Search

A demerit score-based fish quality index (FQI) has been developed to assess the quality/freshness of fresh fish by considering five general characteristics in the demerit score like appearance of f...

Increasing environmental pollution and limited biological resources has emphasized the need for better utilization of fish processing waste. In the present study, visceral proteases from little tuna (Euthynnus affinis), catla (Catla catla) and tilapia (Oreochromis mossambicus) belonging to different habitats using acetone, ethanol and ammonium sulfate fractional precipitation were isolated and characterized. Enzymes precipitated from little tuna and tilapia exhibited higher specific activity at 40% saturation for ammonium sulfate fractional precipitation and the specific activities were 18.19 and 13.67 U/mg for little tuna and tilapia enzymes, respectively. Enzymes precipitated from catla reported higher specific activity of 8.32 U/mg at 60% saturation for ammonium sulfate fractional precipitation. Acetone precipitated fraction exhibited higher recovery for all crude enzymes studied. The effect of different combinations of crude tuna visceral waste enzyme and papain enzyme on hydrolysate properties was optimized using response surface methodology. Second order response surface regression model was used to explain the total variability in terms of quadratic and interaction effects of combination enzyme concentration on the properties of croaker protein hydrolysate with a significant R2 value for protein content (0.92), tyrosine content (0.99), degree of hydrolysis (0.99), DPPH free radical scavenging activity (0.97), ferric reducing antioxidant power (0.93), metal chelating activity (0.88), foaming capacity (0.92) and foam stability (0.88). Based on the desirability score, papain at 0.81% concentration and crude tuna visceral protease at 4.36% was found to be optimal for achieving desired properties of croaker protein hydrolysate.

Air frying technique was used for the preparation of fish cutlet-a popular fish snack with low fat content, better protein content and color. The process conditions viz: temperature varying from 160 to 200 °C and time varying from 5 to 15 min were optimized using response surface methodology. A factorial design with 9 runs satisfying rotatability conditions under correlated errors was formulated for the experiment. The parameters of first order response surface model with interaction were estimated by generalized least square method. The optimum temperature—time combination for air-frying condition was found to be 180 °C and 12 min, respectively for low fat content, better protein content and colour, comparable texture profile and sensory acceptability when compared to deep fried fish cutlet samples. Air-fried fish cutlets can be a healthier protein rich snack product as an alternative to deep fat fried fish cutlets.

In this study, the gelation and thermal characteristics of microwave extracted fish scale gelatin blended with natural gums such as gum arabic (AG), xanthan gum (XG), guar gum (GG), and tragacanth gum (TG) was evaluated. The nature of interaction and behavior of gelatin in presence of various gums was confirmed by particle size analysis, viscosity profile, FT-IR analysis and turbidity measurements. DSC data revealed that addition of AG, TG and GG remarkably improved the thermal stability of fish gelatin gel. The composite gels of TG, AG, and XG exhibited higher hardness and bloom strength values as compared to pure fish gelatin implying its textural synergy. Based on qualitative descriptive analysis, TG was found to be superior in improving the stability of fish gelatin gel, closely followed by AG. The results suggest that addition of these gums can reduce syneresis and retard melting of gelatin gels at ambient temperature, which are otherwise soft and thermally unstable.

Masmin is a traditional smoked and dried fishery product from Lakshadweep, India. Heavy smoking applied during its production leads to accumulation of carcinogenic Polycyclic Aromatic Hydrocarbons (PAH) in masmin. Present study was aimed at development of masmin flakes-a convenience based product of masmin by completely replacing traditional smoking practices with liquid smoking. Process parameters for producing masmin flakes by spraying, soaking and blending with a commercial liquid smoke were separately standardized. Spray application of the commercial liquid smoke [diluted in 1:3 proportion with distilled water and added with 9.25% (w/v) salt] for 90 min at a flow rate of 1 L/h and a chamber temperature of 45 °C was found to give products with matching flavour of traditional masmin. Developed products had a Total PAH content of 67.99 ± 19.30 μg/kg and PAH4 content of 16.04 ± 5.81 μg/kg. Benzo(a)pyrene was not detected in the product. Physico-chemical changes of the product during storage under two packaging; 90 μ Low Density Polyethylene (PE) and laminate of 12 μ Polyester and 300 gauge Polyethylene (PEST/PE) was investigated. Significant difference was observed between products packed in the two packaging materials in terms of TVB-N and TMA-N content (p 0.05). The products were found to be shelf stable even after 12 months of storage.