Direct Treatment of Isada Krill under Subcritical Water Conditions to Produce Seasoning with Shrimp-Like Flavor

Abstract

SummaryCharacterization, sensory evaluation, and astaxanthin stability of isada krill under various subcritical water conditions were investigated to optimize the quality of krill extract and residue for producing food seasoning. Raw krill (82 % wet basis moisture content) without additional water was treated in a pressure-resistant vessel for 10 min at a temperature range of 100-240 °C. The yield of water-soluble protein was maximized by treatment at 200 °C and decreased with treatment at higher temperatures. The degradation of large molecules and the concomitant production of small molecules depended on the treatment temperature. Astaxanthin in the krill was unstable at temperatures higher than 140 °C. The odour intensities of krill extract and residue increased with higher treatment temperature; however, the highest intensity of pleasant shrimp-like fl avour was obtained by treatment at 140 °C. Subjective preference scores were the highest for extract and residue obtained at 140 °C. Thus, treatment at 140 °C is the most promising method for production of seasoning with shrimp-like fl avour from isada krill.

Astaxanthin stability and color change of krill during subcritical water treatment

“…The vessel was maintained at a constant temperature for 0-10 min before it was removed and cooled in an iced water bath. The liquid and solid fractions were separated and collected as described in our previous work (Koomyart et al 2016). To assess the color and content of astaxanthin, the solid residue was frozen at -30°C for 12 h, lyophilized at -50°C and 90 Pa for 48 h, and then ground into a powder form using a mortar and pestle.…”

Preparation of Powdered Seasoning with Shrimp-like Flavor from the Aqueous Residue of Isada Krill by Subcritical Water Treatment and Spray-drying

“…We have previously reported that the treatment of Isada krill [6][7][8][9][10], or that of its residual waste solution [11], under subcritical water conditions at 140-200℃ reduced the fishy odor and enhanced shrimp-like flavor.…”

Seasoning Production from the Residual Waste Solution of Isada Krill Processing by Its Treatment under Subcritical Water Conditions

“…We have previously reported that the subcritical water treatment of raw Isada krill results in the decrease in the fishy smell and increases the shrimp-like fragrant smell [13][14][15]. As the residual solution may retain some of the original components from Isada krill, its treatment with subcritical water would be favorable to improve the smell of the solution.…”