Digestibility of Alternative Protein‐Rich Feedstuffs for Channel Catfish,Ictalurus punctatus

Apparent digestibility coefficients (ADCs) of amino acids, crude protein, gross energy, and dry matter of canola meal, corn gluten feed, fish offal meal, shrimp and fish offal meal, poultry by‐product meal, and hydrolyzed feather meal were determined for channel catfish, Ictalurus punctatus. Experimental diets contained 30% test ingredient, 69.5% casein‐based reference diet, and 0.5% chromic oxide. Groups of 20 fish (102.45 g) were fed the experimental diets twice a day at 3.5% body weight. Fecal samples were collected in triplicate daily at 0000 h and 0600 h after settlement into collection devices. Shrimp and fish offal meal and corn gluten feed presented significantly lower (P < 0.05) ADC for dry matter (59.5 and 39.3%) suggesting their low value as feedstuffs for catfish feeds. Although ADC values for crude protein were above 80% for all the test ingredients, amino acid digestibility varied significantly, except for histidine whose ADC remained constant regardless of the protein source. Lysine was the first limiting amino acid in most of the test ingredients, except in fish offal meal and poultry by‐product meal. Among the protein sources tested, only fish offal meal and poultry by‐product meal met channel catfish amino acid requirements for a 28% digestible protein grow‐out diet.     

Postprandial changes in serum amino acids of channel catfish fed diets containing different levels of protein and energy

Five purified diets were utilized to investigate the effect of varying protein and energy intake on postprandial changes in systemic serum amino acid levels of channel catfish (Ictalurus punctatus). The diets contained 25, 30 or 35% crude protein at one of three different energy levels. Systemic serum free amino acids and glucose were determined at 0, 2, 4, 8, 12 and 24 h after feeding each diet. In general, for each diet tested, most of the systemic serum free amino acid levels increased within 2 h after feeding, remained elevated for up to 12 h, and returned to fasting levels within 24 h after feeding. Varying the protein to energy ratios in the diets did not profoundly affect postprandial systemic serum free amino acid patterns. There was a significant positive correlation between the levels of systemic serum free essential amino acids and dietary levels. No such correlation was observed for non-essential amino acids. Serine and alanine were the most abundant free amino acids in catfish serum. Glutamic acid, glycine and proline remained relatively low throughout all treatments. A reciprocal relationship was observed between levels of glucose and total free amino acids in the serum.     

Amino Acid Profiles of Bivalve Mollusks from Beibu Gulf,China

Three bivalve mollusks—clam (Meretrix meretrix), oyster (Crassostrea rivularis), and paphia (Paphia papilionacea) from the Beibu Gulf, China—were analyzed for amino acid profile. Essential amino acids were used for nutritional quality evaluation, and free amino acids were used for taste impact evaluation. The amino acid compositions of the mollusks were quite similar; however, the contents of glycine, alanine, and tryptophan were different. Tryptophan seemed to be the limiting amino acid in clam and paphia meat protein. Oyster, on the other hand, seemed to be a source of high quality protein with well-balanced composition in essential amino acid. Glutamic acid, alanine, glycine, and arginine were the major taste-active amino acids found in the mollusks. According to the taste activity values of free amino acids, paphia was assumed to be the best savory food, followed by clam and oyster.     

Calculated Taste Activity Values and Umami Equivalences Explain Why Dried Sha-chong (Sipunculus nudus) Is a Valuable Condiment

ABSTRACT

Active nonvolatile taste active compounds—including free amino acids, flavor 5?-nucleotides, lactic acid, succinic acid, and four kinds of inorganic ions in dried Sha-chong (Sipunculus nudus)—were analyzed. The results were then used to calculate taste activity values (TAVs) and equivalent umami concentration (EUC) to evaluate their potential contributions to depth of flavor. Our results showed that the total free amino acid content of dried Sha-chong was 56.62 mg/g; glycine, arginine, and alanine as the major free amino acids, accounting for more than 76% of the total free amino acids; 5?-adenosine monophosphate (AMP) and 5?-inosine monophosphate (IMP) were the main flavor 5?-nucleotides (128.8 and 121.0 mg/100 g); guanosine monophosphate (GMP) was present in a small amount, only 14.6 mg/100 g. Eight amino acids—especially Gly, Arg, and Ala,—three flavor 5?-nucleotides, succinic acid, sodium, potassium, phosphate, and chloride ions were of high TAV greater than 1. The EUC of dried Sha-chong was 49.12 g MSG/100 g, which meant that the dried Sha-chong has a strong umami taste and is suitable for use as umami condiment.     

