Search

Development of a heat-pasteurization process is described for picked meat of Dungeness crabs (Cancer magister) contained in oxygen-impermeable flexible pouches, For each time-temperature treatment, 30 samples, each inoculated with an equal mixture of three strains of C. botulinum nonproteolytic type B, for a total of 107 spores, provided the basis for calculation of the thermal resistance (a 7D process). Following heat processing, the crabmeat was removed from the pouches and transferred to enrichment medium where it was incubated anaerobically for 150 days. Endpoints at which spores survived were determined by the presence of toxin in the enrichment medium. Process times ranged from 90 min at 88.9°C to 20.3 min at 94.4°C. D values (the time at each temperature required to reduce the inoculum by 1 log) ranged from 12.9 for the 88.9°C process to 2.9 for the 94.4°C process. The relative sterilization value, F0 was .054 and the pasteurization value, , was 240. This pasteurization process safely extends refri...

The survival of Listeria monocytogenes preinoculated into ice cream and mozzarella cheese prior to gamma-irradiation treatment was determined. Samples were maintained at -78°C and exposed to targeted doses of 2,4,8,16, and 32 kGy of gamma-irradiation. The calculated D10 values were 1.4 kGy for mozzarella cheese and 2.0 kGy for ice cream. The effective level of irradiation (12D) for inactivating L. monocytogenes was 16.8 kGy for mozzarella cheese and 24.4 kGy for ice cream.

Survival of naturally occurring larvae of Anisakis simplex in fresh arrowtooth flounder (Atheresthes stomia) was determined after storage for specified periods at four freezing temperatures. All larvae were killed by 96, 60, 12, and 9 h at temperatures of -15, -20, -30, and -40 degrees C, respectively. The average percentages of live larvae per fillet at the next shortest holding time were as follows: 72 h at -15 degrees C, 0 to 3%; 48 h at -20 degrees C, 11 to 30%; 9 h at -30 degrees C, 5%; and 6 h at -40 degrees C, 0 to 3%. Larval survival was directly related to fillet thickness or weight (P < or = 0.05). Larval death was directly correlated to freezing temperatures. Holding time necessary to kill larval nematodes decreased as storage temperature decreased.

The suitability of soybean/corn lecithin and poultry fat as partial replacements for menhaden oil in feeds for post-juvenile rainbow trout (initial weight 46.0 g) was investigated. For 16 weeks, fish were fed experimental diets in which either 10% menhaden oil (FO), 10% poultry fat (PF), 10% lecithin (soybean/corn, L10), or 15% lecithin (soybean/corn, L15), plus 5% supplemental menhaden oil was added to fish meal-based diets. There were no significant differences in body weight gain among all treatments (328–347 g/fish), although fish fed the L15 diet consumed significantly more feed (299 g/fish) than fish fed the PF diet (269 g/fish). Sensory analysis indicated that raw L10 fillets stored for 4 and 12 weeks at −20 °C were significantly more yellow than raw FO fillets. Raw and cooked L15 fillets stored for 1 and 8 days at 5 °C, or for 17 days, 4 weeks, and 12 weeks at −20 °C had significantly higher colorimetric b* values (more yellow) than raw and cooked FO, PF, and L10 fillets. There was a trend for FO fillets to have higher TBARS values compared to fillets of the other treatments when stored under all time/temperature conditions tested. Although fillets of fish fed diets containing soybean/corn lecithin were more yellow in color, either lecithin (soybean/corn) or poultry fat was a nutritionally suitable substitute for most of the fish oil added to fish feeds.

This study was conducted to determine the effects of increasing dietary lipid concentrations on fillet characteristics of post-juvenile rainbow trout. A feeding trial was conducted with fish meal based diets containing 10, 15, 20, 25, or 30% lipid for 24 wk. Menhaden oil was the lipid ingredient. Weight gain was significantly greater in fish fed the 30% lipid diet than in fish fed either 10%, 15% or 20% lipid diets. There were no significant differences in visceral somatic index. Fillet lipid concentration of fish fed the 30% lipid diet (9.2-g lipid/ 100-g fillet) was significantly higher (P < 0.05) than fish fed either the 10% or 15% lipid diets (5.8- and 6.9-g lipid/100-g fillet, respectively). In samples stored for 3 d at 5 C or S wk at -20 C, sensory panelists reported that the cooked fillets from fish fed the 30% lipid diet were “more fishy” than fish fed the 15% lipid diet, and preferred the cooked fillets from the 15% lipid treatment over the 30% lipid treatment. Triangle tests and fillet colorimetry showed no significant differences between fillets from fish fed the 15% and 30% lipid diets at any sampling time point. No significant differences in fillet concentrations of thiobarbituric reactive substances were observed among dietary treatments stored at either 5 C or -20 C. These results suggest that two main effects of feeding a 30% lipid diet (with fish oil as the lipid source) are a higher lipid concentration in the fillet and a “fishier” aroma compared to fillets from fish fed a 15% lipid diet.

Four different methods of pelleting—extruded (EXT), steam pelleted (STM), using a Universal Pellet Cooker (UPC), and expanded (EXP)—were performed on subsamples of a single batch of mash to determine the effects on feed pellet characteristics, in vivo feed digestibility, and performance of rainbow trout Oncorhynchus mykiss fed the diets for 16 wk. Results indicated that the STM feed was the most (851 g/L) and UPC feed the least (672 g/L) dense, and that UPC feed had the highest % float (8.3%) and, of the pellets that sank, the fastest sink rate (15.1 cm/sec). While some differences occurred among pelleted diets in loss of dry matter (% dry loss) after incubation in a water bath for up to 10 min, the overall % dry loss was only approximately 1–2%. The method of pelleting did not affect fish weight gain, feed conversion ratio, or specific growth rate. Measurement of the apparent digestibility coefficient of dry matter of the test diets using Cr2O3 as the marker ranged from 71–89%. While it appeared that the method of pelleting can affect feed characteristics and the amount of feed offered to the fish, fish performance was not affected.

