十七种蛋白质饲料原料中必需氨基酸含量的聚类分析

利用12种必需氨基酸含量的不同，对大豆、大豆饼、大豆粕、棉籽饼、棉籽粕、菜籽饼、菜籽粕、花生仁饼、花生仁粕、血粉、羽毛粉、啤酒酵母、鱼粉(国产)、鱼粉(进口)、粉浆蛋白、皮革粉、肉骨粉进行了聚类分析，为饲料原料之间的相互替代提供了一条新的思路。

Enzymatic Hydrolysis of Defatted Mackerel Protein with Low Bitter Taste

Ultrasound-assisted solvent extraction was confirmed as a novel,effective method for separating lipid from mackerel pro-tein,resulting in a degreasing rate (DR) of 95% and a nitrogen recovery (NR) of 88.6%.To obtain protein hydrolysates with high ni-trogen recovery and low bitter taste,enzymatic hydrolysis was performed using eight commercially available proteases.It turned out that the optimum enzyme was the ‘Mixed enzymes for animal proteolysis’.An enzyme dosage of 4%,a temperature of 50℃,and a hydrolysis time of 300 min were found to be the optimum conditions to obtain high NR (84.28%) and degree of hydrolysis (DH,16.18%) by orthogonal experiments.Glutamic acid was the most abundant amino acid of MDP (defatted mackerel protein) and MDPH (defatted mackerel protein hydrolysates).Compared with the FAO/WHO reference protein,the essential amino acid chemical scores (CS) were greater than 1.0 (1.0 1.7) in MDPH,which is reflective of high nutritional value.This,coupled with the light color and slight fishy odor,indicates that MDPH would potentially have a wide range of applications such as nutritional additives,functional ingredients,and so on.

Comparative study of the nutritional composition and toxic elements of farmed and wild Chanodichthys mongolicus

Information of the difference in quality between farmed and wild fish is central to better ensuring fish products produced in aquaculture meet regulatory and consumer requirements. Proximate composition, amino acid and fatty acid profiles, and toxic elements contents of fanned and wild Chanodichthys mongolicus were established and compared. Significantly higher crude protein content while lower moisture content in farmed fish compared to wild fish were observed （P〈0.05）. The percentages of total amino acids （TAA）, total essential amino acids （TEAA）, total non-essential amino acids （TNEAA） and total delicious amino acids （TDAA） in farmed fish were all significantly higher than those in the wild equivalent （P〈0.05）. Compared to the FAO/WHO recommended reference values, the ratios of TEAA/ TAA （39.84%o-40.33%） were comparable to 40% and TEAA / TNEAA （66.22%-67.60%） were above 60%. Fatty acid profiles in both farmed and wild C. mongolicus were dominated by monounsaturated fatty acid （MUFA）, with farmed fish contained much more MUFA content compared to wild counterpart （P〈0.05）. Notably, wild fish exhibited significantly higher levels of total polyunsaturated fatty acid （PUFA） including eicosapentaenoic acid （EPA） and docosahexaenoic acid （DHA） than fanned fish （P〈0.05）. The EPA （C20：503） and linoleic acid （C18：206） were the predominant PUFA in wild and farmed C. mongolicus, respectively. Moreover, farmed fish displayed an overall lower toxic element levels （As, Cd, Pb and Hg） in comparison with wild fish, and both were far lower than the established limit standard. In conclusion, our results suggest that the nutritional quality of fanned C. mongolicus was inferior to their wild counterpart with respect to fatty acids nutrition, and therefore further studies should focus on the improving C. mongolicus diet in order to enhance the overall nutritional composition.

Seasonal biochemical changes in composition of body wall tissues of sea cucumber Apostichopus japonicus

Seasonal variation in proximate, amino acid and fatty acid composition of the body wall of sea cucumber Apostichopus japonicus was evaluated. The proximate composition, except for ash content, changed significantly among seasons （P〈0.05）. Alanine, glycine, glutamic acid and asparagic acid were the most abundant amino acids. Total amino acid and essential amino acid contents both varied clearly with seasons （P〈0.05）. 16：0 and 16：1n7 were the primary saturated fatty acid （SFA） and monounsaturated fatty acid （MUFA） respectively for all months. EPA （20：5n-3）, AA （20：4n-6） and DHA （22：6n-3） were the major polyunsaturated fatty acids （PUFA）. The proportions of SFA and PUFA yielded significant seasonal variations （P〈0.001）, but MUFA did not changed significantly. The results indicated that the biochemical compositions of the body wall in A. japonieus were significantly influenced by seasons and that the body wall tissue is an excellent source of protein, MUFA and n-3 PUFA for humans.

