K.A. Martin Xavier

Packaging performance of organic acid incorporated chitosan films on dried anchovy (Stolephorus indicus).

Antimicrobial chitosan films were prepared with acetic acid and propionic acid with glycerol as plasticizer and its efficiency was compared with polyester-polyethylene laminate (PEST/LDPE). The tensile strength of acetic acid/chitosan (ACS) films were higher than propionic acid/chitosan (PCS) films. The elongation percentage (6.43-11.3) and water vapour permeability (0.015-0.03 g/m(2)/day) were significantly lower (p<0.05) for chitosan films when compared to control. Oxygen transmission rate (OTR) of control and propionic acid/chitosan (PCS) films were significantly higher (p<0.05) than acetic acid/chitosan (ACS) films. Dried anchovy (Stolephorus indicus) wrapped in these films were stored at ambient temperature for three months. Quality indices like peroxide value (PV), thiobarbituric acid value (TBA) and microbiological parameters such as aerobic plate count (APC) and total fungal count (TFC) were periodically determined. In terms of microbial and chemical indices, anchovies wrapped in ACS and PCS films were superior to those wrapped with PEST/LDPE films during storage. Study revealed the suitability of chitosan film as wraps for increasing storage stability of dried fish.

Development of functional extruded snacks by utilizing paste shrimp (Acetes spp.): process optimization and quality evaluation

BACKGROUND Functional extruded snacks were prepared using paste shrimp powder (Acetes spp.), which is rich in protein. The process variables required for the preparation of extruded snacks was optimized using response surface methodology. Extrusion temperature (130-144 °C), level of Acetes powder (100-200 g kg-1 ) and feed moisture (140-200 g kg-1 ) were selected as design variables, and expansion ratio, porosity, hardness, crispness and thiobarbituric acid reactive substance value were taken as the response variables. RESULTS Extrusion temperature significantly influenced all the response variables, while Acetes inclusion influenced all variables except porosity. Feed moisture content showed a significant quadratic effect on all responses and an interactive effect on expansion ratio and hardness. Shrimp powder incorporation increased the protein and mineral content of the final product. The extruded snack made with the combination of extrusion temperature 144.59 °C, feed moisture 178.5 g kg-1 and Acetes inclusion level 146.7 g kg-1 was found to be the best one based on sensory evaluation. CONCLUSION The study suggests that use of Acetes species for the development of extruded snacks will serve as a means of utilization of Acetes as well as being a rich source of proteins for human consumption, which would otherwise remain unexploited as a by-catch.

Functionality of chitosan in batter formulations for coating of fish sticks: Effect on physicochemical quality

Chitosan is a natural polymer having diverse applications in food industry. The present study was undertaken to evaluate chitosan as a hydrocolloid in batter composition in developing enrobed fish sticks with better functional properties and improved quality. Different concentrations of chitosan gel were made in acetic acid medium and incorporated into batter for making enrobed fish sticks. Coating parameters, fat uptake, oil reduction, chemical quality parameters, instrumental texture analysis and colour were studied. Addition of chitosan gel had a significant effect (P<0.05) on the coating pickup, adhesion degree and cooking yield of the product. Total volatile basic nitrogen, pH, lipid oxidation parameters like peroxide value and thiobarbituric acid reactive substances of par-fried fish sticks also showed significant differences. The oil reduction in par-fried samples were 36.84, 65.05, 73.83, 77.65% respectively for 0.5, 1.0, 1.5, 2.0% chitosan added samples. Addition of chitosan significantly reduced crispness, gumminess, Warner-Bratzler shear force and toughness (P<0.05) of the product. The study clearly demonstrated that the inclusion of chitosan at 1.0% in batter can improve functional and other quality aspects of enrobed products.

Fortification of extruded snacks with chitosan: Effects on techno functional and sensory quality

Chitosan is a dietary fibre that possesses numerous functional, technological and physiological properties useful in improving food quality. Owing to its fat absorbing ability, chitosan is widely consumed as a health supplement in the form of tablets and capsules. With a view to enhance it consumption and availability, the current work was taken up to evaluate techno-functional quality improvement of shrimp based extruded snacks fortified with chitosan. Chitosan powder at 1, 2 and 3% (w/w) level was added to the base material (corn flour and rice flour in the ratio of 70:30 and 15% Acetes powder) for extrusion. Addition of chitosan in acetes based snacks significantly reduced expansion ratio, porosity and crispiness and increased the hardness value of the product. Chitosan addition had a significant effect (p > 0.05) on the moisture retention and total protein contents of the products as well. Thiobarbituric acid reactive substances (TBARS) value of chitosan fortified extrudate showed a significantly lower value than the control sample. A higher level of chitosan also resulted in colour reduction of the final product. The FTIR spectra of extrudate confirmed the stability of chitosan during extrusion conditions. The sensory score revealed that extrudate fortified with 1% chitosan was comparable to control sample. From this study it is concluded that 1% chitosan can be incorporated in Acetes based extruded snacks for an increased level of functionality.