The functional, nutritional, and antioxidative properties of hydrolyzed herring and herring byproducts (head and gonad) were evaluated. All freeze-dried herring fish protein hydrolysate (FPH) powders were light yellow and contained 77% to 87% protein. The degree of hydrolysis was 18.3%, 13%, 13%, and 10.1%, respectively, for head, whole fish, body, and gonad after 75 min digestion. All FPH powders had desirable essential amino acid profiles and mineral contents. The emulsifying capacity and stability of all FPH powders were lower than those of egg albumin and soy protein; the fat adsorption was comparable to that of egg albumin. The antioxidative activity of whole herring FPH was highest, followed by that of body, gonad, and head.

The ovary of Stichopus californicus consists of several size classes of tubules, which insert into a central gonad basis. The largest tubules contain the oocytes that will be spawned in the current season. All tubules are composed of three layers. Outermost is a complex peritoneum composed of epithelial cells, axons and muscle cells. The fine structure of the peritoneal neurons suggests their involvement in neurosecretory activity. Between the basal laminae of the peritoneum and the inner epithelium is the ovarian connective tissue compartment, including the genital hemal sinus. This sinus probably conveys nutrients from the periphery of the tubule to oocytes located deep within. The inner epithelium is composed of parietal and follicular epithelial cells and the oocytes. Stichopus oocytes contain three classes of microtubules based upon their location, orientation, and lability during fixation. Microtubules from the apical protuberance encircle the germinal vesicle. Cortical microtubules lie just under the cell surface and run parallel to it. Deep cytoplasmic microtubules run radially from the interior of the oocyte towards the cell surface. Oocytes are held within follicles by junctional complexes until the time of ovulation. Ovulation can be monitored in severed follicles of this species because an oolamina insures follicle integrity after detachment from the ovary. The onset of ovulation is marked by the dissolution of junctional complexes. This is followed by a cytochalasin B sensitive contraction of the follicle cells. The follicle contracts down around the oocyte, to lie collapsed against the ovarian wall while the oocyte is free within the ovarian lumen.

Descriptions of holothurian metamorphosis are based on data from the relatively specialized order Apoda. Metamorphosis for a relatively unspecialized aspidochirote, Stichopus californicus, is described here. Metamorphosis in Stichopus is characterized by the following features: the madreporic vesicle is a calcite secreting syncytium, not a coelom. Stichopus has no separate axocoel and no transient axial complex forms during metamorphosis. The buccal podia form from the water vascular ring, not the radii. The axes of bilateral larval symmetry and the pentaradial adult symmetry are congruent; therefore, the secondarily derived symmetry in holothurians is the pentaradial symmetry of the adult, as in the other extant echinoderms. No axial or visceral torsion occurs during metamorphosis. The enclosed ambulacra form in a manner distinct from that of the ophiuroids and echinoids. Perivisceral coelomic pores develop near the end of metamorphosis, and before the definitive anus forms. Assignment of holothurians with echinoids to the subphylum Echinozoa is discussed.

The objective of this study was to investigate quality changes of salmon fillet muscle during thermal sterilization processes. Small samples (D 30 mm x H 6 mm) from the central dorsal region were heated in an oil bath at 121.1 degrees C for periods varying from 5 to 120 min. The quality variations along the longitudinal axis of salmon fillets (raw and heated) were examined. The quality properties studied included shear force, color, cook loss, and shrinkage. To minimize the influence of the heterogeneity of the salmon muscle, a multiple thin blade texture device was developed for shear force measurement and a computer vision system was used to facilitate accurate measurements of color and shrinkage. The red muscle was firmer than the white muscle in the raw but not in heated samples. Muscle from the central dorsal region had a lower cook loss and less shrinkage than samples from either the anterior or posterior region following heating. The greatest change in quality occurred within the 1st 10 min of heating at 121.1 degrees C. Shear force measurements following heating indicated 2 peaks, one corresponding to 5 min and the second for 60 min processing at 121.1 degrees C. Possible mechanisms were discussed.

Giant red sea cucumbers, Parastichopus californicus, are commercially harvested in the U.S. Pacific Northwest; however, the nutritional and chemical properties of its edible muscle bands and body wall have not been fully elucidated. In particular are the fatty acid profiles of P. californicus tissues, which have not been documented. Sea cucumbers were delivered live and muscle bands and body wall freeze dried, vacuum packed, and stored at –30°C until analyzed. Proximate composition of freeze-dried tissues varied greatly with muscle bands being composed of 68% protein, 12% ash, 9% carbohydrate, and 5% lipids, while the body wall was composed of 47% protein, 26% ash, 15% carbohydrate, and 8% lipids. The hydroxyproline, proline, and glycine contents of the body wall were much higher than those in muscle bands, consistent with the larger amount of connective tissue. Calcium, magnesium, sodium, and iron contents were higher in the body wall than those in muscle bands, whereas the opposite was observed for zinc content. Total long-chain n-3 fatty acid contents were 19% and 32% of total fatty acids in body wall and muscle bands, respectively. Muscle bands had higher content of eicosapentaenoic acid (20:5n-3) than body wall at 22.6% and 12.3%, respectively. High content of arachidonic acid (20:4n-6) was recorded in both body wall (7.1%) and muscle bands (9.9%). Overall, the fatty acid profiles of body wall and muscle bands of P. californicus resemble those described for other species; however, the distribution and occurrence of certain fatty acids is unique to P. californicus, being representative of the fatty acid composition of temperate-polar marine organisms. The chemical characterization of freeze-dried edible tissues from P. californicus demonstrated that these products have valuable nutritional properties. The body wall, a food product of lower market value than muscle bands, could be better utilized for nutraceutical and pharmaceutical applications.