野生与养殖黄颡鱼鱼卵的营养成分比较

以贵州省铜仁锦江河漾头河段野生黄颡鱼鱼卵和同一区域内养殖黄颡鱼鱼卵为研究对象,采用常规生化方法测定了野生与养殖黄颡鱼鱼卵氨基酸组成和含量,采用气相色谱技术检测了野生与养殖黄颡鱼鱼卵脂肪酸组成和含量。氨基酸测定结果表明,野生黄颡鱼鱼卵的氨基酸总量、必需氨基酸总量、鲜味氨基酸总量显著低于养殖黄颡鱼鱼卵(P0.05),第一限制性氨基酸均为甲硫氨酸+半胱氨酸,必需氨基酸指数分别为55.60和59.12。脂肪酸测定结果表明,野生黄颡鱼鱼卵的饱和脂肪酸总量极显著高于养殖黄颡鱼鱼卵(P0.01),单不饱和脂肪酸总量二者差异不显著(P0.05),多不饱和脂肪酸总量极显著低于养殖黄颡鱼鱼卵(P0.01),但野生黄颡鱼鱼卵的二十碳五烯酸和二十二碳六烯酸的总量极显著高于养殖黄颡鱼鱼卵(P0.01),野生黄颡鱼鱼卵的n-3系列的多不饱和脂肪酸总量与n-6系列不饱和脂肪酸总量的比值(1.57)低于养殖黄颡鱼鱼卵(1.80)。     

Arginine and phenylalanine requirement of juvenile silver perch Bidyanus bidyanus and validation of the use of body amino acid composition for estimating individual amino acid requirements

An experiment was conducted in a closed system to quantify the arginine requirement of juvenile silver perch Bidyanus bidyanus . Five experimental diets were formulated to contain 40% crude protein with five graded levels of arginine. The diets contained casein and gelatine as protein sources supplemented with crystalline L -amino acids to simulate the reference amino acid profile (except for arginine) of silver perch tissue protein. The experiment lasted 12 weeks and, based on growth data using broken-line analysis, the arginine requirement of juvenile silver perch was found to be 2.7 g 100 g⁻¹ dry diet (or 6.8% of protein).
Based on whole-body amino acid composition, A/E ratios (essential amino acid/total essential amino acids + (cystine + tyrosine) × 1000) were estimated. Using the experimentally determined requirement for arginine and A/E ratios, the phenylalanine requirement of silver perch was predicted to be 5.5 g 100 g⁻¹ protein. Another feeding trial was conducted to determine the phenylalanine require-ment of silver perch using a series of diets with various amounts of phenylalanine and a protocol similar to the previous one. It was found that the experimentally determined phenylalanine requirement of juvenile perch was similar to that predicted. The A/E ratios have been hitherto utilized for the estimation of essential amino acid requirements in three salmonids, common carp and channel catfish: the present findings extend the validity of the method to other fish species.     

Comparison of the amino acid contents of roe, whole body and muscle tissue and their A/E ratios for largemouth bass Micropterus salmoides (Lacepéde, 1802)

Nutritional amino acid requirements of varying size classes of largemouth bass were estimated using A/E ratios. Nutrient and amino acid contents of roe and carcass of the different size classes were determined and compared to results of selected, classic works related to the concept of ideal protein and relationship between the contents of individual, essential amino acids and the total contents of essential amino acids – A/E ratios. Protein content in the roes of the largemouth bass were higher in comparison to the carcass, but the content of lipids of the roes and of the carcass didn’t present significant difference (P<0.05). Largemouth bass showed higher muscle protein content in comparison to other species. Although some authors report variation in the contents of some amino acids in the carcass of selected species, differences observed in this study regarding carcass amino acid contents of tilapia, speckled catfish and largemouth bass were not significant (P<0.05), values of the ratio A/E followed the same trend. Results, herein presented, indicate that the amino acid profile of largemouth bass could be used as complementary tool for balancing amino acids in formulated feed for the species, and in the validation of amino acid requirements determined in performance studies.     

