Effects of activated earth, activated alumina, and chitosan adsorption processes on thermal and rheological and chemical characteristics of menhaden oil.

The objective of this study was the effectiveness of using activated earth, activated alumina, and/or chitosan, either separately or in combination, as adsorbents to remove free fatty acids (FFA) and peroxides from unpurified menhaden oil (MO). Thermal and rheological properties of MO were also evaluated. Five different combinations of absorbents were used to purify MO: Processes 1-3 involved purifications of MO by 5% chitosan (wt/wt of oil), 5% activated earth, and 5% activated alumina, respectively, process 4 involved MO purification with a combination of 6.5% chitosan, 3.5% activated earth, and 5% activated alumina, and process 5 involved MO purification process with a combination of adsorbents of 9% chitosan, 1% activated earth, and 5% activated alumina. All the adsorption processes were conducted at 25°C. Purified MO and MO were evaluated for their fatty acid profile, FFA, peroxide value (PV), moisture content (MC), minerals, and color. Triplicate experiments were conducted, and data were statistically analyzed using α = 0.05. Processes 4 and 5 were effective in reducing PV, FFA, and MC in MO. Thermal properties indicated processes 4 and 5 produced purer MO than processes 1-3. All the oil samples became less viscous, and the flow behavior index of MO was close to 1 after the adsorption processes. This study demonstrated that adsorption processes that include chitosan, activated earth, and activated alumina could effectively improve MO quality.

Instrumental Texture Differentiation of Channel (Ictalurus punctatus) and Hybrid (Channel × Blue, Ictalurus furcatus) Catfish Fillets.

An analysis of instrumental texture differences between channel (Ictalurus punctatus) and hybrid (female channel × male blue, I. furcatus) catfish fillets is presented. Factors including cold-storage type (fresh, frozen, or individually quick frozen (IQF)) and gender were included in the comparisons. Texture was measured at eight positions per fillet by a texture profile analysis (TPA) method that provided seven texture attributes: firmness, toughness, cohesiveness, adhesiveness, chewiness, resilience, and springiness, plus the thickness of the fillets (238 total). All attributes except adhesiveness were found to be statistically different (p < 0.05) between channel and hybrid fillets, with channels having the highest value in each attribute. When cold-storage type was included in the analysis, channels still produced the highest attribute values, but the number of attributes differed with firmness, toughness, and chewiness most associated with the differences in the type of catfish, while the other attributes were affected by cold-storage type. Thickness was found to be a strong covariant to some of the texture attributes, especially toughness, but the determination of difference between channels and hybrids was not affected and TPA profiles provided high levels of differentiation between catfish types.

Characterization of Anti-Ana o 3 Monoclonal Antibodies and Their Application in Comparing Brazilian Cashew Cultivars.

Ana o 3 is an immuno-dominant cashew nut allergen. Four monoclonal antibodies to Ana o 3 (2H5, 6B9C1, 19C9A2, and 5B7F8) were characterized by ELISA and in silico modeling. The 2H5 antibody was the only antibody specific for cashew nut extract. In addition to cashew nut extract, the 6B9C1 and 19C9A2 antibodies recognized pistachio extract, and the 5B7F8 recognized pecan extract. All four antibodies recognized both recombinant Ana o 3.0101 and native Ana o 3. ELISA assays following treatment of purified Ana o 3 with a reducing agent indicated that the 6B9C1 and 19C9A2 antibodies likely recognize conformational epitopes, while the 2H5 and 5B7F8 antibodies likely recognize linear epitopes. In silico modeling predicted distinct epitopes for each of the anti-Ana o 3 antibodies. Screening extracts from 11 Brazilian cashew nut cultivars using all four antibodies showed slight differences in Ana o 3 bindings, demonstrating that these antibodies could identify cultivars with varying allergen content.

Proximate Composition and Nutritional Attributes of Ready-to-Cook Catfish Products.

To increase the demand for U.S. farm-raised catfish, five healthy, convenient ready-to-cook products were developed to expand consumers' options beyond basic fresh or frozen fillets. Five new catfish products were produced, consisting of one hundred samples of each, including three size-types of Panko-breaded fish products (strips, center cuts of regular fillets, and center cuts from Delacata fillets) and two marinated products (sriracha and sesame-ginger). The breaded products were to be prepared by baking for convenience over traditional frying methods, while the marinated products were to be microwaved as healthy and convenient products. The nutrient content of the samples was analyzed, including protein, moisture, fat, fiber, ash, and carbohydrate, as well as minerals, amino acid, and fatty acid constituent content, with associated atherogenic index (AI) and thrombogenic index (TI), showing unique differences between the Panko-breaded and marinated products. In addition, a trend was observed showing an increase in moisture, protein, ash, and carbohydrate percentages, and a decrease in lipid content related to the volume-to-surface-area ratio, having the order of strips < standard fillets < Delacata fillets.

