Chitosan, gelatin and pectin based bionanocomposite films with rosemary essential oil as an active ingredient for future foods.

Bionanocomposite films of three biopolymers including chitosan, gelatin, and pectin incorporated with rosemary essential oil (REO) were developed and characterized in terms of their physical, structural, mechanical, morphological, antioxidant, and antimicrobial properties. Incorporation of REO showed an increased hydrophobic nature thus, improved water vapor transmission rate (WVTR), tensile strength (TS), elongation-at-break (EAB), and thermal stability significantly (P ≤ 0.05) as compared to the control films. The addition of REO leads to more opaque films with relatively increased microstructural heterogeneity, resulting in an increase in film opacity. Fourier transform infrared spectroscopy (FTIR) and particle size revealed that REO incorporation exhibits high physicochemical stability in chitosan, gelatin, and pectin bionanocomposite films. Incorporation of REO exhibited the highest inhibitory activity against the tested pathogenic strains (Bacillus subtilis and Escherichia coli). Furthermore, the addition of REO increased the inhibitory activity of films against ABTS and DPPH free radicals. Therefore, chitosan, gelatin, and pectin-based bionanocomposite films containing REO as food packaging could act as a potential barrier to extending food shelf life.

Nanoencapsulation of hydroxytyrosol in chitosan crosslinked with sodium bisulfate tandem ultrasonication: Techno-characterization, release and antiproliferative properties.

This research includes production of chitosan nanocapsules through ionic gelation with sodium bisulfate for nanoencapsulation of hydroxytyrosol (HT) using ultrasonication in tandem. The resulting nanocapsules encapsulating HT were analyzed for particle size, ζ-potential, packaging characteristics, FESEM, ATR-FTIR, XRD, DSC, in vitro release, antioxidant potential and antiproliferative properties. The nanocapsules (size 119.50-365.21 nm) were spherical to irregular shaped with positive ζ-potential (17.50-18.09 mV). The encapsulation efficiency of 5 mg/g HT (HTS1) and 20 mg/g HT (HTS2) was 77.13% and 56.30%, respectively. The nanocapsules were amorphous in nature with 12.34% to 15.48% crystallinity and crystallite size between 20 nm and 27 nm. Formation of nanocapsules resulted in increasing the glass transition temperature. HTS2 delivered 67.12% HT (HTS1 58.89%) at the end of the simulated gastrointestinal digestion. The nanoencapsulated HT showed higher antioxidant and antiproliferative (against A549 and MDA-MB-231 cancer cell lines) properties than the free HT.

Effects of xanthan gum, canning and storage period on fatty acid profile and cholesterol oxidation of restructured low-fat meat product of India.

This study evaluated the impact of xanthan gum (XG), canning and storage on fatty acids (FAs) contents and formation of cholesterol oxidation products (COPs) in low-fat meat product (goshtaba) of Jammu and Kashmir (J&K), India. The FAs composition i.e. saturated FAs, monounsaturated FAs, polyunsaturated FAs and trans FAs during processing and storage showed non-significant difference in all goshtaba products (P > 0.05). The cholesterol content decreased significantly after canning in all products (P < 0.05) while, maximum reduction was observed in high-fat goshtaba (HFC). During storage all products exhibited significant decrease in cholesterol upto 6th month, thereafter showed non-significant variation. The COPs determined were 7-ß-OH-ch, 5-ch-3ß-ol-7-one and 25-OH-ch. After canning two COPs (7-ß-OH-ch, 5-ch-3ß-ol-7-one) were produced in all products. But during storage there was formation of 25-OH-ch, increase in 7-ß-OH-ch and decrease in 5-ch-3ß-ol-7-one and lower COPs were observed in low-fat goshtaba containing 1.5% XG. The results concluded that fat replacer (XG), processing and storage had no significant effect on the FAs compositions of all goshtaba products including HFC. However, cholesterol content exhibited significant variation and minimum reduction in cholesterol and formation of lower COPs were observed in low-fat goshtaba formulated with 1.5% XG.