Protein Hydrolysate from Visceral Waste Proteins of Bolti Fish (Tilapia nilotica): Chemical and Nutritional Variations as Affected by Processing pHs and Time of Hydrolysis

The main objective of the current work was to evaluate the proximate chemical composition and nutritional quality of amino acids of protein hydrolysates from viscera of Tilapia nilotica fish. The results of amino acid composition showed that all hydrolysates contained sufficient and/or excessive amounts of both essential and nonessential amino acids, with appreciable values of essential amino acid/nonessential amino acid ratio (0.77 to 1.59) and essential amino acid/total amino acid ratio (43.35 to 61.35). All protein hydrolysates had a high content of the flavor enhancer amino acids. The lowest values of essential amino acids were found for phenylalanine and methionine with chemical scores ranging from 0.04 to 0.77 and 0.09 to 1.06, respectively, except for 18 h hydrolysates. The protein efficiency ratio had values greatly exceeding 2.0, which is considered a high quality. On the other hand, the levels of sugar and ash contents ranged from 2.69 to 3.32 g L^?1 and 0.48 to 2.1%, respectively, with 9.2 to 14% dry matter. Mineral composition showed that sufficient amounts of calcium, sodium, potassium, magnesium, and iron were present. The results suggest that the studied hydrolysates are appropriate for use in balanced human or animal diets.     

Effect of sex and protein level on the intermediary metabolism,growth, deposition of nutrients and profile of volatile compounds of silver catfish (Rhamdia quelen)

This study aimed at evaluating the intermediary metabolism, growth, nutritional deposition and volatile compounds of fillet of female and male silver catfish created in cages having commercial diets at two levels of crude protein. A total of 1,200 silver catfish were randomly distributed in 12 cages with initial weight of 130.05 ± 0.14 g and visually sexed. Commercial diets with 280 g/kg and 320 g/kg of crude protein were offered twice a day in the amount of 30 g/kg their biomass/day, for 90 days. At the end of the experimental period, biometry was performed to collect data, blood and tissue for later determination of plasma metabolites, hepatic metabolites, digestive enzymes, volatile compounds, deposition of nutrients and calculation of growth variables. There were metabolic differences due to the sex of silver catfish, reflecting greater productive efficiency on the females. For the plasma metabolites, in male, there were higher values of triglycerides and free amino acids than in female. For hepatic glucose, males fed with diet containing 280 g/kg of crude protein showed higher values. For protein and free amino acids, the interaction between males that received 320 g/kg of crude protein was higher. In males, there were higher values of AST and hepatic glycogen than in females. In turn, hepatic ammonia was higher in females. There was greater activity of acid protease enzymes and trypsin in the silver catfish that received diets containing 320 g/kg of crude protein. Regardless of sex, in this cultivation phase, diets with 320 g/kg of crude protein provided better performance to silver catfish. The profile of volatile compounds suggests mild odour for the fillet of silver catfish, which can be a competitive advantage of the species.     

Biochemical Properties and Stability of Antioxidative Activity of Half-Fin Anchovy (Setipinna taty) Fermented Product

The aim of this work was to investigate the biochemical properties of fermented product of half-fin anchovy (HAFP; Setipinna taty) made by Natto bacillus fermentation—including molecular weight distribution, amino acid composition, solubility, foaming, and emulsifying profiles. Furthermore, the influences of thermal processing, pH alteration, and in vitro simulated gastric and intestinal digestion on the antioxidative stability of HAFP in terms of the scavenging 1,1-diphenyl-2-picrylhydrazayl (DPPH) radical were evaluated. Results showed that HAFP contained small peptides (< 1,500 Da) and free amino acids. The amounts of essential amino acids and flavor amino acids were 155.219 and 178.636 mg/g of dry HAFP, respectively. Moreover, HAFP contained high levels of antioxidative and hydrophobic amino acids. In suitable pH values, HAFP exhibited good solubility, foaming, and emulsifying properties. The antioxidative activity of HAFP on the scavenging DPPH radical increased after thermal processing. Furthermore, the DPPH radical scavenging activity of HAFP was enhanced slightly or dramatically after being treated under pH values from 3 to 6, or in vitro simulated gastric and intestinal digestion. It can be concluded that HAFP could have potential application in foods as a natural antioxidative ingredient.     

