acid in all ASCs with relatively high contents of alanine, hydroxyproline and proline. Fourier transform infrared spectroscopy indicated that triple helical structures of all ASCs were well preserved and scanning electron microscope exhibited fibrillary structure of ASC-B while sheet structure in others. Thermal stability of ASCs was determined by differential scanning calorimetry, rheometer and thermogravimetric (TG), respectively. It was concluded that all ASCs had different maximum transition (Tmax), denaturation (Td) and onset decomposition (To) temperatures. Besides, film-forming properties of ASCs from loach were also evaluated with ASC-F film showing strong tensile strength, best extensibility and barrier property compared with others, which suggested that ASCs from different by-products of loach had tremendous potential for applications in food packaging and coating in future.
查看更多>>摘要：Pulsed light (PL) is one of the promising non-thermal decontamination methods. The aim of this study was to investigate the effect of PL treatment on microbial quality, bioactive compounds concentration, and water state during storage of red bell pepper fresh-cuts. Fresh-cuts were subjected to PL treatment with the fluence of 4-32 J/cm(2) and stored for 7 days. Results showed that PL radiation preserves bioactive compounds such as vitamin C (up to 36%), phenolics (up to 19%), or carotenoids (up to 7%) for 7 days of storage in comparison to untreated material. PL processed fresh-cuts exhibited also better free radical scavenging activity (by 23%), especially when applied fluence was 32 J/cm(2). PL treatment at 4 J/cm(2) was not sufficient to destroy microbiota. However, an application of PL at 16 J/cm(2) reduced tested microorganisms by 1.59-2.13 log cycles. Yeasts and molds were more sensitive to PL application in comparison to bacteria. Moreover, PL treatment can reduce the mobility of water located in the vacuoles, which is the "most available" fraction for deterioration reactions. Obtained results indicated that PL treatment with fluence above 4 J/cm(2) may be used for decontamination of red bell peppers without any negative changes of their chemical properties.
Rauber Wurfel, Simone de FatimaPrates, Denise da FontouraKleinubing, Natalie RauberDalla Vecchia, Joline...
7页
查看更多>>摘要：The aim of this study was to perform a comprehensive characterization of 48 Campylobacter isolates obtained from broiler meat products in Southern Brazil, which had been previously typed by pulsed-field gel electrophoresis (PFGE). The antimicrobial resistance (AMR) profile and the presence of 30 virulence-associated genes (VAGs) were investigated. Six AMR patterns and 26 VAG patterns were found, indicating a great genetic diversity among the isolates. It is noteworthy that 79.2% of Campylobacter isolates were resistant to one or more antimicrobial agents, and MDR was found in 35.4%, being more prevalent in C. jejuni isolates. Data analysis for the combination of AMR and VAG profiles indicated that the antimicrobial resistance and virulence profile were not related to a particular species. The combination of the PFGE, AMR and VAG sets of data improved the discrimination power. In addition, the presence of antimicrobial-resistant Campylobacter isolates carrying virulence genes such as hcp (T6SS marker), cgtB and wlaN (LOS biosynthesis markers), among others, represents a potential emerging threat to public health. The findings also demonstrate the need for more rigorous control measures for Campylobacter in the Brazilian poultry production chain to avoid the dissemination of antimicrobial resistant and virulent Campylobacter isolates through the poultry meat.
