The effect of washing, frozen storage, and various additives on the properties of Sardine (Sardina pilchardus) mince kamaboko gels

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Comparison of direct steam injection and steam-jacketed heating in squid protein hydrolysis for energy consumption and hydrolysis performance

Direct steam injection (DSI) and conventional steam-jacketed (SJ) heating systems were compared for energy consumption and hydrolysis performance in producing squid hydrolysates (SH). Hydrolysis was carried out with endogenous enzymes at 55°C for 90min and native pH (6.5±0.2), followed by pasteurization at 75°C for 30min. Hydrolysis performance was evaluated by monitoring the changes in viscosity, degree of hydrolysis (DH), and protein profile during the course of hydrolysis. The DSI heating process was more energy efficient than SJ heating with significantly less energy usage (~30% energy reduction), shorter come-up times, and total processing time. While considerable fouling was evident with SJ heating, no fouling was observed with DSI heating. No appreciable differences in hydrolysis performance were observed between DSI and SJ heating, although the DSI-treated hydrolysate exhibited slightly lower values in viscosity and DH, as well as weaker protein band intensities due to dilution caused by steam condensation. The use of a steam filtration unit in DSI not only filtered the incoming steam, but also reduced condensation. Results suggest that DSI heating with steam filtration is an energy efficient and fouling-free process for preparing SH and potentially for other type of enzymatic protein hydrolysates. © 2014 Elsevier Ltd

Recovery of Bioactive Peptides and Omega-3 Fatty Acids-Containing Phospholipids from Squid Processing By-Product Hydrolysate

ABSTRACT: The present study examined whether bioactive peptides and omega-3 fatty acids-containing phopholipids could be recovered from squid processing by-product (SPB) hydrolysate. The hydrolysate was produced at 55°C for varying times with endogenous proteases and centrifuged to yield peptides-containing supernatant and phospholipids-containing precipitate. The supernatant showed angiotensin I-converting enzyme (ACE) inhibitory activity with half maximal inhibitory concentration (IC50) values decreasing with hydrolysis time from 2.11 mg (0 h) to 1.71 mg (1 h), 1.38 mg (1.5 h), and 1.34 mg (2 h). Two-hour squid hydrolysate was further fractionated to isolate the most active fraction whose molecular weight was found to be below 10 kDa with IC50 of 0.32 mg. The phospholipids-containing precipitate (45.6 g/100 g oil) was analyzed for a fatty acid profile, with the levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) being 16.86 and 29.24 g/100 g oil, respectively. The ACE inhibition by hydrolysate peptides and omega-3 fatty acid recovery support the nutraceutical potential of the SPB hydrolysate

Partial Replacement of Fish Meal with Plant Protein Sources Singly and in Combination in Diets for Summer Flounder, Paralichthys dentatus

Soybean meal (SBM), corn gluten meal (CGM), and canola protein concentrate (CPC) as alternative protein sources to fish meal (FM) were individually evaluated for growth performance at 0, 20, 30, 40, and 50% replacement with amino acid (AA) supplementation using juvenile summer flounder, Paralichthys dentatus, in an 8-wk feeding. Two-way ANOVA indicated no significant main effect for plant protein source, but a significant main effect for replacement level. Comparison of the individual treatments revealed significant differences in weight gain (WG) between the FM treatment and 50% replacement level for all protein sources, as well as between the FM treatment and 30% replacement with CPC. Replacement of FM with SBM at 40% resulted in the least cost/kg WG. In a follow-up study, a combination of SBM-CGM-CPC at 40% replacement was evaluated with and without AA, phytase (0.2%), or taurine (1%), versus FM and SBM (40% replacement of FM) with AA. The SBM-CGM-CPC diet with either AA or taurine provided a significantly better food conversion ratio and less cost/kg WG than the SBM diet, and the SBM-CGM-CPC diet with taurine provided a significantly better protein efficiency ratio than the SBM diet. On the basis of these results, more study of taurine in plant protein diets for summer flounder appears warranted. © by the World Aquaculture Society 2011