Phenolic contents, antioxidant potential and associated colour in sweet sorghum syrups compared to other commercial syrup sweeteners.

BACKGROUND: Knowledge of the bioactive content of sweet sorghum syrups compared to other common food-grade syrups will expand their utilisation as a food source. Total phenolic content (TPC), phenolics evaluated by high-performance liquid chromatography, antioxidant 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activities and oxygen radical absorbance capacity (ORAC), as well as colour of high-fructose corn syrup (HFCS), corn, honey, maple, agave, rice and grain sorghum syrups, were compared to 10 commercial sweet sorghum syrups. RESULTS: Sweet sorghum syrups contained markedly higher (P ≤ 0.05) TPC (6471 ± 1823 mg L-1 ) compared to the other syrups (596 ± 497 mg L-1 ). HFCS, corn, white grain sorghum and rice syrups had negligible and low DPPH radical scavenging activities and ORAC values, respectively. DPPH activities, ORAC and colour values of the sweet sorghum syrups were also markedly (P ≤ 0.05) higher than other syrups and highly related. The predominant phenolic components identified in sweet sorghum syrups were phenolic acids. Ellagic acid and protocatechuic acid were found in sorghum syrups ranging in concentration from 335-1177 and 53-485 µg g-1 , respectively. Sinapic acid was detected in several sorghum syrups, ranging in concentrations between 21 and 3654 µg g-1 . CONCLUSION: HFCS, corn, white grain sorghum and rice syrups demonstrated low bioactivity with negligible and low DPPH activities and ORAC values, respectively. The TPC, DPPH, ORAC and colour values of the sweet sorghum syrups were related to each other and markedly (P ≤ 0.05) higher compared to the other syrups. Phenolic acids were the predominant phenolic compounds identified in sorghum syrups and represent potential for health benefits. Published 2020. This article is a U.S. Government work and is in the public domain in the USA.

Properties of bone from Catfish heads and frames.

The objective of this paper was to evaluate methods of producing purified Catfish bone fractions from Catfish frames and heads and determine the composition of the purified bone fraction. Fresh samples of Catfish frames and heads were obtained from a large commercial Catfish processor. Triplicate samples were processed for all treatments. Two methods were developed to remove nonbone tissue from the frames: (a) use of a proteolytic enzyme to digest the nonbone tissues and (b) after boiling the frames, removal of the nonbone tissues with high-pressure water. The ash, protein, and lipid contents of unprocessed dried frames were 17%, 33%, and 41%, respectively. After the enzymatic or high-pressure water treatment processes, the frame bone compositions for the two processes were 62% and 54% ash, 35% and 33% protein, and 9% and 2% lipid, respectively. Bone from both processing treatments had a calcium content of 21%-25%, phosphorus content of 10%-11%, and contents of magnesium, manganese, zinc, and nickel were increased. Hydroxyproline content increased from 4% of the amino acids in the untreated bone to 7%-8% for the processed treatments. Tissues were removed from Catfish heads by digestion with a proteolytic enzyme and collection of the bone with a sieve. After the longest digestion period, dried head bone was 51% ash, 38% protein, and 7% lipid. The amino acid profiles showed high levels of hydroxyproline and lower levels of many essential amino acids. With increased enzymatic hydrolysis time, percent calcium and phosphorus increased. Results from this study will be used in the development of new value-added food and feed ingredients from Catfish bone.

Comparative studies on the yield and characteristics of myofibrillar proteins from catfish heads and frames extracted by two methods for making surimi-like protein gel products.

Fish protein isolates (FPI) were recovered from catfish heads and frames by alkaline extraction (AE) and salt extraction (SE) and made into surimi-like gels. Protein patterns and content, moisture, color, and texture of cooked protein gels were compared with commercial products. Sodium-dodecyl-sulfate poly acrylamide gel electrophoreses (SDS-PAGE) indicated that the integrity of major myofibrillar proteins was maintained during the extraction process, and the protein patterns were almost the same with that of the commercial surimi products. The yields of AE-FPI (heads: 36%; frames: 55%) were much higher (p < 0.05) than that of SE-FPI (heads: 9%; frames: 16%). Firmness of cooked protein gels made from heads was similar with that made from frames. Firmness of cooked protein gels made from FPI extracted by the SE method (heads: 0.45 kg/cm2; frames: 0.43 kg/cm2) was significantly lower (p < 0.05) than that made from FPI extracted by the AE method (heads: 1.96 kg/cm2; frames: 1.85 kg/cm2).

