To characterize the food components of two abalones [middle-sized abalone Haliotis discus hannai, 10-15 animals/kg (MA), and small-sized abalone Haliotis discus hannai, 30-35 animals/kg (SA)] in Korea, we examined the proximate composition, fatty composition and amino acid content. Regarding the proximate composition, MA had lower moisture and carbohydrate levels and higher crude protein contents than SA. Total amino acid contents of MA and SA were 15,734.4 and 11,379.1 mg/100 g, respectively, and the major amino acids were glutamic acid, aspartic acid, serine, glycine, alanine, leucine, arginine and lysine. The major fatty acids of MA and SA were 16:0, 18:0, 18:1n-9, 18:1n-7, 20:4n-6, 20:5n-3 and 22:5n-3, which did not differ significantly between the two abalones.
Extraction methods for cultured small-sized recessive abalone Haliotis discus hannai and the quality characteristics of resulting extracts were investigated. Extracts were prepared using three different methods: hot-water extraction (WE), scrap enzymatic hydrolysate extraction (SE), and complex extraction (CE). The pH, total nitrogen and amino nitrogen contents of the WE and SE were 6.32 and 6.05, 1.36% and 1.52%, and 342.1 and 403.1 mg/100 g, respectively. Their extraction yields were 1,317, 440, and 1,757 mL/kg, respectively. The CE method was superior to the traditional WE method in terms of extraction yield, amino nitrogen content, and organoleptic qualities. Active taste components were evaluated and the total free amino acid content of the WE and SE methods was 8,721.1 and 9,070.7 mg/100 g, respectively. The concentrations of major components were as follows: arginine (2,633.1 and 1,145.0 mg/100 g), glycine (1,635.7 and 1,310.0 mg/100 g), glutamic acid (857.5 and 1,268.3 mg/100 g), alanine (917.6 and 825.2 mg/100 g), lysine (399.0 and 526.2 mg/100 g), and valine (259.1 and 443.7 mg/100 g). In conclusion, these results demonstrate that there is potential for using the CE method to expand the commercial utilization of small-sized recessive abalones as a flavoring substance resource.
To develop a high value-added product from small-sized recessive abalones Haliotis discus hannai, we prepared the retort pouched abalone soup (RAS). We investigated the processing conditions, quality metrics and taste compounds in RAS. RAS was manufactured according to following manufacturing process; washing with 3% saline solution of raw abalones, removing shell and intestine, blanching, filling in retort pouch with other ingrediants i.e., base soup stock including 3% abalone complex extract, sea cucumber, Pak choi, and shiitake mushroom, sealing, retort sterilization (Fo-value 10 min at 120℃), cooling and packaging inspection. Total amino acid contents of the RAS was 5,045.9 mg/100 g, the major amino acids was aspartic acid, glutamic acid, glycine, cysteine, isoleucine, leucine and arginine. And the primary minerals in RAS was Na, K, S, Ca and P. Regarding the active taste compounds, total free amino acid contents of the RAS was 1,026.9 mg/100 g, the major amino acids was asparagine, methionine, glutamic acid, arginine, β-alanine, aspartic acid and glycine. And the primary inorganic ions were Na, K and S. As a result of physicochemical experiments for quality stability during incubating test at 35-37℃, RAS showed very good conditions for preserving the organoleptic quality, and could be reserved in acceptable conditions for storaging 60 days or more. So it is suitable for commercialization as high value-added abalone product.