Comparison in nutritional quality between wild and cultured cuttlefish Sepia pharaonis

In this study, the proximate composition and the amino and fatty acid profiles of shrimp Litopenaeus vannamei （prey） and wild and cultured cuttlefish Sepiapharaonis （the latter fed the prey） were determined and compared with FAO/WHO recommendations. The resulting scores for isoleucine, phenylalanine＋tyrosine, histidine, lysine, threonine, and tryptophan in cultured cuttlefish were 〉150. The ratio of EAA （essential amino acids）/nonessential amino acids in cultured cuttlefish （0.82） was higher than in the wild form （0.80）. All EAA amino acid scores for cultured cuttlefish were higher than their wild counterparts, except for histidine and tryptophan. Both groups of cuttlefish possessed similar saturated fatty acid content, with the cultured containing much more total （E） monounsaturated fatty acids, E n-6 polyunsaturated fatty acids （PUFA）, and eicosapentaenoic acid （C20：5 n-3） but less E n-3 PUFA, arachidonic acid （C20：4 n-6）, and docosahexaenoic acid （C22：6 n-3） than their wild counterparts. Therefore, the present results suggest that these cultured cuttlefish were better than the wild form for human health. Notably, these results also indicate that the nutritional composition of these cuttlefish might have been significantly affected by diet.

Body composition and compensatory growth in Nile tilapia Oreochromis niloticus under different feeding intervals

We investigated the growth and body composition of Nile tilapia under five different feeding regimes. A control group was fed to satiation twice daily for 185 days; four treatment groups were fed at intervals of 2, 3, 4 or 7 days(dietary ‘restricted' period, days 0–80) and then fed to satiation(‘refeeding' period, days 80–185). Compensatory growth in weight and length of the feed-restricted groups was observed during the refeeding period. However, the growth of none of the restricted groups caught up with that of the control group over the experimental period. Feed intake upon refeeding increased with the duration of deprivation. There were no significant differences in feed efficiency between the restricted and control groups during the refeeding stage, suggesting that hyperphagia was the mechanism responsible for the increased growth rates during this period. Tilapia preferentially used n-3 polyunsaturated fatty acids and nonessential amino acids during the restricted-feeding period. Higher production was achieved by higher feed consumption. We suggest that if attainment of market size in minimum time is required, fish should be consistently fed to satiation, while taking care to avoid the possible negative consequences of overfeeding.

Biochemical composition of the alligator pipefish, Syngnathoides biaculeatus (Bloch, 1785)

Considering the economic importance in traditional Chinese medicine(TCM) and lack of baseline information, we evaluated the proximate composition, fatty acid and amino acid profiles, trace element content and C:N ratio in the alligator pipefish, Syngnathoides biaculeatus. Amongst proximate principals, a crude protein formed the major biochemical component((58.9±2.2)% dry weight). Mean percent concentrations(dry weight) of other components such as a total lipid(TL), ash and nitrogen-free extract measured were,(1.8±0.2)%,(19.2±2.2)% and(20.1±0.45)%, respectively. The fatty acid profile revealed the presence of 27 saturated fatty acids(SFA) with 13 straight-chained and 14 branched-chained, 28 unsaturated fatty acids(UFA) with 14 monounsaturated and 14 polyunsaturated and nine other minor fatty acids. Mean percent contributions of total SFAs and UFAs to TL were found to be(55.41±0.24)% and(44.05±0.25)%, respectively. Altogether, 16 dif ferent amino acids with an equal number of essential(EAA) and non-essential(NAA) ones were identified. Percent contributions by EAA and NAA to the total amino acid content were 38.11% and 61.89%, respectively. Trace metal concentrations in S. biaculeatus were generally low and their distribution followed the order, Mg>Fe>Zn>Mn>Cu>Cr>Ni>Hg>Co. The C:N ratio was(4.37±0.04)%. The profile of major biochemical constituents in alligator pipefish, S. biaculeatus revealed its potential use in TCM as well as a nutritional diet for human consumption. The results of the study would also form the basis for formulation and optimization of diets for the culture of S. biaculeatus.

Grasshoppers Sphenarium Purpurascens Ch Source of Proteins and Essential Amino Acids

Protein malnutrition is quite common worldwide; its deficiency has adverse effects in all organs. Edible insect＇s traditional cultural food, commonly consumed in rural communities, now intake is also being incorporated in some countries. Grasshoppers comprise proteins, the building blocks of AA （amino acids）, that are one of the five classes of complex biomolecules found in cells and tissues that play an important role in human metabolism and nutrition. This research was conducted to determine proximal composition of Sphenarium purpurascens Ch, grasshoppers, focused on proteins and AA. Sampling was performed during autumn, 2013, in Oaxaca State. Dry raw adult insects were ground and proceeded to macro molecules proximal analysis, protein by Kjeldahl AOAC （Association of Official Analytical Chemists） method and essential AA in a Beckman 6300 equipment. Obtained data were： total proteins 71.56%; lipids 8.14%; minerals 3.52%; fiber 7.48%; soluble carbohydrates 9.30%. Essential AA （mg/16 g-N）： isoleucine 4.5; leucine 8.1; lysine 5.4; methionine ＋ cysteine 5.1; phenylalanine ＋ tyrosine 8.5; threonine 3.5; tryptophan 0.6; valine 5.5. Sphenarium purpurascens Ch, Grasshoppers represent a good source of proteins and essential AA that can grow almost everywhere, available mostly all year round and affordable to all social groups, thus being a good option to improve human health.