Comparison of sensory and instrumental methods for the analysis of texture of cooked individually quick frozen and fresh-frozen catfish fillets.

Catfish fillet texture is important to consumers, especially if the texture is not what the consumer expects. Therefore, it is important to be able to assure that texture quality is consistent. Texture is a humanly perceived sensory trait and can be costly to processors when texture quality is substandard. Instrumental methods of monitoring texture are much less costly over time than maintaining a sensory quality panel. The purpose of this research was to develop methods for monitoring texture quality using reliable instrumental methods. A descriptive sensory texture panel evaluated fresh-frozen and individually quick frozen (IQF) catfish fillets and was compared to the instrumental analysis of the same cooked fish, using texture profile analysis (TPA). The TPA evaluation was more successful for identifying differences between IQF and fresh-frozen catfish, with the most significance (p < 0.02) seen for the attributes springiness, resilience, chewiness-1, hardness-1, and residual parameters of springiness, chewiness-1, chewiness-1b, and hardness-1b. For sensory evaluation, only moisture release and moisture retention were this significant. Overall, IQF fillets were more moist and cohesive, with fresh-frozen fillets greater in all other parameters. Predictive equations were developed for sensory texture attributes from various TPA attributes calculated from the compression-force curves generated from two compressions of a ball probe. In the fresh-frozen catfish, sensory attributes firmness, flaky, moisture retention, and residual cohesiveness of mass had correlation coefficients (R) of 0.50 or greater. For the IQF catfish, all sensory attributes had an R of less than 0.4. The firmness sensory attribute had TPA predictor variables in both fresh-frozen and IQF that consisted mainly of hardness, chewiness, or thickness-related attributes. Based on results, instrumental texture of catfish should be measured before further processing, such as IQF.

Effect of Par Frying on Composition and Texture of Breaded and Battered Catfish.

Catfish is often consumed as a breaded and battered fried product; however, there is increasing interest in breaded and battered baked products as a healthier alternative. Par frying can improve the texture properties of breaded and battered baked products, but there are concerns about the increase in lipid uptake from par frying. The objective of this study was to examine the effect of different batters (rice, corn, and wheat) and the effect of par frying on the composition and texture properties of baked catfish. Catfish fillets were cut strips and then coated with batters, which had similar viscosities. Half of the strips were par fried in 177 °C vegetable oil for 1 min and the other half were not par fried. Samples were baked at 177 °C for 25 min. Analysis included % batter adhesion, cooking loss, protein, lipid, ash, and moisture, plus hardness and fracture quality measured using a texture analyzer. A trained sensory panel evaluated both breading and flesh texture attributes. Results found the lipid content of par fried treatments were significantly higher for both corn and wheat batters than for non-par fried treatments. Sensory analysis indicated that the texture of the coatings in the par fried treatments were significantly greater for hardness attributes. Fillet flakiness was significantly greater in the par fried treatments and corn-based batters had moister fillet strips compared to the wheat flour batters. Texture analyzer hardness values were higher for the par fried treatments.

Chemical and nutritional properties of channel and hybrid catfish byproducts.

The objective of this study was to chemically characterize both channel and hybrid catfish parts including heads, frames, viscera, skin, and fillet trimming mince. Triplicate samples of channel and hybrid catfish byproduct parts were obtained from a large commercial catfish processor and analyzed for percent moisture, lipid, protein, ash, and amino acid and fatty acid profiles were determined. The content of the off-flavor compounds, 2-methylisoborneol (MIB) and geosmin were also determined. The lipid content of samples were 13.6% and 10.0% for channel and hybrid skins, 17.7% and 21.4% for channel and hybrid viscera, 20.0% and 19.1% for channel and hybrid frames, and 9.7% and 9.3% for channel and hybrid heads. The protein content of samples ranged from a high of 22.8% for channel catfish skins, to a low of 13.4% for channel frames. Low levels of geosmin, <1 ppb, were detected in the byproduct samples, while no MIB was detected. Palmitic, oleic, and linoleic acid comprised approximately 80% of the fatty acids in the byproduct tissues. The amino acid profiles indicated that the catfish mince had high levels of lysine and methionine and other essential amino acids. Results from this study will be used in the development of new value-added products from catfish byproducts.

