Development of shelf-stable, ready to cook (RTC) intermediate moisture (IM) shrimp and its shelf life extension using hurdle technology

Abstract

Frozen shrimp is a major commodity exported from India. A hurdle technology was employed for the shelf life extension of intermediate moisture (IM) shrimp at ambient temperature. The shrimps were salted (10% w/v), dried in an infra-red dryer (60 °C, 6–8 h) to the moisture level of 30–32%, packaged in PET/POLY (polyethylene terephthalate) bags, subjected to gamma radiation (5 kGy) and stored at ambient temperature (26–28 °C) for 6 months. Initial bacterial count (TBC) was 3.20 ± 0.26 and 1.61 ± 0.09 log CFU/g for control and irradiated (5 kGy) samples respectively. TBC reduced to 2.03 ± 0.17, 0.36 ± 0.09 log CFU/g for control and 5 kGy samples respectively after 6 months of storage at room temperature. The total volatile base nitrogen (TVBN) content was increased to 95.22 ± 4.78, 84.72 ± 2.58 mg N/100g for control and 5 kGy samples from initial value of 33.20 ± 0.40 and 33.32 ± 0.40 mg N/100g respectively. Similarly, trimethyl amine (TMA) content was found to be increased from 4.54 ± 0.62, 6.31 ± 0.22 to 25.03 ± 0.84, 23.59 ± 1.02 mg N % in case of control and irradiated sample respectively. Initial thiobarbituric acid reactive species (TBARS) content of control and 5 kGy sample was 1.85 ± 0.06 and 2.89 ± 0.13 μg malonaldehyde (MDA)/g respectively which was further enhanced to 9.18 ± 1.13 and 6.36 ± 0.41 μg MDA/g. However, based on sensory evaluation, control samples were acceptable till 4-months with sensory score of 3.78 ± 0.34 whereas irradiated samples were acceptable till 6 months of storage with sensory score of 4.5 ± 0.73. We conclude that hurdle treatments (salting, drying and irradiation) can be efficiently employed to develop shelf-stable, microbiologically safe IM shrimp with improved sensory quality and economic value. • Shelf-stable, hygienic and safe Intermediate Moisture (IM) shrimp. • Salting, infra-red drying and gamma irradiation were used as hurdles. • Well acceptable sensory, texture quality with good rehydration capacity. • Ensures longer availability during lean season and to distant/remote places. • Economically beneficial to processers, suitable for import and export.