Effects of dietary scallop and squid hydrolysates on growth of European seabass, Dicentrarchus labrax; California yellowtail, Seriola lalandi; and barramundi, Lates calcarifer

Squid processing byproducts and scallop viscera were homogenized and subjected to hydrolysis at 55°C for 1.5 hr, followed by pasteurization at 75°C for 30 min. The respective hydrolysates were incorporated into diets in which 30–70% of fishmeal (FM) was replaced with soybean meal (SBM) and evaluated as is (wet), dried, or impregnated into SBM for their effects on growth of European seabass, Dicentrarchus labrax; California yellowtail, Seriola lalandi; and barramundi, Lates calcarifer, in a series of 8-week experiments. No adverse thermal deterioration in the quality of hydrolysate occurred because of drum drying, compared to the wet hydrolysate. No differences were observed in growth of California yellowtail between SBM mixed with dry hydrolysate and SBM impregnated with wet hydrolysate. Dietary inclusion of hydrolysate improved feed attractability and growth and was beneficial in the early juvenile stage but not in the growout stage for European seabass and California yellowtail. However, in barramundi, no discernable benefit was observed from the addition of hydrolysates. The improved feed attractability and growth appear to be dependent on species and type of hydrolysate. The texture of fillets of yellowtail fed 70% FM replacement with SBM + squid hydrolysate diets was significantly firmer than without squid hydrolysate

Comparison of direct steam injection and steam-jacketed heating in squid protein hydrolysis for energy consumption and hydrolysis performance

Direct steam injection (DSI) and conventional steam-jacketed (SJ) heating systems were compared for energy consumption and hydrolysis performance in producing squid hydrolysates (SH). Hydrolysis was carried out with endogenous enzymes at 55°C for 90min and native pH (6.5±0.2), followed by pasteurization at 75°C for 30min. Hydrolysis performance was evaluated by monitoring the changes in viscosity, degree of hydrolysis (DH), and protein profile during the course of hydrolysis. The DSI heating process was more energy efficient than SJ heating with significantly less energy usage (~30% energy reduction), shorter come-up times, and total processing time. While considerable fouling was evident with SJ heating, no fouling was observed with DSI heating. No appreciable differences in hydrolysis performance were observed between DSI and SJ heating, although the DSI-treated hydrolysate exhibited slightly lower values in viscosity and DH, as well as weaker protein band intensities due to dilution caused by steam condensation. The use of a steam filtration unit in DSI not only filtered the incoming steam, but also reduced condensation. Results suggest that DSI heating with steam filtration is an energy efficient and fouling-free process for preparing SH and potentially for other type of enzymatic protein hydrolysates. © 2014 Elsevier Ltd

Recovery of Bioactive Peptides and Omega-3 Fatty Acids-Containing Phospholipids from Squid Processing By-Product Hydrolysate

ABSTRACT: The present study examined whether bioactive peptides and omega-3 fatty acids-containing phopholipids could be recovered from squid processing by-product (SPB) hydrolysate. The hydrolysate was produced at 55°C for varying times with endogenous proteases and centrifuged to yield peptides-containing supernatant and phospholipids-containing precipitate. The supernatant showed angiotensin I-converting enzyme (ACE) inhibitory activity with half maximal inhibitory concentration (IC50) values decreasing with hydrolysis time from 2.11 mg (0 h) to 1.71 mg (1 h), 1.38 mg (1.5 h), and 1.34 mg (2 h). Two-hour squid hydrolysate was further fractionated to isolate the most active fraction whose molecular weight was found to be below 10 kDa with IC50 of 0.32 mg. The phospholipids-containing precipitate (45.6 g/100 g oil) was analyzed for a fatty acid profile, with the levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) being 16.86 and 29.24 g/100 g oil, respectively. The ACE inhibition by hydrolysate peptides and omega-3 fatty acid recovery support the nutraceutical potential of the SPB hydrolysate