Effect of precooking and polyphosphate treatment on the quality of microwave cooked catfish fillets.

In the U.S. market place, there are many examples of precooked poultry products designed to be reheated in a microwave oven and, to a lesser extent, fish products such as tilapia. However, few U.S. catfish products are designed to be microwave cooked or reheated. The first objective of this study was to examine the properties of microwave cooked raw frozen catfish fillets and oven precooked (to 62.8°C) frozen fillets and then reheated by microwave cooking. The second objective was to evaluate changes in properties as a consequence of treatment with a commercial polyphosphate blend (Individually Quick Frozen [IQF]). The sample analysis included weight loss, proximate content, color (CIE L*a*b*), pH, mechanical texture (hardness), and lipid peroxidation (TBARS) measurements. Frozen fillets which contained polyphosphate showed <4% moisture loss after microwave cooking, relative to a 12% moisture loss for fillets without polyphosphate. A large cooking loss of ~40% was observed for precooked fillets after microwave cooking, correlated with a higher percent moisture loss (11% and 13% for fillets with and without polyphosphate, respectively) to comparable samples that were not precooked. For both types of fillets, an increased amount of yellow color was observed for precooked fillets after microwave cooking, relative to comparable fillets that were not precooked. Fillet hardness determined by peak force revealed an overall harder texture (~1.1-1.8 times) for fillets without polyphosphate than fillets with polyphosphate. This study will be used to develop precooked catfish products that can be reheated in a microwave oven.

RNA-Seq Analysis of Developing Pecan (Carya illinoinensis) Embryos Reveals Parallel Expression Patterns among Allergen and Lipid Metabolism Genes.

The pecan nut is a nutrient-rich part of a healthy diet full of beneficial fatty acids and antioxidants, but can also cause allergic reactions in people suffering from food allergy to the nuts. The transcriptome of a developing pecan nut was characterized to identify the gene expression occurring during the process of nut development and to highlight those genes involved in fatty acid metabolism and those that commonly act as food allergens. Pecan samples were collected at several time points during the embryo development process including the water, gel, dough, and mature nut stages. Library preparation and sequencing were performed using Illumina-based mRNA HiSeq with RNA from four time points during the growing season during August and September 2012. Sequence analysis with Trinotate software following the Trinity protocol identified 133,000 unigenes with 52,267 named transcripts and 45,882 annotated genes. A total of 27,312 genes were defined by GO annotation. Gene expression clustering analysis identified 12 different gene expression profiles, each containing a number of genes. Three pecan seed storage proteins that commonly act as allergens, Car i 1, Car i 2, and Car i 4, were significantly up-regulated during the time course. Up-regulated fatty acid metabolism genes that were identified included acyl-[ACP] desaturase and omega-6 desaturase genes involved in oleic and linoleic acid metabolism. Notably, a few of the up-regulated acyl-[ACP] desaturase and omega-6 desaturase genes that were identified have expression patterns similar to the allergen genes based upon gene expression clustering and qPCR analysis. These findings suggest the possibility of coordinated accumulation of lipids and allergens during pecan nut embryogenesis.

Physicochemical Properties of Microencapsulated ω-3 Salmon Oil with Egg White Powder.

The objective of this study was to produce microencapsulated omega(ω)-3 fatty acids (PUFAs) fortified egg white (EW) powders and to characterize their nutritional and physical properties. Stable emulsions (E-SO-EW) containing 3.43 (g/100 g) salmon oil (SO), 56.21 (g/100 g) EW, and 40.36 (g/100 g) water and a control (E-EW) containing EW and water were prepared. E-SO-EW and E-EW were separately spray dried at 130, 140, and 150 °C inlet air temperatures. This resulted in 3 microencapsulated SO fortified EW powders (SO-EW), and 3 dried EW powders (DEW). The powders were analyzed for microencapsulation efficiency (ME), color, fatty acids methyl esters, protein, fat, moisture, ash, amino acids, minerals, microstructure, and particle size. The EPA and DHA content of SO and the ME of the powders were not affected by the inlet air temperature. The crude protein content of SO-EW powders was approximately 24 (g/100 g) lower than dried EW powders. Leucine was the most abundant essential amino acid found in all the powders. Most of the powders' median particle size ranged from 15 to 30 µm. The study demonstrated that microencapsulated ω-3 salmon oil with high quality EW protein can be produced by spray drying.