The recent trend for rainbow trout feeds to be higher than 15% lipid may improve feed conversion ratios (FCRs) and increase the lipid concentration of the fish. However, one disadvantage of the higher lipid concentration in fish is the potential for increased rates of lipid oxidation, which could affect fish health and contribute to off-flavors in fillets. The objective of this experiment was to determine the effects of adequate and high concentrations of dietary lipid and the antioxidant vitamin E on fish performance, fish health, and fillet product quality of rainbow trout. A 10-week feeding trial was conducted with diets containing either 15 or 30 g lipid/100 g feed, and either 300 (e) or 1500 (E) mg dl-α-tocopheryl acetate/kg feed (15e, 15E, 30e, and 30E). Fish fed 30% lipid diets had significantly higher final body weight, specific growth rate (SGR), and protein efficiency ratio (PER) than fish fed 15% lipid diets. All health parameters of fish measured in the experiment were within normal ranges of healthy fish although several parameters were affected by increasing dietary lipid concentration. Lipid concentration in fish body (whole body, fillets, and viscera) reflected dietary lipid concentration. Increasing the lipid concentration in the feed from 15% to 30% increased the fillet lipid concentration from 8.4 to 9.6 g lipid/100 g fillet. Vitamin E concentrations in fillets reflected dietary vitamin E concentration and ranged from 8.3 mg/kg (30e) to 49.1 mg/kg (15E) (P

Effects of thermal and enzymatic treatments of soybean meal on apparent absorption of total phosphorus, phytate phosphorus, nitrogen (protein), ash, calcium, magnesium, copper, iron, manganese, strontium and zinc were examined using rainbow trout, Oncorhynchus mykiss (Walbaum), as the test species. Absorption of the test nutrients was estimated using yttrium as an inert non-absorbable indicator. Thermal treatments (microwaving, dry roasting, steam heating, cooking) had no measurable effect on the apparent absorption of phosphorus and other minerals. Phytase supplementation increased the apparent absorption of phosphorus, nitrogen (protein), ash, calcium, magnesium, copper, iron, strontium and zinc in low-ash diets containing soybean meal, but had little effect in high-ash diets containing both soybean and fish meal. In low-ash diets, the apparent absorption of phosphorus increased in accord with the level of phytase added to the diet, from 27% (no phytase added) up to 90% (phytase added, 4000 units kg−1 diet) or 93% (predigested with phytase, 200 units kg−1 soybean meal). In high-ash diets, dietary acidification with citric acid decreased the effect of phytase, whereas in low-ash diets, acidification markedly increased the effect of the enzyme. Excretion of phosphorus in the faeces of fish fed a low-ash diet containing phytase-treated soybean meal was 0.32 g per kg diet consumed, a 95%−98% reduction compared with phosphorus excretion by fish consuming commercial trout feeds.

The suitability of meals derived from fish processing wastes as the protein fraction in practical diets for hatchery-reared coho salmon was investigated. The study compared the performance of coho salmon fed diets containing three products: a skin-and-bone meal (SB), a deboned meal (DM), and a whole-fish meal (WM) made directly from the fish wastes. A commercial trout diet (CO) was fed to a fourth treatment group. Diets were fed at 3% of body weight per day to juvenile coho salmon for 12 wk. Survival (> 94%) was not significantly different among treatment groups. Average fish weight, feed conversion ratio, whole body proximate and mineral composition, and protein and phosphorus retention were compared. There were no significant differences after 12 wk of feeding in fish weight between WM, DM, and CO, but SB had significantly lower weight and whole body lipid, and significantly higher ash. Compared to WM, DM had a significantly lower feed conversion ratio and higher retention of protein and phosphorus, but these indices were not significantly different from CO. It is concluded that DM is a potentially superior protein ingredient compared to WM, while specific characteristics of SB will limit its use as a protein source in feeds for salmonids. However, SB may prove to be a suitable mineral supplement when added at a low level. Utilization of fish processing wastes in salmonid diets could be a commercially viable alternative to direct disposal of processing wastes.

A series of experiments was conducted to research sensitive indicators for phosphorus status of fish using post-juvenile rainbow trout. Fish were fed up to 24 days with semipurified diets that varied in phosphorus content. Concentrations of glucose-6-phosphate, ATP, creatine phosphate, glucose, total lipids and total cholesterol in blood or skeletal muscle were relatively unchanged by the 24 days of dietary phosphorus restriction. Inorganic phosphorus and ATP levels in the blood, however, correlated significantly and positively. Inorganic phosphorus levels in plasma and urine were significantly lower in fish fed phosphorus-deficient diets than phosphorus-supplemented diets. Urinary phosphorus excretion peaked 6–10 h after feeding fish with diets containing potassium phosphate. Fish receiving either commercial feeds or experimental diets containing phosphorus as fish bone excreted trace amounts of phosphorus in the urine. Faecal content of phosphorus significantly increased when the diet containing potassium phosphate was supplemented with calcium carbonate. Urinary phosphorus concentration was found to be a rapid and sensitive indicator for dietary intake of phosphorus and probably phosphorus status of the fish, and had an advantage over conventional response variables in estimating dietary phosphorus requirement especially with large commercial-size fish.

The apparent digestibilities (availabilities) of dry matter, protein, phosphorus and selected minerals in fish and animal by-products were determined using rainbow trout Oncorhynchus mykiss (Walbaum). Blood meal (ring-dried), feather meal and deboned fish meal had relatively high concentrations of protein, low concentrations of phosphorus and many minerals, and high digestibilities (availabilities) of these nutrients. Other animal by-products, however, had high concentrations of minerals, including phosphorus, which are associated with the bone fraction. Availabilities of manganese and zinc in the diet were reduced by the inclusion of high-ash animal by-products in the diet, whereas availabilities of potassium, sodium and copper were relatively unaffected. Dietary concentrations of bone minerals (calcium, phosphorus) and ash were inversely correlated with availabilities (% of intake) of most minerals except copper in the diet. Also, dietary concentrations of bone minerals correlated inversely with the net absorption (mg g−1 diet) of zinc, manganese and magnesium in the diet. When rainbow trout were fed diets containing incremental concentrations of fish bones, the apparent availabilities of phosphorus, calcium, magnesium and iron decreased as fish bone content in the diet increased. Reducing the bone fraction of high-ash (high-phosphorus) by-product meals is therefore an essential approach to using such ingredients in low-pollution fish feeds.

