Hammondhoppe9634

Abuse of tobramycin (TOB) causes a series of diseases. Therefore, the development of rapid and sensitive method for analyzing TOB in food products is necessary. In this work, aptamer modified SnO2/Bi2S3-based photoelectrochemical (PEC) sensor was developed for the determination of TOB in milk. Under optimal condition, a wide linear response for TOB from 5 to 50 nmol/L with a limit of detection of 4.28 nmol/L is reached. The possible detection mechanism is that TOB molecules are specifically captured by aptamer, increasing electron transfer resistance and declining the photocurrent. Thanks to the favorably matched energy level of SnO2, and Bi2S3, the PEC aptasensor exhibits high sensitivity, and with the aid of oxalate, the sensitivity of the sensor is further improved. Importantly, the stability of the PEC aptasensor is also satisfactory due to the calcination of SnO2/Bi2S3 at 450 °C.A green vortex assisted based liquid-liquid microextraction (VA-LLME) method was developed for preconcentration of selenium. Ammonium pyrrolidine dithiocarbamate (APDC) was used to form a hydrophobic complex with selenium in natural water, agricultural soil and food samples by GFAAS. Whereas Triton X-114, a nonionic surfactant and 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid were used for Se extraction as a dispersing medium. p38 MAPK apoptosis The conical flasks contents were shack on a vortex mixer to increase the extraction efficiency. Multivariate techniques were used to evaluate extraction parameters; pH, vortex time, APDC amount, volume of ionic liquid and Triton X-114 and centrifugation rate on the recovery of Se. The central composite design (CCD) was used for further optimization of the essential extraction parameters. The enhancement factor and limit of detection were obtained as 98.7 and 0.07 µg L-1. The certified reference materials was used for accuracy of method and the related standard deviation was found to be 3.51%. The resulted data indicated that concentrations of Se in all types of water samples were below the permissible limit recommended by WHO.White-salted noodles are prepared, stored and consumed in various ways. However, relationships among cooking and storage conditions on nutritional functionality are not fully understood. The manuscript elucidates the mechanism of formation of resistant starch (RS) leading to slower digestion rate of variously cooked (boiled, steamed, stir-fried, fried and microwave heated) noodles followed by storage under different conditions (-18, 4 and 25 °C for 4, 24 and 48 h). RS content of noodles stored at 25 °C was higher than noodles stored at 4 °C, which was consistent with increases in the degree of crystallinity during storage. We showed that the residual moisture content primarily facilitated the mobility of starch chains and contributed towards the increase in RS associated with the decrease of enzyme susceptivity of noodles after storage. Evidence that supramolecular organization (helical structure and crystallinity) had a more pronounced effect than the macroscopic structure such as compactness or bulk density was also provided.In this study, different variants of egg-free mayonnaise containing free and immobilized Lactobacillus plantarum LBRZ12 cells and essential oils taken from basil and dill were prepared. The composition and antimicrobial properties of essential oils were investigated. The main constituents of basil oil were methyl chavicol (36.81%), methyl eugenol (20.40%), β-linanool (14.35%), eugenol (10.55%), and L(-)-carvone (39.05%), whereas dill oil contained mostly d-limonene (21.11%) and α-phellandrene (22.68%). The essential oils exhibited strong antimicrobial activity against all test-microorganisms. The mayonnaise variants were kept refrigerated for 40 days and changes in pH, concentration of viable cells of lactobacilli, microbiological, and organoleptic characteristics were monitored. The pH decreased from 6.5 to 4.5 over the period of storage. The number of undesired microflora in mayonnaise preserved with lactobacilli and essential oils decreased significantly (0 after the 20th day) indicating their effectiveness as biological preservatives. The mayonnaise variants demonstrated pleasant organoleptic characteristics, thus meet customers' requirements.Bactericidal properties of honey depend on botanical and geographical origin, where thermal treatment can have a significant affect. The aim of this study was to investigate the effect of temperature on minimum bactericidal concentration (MBC), vitamin C content, total polyphenols content and antioxidant capacity of ferric reducing antioxidant potential (FRAP) of several nectar honey varieties from northern Poland (lime, rapeseed, multifloral and buckwheat). The honeys were subjected to thermal treatment at 22 °C, 42 °C, 62 °C, 82 °C and 100 °C for two exposure times. The results showed a significant reduction of antimicrobial properties (MBC ⩾50%) at 82 °C and 62 °C after 15 and 120 min exposure time for most samples. Short time exposure reduced vitamin C content (⩽50 %) but increased total polyphenols content (⩾27%) and FRAP value (⩾106%).Starch gelatinization under non-isothermal conditions with limited moisture content is a common industrial process involved in the processing of many starchy foods, while the nature of its asymmetric differential scanning calorimetry thermograms is still undefinable. This study for the first time developed a kinetics-based mathematical model, which could yield a parameterization of gelatinization thermograms that are essentially the same as experimental ones. Even more, the model is capable of decomposing gelatinization thermograms into kinetics-based sub-patterns, and revealing hidden features. By applying this newly developed methodology to nine starches with different plant origins and correlated with their lamellar structures, the results indicated that distinctly arranged groups (sub-components) of semi-crystalline lamellae with different thermal stabilities are existed in the native starch granules. This gives ways to better understand starch structure-property relations, and suggests useful directions for food manufactures to produce functional foods by understanding and differentially controlling the starch gelatinization sub-components.