Warfarin users prone to coagulopathy in first 30 days after hospital discharge from gastric bypass.

BACKGROUND: Lehigh Valley Health Network (LVHN), a nonprofit tertiary care facility in Allentown, Pennsylvania, is an accredited American College of Surgeons Bariatric Surgery Center Network (ACSBSCN) Level 1 site performing 400+ bariatric procedures annually. Bariatric data submission began in April 2008. Complication review revealed that approximately 17 % of patients on chronic anticoagulation (warfarin) therapy preoperatively were readmitted with supratherapeutic international normalized ratios (INRs), postsurgical bleeding, anastomotic ulcer, or other intraluminal hemorrhage. Opinion level recommendations have been published regarding the adjustment of warfarin dosages post-bariatric procedures with no widespread consensus. Case series have been published detailing perioperative hemorrhage risk for bariatric patients on preoperative anticoagulation. Little data of post-discharge hemorrhage rates have been published. With increasing numbers of bariatric surgical procedures performed annually, there is a potential for developing serious coagulopathic complications in those patients who resume their anticoagulation therapy postoperatively. METHODS: Retrospective review of LVHN data from the ACSBSCN database was analyzed for 30-day readmissions due to documented extra- or intraluminal hemorrhage with INR and coagulopathy. Follow-up INR and warfarin doses were collected up to 6 months postoperatively. RESULTS: Over a 3-year period, 38 patients undergoing bariatric procedures were identified as being on preoperative warfarin therapy. Six of 38 developed hemorrhage within 30 days. Two patients presented beyond 30 days with bleeding. Supratherapeutic INR was present in five of six readmitted patients. Mean INR was 5.8. Warfarin sensitivity was present in a statistically significant higher number of patients within 30 days of surgery. After 30 days, a resistance to warfarin was demonstrated. CONCLUSIONS: Bariatric surgery patients taking warfarin are prone to coagulopathy in the early post-op period requiring vigilant monitoring to prevent supratherapeutic INR and corresponding risk of hemorrhage.

Properties of electrospun pollock gelatin/poly(vinyl alcohol) and pollock gelatin/poly(lactic acid) fibers.

Pollock gelatin/poly(vinyl alcohol) (PVA) fibers were electrospun using deionized water as the solvent and pollock gelatin/poly(lactic acid) (PLA) fibers were electrospun using 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as the solvent. The chemical, thermal, and thermal stability properties were examined for the electrospun samples. The electrospun PVA samples generally had thinner and more uniform fibers than the electrospun PLA samples. For the PVA samples, an increase in total solids content and PVA to gelatin ratio generally resulted in higher average fiber diameter values and wider diameter distributions. Pollock gelatin in both types of electrospun samples remained amorphous. The PVA in electrospun samples had comparable melting temperatures to that of neat PVA, whereas the PLA in electrospun samples had slightly lower melting temperatures than that of neat PLA. Also, the PLA in electrospun samples had crystallization temperatures approximately 30 °C lower than that in neat PLA. This was due to better alignment of PLA chains during electrospinning, which resulted in the chains being more readily crystallized at lower temperatures. In addition, the electrospun PVA samples completely dissolved in water at room temperature after soaking for one day, whereas the electrospun PLA samples remained intact even after soaking for three days.

Supplementing long-chain n-3 polyunsaturated fatty acids in canned wild Pacific pink salmon with Alaska salmon oil.

Establishing n-3 polyunsaturated fatty acid contents in canned wild Alaska pink salmon products is challenging due to ample natural variation found in lipid content of pink salmon muscle. This study investigated the effect of adding salmon oil (SO) to canned pink salmon produced from fish exhibiting two opposite degrees of skin watermarking, bright (B) and dark (D). Specific goals of the study were to evaluate the benefits of adding SO to canned pink salmon with regard to nutritional value of the product, sensory characteristics, and the oxidative and hydrolytic stability of the lipids over thermal processing. Six groups of canned pink salmon were produced with variable levels of SO, either using bright (with 0, 1, or 2% SO) or dark (with 0, 2, or 4% SO) pink salmon. Compositional analysis revealed highest (P < 0.05) lipid content in sample B2 (8.7%) and lowest (P < 0.05) lipid content in sample D0 (3.5%). Lipid content of samples B0, B1, D2, and D4 was not significantly different (P > 0.05) ranging from 5.7% to 6.8%. Consequently, addition of SO to canned pink salmon allowed for consistent lipid content between bright and dark fish. Addition of 1% or 2% SO to canned bright pink salmon was not detrimental to the sensory properties of the product. It is recommended that canned bright pink salmon be supplemented with at least 1% SO, while supplementation with 2% SO would guarantee a minimum quantity of 1.9 g of n-3 fatty acids per 100 g of product. Addition of 4% SO to canned dark pink salmon was detrimental to product texture and taste, while supplementation with 2% SO did not negatively affect sensorial properties of the product. Accordingly, canned dark pink salmon should be supplemented with 2% SO so that a minimum n-3 fatty acids content of 1.5 g per 100 g of product.