Techno-functional characterization of chitosan nanoparticles prepared through planetary ball milling.

Planetary ball milling of chitosan microparticles (CMP) for 8 h produced chitosan nanoparticles (CNP) having hydrodynamic diameter of 615.18 nm. The ζ-potential decreased from 56.48 mV (CMP) to 31.52 mV (CNP). High resolution transmission electron microscopy (HRTEM) revealed nanosize, irregular shape and surface roughening of CNP. CNP was whiter than CMP having higher water absorption capacity and decreased flow ability. Both CMP and CNP showed negligible swelling and no water solubility. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) revealed no chemical changes and X-ray diffraction (XRD) showed decreased crystallinity in CNP. In CNP, thermogravimetric analysis (TGA) revealed increased thermal degradation; differential thermogravimetric (DTG) revealed increased rate of thermal degradation; and high temperature differential scanning calorimetry (HDSC) revealed broadening of endothermic and exothermic phases and reduction in glass transition temperature as compared to CMP. In conclusion, planetary ball milling for 8 h produces bright, amorphous and rough CNP with improved functional and comparable thermal properties.

Functional characterization of biopolymer based composite film: Incorporation of natural essential oils and antimicrobial agents.

Rosemary (REO), mint essential oil (MEO), nisin and lactic acid were incorporated at 0.5% to develop a novel functional packaging film including chitosan pectin and starch polymers (0.75:1.5:0.75 w/w). Inclusion of REO and nisin significantly (p ≤ 0.05) improved water barrier properties (0.014 g.mm/m224h), tensile strength (25.95 MPa) and thermal stability as compared to control. ATR-FTIR spectra and XRD pattern elucidated structural interaction between EO's and biocomposite films. Addition of REO of and nisin increased microsctructural heterogeneity and opacity (2.78). Incorporation of REO and nisin exhibited the highest inhibitory activity against all tested pathogenic strains (Bacillus subtilis, Escherichia coli, and Listeria monocytogenes). The antioxidant properties of biocomposite films were analyzed using reducing power, metal chelation, DPPH and ABTS radical scavenging assays, which enhanced significantly (p ≤ 0.05) with the addition of MEO and REO. This study validated that incorporation of natural additives in active biocomposite films offers promising functional ingredients for packaging materials for various food applications.

Application of guar-xanthan gum mixture as a partial fat replacer in meat emulsions.

The physicochemical, oxidative, texture and microstructure properties were evaluated for low fat meat emulsions containing varying levels of guar/xanthan gum mixture (1:1 ratio) as a fat substitute. Partial replacement of fat with guar/xanthan gum resulted in higher emulsion stability and cooking yield but lower penetration force. Proximate composition revealed that high fat control had significantly higher fat and lower moisture content due to the difference in basic formulation. Colour evaluation revealed that low fat formulations containing gum mixture had significantly lower lightness and higher yellowness values than high fat control formulation. However non-significant difference was observed in redness values between low fat formulations and the high fat control. The pH values of the low fat formulations containing gum mixture were lower than the control formulations (T0 and TC). The MetMb% of the high fat emulsion formulation was higher than low fat formulations. The significant increase of TBARS value, protein carbonyl groups and loss of protein sulphydryl groups in high fat formulation reflect the more oxidative degradation of lipids and muscle proteins during the preparation of meat emulsion than low fat formulations. The SEM showed a porous matrix in the treatments containing gum mixture. Thus, the guar/xanthan gum mixture improved the physicochemical and oxidative quality of low fat meat emulsions than the control formulations.

Physico-chemical, functional and structural properties of RS3/RS4 from kidney bean (Phaseolus vulgaris) cultivars.

