Crayfish Hepatopancreatic Extract Improves Flavor Extractability from a Crab Processing By‐product

Abstract

Incorporation of crayfish hepatopancreatic extract (CHE) improved the extraction of volatile flavor compounds and increased the extractability of nonvolatile nitrogen compounds from crab hard tissue (CHT) obtained by mechanical separation of composite processing by-product. Optimum reaction conditions for hydrolysis of CHT protein were 2 hr reaction with 1 mL CHE per log CHT at 45°C. Concentration of volatile flavor compounds increased significantly in CHE-treated CHT compared with those from untreated substrate; however, dienals and aromatic hydrocarbons decreased. Pyrazines, especially 2-ethyl-6-methylpyrazine and 2,3-dimethylpyrazine, were in markedly higher concentrations due to CHE treatment.

Chemical composition and flavour characteristics of a liquid extract occurring as waste in crab (Ovalipes punctatus) processing

“…2,4‐Dimethyl‐1‐heptanol, with a woody fragrance, was the dominant alcohol in O. punctatus extract, followed by 2,5‐dimethyl‐11,5‐heptadiene‐3,4‐diol, 3‐octanol and cedrol. However, these alcohols were not found in blue crab, snow crab or green crab . Cedrol is a fragrance ingredient widely used in cosmetics and household cleaners .…”

“…Branched‐chain aldehydes occupied 47.1% of all aldehydes, and they were generally perceived as having a malty and chocolate‐like aroma . Almost all the aldehydes, except for 7,10,13‐hexadecatrienal, were previously detected in blue crab processing by‐products . Therefore, 7,10,13‐hexadecatrienal was a characteristic aldehyde in O. punctatus extract.…”

“…Pyrazines are regarded as having a positive impact on the overall aroma of meat, because they are known to impart desirable roasted and nutty aromas to heated processed food products . Almost all the pyrazines in O. punctatus extract were also detected in mangrove crab, snow crab and blue crab by‐products . The trimethylamine and 1 H ‐indole were also reported in other crab species .…”

“…While benzaldehyde was considered to be an important volatile meat aroma composition with almond and nutty fragrance . Furthermore, benzaldehyde was the predominant compound for flavour of blue crab, snow crab and Charybdis feriatus . Naphthalene and alkyl benzene were considered as unpleasant compounds from environmental pollutants …”

“…46 Almost all the aldehydes, except for 7,10,13-hexadecatrienal, were previously detected in blue crab processing by-products. 47,48 wileyonlinelibrary.com/jsfa Therefore, 7,10,13-hexadecatrienal was a characteristic aldehyde in O. punctatus extract. The concentration of ketones was 128 µg kg −1 and this group occupied 3.85% of all the identified compound areas.…”