Chemical composition of the giant red sea cucumber, Parastichopus californicus, commercially harvested in Alaska.

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.

Ultraviolet-B radiation induced cross-linking improves physical properties of cold- and warm-water fish gelatin gels and films.

Cold- and warm-water fish gelatin granules were exposed to ultraviolet-B radiation for doses up to 29.7 J/cm(2). Solutions and films were prepared from the granules. Gel electrophoresis and refractive index were used to examine changes in molecular weight of the samples. Also, the gel strength and rheological properties of the solutions as well as the tensile and water vapor barrier properties of the films were characterized. SDS-PAGE and refractive index results indicated cross-linking of gelatin chains after exposure to radiation. Interestingly, UV-B treated samples displayed higher gel strengths, with cold- and warm-water fish gelatin having gel strength increases from 1.39 to 2.11 N and from 7.15 to 8.34 N, respectively. In addition, both gelatin samples exhibited an increase in viscosity for higher UV doses. For gelatin films, the cold-water fish gelatin samples made from irradiated granules showed greater tensile strength. In comparison, the warm-water gelatin films made from irradiated granules had lower tensile strength, but better water vapor barrier properties. This might be due to the UV induced cross-linking in warm-water gelatin that disrupted helical structures.

Acute satiety response of mammalian, avian and fish proteins in dogs.

Fish proteins have been reported to be more satiating than meat proteins. The objective was to determine the effect of different animal protein pre-meals on satiety. A total of ten intact female hounds were fed pork loin, beef loin, chicken breast, salmon fillet or pollock fillet. Each pre-meal was fed to contain 100 g protein. Blood was collected at 0, 5, 15, 30, 60, 90 and 120 min postprandially and analysed for glucose, insulin, total ghrelin, active glucagon-like peptide-1 (GLP-1) and plasma amino acids (AA). Dogs were fed 2 ×  metabolisable energy, 3 h following the pre-meal, and intake was determined 30, 60, 180 and 1440 min after food presentation. Glucose decreased over time (P < 0·001), but was lowest (P = 0·01) when dogs consumed pollock or chicken. Insulin increased (P < 0·0001) over time, and was greater (P = 0·09) when dogs consumed salmon. GLP-1 increased (P < 0·001) over time, and was greatest (P = 0·04) when dogs consumed beef. Ghrelin decreased (P < 0·0001) over time for all pre-meals. The tryptophan:large neutral AA ratio tended to be greater (P = 0·08) when dogs consumed pork, salmon and pollock. Different protein sources may influence blood markers in dogs, but it does not appear that fish substrates have different satiating abilities than mammalian or avian sources.

Functional properties of protein fractions of channel catfish (Ictalurus punctatus) and their effects in an emulsion system.

This study demonstrated the feasibility of producing soluble protein (CFSP) and insoluble protein (CFISP) fractions from catfish muscle protein. CFSP and CFISP contained 60.6% and 73.8% protein and 8.6% and 20.3% fat, respectively. Both CFSP and CFISP contained essential amino acids. Differences were observed between physicochemical properties of the 2 protein fractions, including nitrogen solubility, emulsion stability, and fat adsorption capacity. The flow and viscoelastic properties of the emulsions prepared with CFSP and CFISP were investigated using a rheometer. The power law model and the Casson model were used to determine the flow behavior index (n), consistency index (K), and yield stress. Emulsion containing CFSP (ECFSP) had a higher K value than emulsion containing CFISP (ECFISP). Both ECFSP and ECFISP emulsions exhibited pseudoplastic behavior and viscoelastic characteristics. The G' (an elastic or storage modulus) and G″ (a viscous or loss modulus) values for ECFSP were higher than ECFISP. Catfish muscle tissue can be easily separated into soluble and insoluble protein powders that have desirable functional properties.