Starch isolated from four kidney bean cultivars (Yellow bean, Red bean, Black bean and White bean) were physically and chemically modified in order to prepare resistant starch (RS3/RS4). Following the Heat-moisture treatment (HMT) and Citric acid modification (CT) of the native starch, the amylose content got decreased whereas bulk and tapped density (g/ml) increased. Both HMT and CT reduced the swelling power and the solubility of native starch. Pasting temperature increased and peak, breakdown, final, and set-back viscosity decreased after both the modifications. Fourier Transform Infrared Spectroscopy (FTIR) analysis displayed peaks at 1020cm(-1) in HMT and 1724cm(-1) in CT starches. Differential Scanning Calorimetry (DSC) analysis revealed that samples were more stable after modification. X-ray diffraction (XRD) analysis revealed reordering of chain segments to more crystalline structure. These results suggested modifications resulted in starch with improved properties and could be a possible method for the RS preparation with better thermal stability.

Xanthan gum as a fat replacer in goshtaba-a traditional meat product of India: effects on quality and oxidative stability.

Goshtaba is a restructured meat product of Kashmiri wazwan prepared from meat emulsion with added fat (20 %), salt, spices and condiments and cooked in the curd. The present study was undertaken for the development of low fat goshtaba with the addition of xanthan gum as a fat replacer and was evaluated for proximate composition, pH, colour, lipid and protein oxidation, texture, microstructure and sensory properties. Low fat goshtaba formulations containing xanthan gum were higher in protein and moisture contents but, lower in fat content and pH value than the high fat control (p < 0.05). Colour evaluation revealed that high fat goshtaba had significantly higher L* value, but lower a* value than its low fat counterparts (p < 0.05). The significant decrease of TBARS values, protein carbonyls and loss of protein sulphydryl groups in low fat goshtaba formulations reflects the potential antioxidant activity of xanthan gum (p < 0.05). Hardness was significantly higher in high fat control but, cohesiveness, gumminess, and chewiness did not show any significant difference. Springiness increased with the increasing concentration of xanthan gum (0.5-1.5 %) and was higher in low fat product containing 1.5 % xanthan gum. SEM results indicate that xanthan gum lead to formation of an additional gel network which holds more water. Sensory evaluation revealed that goshtaba product with 0.5 % xanthan gum had quality characteristics that were similar to the control product containing 20 % fat.

THE EMERGENT CONCERN OF SEROPOSITIVE STATUS OF HEPATITIS-B VIRUS AND HEPATITIS-C VIRUS IN THE PREGNANT FEMALES ATTENDING A TERTIARY CARE HOSPITAL.

BACKGROUND: Viral hepatitis is a global problem affecting millions of people including pregnant females. Viral hepatitis during pregnancy is associated with both maternal and neonatal mortality and morbidity. This study was an attempt to assess the seropositive status of hepatitis-B and C infection among pregnant women in Karachi, Pakistan. METHODS: This cross sectional observational study was conducted at Sir Syed College of Medical Sciences and Trust Hospital, Karachi from January to September 2012. Patients were recruited by consecutive sampling. At the booking visit, blood was drawn and tested for HbsAg and Anti HCV by Eliza method. RESULTS: Among the screened population, 2% were reactive for HBV and 13.3% were found reactive for HCV. All HbsAg and HCV positive pregnant patients had one or more than one delivery. CONCLUSION: In our study sample, high frequency of HBV and HCV is suggestive of the importance of antenatal screening of these viral diseases, which has impact on the mother as well as the new born baby. HCV was more common as compared to HBV which is quite alarming.

Controlled evaluation of Bactec Peds Plus/F and Bactec lytic/10 anaerobic/F media for isolation of Salmonella enterica serovars typhi and paratyphi A from blood.

We compared anaerobic lytic (AL) and pediatric aerobic resin-containing (Peds Plus/F) blood culture media for the isolation of Salmonella enterica serotype Typhi or Paratyphi A from children. The yields from AL and Peds Plus/F media were the same with equal volumes of blood, but recovery was faster from AL medium than Peds Plus/F medium (10.7 and 16.4 h, respectively) (P < 0.001).