Effect of Tartary Buckwheat Peptides on Shelf Life of Tilapia (Oreochromis niloticus) Fillets.

Tartary buckwheat peptides (TBPs), produced from tartary buckwheat through solid-state fermentation, were used as a dip treatment solution to preserve tilapia fillets. Fillets were dip treated with different concentrations of TBPs (0.5, 1, and 2% [v/v]) and stored at 4°C for 12 days. The effect of TBPs on thiobarbituric acid, total volatile base nitrogen, surface color, texture profile analysis, total viable counts, and changes in sensory properties of tilapia fillets during storage was investigated. Compared with the control group, the groups treated with TBPs displayed reduced rates of quality deterioration in physicochemical, bacteriological, and sensory characteristics. Based on total volatile base nitrogen content, total viable counts, and sensory scores, the shelf life of control tilapia fillets was 4 days and that for TBP-treated fillets was 8 days, twice as long as that of the control group. Thus, TBPs can be used as preservatives to maintain the quality and extend the shelf life of tilapia fillets stored at 4°C.

Preparation and Characterization of a Pectin Membrane-Based Optical pH Sensor for Fish Freshness Monitoring.

In a simple and instant procedure for detecting fish freshness, a hydrogel and hydrophilic pectin matrix membrane was used successfully as an optical pH sensor by immobilizing the chromoionophore ETH 5294 (CI), which is very selective and sensitive for the membrane. The Pe/CI optical pH sensor exhibited excellent linearity between pH 5 and pH 9, with a sensor response time of 5 min and reproducibility of 1.49% relative standard deviation (RSD). The sensor showed response stability for 15 days and a response reduction of 8.6%. The sensor's capability was demonstrated by the detection of fish freshness for 17 days at 4 °C.

Study on the synergic effect of natural compounds on the microbial quality decay of packed fish hamburger.

The effectiveness of natural compounds in slowing down the microbial quality decay of refrigerated fish hamburger is addressed in this study. In particular, the control of the microbiological spoilage by combined use of three antimicrobials, and the determination of their optimal composition to extend the fish hamburger Microbiological Stability Limit (MAL) are the main objectives of this work. Thymol, grapefruit seed extract (GFSE) and lemon extract were tested for monitoring the cell growth of the main fish spoilage microorganisms (Pseudomonas fluorescens, Photobacterium phosphoreum and Shewanella putrefaciens), inoculated in fish hamburgers, and the growth of mesophilic and psychrotrophic bacteria. A Central Composite Design (CCD) was developed to highlight a possible synergic effect of the above natural compounds. Results showed an increase in the MAL value for hamburgers mixed with the antimicrobial compounds, compared to the control sample. The optimal antimicrobial compound composition, which corresponds to the maximal MAL value determined in this study, is: 110 mgL(-1) of thymol, 100 mgL(-1) of GFSE and 120 mgL(-1) of lemon extract. The presence of the natural compounds delay the sensorial quality decay without compromising the flavor of the fish hamburgers.

Effects of fish meal in beef cattle diets on growth performance, carcass characteristics, and fatty acid composition of longissimus muscle.

We investigated the effects of fish meal (FM) in beef cattle diets on growth performance, carcass characteristics, and fatty acid (FA) composition of longissimus muscle in 63 yearling steers (335 +/- 23 kg). High-moisture corn and alfalfa silage diets were supplemented with either a corn gluten/blood meal mixture or FM at 10% of the diet. Fish meal contained (as-is basis) 5.87 g/kg eicosapentaenoic acid (EPA) and 9.84 g/kg docosahexaenoic acid (DHA). Seven strategies were developed to feed either a control diet (no FM) or diets containing 5 or 10% FM with FM fed for either 56, 112, or 168 d before slaughter. Average daily gain and feed efficiency were not affected (P > .10) by FM feeding but DMI decreased. Within FM diets, cattle fed 5% FM consumed more (P < .01) DM and gained more (P < .02) than cattle fed 10% FM. Carcass traits were not affected (P > .05) by feeding strategy except for fatter (P < .05) and lower (P < .06) yielding carcasses in cattle fed 5 vs 10% FM diets. Fish meal feeding increased (P < .01) concentrations of (n-3) FA, including EPA and DHA, and decreased (P < .05) concentrations of arachidonic acid. Increasing the amount of dietary FM further increased (P < .01) concentrations of EPA and DHA and decreased (P < .05) concentrations of (n-6) FA. We estimate that a 114-g steak from cattle fed 10% FM would supply 35 to 90% of the current average daily intake of EPA and DHA in North America. The results indicate that FM may have a role in niche marketing of beef provided that eating quality is not compromised.