A new method was developed to estimate the minimum dietary requirement of phosphorus (P) for large fish for which conventional methods are not suitable. The method is based upon nonfecal (mainly urinary) excretion of inorganic P and total nitrogen from fish placed in a metabolic tank. In the first experiment, small and large rainbow trout (body wt 203 and 400 g, respectively) and, in the second experiment, P-sufficient, P-deficient and starved rainbow trout (different in diet history; body wt 349-390 g) were fed a constant amount (standard feeding rate) of semipurified diets with incremental P concentrations once daily at 15 degrees C. In all cases, there was no measurable excretion of P when dietary P concentration was low; however, beyond a specific dietary concentration, excretion of P increased rapidly. The point where the fish started to excrete P was assumed to be the minimum dietary requirement. By d 3 of consuming the experimental diets, the response of the fish to dietary P concentration stabilized, and excretion of P remained constant within dietary treatment groups for the subsequent sampling days (d 6, 9 and 12). The minimum dietary requirement of available P for fish having body wt of 203 and 400 g was estimated to be 6.62 and 5.54 g/kg dry diet, respectively, and that for P-sufficient, P-deficient and starved fish was estimated to be 4.06, 5.83 and 4.72 g/kg dry diet, respectively, when feed efficiency is 1.

An in vivo digestibility trial and a feeding trial were conducted to determine the extent to which heat treatment, nutritional quality, and palatability of hexane-extracted, defatted soy flour (SF) influenced growth of fingerling coho salmon. Heat treatment of SF (autoclave, 1.7 atm, 121°C) lowered trypsin units inhibited (TUI) from 181 to 1.8 after 20 min and lowered protein solubility from 98% to 70%. Longer heating periods further reduced SF protein solubility, but did not substantially reduce TUI. The apparent digestibility coefficient (ADC) of protein from heated SF (90.8) was significantly higher than the ADC of unheated SF (74.3), but significantly lower than the ADC of the wheat gluten basal diet (98.2). In the feeding trial, fish weight gain was reduced in a step-wise fashion at each level (15, 20, or 25%) of unheated SF inclusion in the diet. Fish fed diets containing heat-treated SF gained more weight at each SF inclusion level compared to their corresponding unheated treatment groups, but inclusion of heat-treated SF greater than 15% substitution of herring meal protein resulted in reduced weight gain compared to fish fed the control diet. Krill supplementation (5%, combination of dried and frozen) increased weight gain in fish fed diets containing 25% heated or unheated SF, primarily by restoring feed intake. In fish fed the heated 25% SF diet with krill, feed intake and average weight gains were equivalent to control diet levels. Fish fed the unheated SF diet with added krill had higher feed intake and weight gains than fish fed the equivalent diet without added krill, but gains were significantly lower than controls. Calculated indices of fish performance, e.g., specific growth rates, feed conversion ratios, protein retention ratios, and apparent net protein utilization (percentage protein retention) displayed patterns similar to weight gain results. In this study, a 20 min heat treatment of SF reduced trypsin inhibitor activity to physiologically insignificant levels, increased protein digestibility, and also allowed a successful 15% substitution of SF for herring meal protein. It appears that reduced feed intake associated with unheated SF was responsible for approximately one-half of the observed reduction in weight gain. Lower nutritional value of the unheated or insufficiently heated SF was responsible for the remaining reduction in fish performance. Therefore, a combination of proper heat treatment and supplementation with palatability-enhancing feed ingredients can overcome these problems, even in young Pacific salmon which are known to be extremely sensitive to soybean meal in their feeds.

Approximately two-thirds of phosphorus in various grains is present as phytate, which is not well-utilized by fish and other monogastric species. Besides its low availability of phosphorus, phytate is reported to reduce the availability of other dietary nutrients to animals. Single-gene, non-lethal low phytic acid (lpa) mutations in corn and barley cause the seed to store most of the phosphorus as inorganic phosphorus instead of as phytate phosphorus. Theoretically, using these mutant grains containing lower levels of phytate in animal feeds should reduce phosphorus excretion by the animals, provided that available phosphorus levels in feeds containing these grains are appropriately adjusted downward. This study was conducted as a first step to determine if the biological availability of phosphorus in the low-phytate mutants of barley, dent corn and flint corn differed significantly from that in ordinary grains for fish. Also of interest was the effect, if any, on the availability of other minerals in formulated feeds containing the low-phytate grains. Feeding trials demonstrated that the apparent availability of phosphorus in low-phytate grains was significantly higher than that in ordinary grains when they were combined with low-ash ingredients. Fecal phosphorus content (on average) decreased 50.2% (in phytate-phosphorus) or 42.9% (in total phosphorus) by replacing ordinary grains with low-phytate grains in the low-ash diets. The apparent availabilities of calcium, iron, zinc and strontium also were significantly higher in the low-ash diet containing low-phytate dent corn than that containing ordinary dent corn. However, no such increase was observed with low-phytate barley or low-phytate flint corn over their counterpart grains in either calcium, iron or zinc. The apparent availabilities of copper, manganese, magnesium, potassium and sodium were not significantly different between ordinary and low-phytate grains. The apparent digestibility of dry matter also was not significantly different between ordinary and low-phytate grains. The results of this study suggest that a substantial reduction of phosphorus discharge from fish, poultry and animal farms could be achieved simply by replacing ordinary grains with low-phytate mutant grains in low-ash feeds.

