Changes in lipids of shrimp (Acetes vulgaris) during salting and fermentation

Abstract

Changes in lipids of shrimp Acetes vulgaris during production of Kapi (salted shrimp paste of Thailand) were investigated. Shrimp had lipid content of 4.21% (dry weight basis). Lipids mainly consisted of triacylglycerol (TAG) 28.03 g/100 g and sterol (ST) 24.03 g/100 g. Lipid content decreased during salting, drying and the first period of fermentation (p < 0.05). Both TAG and ST gradually decreased, while free fatty acid (FFA) increased and became dominant in the final product (49.29%). Phospholipids including phosphatidylethanolamine (PE) 4.80 g/100 g and phosphatidylcholine (PC) 5.67 g/100 g were also found in fresh shrimp and still remained in the final product. Palmitic acid (C16:0) was the major fatty acid in shrimp (27.95%). Eicosapentaenoic acid (EPA) (C20:5(n‐3)) and docosahexaenoic acid (DHA) (C22:6(n‐3)) were found at high content (19.03%). When different fractions were isolated from crude lipids, varying fatty acid profiles were obtained. TAG and FFA fractions mainly consisted of saturated and monounsaturated fatty acids. Polyunsaturated fatty acids were accumulated in PE and PC fractions. Peroxide value and TBARS value increased during Kapi production, suggesting that lipid oxidation took place. Overall, lipolysis and oxidation of shrimp lipids occurred throughout the processes, thereby affecting lipid constituents. Those changes might partially contribute to the Kapi characteristics, especially flavor. Practical applications: Kapi, salted shrimp paste, is one of the most popular traditional condiments used in Thailand. Over the last decade, shrimp Acetes vulgaris, by‐catch from commercial fishing, has become the alternative raw material for Kapi production instead of krill (Mesopodopsis spp.). During processing, changes in lipids via both lipolysis and lipid oxidation occurred. This work provides the information about lipids from this shrimp species and their changes during Kapi production, which might determine sensory properties, especially odor or flavor, as well as nutritive value of the final product. Lipids of shrimp Acetes vulgaris, alternative source for Kapi production, consisted of TAG and ST as dominant lipids. PUFA was accumulated in PE and PC fractions, while TAG had SFA and MUFA as dominant fatty acids. During making Kapi, both lipolysis and lipid oxidation occurred, as indicated by the increases in FFA content and lipid oxidation products, respectively. These changes could be related with the final Kapi characteristics, and its nutritional value.

Mie Krill: Incorporation of Indigenous Udang Saih (Sumatran Krill) Extract Containing Astaxanthin and Essential Fatty Acids into an Instant Noodle Product Made from Composite Flour

“…Furthermore, PUFAs comprised of omega-3 (25.41%) and omega-6 (12.70%) was the main component of UFAs compared to MUFAs. The long-chain eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (21.88%) as the omega-3 PUFAs were the most abundant fatty acid group in super-concentrated astaxanthin of the SK extract which were similar results to other fatty acid studies on Euphausia superba [10] and Acetes vulgaris [35].…”

Chitosan‐Tripolyphosphate Nanoparticles Improves Oxidative Stability of Encapsulated Shrimp Oil throughout the Extended Storage

“…Shrimp oil was reported to constitute phospholipid of 45.98%. [ 6 ] Shrimp oil was also found to contain 25% sterols, [ 48 ] out of which 6.5–7.5% was identified as cholesterol. [ 49 ]…”

Impact of different drying processes on the lipid deterioration and color characteristics of Penaeus vannamei

“…It is widely accepted that marine shrimp is a good source of high‐quality protein (22% of wet basis) and functional lipids (10.7% of dry basis), and the latter is abundant in long‐chain polyunsaturated fatty acids (PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) . Omega‐3 PUFA are highly susceptible to lipid peroxidation triggered by free radicals, leading to the formation of reactive compounds that result in an unpleasant odor and even potentially toxic biological effects …”

“…4 Omega-3 PUFA are highly susceptible to lipid peroxidation triggered by free radicals, leading to the formation of reactive compounds that result in an unpleasant odor and even potentially toxic biological effects. 5,6 Fresh shrimp deteriorates easily; thus, it must be preserved and processed soon after harvest to increase its shelf life. The boiling process can inhibit the activity of the enzyme, and the boiled shrimp can usually be stored for 6-10 h at room temperature in terms of eating taste.…”