[Growth and carcass quality of carp (Cyprinus carpio L.) fed different cereals, lupin seed or zooplankton]. / Wachstum und Schlachtkörperqualität von Karpfen (Cyprinus carpio L.) bei Verfütterung von verschiedenen Getreidearten, Lupinen oder Zooplankton.

120 carp (Cyprinus carpio L.) with an average initial weight of 516 g, were kept in 20 tanks at a water temperature of 23 degrees C and given five different commercially practical diets to an end weight of approximately 1000 g. Four of the diets consisted of more than 50% of the traditional sole feeds wheat (W), rye (R), maize (M), or lupin seed (L), mixed with other ingredients to give diets with similar concentration of energy and crude protein. The fifth diet consisted exclusively of deep frozen zooplankton (Z). The fish were given a daily feed amount of 1.8% of bodyweight. The bodyweights of the carp on the cereal diets or the lupin seed diet were similar at the end of the experiment, after 105 days, (W) 995 g, (R) 916 g, (M) 979 g, (L) 979 g, but were significantly lower on diet (Z) at 659 g. Average OM digestibility coefficients for the diets were 77-79% for the cereal-rich diets, 68% for (L), and 75% for (Z). The contents of skinless fillet (average 38.7%), viscera (average 13.2%) and residual carcass (average 48.2%) were similar for the diets with cereals or lupin seed, while fish on diet (Z) had significantly lower fillet proportion (33.6%), coupled with an increase in residual carcass (53.0%). The chemical composition of the fillet, viscera and the residual carcass was also affected. Fish on diet (M) had the highest fat content in the whole body (14.5% of the FM), followed by those on diets (W) and (R) at 13.3% and 12.9%, while fish on diets (L) and (Z) had significantly lower fat contents at 10.7% and 8.2%. Protein contents in the whole body (% of FM) were for diets (L) 16.7%, (W) 16.4% (R) 16.3%, (M) 16.2%, and (Z) 15.5%.

Alpha-linolenic acid in rapeseed oil partly compensates for the effect of fish restriction on plasma long chain n-3 fatty acids.

OBJECTIVE: To examine the ability of alpha-linolenic acid (ALA) in low erucic acid rapeseed oil (RO) to compensate for the effects of a restriction in fish intake on plasma fatty acid composition. DESIGN AND SUBJECTS: Two times 6 weeks' randomized dietary intervention was used with blind crossover design in 40 healthy unconfined women and men (age 20-46y). INTERVENTIONS: Subjects were assigned to two fish restricted diets, namely RO diet and Trisun-sunflower oil (TSO) diet, with similar proportions of saturated : monounsaturated : polyunsaturated fatty acids (11.5:17.5:8.5% of total energy, En%), but differing in their ALA content (2.2 and 0.3 En%) and n-6 : n-3-ratio (3 : 1 and 23 : 1, respectively). The fatty acid compositions of plasma triglycerides (TG), cholesterol esters (CE), and phospholipids (PL) were analyzed by gas chromatography. Dietary intake was evaluated based on 3- to 7-day food records. RESULTS: The proportion of TG and CE ALA decreased on the TSO diet (from 1.6% to 0.9% and from 0.9% to 0.4%, respectively, P < 0.001) and increased on the RO diet (from 1.7% to 3.4% and from 0.9% to 1.3%, respectively, P < 0.001) compared to the baseline level. The proportion of eicosapentaenoic acid (EPA) in all three plasma fractions decreased on the TSO diet but not on the RO diet. The proportions of docosa-hexaenoic acid (DHA) decreased on both experimental diets and there was no difference in CE DHA between the diets. PL docosa-pentaenoic acid (DPA) and PL DHA remained at a higher level on the RO diet compared to the TSO diet (P < 0.001 and P < 0.05, respectively). CONCLUSIONS: ALA is metabolized to EPA in humans to a significant extent. The degree to which rapeseed oil (ca 50g/day) affects the proportion of EPA resembled the effect of a weekly portion (50-100g) of fatty fish depending on the fat content of the fish.