Rainbow trout were fed one of three diets for 12 weeks: a low phosphorus diet containing corn gluten, a low phosphorus diet containing wheat gluten, or a commercial control diet. Fillets were analyzed by a colorimeter and by sensory preference tests. Raw fillets from fish fed the corn gluten-based diet had the highest b* values (yellow color) and received significantly lower visual acceptance scores than fillets from the other dietary treatments. Dietary supplementation with 100 μg/g canthaxanthin increased the a* values (red color) and improved visual preference scores of raw fillets from the corn-gluten fed fish. Incorporation of either corn gluten or wheat gluten into the diet did not adversely affect flavor of the fillets.

Preliminary studies were conducted to determine if several feed supplements with the potential to improve dietary mineral availabilities in fish meal had any measurable effect in fish feeds. In the first study with rainbow trout, 11 supplements were tested: citric acid; sodium citrate; potassium chloride; sodium chloride; histamine dihydrochloride; EDTA disodium salt; sodium bicarbonate; a mixture of amino acids; ascorbic acid; a mixture of inositol and choline; and cholecalciferol. Apparent availability of calcium, phosphorus, magnesium, sodium, iron, manganese and strontium in fish meal-based diets was determined using both yttrium oxide (Y2O3) and chromium oxide (Cr2O3) as inert dietary markers. Apparent availability was expressed as the fractional net absorption (%) of minerals from diets. After a 7-day acclimation period with test diets, fecal samples were collected for five consecutive days using passive collection systems. Apparent availability of calcium, phosphorus, magnesium, iron, manganese and strontium was increased by citric acid supplementation. Apparent availability of manganese also was increased by EDTA and sodium citrate. The other supplements had no measurable effect on the apparent availability of minerals in fish meal. In the second study, the effect of supplemental citric acid was further investigated using monogastric (rainbow trout) and agastric fish (goldfish). Fish were fed for 5 weeks (rainbow trout) or 3 weeks (goldfish) with fish meal-based diets containing either 0% (control), 2% or 5% citric acid on a dry basis. Feces were collected by settling and by stripping. Apparent availabilities of calcium and phosphorus were greatly affected by citric acid supplementation in rainbow trout but not in goldfish. Phosphorus levels in feces of fish fed a diet with 5% citric acid were approximately half of that of fish fed the control diet (0% citric acid) in the rainbow trout trial. This pattern was consistent during the 5-week feeding trial. A dietary supplement of citric acid as high as 5% did not reduce feed intake or appetite of rainbow trout. Conversely, this level of dietary acidification led to a marked reduction of feed intake in goldfish. Dietary supplementation of citric acid at 2% level did not reduce feed intake of goldfish; however, this level of dietary acidification had little effect on the apparent availability of major minerals in fish meal-based diet. Levels of non-fecal excretion of calcium and phosphorus, inorganic phosphorus in urine, and citric acid in feces were increased in rainbow trout fed 5% citric acid. The pH values of the feces and urine were decreased in rainbow trout fed citric acid. Plasma bicarbonate, plasma calcium and phosphorus, and blood pH of rainbow trout tended to increase by a 5% dietary supplementation of citric acid. The soluble inorganic phosphorus content increased in the diets and decreased in the feces of rainbow trout by supplementing the diet with 5% citric acid. Feces samples of rainbow trout collected by stripping provided similar availability values to data collected by settling for most elements except sodium, which had negative values in all dietary treatments.

Apparent digestibility of protein and availability of minerals (Ca, K, P, Mg, Na, Cu, Fe, Mn, Sr, Zn) in various feed ingredients were determined for coho salmon and rainbow trout using yttrium oxide (Y2O3) as the inert marker and passive feces collection tanks. The feed ingredients were herring meal, menhaden meal, anchovy meal, deboned whitefish meal, poultry by-product meal, feather meal, soybean meal, corn gluten meal, wheat gluten meal, wheat middling and wheat flour. Apparent digestibility (%) of protein and availability (%) of minerals were determined as a fractional net absorption of nutrients from diets. Apparent digestibility of protein and availability of K was high (>80%) in all feed ingredients, whereas digestibility of dry matter and availability of Ca, Cu, Fe, Mg, Mn, Na, P, Sr and Zn were variable among ingredients. Apparent availability (%) of mineral elements was not significantly correlated to the amount of nutrient intake (μg nutrient g−1 BW day−1) in any test diet. Net nutrient absorption (μg g−1 BW day−1) was positively correlated (P

The objectives of this study were to determine which indicators were most responsive to suboptimal phosphorus intake in fingerling rainbow trout, and to observe the magnitude of these changes over time. Fish with an initial mean weight of 1.8 g were hand-fed one of five semipurified wheat-gluten based diets containing between 0.23%–1.16% dietary phosphorus, or a fish meal control diet (1.8% P) for 8 weeks. Phosphorus, calcium and magnesium concentrations in whole body, skin (with scales), and plasma were measured bi-weekly. Alkaline phosphatase activity was determined in plasma and in a crude intestinal homogenate. There was no correlation between dietary phosphorus concentration and body weight of rainbow trout. Of all tissues and metabolites examined, skin was the most responsive to differences in dietary phosphorus concentration. Dietary treatment had a significant effect on the concentrations of ash, phosphorus, calcium and magnesium in rainbow trout skin at weeks 4 and 8. Whole body ash, phosphorus, calcium, and magnesium concentrations were also highly responsive to graded levels of dietary phosphorus at week 8. Rainbow trout fed suboptimal phosphorus diets had significantly lower plasma phosphorus concentrations and alkaline phosphatase activity, and significantly higher whole body lipid than those fed adequate phosphorus diets. Alkaline phosphatase activity of the intestinal homogenate was not significantly correlated with dietary phosphorus intake.

