Effect of added calcium and heat setting on gel forming and functional properties of Sardinella fimbriata surimi.

Present study evaluates the effect of calcium and heat setting on gel characteristics of lesser sardine (Sardinella fimbriata) surimi. Total seven formulations were made namely, S. fimbriata minced meat without heat setting (A1), minced meat with heat setting (A2), S. fimbriata surimi control (without addition of calcium) without heat setting (B1), control (without addition of calcium) with heat setting (B2), surimi added with 0.3% calcium without heat setting (C1) and surimi added with calcium with heat setting (C2) and refiner meat without addition of calcium and with addition of sodium bicarbonate (D). C1 exhibited gel strength of 329 g cm (Grade KA) whereas C2 sample exhibited gel strength of 556.2 g cm (Grade AA) as a result of gel setting at 35 °C for 45 min. Textural parameters such as hardness, chewiness, gumminess and cohesiveness were improved in C2 when compared with all other formulations. Addition of calcium and sodium bicarbonate significantly improved whiteness of surimi with gel setting in comparison to other treatments (p < 0.05). C2 samples exhibited reduced thio barbituric acid (TBA) values indicating lower oxidation. Results indicated potential for use of fish species with high fat content and darker meat for surimi manufacture with gel setting of sol and addition of sodium bicarbonate and calcium as ingredients.

Food grade zinc oxide bulk particle composite can replace the toxic zinc oxide nano composite towards the control of pathogenic and spoilage bacteria.

ZnO-Nanoparticle-Chitosan (ZnO-NP-CH) composite has potential biomedical and food applications due to its better antimicrobial activity. However, the presence of nano-metal-oxide in the composite makes the material unsuitable for any food applications. Moreover, the cost involved in the preparation of Zinc Oxide-Nano-Particle (ZnO-NP) is a major limitation for commercial food applications. Hence a suitable alternative for ZnO-NP is highly needed for food application. Since ZnO-Bulk Particles (ZnO-BP) are food grade and there is no study on the composite prepared from ZnO-Bulk Particle-Chitosan (ZnO-BP-CH), in the present study, antimicrobial activity was assessed for ZnO-BP-CH and compared with ZnO-NP-CH. Based on the study, it was observed that in the individual form of ZnO-NP possessed significantly higher antimicrobial activity than ZnO-BP. The composite form of ZnO-NP-CH and ZnO-BP-CH possessed higher antimicrobial activity than chitosan. However, no significant difference was observed between the composite forms. Hence, ZnO-BP-CH could be recommended as a suitable alternative to ZnO-NP-CH for future studies related to chitosan with ZnO composite to avoid costly nanomaterials preparation.

Structural and oxidative stabilization of spray dried fish oil microencapsulates with gum arabic and sage polyphenols: Characterization and release kinetics.

The synergistic efficacy of gum arabic and sage polyphenols in stabilising capsule wall and protecting fish oil encapsulates from heat induced disruption and oxidative deterioration during spray drying was assessed. The emulsions prepared with sodium caseinate as wall polymer, gum arabic as wall co-polymer and sage extract as wall stabiliser was spray dried using a single fluid nozzle. Fish oil encapsulates stabilised with gum arabic and sage extract (SOE) exhibited significantly higher encapsulation efficiency compared to encapsulates containing gum arabic alone (FOE). Scanning electron microscopic and atomic force microscopic images revealed uniform encapsulates with good sphericity and smooth surface for SOE, compared to FOE powder. In vitro oil release of microencapsulates indicated negligible oil release in buffered saline whereas more than 80% of the oil loaded in encapsulates were released in simulated GI fluids. The encapsulates containing sage extract showed a lower rate of lipid oxidation during storage.

Effect of chitosan on shelf life of restructured fish products from pangasius (pangasianodon hypophthalmus) surimi during chilled storage.

In the present study, restructured products were prepared from pangasius surimi and their qualities were analysed under chilled storage. Pangasius surimi had 75.82 % moisture, 16.91 % protein, 2.76 % fat and 0.95 % ash. Restructured products were prepared in three different formulations by incorporating corn starch (10 %) and chitosan (0.75 %). Formulation containing only corn starch (10 %) was served as control. In all the formulations, mono unsaturated fatty acids were higher (45.14 %). The total volatile base nitrogen (TVB-N) showed an increasing trend and it was found to be higher in control (4.8 mg/100 g) on 10(th) day than the chitosan incorporated sample (3.5-4.2 mg/100 g) on 17(th) day during chill storage. Similarly, peroxide value (PV) was found to higher (8.85 milliequivalent of O2/kg) in control than the chitosan incorporated sample (4.5-6.8 milliequivalent of O2/kg) on 10(th) day. All the three formulations had an acceptable level of thiobarbituric acid (TBA) value that ranged between 0.023-0.098 mg of malanoldehyde/kg during chilled storage. Based on the sensory and microbiological analysis, products prepared without chitosan had a shelf life of 10 day whereas, products incorporated with chitosan had an extended shelf life of 17 day.

