From cooked shrimp

Identification and Formation of Characteristic Volatile Compounds from Cooked Shrimp... 

Figure 1. Compositions of Main Heterocycles in the Volatiles from Cooked Shrimps.

Both these methylketones were detected together in the volatiles from all cooked samples of S. lucens, A. japonicus, P. muelleri and Eh superba. It appears that these novel methylketones are important constituents in addition to the above-described heteroatomic substances of the flavors of cooked shrimps. 

Various kinds of heterocycles and two unsaturated methylketones were identified as characteristic components in the volatiles from cooked small shrimps. Without exception, they were all thermally generated compounds. Some volatile components from cooked small shrimps were in common with those of other animal protein foodstuffs like meat however, various types of compounds found in another foodstuffs were composed of the volatiles from specific shrimp species. Both the precursors and the formation pathways for the typical aroma compounds have already been elucidated, even though it is difficult to explain the different constituents of the volatile components among shrimp species. In future, it will be necessary to investigate the key factors which define the possible pathway to form characteristic volatiles in each foodstuff. 

Vandanjon et al. [37] reported on using a combination of UF and RO, or UF and nanofiltration (NF) to remove both volatiles and non-volatiles from the cooking water of shrimp, buckies, and tuna. The preliminary use of UF is common in that it removes the larger materials that would clog the subsequent membrane steps. NF was not found to be as efficient in the recovery of volatiles as RO. Unfortunately, the authors did not evaluate the use of the recovered materials as flavourings. 

Lobster and shrimp dine on carotenoid-containing plankton, and the compounds become concentrated in their shells. Here the carotenoids are bound up with protein molecules, and the carotenoid-protein complex has a dark green color. When the protein is heated, it is denatured. In other words, it breaks down and disassociates from the reddish pigment, astaxanthin, which then becomes visible. To a smaller extent this is also evident in cooked carrots, which become more orange than they were before. This was another experiment my daughter and I decided to try. We cooked up some fresh carrots to see if they would become more orange. They did, but the effect was not as pronounced as it was with the shrimp, because carrots have little protein. 

It was a characteristic of small shrimp flavor that many varieties of cyclic polysulfides were formed during cooking. Some distinction in the composition of these heterocyclic substances were also observed among the shrimp species or from the treatment before heating, and led to the following conclusion the content of free amino acids should give the initiative for the formation pathway of the heterocyclic substances in small shrimps. 

Strike has been very disappointed in the lack of responses regarding the shrimp recipes from the last edition. Only two people contacted Strike saying they had tried them. Naturally it was the best food they had ever had. Strike can t understand what was wrong. Was it a problem with translation for the Europeans (hint shrimp in European is prawn , possibly langoustine ) Was it that all of you can t afford shrimp Can t cook If you can t cook then this book is of no use to you. 

Why do lobster and shrimp change to a reddish-orange color from a grayish-blue color when we cook them ... 

Fig. 3. Chitin and chitosan are commonly isolated from the shells of crab and shrimp. On the right-hand side is the original, cooked crab shell. On the left-hand side is the underlying matrix of chitin, after the proteins and minerals have been removed. Chitin is biosynthesized as an ordered assembly of chains jdelding microfibrils, which are seen in the scanning electron micrograph insert. The scale bar in the insert is 2000 nm.

Cooked meat—The cooked meat is picked from the shell of cooked crab, lobster, and shrimp and is available either fresh, frozen, or canned. 

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