In the present investigation, emulsifying potential of galactan exopolysaccharide (EPS) extracted from Weissella confusa KR780676 has been evaluated with various food grade flavours (vanilla, cardamom and pineapple). Concentration of EPS was optimized as 1% with these flavours, in addition to the effect of salinity (NaCl), monovalent ion (KCl) and temperature on emulsion activity (EA), and emulsion stability (ES) was also inspected. Filter paper wetting test exhibited water-in-oil-in-water (w/o/w) and oil-in-water (o/w) type emulsions. The extent in granule disintegration and the retrogradation process of flavour emulsions were studied with pasting properties. Electron micrography and particle size analysis revealed the morphology and the size of emulsion droplets. Thermal stability of emulsions has found 100% at various temperatures (−20 to 60 °C) for vanilla and pineapple flavour, whereas, it was varying for cardamom as per the temperature disparity. Emulsion stability of vanilla and pineapple flavour was retained as such for various concentrations of NaCl whereas decreased for cardamom in direct proportion. In case of KCl all the three flavours showed greater stability. These emulsifying properties indicate that galactan EPS can be a prospective alternative to commercial biopolymers in food and pharmaceuticals industries.

Salmonella can survive for extended periods of time in low-moisture environments posing a challenge for modern food production. This dangerous pathogen must be controlled throughout the production chain with a minimal risk of dissemination. Limited information is currently available describing the behavior and characteristics of this important zoonotic foodborne bacterium in low-moisture food production environments and in food. In our study, the phenotypes related to low-moisture survival of 46 Salmonella isolates were examined. Most of the isolates in the collection could form biofilms under defined laboratory conditions, with 57% being positive for curli fimbriae production and 75% of the collection positive for cellulose production, which are both linked with stronger biofilm formation. Biocides in the factory environment to manage hygiene were found to be most effective against planktonic cells but less so when the same bacteria were surface dried or present as a biofilm. Cellulose-producing isolates were better survivors when exposed to a biocide compared with cellulose-negative isolates. Examination of Salmonella growth of these 18 serotypes in NaCl, KCl, and glycerol found that glycerol was the least inhibitory of these three humectants. We identified a significant correlation between the ability to survive in glycerol and the ability to survive in KCl and biofilm formation, which may be important for food safety and the protection of public health.

The aim of this study was to determine thermal properties of pseudoplastic polysaccharides (guar gum, κ-carrageenan and xanthan gum) which find many applications as food hydrocolloids in food industry. There was an obvious relationship between thermal dependency of heats of fusion of hydrocolloids in powder form and activation parameters of hydrodynamic flow in solutions, respectively. Results of thermal analysis confirmed, that powder samples of hydrocolloids as typical foodstuffs of low moisture content less than 15 w% after room conditioning, exhibited varying ability to bind water as depending on their molecular structure. The peak temperature of the endothermic polysaccharide order-disorder phase transition process was found in the temperature range of 50–85 °C. It was influenced simultaneously by the applied heating rate and the samples moisture content. Studied samples moisture content was ranging between 9–40 w.% as was obtained after different conditioning. Observed reaction enthalpy (ΔH) associated with phase transition and water evaporation (proved by appropriate weight loss of the samples Δmw) was ranging from 140 to 670 J/g. Activation energy (Eₐ) of this process in powder samples was calculated from the kinetic parameters using three kinetic models developed by Friedman, Kissinger and model-free kinetics. The latter kinetic models were compared with the Arrhenius model, which was used to determine Eₐ of polysaccharide solutions on reflecting sensitivity of their molecular structure to the temperature and the solvent. According to the Arrhenius model, there were obtained the highest values of Eₐ for κ-carrageenan solutions, indicating the highest resistance of their molecular structure to temperature. This fact can be related to the observed the lowest value of the reaction enthalpy in the case of powder samples, suggesting that energy obtained during the order-disorder transition to change the carrageenan powder structure is limited. On the other hand, xanthan gum was the least temperature dependent sample; activation energy of xanthan solutions was only in the range of 2–6 kJ/mol. Concurrently, ΔH of xanthan powder was determined as the largest of all samples under study. In general, there was found an indirect relationship between activation energy of the solutions determined by viscometry and reaction enthalpy of the powders determined by thermal analysis. Results of the Arrhenius model also indicate that the energy necessary to promote viscous flow of solutions is higher for hydrocolloids in distilled water rather than in 0.07 M KCl aqueous solutions, suggesting the suppression of the polyelectrolyte effect. In both cases, Eₐ was substantially reduced by application of higher shear rate.

A simple and efficient determination of curcumin in water and food samples based on the combination of dispersive liquid–liquid microextraction (DLLME) and spectrophotometric estimation has been described. The effects of DLLME effective parameters [extraction solvent (CHCl₃), disperser solvent (ethanol), pH, centrifugation time, and KCl concentration] were optimized via central composite design (CCD) and response surface methodology (RSM) and desirability function (DF) using STATISTICA. At optimum condition specified as 150 μL of chloroform, 900 μL of ethanol, pH = 4.0, and 4 min of centrifugation time in the absence of any salt, a linear calibration graph in the range of 10–2000 ng mL⁻¹ of curcumin with R ² = 0.99942 (n = 6) confirms good applicability of the method for quantification of analytes over a wide range of analytes. The reasonable limit of detection (LOD) and quantification (LOQ) (0. 23 and 0.78 ng mL⁻¹, respectively) makes it suitable for trace analysis. Good relative standard deviation [1.16–2.3 % (n = 12)] and high enrichment factor (EF) 2182.04 are a good remark of the present method. Curcumin with relative standard deviation (RSD) less than 3 % (n = 4) and recoveries in the range 91.76–100 % can be successfully quantified in different real samples.