查看更多>>摘要：The main purpose of this study was to determine proteolysis model and peptide diverseness of goat skin Tulum cheese using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and liquid chromatographytandem mass spectrometry (LC-MS/MS) analyses, respectively. Furthermore, bioactive properties of identified peptide sequences were investigated using online databases. Tulum cheeses produced from raw milk (without starter culture) by traditional methods in Mut province (Turkey) were obtained from local producers following their production and analyzed during 180 days of ripening. The evaluation of electrophoretic profiles by SDSPAGE analysis indicated that 51.96% of alpha s-casein and 56.08% of 13-casein hydrolyzed at the end of the cheese ripening. According to mass spectrometry results, 179 peptides were sequenced; of these, 65 from alpha s1-casein, 7 from alpha s2-casein, and 107 from 13-casein. However, kappa-casein derived peptides were not determined in Tulum cheeses during ripening. Generally, alpha s1-casein derived peptides originated from the N-terminal part of alpha s1-casein while 13-casein derived peptides arose from the C-terminal part of precursor protein. Ten different functional activities ACE inhibitors, antimicrobial, antioxidant, anticarcinogenic, GLP-1 enhancer, DPP-4 inhibitor, immunomodulator, brain function enhancer, antidiabetic, and cathepsin B inhibitor have been detected. Among these functional features, ACE inhibitory peptides were found to have higher counts.
Akpabli-Tsigbe, Nelson Dzidzorgbe KwakuMa, YongkunEkumah, John-NelsonOsabutey, Juliet...
13页
查看更多>>摘要：This study investigated the extraction of 5-O-caffeoylquinic acid (5-CQA) with increased yield and enhanced antioxidant activity from heilong48 soybean (HS) under solid-state fermentation (SSF). Plackett-Burman design and Box-Behnken design were sequentially used for screening and optimization of significant SSF conditions respectively. Screening results showed that temperature, pH, incubation time and liquid-solid ratio were the significant SSF conditions that influenced 5-CQA yield, fermentation efficiency and antioxidant activity. The optimum SSF conditions obtained by Box-Behnken design were 49.90 degrees C (temperature), 7.00 (pH), 25.81 h (incubation time) and 0.67 (liquid-solid ratio). For these conditions, the experimental data obtained [5-CQA yield (11.41 +/- 0.27 mg/g), fermentation efficiency (30.49 +/- 1.14%), and antioxidant activity (46.13 +/- 1.94 mu mol AA eq/g dry sample)] were consistent with predicted values, higher than that of unfermented HS flour (RSHF), and supported by Atomic force microscopy (AFM), Fourier transform infrared (FTIR) and Scanning electron microscopy (SEM) microstructure. The results demonstrated that optimized SSF conditions significantly influenced 5-CQA yield, fermentation efficiency and antioxidant activity. This study showed that the use of optimized SSF conditions to extract 5-CQA with increased yield and enhanced antioxidant activity was efficient. Hence, this could be useful to the food and/or pharmaceutical industry in producing 5-CQA from HS.
查看更多>>摘要：Pseudomonas fluorescens and Shewanella baltica are specific spoilage organisms (SSOs) of most seafood products. Both of them can cell-to-cell communicate through quorum sensing (QS), facilitating the spoilage activities such as protease secretion, flagellar movement, and biofilm formation. Thus, it is important to screen the quorum sensing inhibitors (QSI) of P. fluorescens and S. baltica. In this study, we tried to apply a high-throughput virtual screening technology to select QSIs candidates. Three amino acid sequences from the key QS regulator-LuxR/I family (the LuxR and LuxI proteins of P. fluorescens, and the LuxR of S. baltica) were targeted and analyzed. Their 3D structures were subsequently constructed for the QSIs candidates' screen of both P. fluorescens and S. baltica. The candidates of cytidine-5'-monophosphate (5'-CMP) and 5'-adenylic acid (5'-AMP) with high scores exerted strong antagonistic effects against both P. fluorescens and S. baltica QS. The addition of 5'-CMP and 5'-AMP also inhibit QS-controlled phenotypes (swimming motility, protease activity, EPS, and biofilm formation) in P. fluorescens and S. baltica. Furthermore, the exogenous addition of 5'-CMP and 5'-AMP could retard the spoilage process of salmon slices during low-temperature storage by inhibiting the production of extracellular protease, siderophores, and Total Volatile Basic Nitrogen (TVB-N).
Calado, RicardoAmeixa, Olga M. C. C.Valcarcel, JesusAntonio Vazquez, Jose...