Food hypersensitivity in 20 dogs with skin and gastrointestinal signs.

Canine food allergy can be defined as a nonseasonal, pruritic skin disorder of dogs that is associated with the ingestion of a substance found in the dog's diet. This study records the use of a proprietary dried fish, corn and soya-based diet for the investigation and maintenance of food allergic dogs when fed initially as a restricted allergen diet and then as a maintenance diet after challenge. All the dogs showed evidence of pruritic skin disease and in addition demonstrated gastrointestinal signs. These included the presence of faecal mucus and blood, tenesmus and increased faecal frequency; all the signs associated with colitis. Both cutaneous and gastrointestinal signs resolved when an elimination diet was fed and could be reproduced when the animal was appropriately challenged. Ten dogs were trialled on a home cooked diet of fish and potato and 10 dogs on the proprietary complete food. All the dogs were challenged to identify their food allergies. Nineteen of the dogs have subsequently been successfully maintained on the proprietary food.

Value of feather meal in a molasses-based liquid supplement fed to yearling cattle consuming a forage diet.

Hydrolyzed feather meal (FM) was compared to other sources of CP to determine its value as a protein source in a molasses-based liquid supplement. Ruminal N escape values (measured in situ) for FM, ring-dried blood meal, cottonseed meal, and soybean meal approximated reported values. Ruminal N escape value for catfish meal was lower than values reported for other fish meals. In two trials (194 d), 84 yearling heifers were allotted to 12 pastures (3 pastures/treatment) and fed one of four supplements (1.7 kg of DM.heifer-1.d-1) containing either molasses and urea; molasses, urea,and FM; molasses, urea, FM, and catfish meal; or molasses, urea, FM, and catfish oil. Heifers were exposed to bulls for 60 d. In two trials, 112 steers were allotted to 16 pastures (4 Pastures/treatment) and fed one of four supplements (1.7 kg of DM.steer-1.d-1) containing molasses and urea; molasses, urea and FM; molasses, urea, FM and ring-dried poultry blood meal; or molasses, urea, and poultry feathers and blood hydrolyzed together. In all trials, cattle fed molasses containing FM had faster gains (P < .05) and heifers had heavier live weights at breeding (P < .05) and higher pregnancy rates (P < .05) than cattle fed molasses and urea. Combining poultry blood with molasses, urea, and FM improved (P < .05) steer gains in one of two trials. Combining catfish meal with molasses, urea, and FM did not improve (P > .05) ADG of pregnancy rate of heifers. Combining catfish oil with molasses, urea, and FM increased (P < .05) ADG in one trial and blood cholesterol and live weight of heifers at breeding in both trials. It is concluded that protein feeds, such as FM, that contain a large portion of ruminally undegradable protein may provide much of the CP in liquid supplements fed to growing cattle consuming moderate-quality forage. Adding catfish oil to a liquid supplement may improve ADG and live weight of yearling heifers at breeding.

Value-added products from underutilized fish species.