The goal of this study was to better understand why dietary soybean products are poorly utilized by salmonids. The influence of dietary intake on coho salmon fingerling weight gain and specific properties of pyloric caeca enzymes was investigated. Fingerlings were fed diets containing heated or unheated soybean meal (SBM) or Promoveal™, as 15–25% herring meal replacer, for 8–12 weeks. Fish fed to apparent satiation with diets containing heated SBM replacer gained more weight than those fed unheated SBM at the same level. Fish increased in body weight at the same rate when fed restricted rations containing either 15% SBM replacer that was variously heated up to 20 min, 15% Promoveal™ replacer or the herring meal basal diet. After the experimental diets were fed, digestive proteinases were isolated from the pyloric caeca. Yield of pyloric caeca enzymes (PCE), recovery of trypsin in PCE, soybean trypsin inhibitor (SBTI) sensitivity of PCE trypsin, specific activity of PCE trypsin and in vitro casein digestibility by PCE were determined for each dietary group. Weight gain vs in vitro casein digestibility by PCE was linear for animals fed unheated SBM to apparent satiation (r2 = 0.71, P

Fish meals produced from fish containing high levels of histamine can be acutely toxic to chickens, causing gizzard erosion (GE), black vomit disease, and death after 3–5 days of feeding. Fish meals are sometimes selected for aquaculture use on the basis of chicken toxicity testing, although little scientific evidence exists to support this practice. In this study, growth, feed intake, and development of gastric abnormalities were assessed in juvenile rainbow trout fed diets containing fish meal acutely toxic to chickens, or fed casein or fish meal diets supplemented with histamine and two suspected potentiators of histamine toxicity, putrescine and cadaverine, and abusively heated. No signs of acute toxicity or mortality occurred in the groups of fish during the course of the 16-week study. Fish fed diets containing GE-positive fish meal had distended stomachs, but no gastric lesions or cellular abnormalities. Similar effects were obtained by feeding diets containing casein or GE-negative fish meal supplemented with histamine (2000 mg/kg dry diet). The addition of putrescine and cadaverine (500 mg/kg dry diet each) to the histamine-supplemented diets had no further effect. Feed consumption, feed efficiency, and growth were similar among dietary treatments, indicating that stomach distention did not reduce feed intake or impair gastric function. This study showed that rainbow trout are less sensitive than chickens to GE-positive fish meal and that there is no correlation between positive GE score and the nutritional value of the fish meal for rainbow trout. This study also showed that stomach distention resulting from feeding diets containing GE-positive fish meal could be duplicated by feeding diets supplemented with 2000 mg histamine/kg diet.

Substitution of high oleic acid sunflower oil for herring oil in formulated salmonid diets affected the fatty acid composition of muscle, liver and visceral fat from coho salmon (Oncorhynchus kisutch) and rainbow trout (O. mykiss). Fish were fed diets containing either high oleic acid sunflower oil or herring oil as the supplemental lipid source (12.4 g/100 g diet) for 1-2 mo. Muscle from fish fed the sunflower oil diet had twice the concentration of oleic acid (approximately 25 g/100 g lipid) as muscle from fish fed the herring oil diet (approximately 12 g/100 g lipid). The maximum concentration of oleic acid in the muscle was obtained after only 2 wk of feeding the sunflower oil diet. Oleic acid concentrations in liver and visceral fat of fish fed the sunflower oil diet were significantly higher than in fish fed the herring oil diet. Rainbow trout fed the sunflower oil diet for 4 wk maintained the higher oleic acid concentrations in muscle and liver when deprived of feed for 2 wk compared with fish fed the herring oil diet. These data indicated that accumulation of oleic acid in coho salmon and rainbow trout muscle was fairly rapidly achieved when a high oleic acid diet was fed. The differences between the fish receiving the two dietary treatments in fatty acid composition and in concentrations of thiobarbituric acid-reactive substances in muscle stored at refrigerated temperatures were consistent with previously reported differences in aroma perceived by a sensory panel.

The in vitro digestibility of protein in various salmonid feeds was determined by pH-stat using enzyme fractions from trout pyloric ceca. Data were compared with in vivo digestibility and growth of fish by linear regression analysis. Results indicated that there were good agreements between the degree of hydrolysis of most feed samples and growth of fish. The pH-stat method is not suited for feed samples that have been partially hydrolyzed during their preparation.

Frozen dairy products intended for low microbial diets of immunosuppressed patients were sterilized by exposure to 40 kGy (4 Mrad) of cobalt-60 irradiation. Levels of vitamin A, amino acids, and selected fatty acids were measured in yogurt bars, ice cream, Cheddar cheese, mozzarella cheese, and nonfat dry milk before and after irradiation. Addition of antioxidants to the frozen dairy desserts prior to irradiation at - 78C was not effective in preventing degradation of vitamin A. There were significant decreases of approximately 90% in levels of vitamin A in Cheddar cheese and mozzarella cheese irradiated at -78C and 0–5C compared to the corresponding nonirradiated products. Levels of vitamin A in nonfat dry milk irradiated at three different temperatures (22C, 0–5C, or - 78C) were variable compared to levels in the nonirradiated product. Levels of palmitic, stearic, oleic, linoleic, and linolenic acids were retained in all irradiated dairy products analyzed. Irradiation at the specified temperatures did not affect levels of individual amino acids in nonfat dry milk or mozzarella cheese.

The purpose of this study was to determine if substituting high oleic acid sunflower oil for herring oil in formulated salmonid diets affected sensory attributes of fillets from coho salmon (Oncorhynchus kisutch) and rainbow trout (Oncorhynchus mykiss). Two feeding trials were conducted in which coho salmon and rainbow trout were fed diets containing either high oleic acid sunflower oil or herring oil as the supplemental lipid source (12.4% of the diet by weight) for 6-8 weeks. In standard directional triangle tests on previously frozen rainbow trout and coho salmon fillets stored at 5¦C for up to 10 days, a significant number of panelists were able to differentiate between fillets from the two dietary treatments based on aroma, and determined that the herring oil fillets had a ofishiero aroma than the sunflower oil fillets. The panelists tended to prefer rainbow trout fillets from the sunflower oil treatment to fillets from the herring oil dietary treatment. These results suggest that increasing the mono...

