To characterize the food components of two mussels (wild hard-shelled mussel (HM) Mytilus coruscus, and cultured sea mussel (SM) Mytilus edulis) in Korea, we examined the proximate composition, fatty composition, amino acid/mineral content, texture, collagen content and chemical and taste compounds. Regarding the proximate composition, HM had lower moisture levels and higher crude protein and carbohydrate contents than SM. The amino nitrogen, volatile basic nitrogen and total amino acid contents of HM and SM were 250.6 and 227.3 mg/100 g, 11.2 and 12.0 mg/100 g, and 17,451.1 and 15,334.8 mg/100 g, respectively. The major amino acids were glutamic acid, aspartic acid, glycine, alanine, lysine and arginine. The major fatty acids of HM and SM were 14:0, 16:0, 16:1n-7, 20:5n-3, and 22:6n-3, which did not differ significantly between the two mussels. HM had a higher n-3 polyene ratio, and a lower saturate and monoene ratio than SM. Regarding the taste-active compounds, the free amino acid contents of HM and SM were 1,116.5 and 961.8 mg/100 g, respectively, and the major free amino acids were taurine, glutamic acid, glutamine, glycine, citrulline, lysine and arginine. The primary minerals in both HM and SM were Na, Cl, K and P which did not differ significantly between the two mussels. The soluble and insolube collagen contents of HM and SM were 265.8 and 228.4 mg/100 g, and 119.5 and 121.8 mg/100 g, respectively.
Extraction methods for cultured sea mussels Mytilus edulis and the quality characteristics of resulting extracts were investigated. The crude protein, carbohydrate and volatile basic nitrogen content of raw sea mussels was 15.2%, 1.9%, and 11.2 mg/100 g, respectively. Extracts were prepared using three different methods: hot-water extract (WE), scrap enzymatic hydrolysate extraction (SE), and complex extraction (CE). The respective extracts contained 5.5%, 8.6%, and 6.6% crude protein; 281.7, 366.0, and 343.0 mg/100 g amino nitrogen,: and 2.0%, 1.1% and 1.8% salinity. Their extraction yields were 689, 323, and 1,012 mL/kg. The CE method was superior to the traditional WE method in terms of extraction yield, amino nitrogen content, and organoleptic qualities, but not odor. Active taste components were evaluated and the total free amino acid content of the WE and CE methods was 5,667.0 and 7,006.3 mg/100 g, respectively. The concentrations of major components (for WE and CE methods, respectively) were as follows: glutamic acid (1,244.0 and 955.4 mg/100 g), taurine (987.9 and 746.8 mg/100 g), glycine (721.2 and 847.0 mg/100 g), alanine (341.9 and 423.8 mg/100 g), arginine (265.5 and 376.5 mg/100 g), lysine (199.8 and 270.4 mg/100 g), and proline (253.9 and 220.3 mg/100 g). In conclusion, these results demonstrate that there is potential for using the CE method to expand the commercial utilization of sea mussels as a flavoring substance resource.
To develop a high value-added product from extract from small and damaged sea mussels Mytilus edulis, we prepared two types of sea mussel sauce (MS): bottled (BMS) and retort pouched (RMS). We investigated the processing conditions, quality metrics and flavor compounds in each type of sauce. We found that the most appropriate base formulation for both BMS and RMS consisted of 40.0% SME (Brix 30°), 15.0% sugar, 6.0% salt, 4.0% monosodium glutamate, 4.0% soy sauce, 3.5% starch, 3.0% yeast extract, 3.5% wheat flour and 21.0% water. The crude protein, salinity, volatile basic nitrogen and amino nitrogen content of the BMS and RMS were 8.7% and 8.8%, 9.3% and 9.2%, 24.9 and 31.4 mg/100 g, and 468.5 and 455.1 mg/100 g, respectively. For comparison, the ranges of these values in commercial oyster sauces (COS) are 4.7-7.5%, 10.7-12.0%, 8.2-12.5 mg/100 g, and 225.7-448.2 mg/100 g, respectively. The total free amino acid content of RMS and Premium COS was 7,215.7 and 6,160.7 mg/100 g, respectively, and the main free amino acids were glutamic acid, taurine, glycine, alanine, arginine, proline and lysine. These results demonstrate that BMS and RMS have favorable organoleptic qualities and good storage stability compared to COS, and are suitable for commercialization as high-flavor seasoning sauces.
To develop a high value-added individually quick frozen (IQF) intermediate product from cultured sea mussels Mytilus edulis, we prepared two types of IQF half-shelled sea mussels for haute cuisine: IQF half-shelled roasted sea mussels (HRM) and IQF half-shelled steamed sea mussels (HSM). We investigated the processing conditions, quality metrics, and chemical and flavor compounds in each type of product. The IQF HRM or HSM using cultured sea mussels were manufactured according to following unit processings; washing and removing byssus of raw sea mussels, electric roasting (225-230℃, 3 min) or steaming (98-99℃, 5 min), half-shelling of roasted or steamed sea mussels, deep freezing (-35±2℃, 2 h), glazing, and refreezing and packaging with plastic film bag. The moisture, salinity, volatile basic nitrogen and amino nitrogen contents of raw sea mussel, HRM and HSM were 78.4%, 71.2% and 72.4%, 2.2%, 1.8% and 1.6%, 14.2, 11.5 and 12.6 mg/100 g, and 809.3, 607.9 and 534.2 mg/100 g, respectively. The viable cell count of raw sea mussel, HRM and HSM was (2.7-5.6)×103, (4.6-6.8)×102 and (3.2-4.2)×102 CFU/g, respectively. The hardness and shearing force of the thawed HRM and HSM were 4.31 and 2.99 kg/cm2, and 992.2 and 507.7 g, respectively, and the free and expressible drip of these products were 8.9% and 10.2%, and 7.0% and 8.1%, respectively. For comparison, the electric roasting method for IQF half-shelled sea mussels was superior to the traditional steaming method in terms of texture, free and expressible drip, and organoleptic qualities. The major fatty acids of HRM and HSM were 14:0, 16:0, 16:1n-7, 18:1n-9, 18:4n-3, 20:5n-3, and 22:6n-3, which did not differ significantly between the two products. HRM and HSM had a lower n-3 polyene ratio, and a higher saturate and monoene ratio than raw sea mussel. Total amino acid contents of the raw sea mussel, HRM and HSM were 10,681.6, 14,630.2 and 13,887.6 mg/100 g, respectively, the major amino acids were aspartic acid, glutamic acid, proline, glycine, alanine, leucine, lysine and arginine. The primary minerals in raw sea mussel, HRM and HSM were Na, S, K, P and Ca which did not differ significantly between the two products. Regarding the taste-active compounds, the free amino acid contents of raw sea mussel, HRM and HSM were 892.0, 763.1 and 560.7 mg/100 g, respectively, and the major free amino acids were taurine, glutamic acid, proline, glycine and alanine. And the primary inorganic ions were Na, S and K. These results demonstrate that HRM has favorable organoleptic and good processing qualities compared to the traditional HSM, and are suitable for commercialization as a high value-added IQF intermediate sea mussel product.