Fish is a rich source of easily digestible protein that also provides polyunsaturated fatty acids, vitamins, and minerals for human nutrition. Nonetheless, a large proportion of total landed fish remains unused due to inherent problems related to unattractive color, flavor, texture, small size, and high fat content. Most of these underutilized fish belong to the abundantly available pelagic species, which are landed as bycatch, and some are unconventional species such as krill. Although some species are used industrially for fish meal manufacture, a need for their conservation and utilization for human consumption has been recognized in order to prevent post-harvest fishery losses. Recovery of flesh by mechanical deboning and development of value-added products are probably the most promising approaches. This article discusses various possibilities for product development using mince from low-cost fishery resources. These include surimi and surimi-based products, sausages, fermented products, protein concentrates and hydrolysates, extruded products, and biotechnological possibilities. The dual advantages of this approach, namely, finding ways for better utilization of low-value fish species and providing protein- rich convenience foods, have been pointed out. However, the key to the success of this approach depends largely on the market strategies utilized.

Fish and heart disease: what is the real story?

A new study shows no significant associations between n-3 fatty acids or fish intake and heart disease among men who are initially free of cardiovascular disease. These conclusions may somewhat diminish enthusiasm for fish and fish oil as a panacea against heart disease.

Effects of protein concentration and protein source on performance of newly arrived feedlot steers.

In Trial 1, 240 crossbred steers (initial BW 243 +/- 8 kg) were used in a 2 x 4 factorial experiment to determine the effects of receiving diet CP concentration (12, 14, 16, or 18%) and source (spray-dried blood meal [SDBM] vs soybean meal [SBM]) on steer performance. There were linear (P < .01) increases in ADG and feed efficiency during wk 1. For the entire trial, there was an increase (P < .01) in feed efficiency with increasing CP concentration and diets containing SDBM compared with those containing SBM. In Trial 2, 240 crossbred steers (initial BW 246 +/- 14 kg) were used in a completely randomized design experiment to determine the effects of receiving diet CP concentration (11, 14, 17, 20, 23, or 26%) on steer performance. Average daily gain and feed efficiency increased (P < .01) with increasing CP concentration during wk 1. There were quadratic (P < .01) responses to CP concentration for final weight, ADG, and feed efficiency. In Trial 3, 216 steers (initial BW 238 +/- 1 kg) were used to determine the effects of receiving diet protein sources on steer performance. The control diet used SBM as the supplemental CP source and was formulated to contain 12.5% CP. The other five protein sources were corn gluten meal (CGM), ring-dried blood meal (RDBM), SDBM, fish meal (FM), and SBM. For these five CP sources, diets were formulated to contain 23% CP during wk 1, 17% CP during wk 2, and 12.5% CP during wk 3 and wk 4. During wk 1, control steers had the lowest ADG (P < .07) and feed efficiency (P < .01) whereas steers fed RDBM and SDBM had the highest (P < .01) feed efficiency. Increased CP concentrations are needed early in the receiving period, when DMI is low.

Different strains of Saccharomyces cerevisiae differ in their effects on ruminal bacterial numbers in vitro and in sheep.