美国红鱼的营养成分分析与评价

测定了养殖红鱼肌肉及鱼体中的蛋白质、脂类、灰分等生化组成，并计算了其比能值，分析了肌肉蛋白质中17种常见氨基酸的含量。结果表明，红鱼肌肉中脂类含量低，属高蛋白低脂肪、低比能值鱼类，肌肉氨基酸含量同其他经济鱼类相比，属中等水平。必需氨基酸的含量低且缺含硫氨基酸，为非完全蛋白。其呈味氨基酸百分含量较其他鱼类高。     

Estimating Amino Acid Requirement of Brazilian Freshwater Fish from Muscle Amino Acid Profile

Information on nutritional requirement of some Brazilian farmed fish species, especially essential amino acids (EAA) requirements, is scarce. The estimation of amino acids requirements based on amino acid composition of fish is a fast and reliable alternative. Matrinxa, Brycon amazonicus, and curimbata, Prochilodus lineatus, are two important Brazilian fish with potential for aquaculture. The objective of the present study was to estimate amino acid requirements of these species and analyze similarities among amino acid composition of different fish species by cluster analysis. To estimate amino acid requirement, the following formula was used: amino acid requirement = [(amount of an individual amino acid in fish muscle tissue) × (average totalEAA requirement among channel catfish, Ictalurus punctatus, Nile tilapia, Oreochromis niloticus, and common carp, Cyprinus carpio)]/(average fish muscle totalEAA). Most values found lie within the range of requirements determined for other omnivorous fish species, in exception of leucine requirement estimated for both species, and arginine requirement estimated for matrinxa alone. Rather than writing off the need for regular dose–response assays under the ideal protein concept to determine EAA requirements of curimbata and matrinxa, results set solid base for the study of tropical species dietary amino acids requirements.     

Changes in tissue free amino acid concentrations in Atlantic salmon, Salmo salar L., after consumption of a low ration

Atlantic salmon (Salmo salar L.) with an average weight of 411 ± 16 g were fed after a period of 7 days without food and the free amino acid concentrations in the pylorus, liver and white muscle measured before and at 3, 6, 9, 15 and 24 h after feeding. There were few significant postprandial changes in tissue free amino acid concentrations. In the white muscle, concentrations of six indispensable amino acids were significantly (p < 0.05) higher after 9 (Ile, Leu, Phe, Thr) or 15 h (Val, Met). Individual feed intake was measured and there were significant positive correlations between amino acid intake and amino acid concentrations in white muscle free pools for total amino acids (p < 0.001), total indispensable amino acids (p < 0.001) and individual indispensable amino acids (Ile, Leu, Lys, Met, Phe, Val). These relationships were due to relatively low feed intake (0.28% body weight) that followed 7 days without feeding. The indispensable amino acid profile of the white muscle free pool was compared with that of standard proteins (the feed, whole body and white muscle), as well as with indispensable amino acids requirements. At different times one of two indispensable amino acids, Phe (at 0, 3, 6, 9, 15 h after feeding) or Trp (at 24 h after feeding), was present at the lowest relative concentrations compared to the other indispensable amino acids. This showed that although changes in tissue free amino acid concentrations following feeding were small the amino acid profile (relative concentrations) in the white muscle free pool changed. It is proposed that the lowest relative concentration of an indispensable amino acid in the white muscle free pool should be considered in relation to its potential to limit the efficiency of protein synthesis and retention.     

