Chemical composition, nutritional quality of protein and mineral content of cod, whiting, scup, squid and monkfish were determined. With a protein content ranging between 15 and 18%, the amino acid composition, in vitro enzymatic digestibility and PER evaluation indicated variation among two species. Protein quality of scup was significantly superior and that of squid was significantly inferior (p < 0.05) when compared to other species. The ratio of essential to nonessential amino acids ranged between a high of 0.72 for whiting and a low of 0.62 for squid. The cholesterol values for all the species, except squid (80.65 mg/lOOg tissue), were between 18.58 and 37.69 mg/lOOg tissue. The elemental analysis indicated scup and squid values deviating from the other species for major essential trace elements.

Okra full‐fat flour, defatted flour, protein concentrate, and protein isolate were prepared from whole okra seeds (Spineless Green Velvet variety). Results of proximate analysis, amino acid profiles, in vitro protein digestibility, and calculated protein efficiency ratios (C‐PER) indicated that okra products have significant potential as a viable new protein source. C‐PER of okra products ranged from 2.16–2.22. Protein solubility indicated that these okra products were generally more soluble than commercial soy products. Emulsion capacity and viscosity of okra products were significantly lower than those for soy products. Overall, foam stability of soy products was consistently higher than that for okra products.

Protein isolate was hydrolyzed with pepsin yielding an approximate degree of hydrolysis of 80%. Frame protein hydrolysates were then employed for plastein synthesis. Enzyme induced plastein was optimized at: (1) pH 5 for pepsin and pH 7 for aipha-chymotrypsin;(2) substrate concentration, 40% w/v; (3) time of incubation, 24 hr; (4) enzyme/substrate ratio, 1: 100 w/w. Percent plastein yields of 33.8 and 27.3 were found for pepsin and alpha-chymotrypsin, respectively, when trichloracetic acid was used as the precipitating agent. However, when plastein was precipitated by ethanol, the percent yield was found to be 46 and 40.5 for pepsin and alphachymotrypsin, respectively.

Flounder frame was used as a raw material for the preparation of protein product. Processing parameters were evaluated using both fresh and frozen ground frames. The results indicate the following optima: (I) pH of extraction medium, 1 I; (2) extraction time, 60 min; (3) volume to weight ratio, 10: 1; (4) extraction temperature, 23°C. Isoelectric precipitation was conducted at pH 5 using KC1 or H,PO,. Results indicate that NaOH was more effective than Ca(OH), in solubilizing frame protein at pH 11. Ground frozen flounder frames gave a 10% decrease in protein extractability when compared to fresh frames using NaOH as the extractant and a 22% decrease when Ca(OH), was employed as the extractant. Approximately 70% of the protein is recovered using the NaOH-HCl system.