8页
查看更多>>摘要：The fishing industry is often targeted as a producer of organic streams with low economic value. Biotechnological approaches can play a crucial role in transforming and adding value to these streams for their further use and upcycle. In this study, Atlantic codfish (Gadus morhua) frames, were subjected to Alcalase hydrolysis, whose optimal conditions were first fine-tuned and established as follows: 56.8 degrees C, pH 8.35, [Alcalase] = 0.25% (v/w) and 3 h of hydrolysis. Subsequently, under these conditions, a set of 5 L-pH-stat reactor validated the optimization tests. Our results showed that fish protein hydrolysates (FPH) exhibited a high yield of digestion (>80%) and a remarkable high degree of hydrolysis (37%). A high content of soluble protein (66 g/L), with an amino acid profile with viability for food and nutraceutical applications and a near total in vitro digestibility (>92%) were revealed. Moreover, antioxidant and antihypertensive activities were also detected. The hydrolysates presented an average molecular weight of 1709 Da and a peptide size distribution of 49% below 1 kDa and 41% in the range of 1-3 kDa. These findings suggest that Alcalase hydrolysis has the potential to recover functional bio compounds from codfish frames, boosting the economy through green technology.
查看更多>>摘要：3-Phenyllactic acid (3-PLA) is a bioactive compound with broad-spectrum antibacterial and antifungal activity and several desirable pharmacological properties. In this study, 351 lactic acid bacterial strains isolated from naturally fermented Chinese vegetable samples were analyzed for their 3-PLA-producing ability, and three strains showing the greatest 3-PLA-producing ability were selected for further optimizing the fermentation conditions to enhance their 3-PLA yields. The results showed that all the strains were able to produce 3-PLA in MRS broth, but there were considerable variations in their 3-PLA-producing ability among the strains and among the species. Lactobacillus crustorum showed significantly higher 3-PLA-producing ability than the other species. In particular, L. crustorum NWAFU 1078 produced up to 45.2 mmol/L 3-PLA with a 73% substrate conversion rate under the optimized fermentation conditions that the culture was inoculated into MRS broth supplemented with 60 mmol/L phenylpyruvic acid as a substrate, 5.0% CaCO3 as a neutralizer and incubated for 48 h at 30 degrees C. This study indicates the possibility of the biotransformation of phenylpyruvic acid by L. crustorum NWAFU 1078 for highly efficient 3-PLA production.
Dantas, Aline MacedoFerreira Batista, Jessica DayanneLima, Marcos dos SantosFernandes, Fabiano A. N....
8页
查看更多>>摘要：This study evaluates atmospheric cold plasma (ACP) effects on deteriorative enzymes, color, and phenolic compounds in acai pulp. The bioaccessibility of the bioactive compounds was also assessed after simulated digestion. Nine different treatments were applied, varying the excitation frequency (50, 500, 750 Hz) and processing time (5, 10, 15 min). ACP processing at low frequencies (50 Hz/15 min) was more effective in inactivating polyphenol oxidase (82.4%) and peroxidase (42.3%) (p < 0.05). Operation at medium excitation frequency and short application time (500 Hz/5 min) increased the phenolic content by 38.8% (p < 0.05). When treated at 500 Hz/5min and 500 Hz/15 min, the anthocyanin contents were similar to the untreated acai pulp. The atmospheric cold plasma treatment 50 Hz/10 min increased the bioaccessibility of catechin (194.70%), epicatechin (383.44%), epigallocatechin gallate (68.84%), procyanidin B1 (130.71%), rutin (16.84%), caffeic acid (341.48%), and chlorogenic acid (57.63%). It increased the antioxidant activity of the bioaccessible fraction assessed by DPPH and ORAC assays. Cold plasma processing of acai pulp contributed to reducing PPO and POD activity; increased the phenolic compounds' bioaccessibility and antioxidant activity, facilitating the absorption of compounds after digestion.
NSTL
Elsevier