An Estimate of the Dietary Lysine Requirement of Juvenile Red Drum Sciaenops ocellatus

Quadruplicate groups of juvenile red drum (initial mean weight 2.7 g; 20 fish per replicate) were fed experimental diets containing 35% crude protein and graded levels of lysine for eight weeks. Lysine concentration in the basal diet was 1.2% and was supplied by a combination of peanut meal and shrimp-head meal. The basal diet was supplemented with lysine-HCI to provide 1.6, 2.0, and 2.4% lysine. Each of these diets contained an essential amino acid (EAA) premix. Two additional diets were formulated to contain 1.2 and 2.4% lysine without the EAA premix. Weight gain and feed efficiency (FE) data indicated between 1.2 and 1.6% dietary lysine was adequate. However, serum lysine concentrations indicated 1.6–2.0% lysine was required. Fish fed 1.2 or 2.4% lysine, without the EAA premix, exhibited reduced weight gain and feed efficiency. Results indicated that red drum were able to utilize crystalline amino acids when incorporated into diets containing intact protein and, when lysine was adequate, the proteins were deficient in at least one other essential amino acid. It is recommended that a dietary lysine level of 5.7% of the dietary protein be used in formulating red drum diets.     

An Estimate of the Dietary Lysine Requirement of Juvenile Red Drum Sciaenops ocellatus

Quadruplicate groups of juvenile red drum (initial mean weight 2.7 g; 20 fish per replicate) were fed experimental diets containing 35% crude protein and graded levels of lysine for eight weeks. Lysine concentration in the basal diet was 1.2% and was supplied by a combination of peanut meal and shrimp-head meal. The basal diet was supplemented with lysine-HCl to provide 1.6, 2.0, and 2.4% lysine. Each of these diets contained an essential amino acid (EAA) premix. Two additional diets were formulated to contain 1.2 and 2.4% lysine without the EAA premix. Weight gain and feed efficiency (FE) data indicated between 1.2 and 1.6% dietary lysine was adequate. However, serum lysine concentrations indicated 1.6-2.0% lysine was required. Fish fed 1.2 or 2.4% lysine, without the EAA premix, exhibited reduced weight gain and feed efficiency. Results indicated that red drum were able to utilize crystalline amino acids when incorporated into diets containing intact protein and, when lysine was adequate, the proteins were deficient in at least one other essential amino acid. It is recommended that a dietary lysine level of 5.7% of the dietary protein be used in formulating red drum diets.     

Poor utilization of dietary free amino acids by white sturgeon

Three separate experiments were conducted to investigate the utilization of dietary free amino acids by white sturgeon,Acipenser transmontanus. In the first experiment, sturgeon were fed for 8 weeks with isoenergetic and isonitrogenous diets containing either intact protein, an amino acid mixture, or a neutralized amino acid mixture of similar composition. Sturgeon fed the two amino acid diets grew significantly (p<0.05) less, mainly because of reduced feed intake. In the second experiment, postprandial changes in plasma free amino acids of sturgeon force-fed the above diets were monitored at 2, 4, 6, 8, 12, and 24 h Total plasma amino acids in sturgeon force-fed the intact protein diet showed a gradual increase and reached peak levels at 8 h. In contrast, plasma amino acids of fish force-fed the amino acid diets showed a rapid increase and reached maximal levels at 2 h. In the third experiment, free amino acid diets showed a urine of sturgeon force-fed the three diets was monitored at 4, 8, 12, 16, 20, and 24 h. In all dietary groups, peak excretion of indispensable amino acids was detected at 8 h after feeding but with significantly higher levels from fish force-fed the amino acid diets. Sturgeon force-fed the neutralized amino acid diet excreted 35% less amino acids compared to fish force-fed the non-neutralized diet. Sturgeon force-fed the intact protein diet excreted significantly higher amounts of ammonia. Under amino acid feeding conditions, sturgeon excreted more amino acids in its urine, but the urinary excretion of amino acids was not a major route in dealing with the rapid absorption of dietary free amino acids.     