The objective of this study was to define a procedure for converting salmon viscera into a co-dried product that could evetually be the major protein ingredient in dry salmonid feeds. A lactic acid bacteria fermented silage, and for comparative purposes, a sulfuric acid silage were prepared from salmon viscera ( Oncorhynchus nerka and Oncorhynchus gorbuscha ). Both ensiled products were separately co-dried with poultry by-product meal in a final ratio of 1:1 ( w/w ) on a dry weight basis. Nitrogen levels of the co-dried products were 9 to 1 1%, sufficiently high to be the main protein source in dry feeds for salmonids. Methionine was the limiting amino acid in the co-dried products. Protein fractionation by size exclusion chromatography of samples obtained on the first and fourteenth day of ensilage showed that proteins were hydrolyzed to low molecular weight proteins, peptides, and amino acids. The co-dried products had low numbers of aerobic bacteria and low water activity, which would enhance storage stability. Formation of high levels of thiobarbituric acid reactive substances in freeze-dried silage was inhibited by the addition of 0.025% ( w/w ) ethoxyquin to the silage prior to drying.

Sterile ice cream and frozen yogurt were offered to immunosuppressed patients recovering from bone marrow transplantation. To obtain sterile products, two of the dairy desserts (prepackaged ice cream and frozen yogurt bars) were exposed to 40 kGy of cobalt 60 irradiation. Four different flavors of ice cream were aseptically prepared under a laminar airflow hood using commercially sterilized ingredients. A commercially sterile, frozen milk-based drink on the low-microbial menu served as the control. Ratings of the seven products by 17 patients indicated that a frozen vanilla milk-based drink and aseptically prepared chocolate ice cream were highly acceptable to recovering immunosuppressed patients who have difficulty eating most foods. However, the seven desserts received higher ratings from a sensory panel of healthy individuals than from the patient panel, confirming that new foods for the low-microbial diet should be "market-tested" by the targeted patient population before inclusion in the menu.

Textural changes and storage stability properties of high fiber yeast breads containing 13% dietary fiber (TDF, as is basis) from either white wheat bran, white wheat distillers' grains with solubles (DDGS), barley spent grains (BSG), soy fiber, or oat fiber were compared. Flour substitution levels ranged from 12% to 23%. There were approximately 100 colony forming units (CFU)/1000 g for the BSG containing breads and 106 to 107 CFU/1000 g for the other products. Mixing and baking properties for breads utilizing these ingredients varied widely. Breads containing wheat distillers’grains retained softness longer during the storage trial than did the other experimental products.

Sensory evaluations by healthy individuals were conducted on cobalt- 60 irradiated retail dairy products which were to be incorporated into the low microbial diets of immunosuppressed patients. Irradiation (40 kGy at -78°C) caused little change in product color or texture, but generally there was a decrease in overall acceptability and an increase in off-flavor and aftertaste. Modified atmosphere packaging (nitrogen, helium, or air) or antioxidant addition (ascorbyl palmitate or a com- bination of butylated hydroxyanisole and butylated hydroxytoluene) prior to irradiation were effective in preserving specific sensory attri- butes, which in some cases resulted in improved overall acceptability (helium packed peppermint ice cream; ascorbyl palmitate treated strawberry yogurt bars) when compared to untreated irradiated prod- ucts. INTRODUCTION COMMERCIALLY STERILIZED dairy products are offered to immunosuppressed patients housed in laminar air flow iso- lation who receive low microbial diets because these patients are vulnerable to infection by low numbers of pathogenic or- ganisms (Tripathy and Mackaness, 1969). High numbers of normally non-pathogenic organisms in foods may also be harmful (Banerjee and Black, 1986). Pasteurization of dairy products inactivates many pathogens, but does not produce a sterile product. Common spoilage organisms in pasteurized milk and milk products include

The effect of granulation, level of soluble solids, and drying method on the mixing properties and baking performance of distillers’grain products from wheat in yeast-raised breads and cookies were evaluated and compared with products containing barley spent grains (BSG). Grinding had a variable effect on baking properties. Breads containing 8% wheat distillers' grains (WDG) (no solubles) had the lowest loaf volume. Breads made with WDG and BSG had the poorest crumb grain. There were few differences observed in the mixing and baking properties of wheat distillers’grains (DDGS or DDG) regardless of whether the materials were dried by harsh (steam tube, tunnel) or milder (atmospheric drum) drying treatments.

A comparison was made between the total and soluble iron, calcium, zinc, and phytic acid content of yeast raised breads, each containing approximately 13% total dietary fiber (TDF, as is basis) as either white wheat bran, white wheat distillers' grains, barley fiber (brewer's spent grains), soy fiber, or oat fiber. Substitution level of the fiber ingredients into the breads varied from 12 to 23% flour replacement (w/w) depending upon the TDF content of the fiber ingredient. The phytic acid content was highest in the wheat bran and oat fiber breads (24 mg/100g and 27 mg/100g, respectively). When formulated on an equal TDF basis, the level of soluble mineral in the fiber ingredient was not predictive of the level of soluble mineral in the bread. The highest amount of soluble calcium was found in the control and white wheat distillers' grain breads, 167 and 146 μg/g, respectively. The highest amount of soluble iron was found in the soy fiber bread (31.6 μg/g) and the greatest amount of soluble zinc (5.3 μg/g) was found in the wheat bran bread.

This study examined the body composition and serum and liver lipids in weanling rats fed diets containing distillers' dried grains with solubles (DDGS) from either white wheat (WW), red wheat (RW), corn (CO) or WW fortified with essential amino acids (FWW) as a sole protein source (1.6 % N in the diet). Although the DDGS-fed groups had significantly lower body weights compared with the casein control (RC) after a 28-day feeding trial, there were no significant differences among the dietary groups in percentages of body water, protein, lipid or ash. Serum cholesterol was significantly higher in rats fed the RW diet, and serum triglyceride was higher in the RC and FWW groups compared with the other dietary groups. Liver cholesterol and triglyceride concentrations (mg g−1 liver) were not significantly different among the five dietary groups.