Effect of fish oil encapsulates incorporation on the physico-chemical and sensory properties of cookies.

A great deal of attention has been focused on the various health benefits apparently associated with consumption of fish oil. The incorporation of fish oils in food products is becoming increasingly widespread and a large variety of products is being marketed. However, the use of fish oil as functional nutritional ingredients in foods has been limited by its oxidative susceptibility. In the present study, attempts were made to develop fish oil fortified cookies as healthy snack foods by incorporating fish oil microencapsulate. Microencapsulation of fish oil was done by spray drying. Commercially available milk was used to form micro sized complexes with fish oil. Fish gelatin/maltodextrin were used as a wall material for encapsulation. Fish oil was added in three forms (fish oil as such, fish oil-in-water emulsion and fish oil microencapsulate) for the preparation of cookies. Cookies prepared without incorporating fish oil was served as control. The physical, chemical and sensory attributes of cookies were evaluated. Encapsulation significantly (P < 0.05) decreased lipid oxidation in the cookies. The sensory evaluation of cookies showed significant (P < 0.05) difference in the overall acceptability. Results from this study, demonstrated the possibility of fish oil incorporation into cookies through emulsification and microencapsulation which may increase the intake of omega-3 fatty acids for nutritional benefits.

Semiorganic nonlinear optical material for frequency doubling: preparation and properties of sodium p-nitrophenolate dihydrate (SPNP).

Sodium p-nitrophenolate (SPNP), a semiorganic nonlinear optical (NLO) material useful for frequency doubling in the IR region, has been synthesized. The solubility studies have been carried out in the temperature range 30-50 degrees C. Single crystals (size 12 mmx7 mmx4 mm) have been grown by slow evaporation of the saturated aqueous solution (methanol as solvent) at 30 degrees C. The lattice parameters of the grown crystals have been determined by single crystal X-ray diffraction technique. The UV-vis-NIR transmittance spectrum has been recorded in the range 200-1500 nm. The molecular structure was confirmed by FT-IR and FT-NMR. SPNP was thermally stable up to 103 degrees C as determined by TG/DTA curves. By a modified Kurtz and Perry method, the powder SHG efficiency was found to be five times that of KDP and its phase matching property was established. Laser damage threshold of SPNP was determined using a Nd:YAG laser.

Spectral and optical studies of 2-amino-5-nitropyridinium dihydrogen phosphate: a semiorganic nonlinear optical material.

2-Amino-5-nitropyridinium dihydrogen phosphate (2A5NPDP) was synthesized and the molecular structure was elucidated by FT-IR, FT-Raman and FT-NMR. The proton and carbon configurations of 2A5NPDP was confirmed through FT-NMR technique. UV-vis-NIR spectrum was recorded and the optical transmittance region was identified as 350 nm. Single crystals were grown from ethanol by slow evaporation technique at 35 degrees C and the unit cell constants were determined. Bulk and powder second harmonic generation (SHG) measurements were carried out using Nd:YAG laser (lambda=1064 nm) and its phase matching condition was determined.

Phase matchable semiorganic NLO material for frequency doubling: L-Arginine tetrafluoroborate.

L-Arginine tetrafluoroborate (C6H15N4(+)O2BF4(-)) is a semiorganic crystalline material exhibiting second harmonic generation (SHG) down to the UV region. The material was synthesized and characterized by elemental analysis, FT-NMR and FT-IR spectra. The lower cutoff wavelength was found to be 270 nm, with a good optical transmittance window covering UV-vis-NIR region. The thermal stability of the compound was determined by TG-DTA curves. The powder SHG efficiency was measured using a Q-Switched Nd:YAG laser assembly by a modified Kurtz and Perry powder technique and its phase matching property was established.

EPR studies of VO2+ ions in kainite single crystals.

Electron paramagnetic resonance (EPR) spectra of VO2+ ions doped in Kainite (a mineral salt) single crystals and powder were recorded at room temperature at X-band frequencies. The angular variation studies of the spectra indicate that the VO2+ ion enters Mg2+ ion site substitutionally. The principal values of g and A-tensors were determined from the EPR spectral studies. Using these EPR parameters, the molecular orbital bonding parameters of VO2+ ion in the lattice have been evaluated and discussed.