兰州鲇肌肉营养成分分析及营养价值评价

利用常规肌肉营养测试方法测定、分析了体质量(278.6±26.7)g兰州鲇肌肉营养成分.试验结果表明,兰州鲇肌肉(鲜样)中各成分的质量分数分别为:水分77.63%,蛋白质17.43%,脂肪3.46%,灰分1.33%,无氮浸出物0.15%.肌肉中含有18种氨基酸,总量为78.28%(质量分数,脱脂干样),其中人体必需氨基酸总量是37.15%,占氨基酸总量的47.46%,必需氨基酸指数为72.15,必需氨基酸的构成比例基本符合FAO/WHO的标准;鲜味氨基酸含量为31.11%,占氨基酸总量的39.74%.脂肪酸中多不饱和脂肪酸(PUFA)占总脂肪酸的33.39%,二十碳五烯酸(EPA)与二十二碳六烯酸(DHA)的含量分别为5.12%、7.65%.微量元素比值合理.     

Effects of feeding diets containing an imbalance of branched-chain amino acids on fingerling channel catfish

A series of studies was conducted to investigate the effects of feeding diets imbalanced with respect to branched-chain amino acids on channel catfish. Basal diets contained casein and gelatin supplemented with crystalline L-amino acids to correspond to the amino acid pattern found in 24% whole egg protein except for the branched-chain amino acids. Basal diets were formulated to be deficient in either leucine, isoleucine, or valine. Excess levels of either leucine, isoleucine, or valine were added to the appropriate basal diet. Growth and feed efficiency data demonstrate that excess leucine depressed growth of fish fed diets deficient in isoleucine or valine, but not in diets adequate in branched-chain amino acids. The deleterious effects of excess leucine could be reversed by supplementation with the deficient amino acid, but not by the other branched-chain amino acid. Growth was also depressed in fish fed excess isoleucine but not valine in leucine-deficient diets. Serum levels of isoleucine and valine suggest that leucine may control the tissue uptake of these amino acids in the channel catfish.     

Tail Muscle Free Amino Acid Concentration of Pacific White Shrimp,Litopenaeus vannamei,Fed Diets Containing Protein‐bound versus Crystalline Amino Acids

Tail muscle tissue free amino acids (FAA) concentration is reported for subadult (4.3 g) Litopenaeus vannamei fed diets containing only protein‐bound amino acids, crystalline lysine as a supplement to protein‐bound lysine, and only crystalline amino acids (CAA). FAA were determined in shrimp at 0.00, 0.25, 0.5, 1, 2, 4, and 8 h postfeeding. Highest total tissue concentrations of essential amino acids and individual amino acids were typically observed 4 h postfeeding for shrimp fed intact and crystalline lysine‐supplemented feeds. Those shrimp offered diets containing only CAA showed no tissue maxima. Similar uptake patterns for lysine shown by shrimp fed the intact and crystalline lysine‐supplemented diet indicate the potential use of small amounts of crystalline lysine in shrimp feeds.     

凡纳滨对虾虾肉和虾头中风味物质的比较

为充分利用和开发虾头资源从而提高对虾经济附加值,同时探讨熟制对虾类风味产生的影响,以凡纳滨对虾生、熟虾肉和生、熟虾头为研究对象,利用氨基酸自动分析仪、高效液相色谱法(HPLC)和气相色谱—质谱联用法(GC/MS)分别对氨基酸、呈味核苷酸、挥发性物质和营养成分的含量进行检测。结果显示,虾头中的蛋白质含量显著高于虾肉,熟制会使粗蛋白的含量下降,但变化差异不显著;虾头中必需氨基酸(EAA)含量和游离氨基酸总量(TFAA)显著高于虾肉,二者主要游离氨基酸种类相同(甘氨酸、精氨酸、脯氨酸、丙氨酸和苏氨酸),对虾头呈味有贡献的游离氨基酸种类更丰富;虾头和虾肉中肌苷酸(IMP)含量最高,腺苷酸(AMP)次之,二者的味道强度值(TAV)均大于1,对鲜味贡献较大。GC/MS共检测出88种挥发性物质,虾肉和虾头中分别特有29种和18种,挥发性物质种类和含量的差异形成虾肉和虾头的特殊气味,熟制产生大量的醛类、酮类和芳香类物质。研究表明,凡纳滨对虾虾肉和虾头中营养物质、游离氨基酸、呈味核苷酸、挥发性物质的组成和含量对风味的贡献存在显著差异。