High hydrostatic pressure has been demonstrated to be a useful technique for treating food to reduce the number of pathogenic organisms and to extend shelf life. Most research in this area has focused on bacteria. However, a concern in the sashimi (raw fish) industry is that nematode worms such as Anisakis simplex occur naturally in cold-water marine fish. The objectives of this research were to perform a pilot study to determine the effect of high hydrostatic pressure on the viability of Anisakis simplex larvae, commonly found in king salmon and arrowtooth flounder, and to evaluate the effects of high hydrostatic pressure on the color and texture of the fish fillets. Pieces of fish (ca. 100 g per bag) containing 13 to 118 larvae were exposed to pressures of up to 80,000 lb/in2 (552 MPa) for up to 180 s. The times and pressures required to kill 100% of the larvae were as follows: 30 to 60 s at 60,000 lb/in2 (414 MPa), 90 to 180 s at 40,000 lb/in2 (276 MPa), and 180 s at 30,000 lb/in2 (207 MPa). For all salmon treatments that killed 100% of the larvae, a significant increase in the whiteness of the flesh was observed. Although high hydrostatic pressure was effective in killing A. simplex larvae in raw fish fillets, its significant effect on the color and overall appearance of the fillet may limit its application to the processing of fish for raw-fish markets.

The purpose of this study was to define the relationship between survival and temperature of nematodes of the species Anisakis simplex in microwave-processed arrowtooth flounder (Atheresthes stomias). Ten fillets (each 126 to 467 g, 0.5 to 1.75 cm thick), with an average of five larvae of Anisakis simplex per fillet, were processed to target temperatures on high (100%) power using a commercial 700-W microwave oven. Fillets were neither covered nor rotated and had a temperature probe inserted to two-thirds depth into the thickest portion. After the fillet was digested using a 1% pepsin solution, the viability of nematodes was determined by viewing them under a dissecting microscope. Survival rates were 31% at 140 degrees F (60 degrees C), 11% at 150 degrees F (65 degrees C), 2% at 160 degrees F (71 degrees C), 3% at 165 degrees F (74 degrees C), and 0% at 170 degrees F (77 degrees C). Microwave processing of standardized fillet "sandwiches," 14 cm long, 4.5 cm wide, and approximately 1.75 cm high, each of which was preinoculated with 10 live nematodes, resulted in no survival at either 160 degrees F or 170 degrees F. Using ultraviolet light to detect both viable and nonviable nematodes in fillet sandwiches as an alternative method to pepsin digestion resulted in survival rates of 1% at 140 degrees F (60 degrees C), 3% at 145 degrees F (63 degrees C), and 0% at 150 degrees F (65 degrees C). Smaller fillet sandwiches, which most likely had fewer cold spots during microwave processing, required 150 degrees F (65 degrees C), whereas larger whole fillets required 170 degrees F (77 degrees C) to kill larvae of Anisakis simplex. The parasites were most likely inactivated by a thermal mechanism of microwave treatment. Damage to the nematodes was often evident from ruptured cuticles that were no longer resistant to digestive enzymes. The high hydrostatic pressure and low chloride content of the pseudocoelomic fluid probably contributed greatly to the damage incurred by the larvae.

Rats fed a 20% xylitol diet were compared to rats fed for 6 weeks a diet of either 20% glucose, cornstarch or sucrose (plus 45% cornstarch), or the AIN-76TM diet (basal diet). There were no differences between the rats (diarrhea-free) fed xylitol and those fed the other carbohydrate sources in the lactate/pyruvate ratio in freeze clamped livers. Gluconeogenesis was measured from 10 mM of various precursors in isolated hepatocytes. Rats fed xylitol had: a) a lower rate of glucose production from lactate compared to rats fed the sucrose, glucose or basal diet; b) a lower rate of gluconeogenesis from xylitol than in rats fed either the basal or glucose diets, and c) equal capacity to produce glucose from pyruvate, glycerol, dihydroxyacetone or alanine as rats fed the other diets. Ethanol added to isolated hepatocyte incubations did not have a greater inhibitory effect on gluconeogenesis in xylitol-fed animals than in those fed the other carbohydrates. Results of this study indicate that dietary xylitol has little effect on the hepatic cytosolic redox state or on the ability of the rat liver to produce glucose in the presence of ethanol, but may have an effect on the rate of glucose production from some precursors.

Frozen dairy products were exposed to 40 kGy (4 Mrad) of cobalt-60 irradiation to sterilize them for the low microbial diets of immunosuppressed patients. In this study, the levels of thiamin, riboflavin, and vitamin B-12 were measured in Cheddar cheese, mozzarella cheese, yogurt bars, ice cream, and nonfat dry milk before and after irradiation at −78°C. There was no significant change in the levels of thiamin, riboflavin, or vitamin B-12 after irradiation. Samples of nonfat dry milk irradiated at three different temperatures (22°, 0 to 5°, or −78°C) sustained no significant loss of thiamin compared to levels in the nonirradiated fresh product. However, in irradiated mozzarella cheese, more thiamin was retained in products irradiated at −78°C than at 0 to 5°C. Irradiation of cheese, yogurt, ice cream, and nonfat dry milk at −78°C appeared to preserve the content of these three B vitamins.

Baguettes, cinnamon rolls, and chocolate chip cookies containing 0, 12.5% or 25% distillers’ dried grains with solubles (DDGS) from soft white winter wheat substituted for flour (w/w) were evaluated by an experienced panel to determine how much DDGS could successfully be incorporated into baked products. Panelists were unable to differentiate control cookies from those containing 12.5% DDGS. Attribute analyses of seven flavor and four texture traits were conducted, and overall acceptability was determined for products found to be different in their sensory properties. Both the control and experimental cinnamon rolls and chocolate chip cookies were rated as highly acceptable. The baguettes containing DDGS were found to be less acceptable than the control because of a stronger flavor and/or off-flavor.

