Instant controlled pressure drop (DIC) coupled to intermittent microwave/airflow drying to produce shrimp snacks: Process performance and quality attributes

Abstract

Effects of operating parameters of the instant controlled pressure drop (DIC) texturing process followed by intermittent microwave (MW) and airflow drying were studied for the manufacture of novel swell-dried shrimp snacks. The DIC processing parameters were the absolute pressure of saturated steam (P = 0.4, 0.55, and 0.7 MPa) and the treatment time (t = 70, 100, and 130 s). Intermittent MW drying with active time t_ON of 30 s and tempering time t_OFF of 60 s followed DIC-texturing of blanched shrimp samples (30 g cubes of 1 cm³). The MW density power $\dot{\wp }$ levels tested were 6, 12, and 24 W/g wb (wet basis). The airflow condition was fixed at 3.2 m/s, 20 °C, and 276 Pa water vapor pressure. Drying performance along with the organoleptic, structural, and functional quality parameters was measured for the dried product. The results showed that the highest DIC processing parameters of P = 0.7 MPa for 170 s were the best texturing conditions, while the MW power level of 24 W/g wb yielded the most effective drying performance when 90% of moisture was removed in 10 min, with organoleptic quality attributes and structural properties better than those of conventionally dried shrimp. Furthermore, the aroma was better preserved, and the exceptionally high absolute expansion ratio (Ɛ_abs = 13.84) and porosity (φ = 92.83%) allowed enhancement of the desired crispness of the snacks as well. The highly porous microstructure also results in improved rehydration performance.

Keywords:

• Swell-drying
• intermittent microwave/airflow drying IMAD
• instant controlled pressure-drop (DIC) texturing
• drying kinetics
• rehydration
• expansion ratio
• porosity

Acknowledgments

The authorsthank ABCAR-DIC PROCESS SASCompany (La Rochelle, France) for providing Lab-scale and pilot-scale DIC units.

Disclosure statement

The authors declare that they do not have any conflict of interest.