A ruminal simulation device (Rusitec) was used to compare the effects of Saccharomyces cerevisiae strains NCYC 240, NCYC 694, NCYC 1026, NCYC 1088, and Yea-Sacc (a commercial product containing S. cerevisiae) on ruminal fermentation. S. cerevisiae NCYC 240, NCYC 1088, NCYC 1026, and NCYC 694 were grown on malt extract at 30 degrees C in aerated fed-batch culture and harvested along with spent growth medium by freeze-drying. Each vessel received daily 20 g of a basal diet consisting of hay, barley, molasses, fishmeal, and a minerals/vitamins mixture at 500, 299.5, 100, 91, and 9.5 g/kg of DM, respectively. Yeast preparations (500 mg/d) were added along with the feed. S. cerevisiae NCYC 240, NCYC 1026, and Yea-Sacc stimulated total and cellulolytic bacterial numbers, whereas S. cerevisiae NCYC 694 and NCYC 1088 had no effect on the numbers of bacteria. The effects of S. cerevisiae NCYC 240, NCYC 1026, and Yea-Sacc on ruminal fermentation were further investigated in vivo using ruminally cannulated sheep fed 1.5 kg/d of the diet used in Rusitec, supplemented with 2 g/d of yeast culture. All treatments tended to stimulate total and cellulolytic bacterial numbers. However, the stimulation was only statistically significant for S. cerevisiae NCYC 1026 with total bacterial numbers and S. cerevisiae NCYC 240 with cellulolytic bacteria (P < .05). Increased bacterial numbers were associated with an increase in the rate of straw degradation in the rumen and a nonsignificant (P > .05) increase in the excretion of purine derivatives in the urine, measured as an index of microbial nitrogen leaving the rumen.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of protein source on nitrogen metabolism in continuous culture and intestinal digestion in vitro.

Eight dual flow continuous culture fermenters were used in four replicated periods to study the effects of protein supplements on ruminal fermentation and CP digestion. A basal diet was supplemented with isonitrogenous amounts of urea and tryptone (control; CTRL), soybean meal (SBM), lignosulfonate-treated SBM (LSBM), corn gluten meal (CGM), blood meal (BM), hydrolyzed feather meal (HFM), fish meal (FM), or meat and bone meal (MBM). Digestion of DM, OM, and carbohydrates was not affected by treatment. Ammonia N concentration was highest (P < .05) for CTRL and lowest (P < .05) for LSBM, CGM, BM, HFM, and FM. Nonammonia N flow was lowest (P < .05) for CTRL. Dietary N flow was lowest (P < .05) for CTRL, intermediate for SBM, and highest (P < .05) for LSBM, CGM, BM, HFM, FM, and MBM. Total N flow, bacterial N flow, and efficiency of microbial protein synthesis were not affected by treatment. Protein degradation was highest (P < .05) for CTRL. Flow of total amino acids (AA) was lowest (P < .05) for CTRL, SBM, and MBM. Diets containing BM provided the largest (P < .05) amounts of essential AA and lysine, and FM provided the largest (P < .05) amounts of methionine in fermenter effluent. Supplementation of diets with proteins low in ruminal degradability increased flows of nonammonia N, dietary N, and total and essential AA and modified the AA profile flowing out of fermenters.

Effects of excess dietary leucine and leucine catabolites on growth and immune responses in weanling pigs.

Two experiments with weanling pigs were conducted to study the effects on growth and immune responses of excess dietary L-leucine (LEU) and dietary supplementation with the LEU catabolites, alpha-ketoisocaproic acid (KIC) and beta-hydroxymethyl butyrate (HMB). In Exp. 1, 80 pigs were randomly allocated according to initial BW and ancestry to five replications of four dietary treatments (four pigs/pen). The control diet contained wheat, oat groats, menhaden fish meal, and dried whey and provided 1.12% LEU. Treatment diets were the control plus 1.12% LEU, 1.12% KIC, or .4% HMB. The experiment lasted 6 wk. In Exp. 2, 36 pigs were randomly allocated to nine replications of four dietary treatments in a 2 x 2 factorial arrangement. Treatments consisted of two concentrations of dietary LEU and a daily i.m. injection of dexamethasone (DEX) or saline. Pigs were fed a control corn-soybean meal and dried whey diet (1.56% LEU) or the control diet plus 1.56% of crystalline LEU. Pigs were individually penned and the experiment lasted 4 wk. Growth performance, plasma free amino acids, plasma urea nitrogen, and humoral and cellular immune responses were measured. Results indicated that LEU concentrations in practical diets and supplementation with KIC and HMB (Exp. 1) did not detrimentally affect growth and immune response. The high LEU concentration and DEX injection used in Exp. 2, however, were detrimental to both growth and immune response.