The concentrations of thiamin, riboflavin, and vitamin B-12 in fermented grain products from white wheat, red wheat, corn, milo, and barely were assayed microbiologically. Vitmain B-12 was produced during the fermentation and was present at levels of 190-560 ng/100 g distillers’grain (dwb). the effects of five different drying methods and of pH prior to drying the fermented mash on the levels of these three vitamins were determined for distillers’dried grains produced from white wheat. Thiamin was most labile during liquefaction and to the drying process. Relatively large amounts of these three vitamins were lost if the soluble solids were not recovered in the finished product.

Orange, grapefruit, and grape juices and lemonade were assayed with three microorganisms to determine their value as dietary sources of folate. The authors comment on data in food tables and the need for revision to include the pattern as well as the total amount of food folates.

Distillers’dried grains with solubles (DDGS) from hard red wheat, soft white wheat and corn were used at a substitution level of 25% by weight for all-purpose flour in a conventional batter mix for fried fish. Fried fish nuggets (Alaskan pollock) prepared with a 25% DDGS batter either with or without a Japanese-style Panko breading were evaluated by a consumer panel (N = 2,546) for acceptability. All experimental products were rated as acceptable. There were no significant differences among the ratings of the products coated with batter only. However, products coated with batter and then with Panko breading were rated differently: the corn DDGS coated sample was rated higher than the control, while the white and red wheat DDGS coated samples received the lowest ratings. International color measurements of the dry batter mixes and the fried fish nuggets containing DDGS were darker than the controls.

Distillers’ dried grains with solubles (DDGS) were prepared from two cultivars of soft white winter wheat, a blend of red wheats and corn. DDGS made from the three whole wheat grains and corn contained, on a dry weight basis, 30–55% neutral detergent fiber (NDF), 10–14% acid detergent fiber, 7–9% crude fiber, and 2–4% lignin, an increase of 3–4 times over that contained in the unconverted whole grains. The significantly higher concentration of DDGS NDF isolated without sodium sulfite (vs with sodium sulfite) in the detergent solution was not due entirely to increased levels of residual protein.

Sprague-Dawley rats were fed diets containing up to 20% xylitol for 49 days. When the rats were fed a xylitol regimen intended to produce adaptation to xylitol, approximately half of the animals adapted to xylitol and remained free from diarrhea during the feeding regimen. The other half did not adapt to xylitol and developed severe and persistent diarrhea accompanied by large volumes of intestinal gas. These non-adapted rats had significantly higher levels of intestinal tract Clostridium perfringens (10(6)--10(11) organisms per gram intestinal contents) than did control rats fed a xylitol-free cornstarch diet (0-10(4) organisms per gram). Rats adapted to dietary xylitol did not have detectable levels of C. perfringens in the gastrointestinal tract.

The effect of alanine on pyruvate kinase was investigated in isolated rat hepatocytes. Alanine at concentrations of 2, 5 or 10 mM increased glucose production by 73% during the first 30 minutes of incubation of hepatocytes with 9 mM lactate and 1 mM pyruvate. After 3 minutes, the rate was not affected by the addition of alanine. A dose-response study showed that maximal stimulation of gluconeogenesis was achieved with 0.5 mM alanine. Using a method that measured recycling of phosphoenolpyruvate to pyruvate, it was found that in either fed or starved rats, alanine significantly decreased the percentage of phosphoenolpyruvate recycling when lactate was the substrate. However, no significant change in recycling was noted when either pyruvate or lactate-pyruvate was the glucose precursor. This study suggests that in intact liver cells, alanine has an inhibitory effect on pyruvate kinase. However, the inhibition is not of sufficient magnitude to completely account for the increase in glucose production when lactate is the substrate. It is hypothesized that alanine may have other effects on gluconeogenesis in addition to that of inhibiting pyruvate kinase.

The chemical composition of distillers' dried grains with solubles (DDGS) produced from two varieties of soft white wheat, a blend of hard red wheats, and corn was determined. On the average, the con- centration of protein increased 2.4-3.1 times, crude fiber 2.6-3.8 times, and lipid 1.4-2.4 times. The carbohydrate decreased by 3(X 50% in DDGS compared to the corresponding starting grain. The ash in DDGS was 3.8-7.8 times that of the original grain. Many of the differences (p < 0.05) in the concentration of lipid, protein, and crude fiber among the starting grains were also present in the DDGS prod- ucts. The whole grains were ground through an alpine pin mill, with 100% passing through a U.S. standard No. 16 sieve. The guidelines for enzyme addition provided by the supplier were followed (Anon., 1980). The enzymes Takatherm L-340 and Diazyme L-200 were used (Miles Laboratories, Elkhart, IN) for liquefaction and saccharifica- tion. An atmospheric batch liquefaction was conducted. A yeast in- oculum of approximately 5 million cells/ml (DADY, Universal Foods, Milwaukee, WI) was added. Fermentation was conducted at 27-30°C. After completion of fermentation, the ethanol was removed by evap- oration or distillation and the whole stillage was concentrated to ap- proximately 20% solids and drum-dried. Calculated ethanol yields were 0.37 L/Kg grain for the hard red wheat blend and Hill 81, 0.35 L/kg grain for corn and 0.30 L/kg grain for Tyee. This corresponded to 89%, 84%, and 63%, respectively, of the practical attainable yield of 0.60 L/kg starch for the different grain products. The grains and the finished DDGS products were analyzed for the following components according to AOAC (1984) methods: moisture, 14.004; ash, 14.006; crude lipid, 14.018; crude fiber, 7.071; and nitrogen, 14.026. The conversion factor of 6.25 was used to determine the protein for corn; 5.70 was used for wheat. Carbohydrate was calculated by difference. Representative samples from each batch were anlayzed at least three times. Data were analyzed by Student's t-test, one-way analysis of vari- ance and Duncan's New Multiple Range Test (Steel and Torrie, 1960).