Effect of High Digestible Essential Amino Acids on Weight Gains and Carcass Compositions of Laying Hens

The objective of this study was to evaluate the effect of high digestible essential amino acids （DEAA） on weight gains and carcass compositions of laying hens. Three hundred and sixty lsa Brown hens in five replications per treatment （12 birds/replicate） were used. Six experimental diets which contained of treatment 1 （negative control） as the conventional layer diet are recommended by NRC （1994） while another dietary treatments; treatments 2 （positive control）, 3, 4, 5 and 6 were formulated to meet 100%, 110%, 120%, 130% and 140% of Standard Ileal Digestible Lysine Levels （SIDLL） without crude protein minimum, while methionine （Met）, threonine （Thre） and tryptophan （Tryp） as related by Ideal Protein Concept （IPC） which suggested by NRC （1994） and INRA （2004）. However, metabolizable energy （ME）, calcium and available phosphorus （Avai P） levels of all experimental diets were meet requirement as recommended by NRC （1994）. The experiment was assigned in CRD and laying hens fed dietary treatments from 28 to 44 weeks of age and cage was the experimental unit （3 hens/cage）. The result shown that percentages of thigh （TP）, feet （FP）, drumstick （DP）, heart （HP）, liver （LP） and gizzard （GP） were not affected by dietary treatment. However, weight gains （WG） and percentage of dressed weight （DWP）, eviscerate weight （EWP） and breast （BP） were increased （P 〈 0.05） and abdominal fat was reduced （P 〈 0.05） when birds fad diets containing 130% of SIDLL as compared with control group and another dietary treatments, when increasing the DEAA levels upper to 130% of SIDLL. The result indicated that diets formulated without crude protein minimum and increased DEAA resulted in increasing the efficiency of converting metabolizable energy （ME） to net energy （NE） for increasing weight gain and improved meat products while fat deposition in carcass composition was reduced.

Amino Acid and Mineral Composition of Meat from Free-range Broilers Reared on Alpine Steppe

An increasing number of consumers demanding health foods have favoured poultry meat from natural production system. Amino acid and mineral elements are essential nutrient, required for numerous metabolic functions, which are provided partly by the poultry. The objective of this study was to evaluate amino acid and mineral composition in meat of free-range broilers fed on grasshoppers on alpine rangeland in the Tibetan Plateau. Eighty, 28-day-old Qinjiaoma male broilers were introduced into a rangeland where there was a dense population of grasshoppers （treatment GC）. Control chicken were reared under intensive condition and given a maize-soybean diet （treatment CC）. At 91 days of age, 24 birds from each treatment were slaughtered. Fresh breast meats were packaged and refrigerated for determination. The results indicated that dietary grasshoppers and rearing condition significantly （P 〈 0.05） affected some amino acid and mineral elements composition. Aspartic, arginine, threonine, isoleucine and lysine were higher in the muscles from GC than those from CC, and the similar trend were also found in the content of total amino acid and essential amino acid. While tryptophan and methionine were lower （P 〈 0.05） in meat from GC than that from CC. Effect of diets and rearing condition on mineral elements was also observed, the concentration of sodium, phosphorus and iron were higher （P 〈 0.05） in muscle from GC, while calcium was higher in muscle from CC. In conclusion, the meat in free-range broilers fed on grasshoppers has the richer amino acid and mineral elements.

Effect of Raw Material for Distillers Grains Production on Protein Quality for Ruminants

The present experiment was focused on quality of dry distillers＇ grains with solubles （DDGS） produced from corn （DDGSc）, wheat （DDGSw）, triticale （DDGSt）, and wet distillers grains from corn （WDGc） for ruminants. The products were tested for dry matter （DM）, crude protein （CP）, neutral detergent fibre （NDF）, acid detergent fibre （ADF） acid detergent insoluble nitrogen （NIAD）, amino acid （AA） profile, CP degradability and intestinal digestibility （ID） of rumen undegraded protein （RUP）. The average content of CP （g/kg DM） ranged from 289.9 （DDGSc） to 356.9 （DDGSw）. The highest content of essential AA was in WDGc （440.1 g/160g N） followed with DDGSc. The most variable was the content of Lys in DDGSw （from 13.69 to 22.79 g/160 g N）. The NIAD was found the highest for DDGSw （from 16.8% to 36.2%）, effective CP degradability was only 50.2% and ID of RUP 82.2%, total essential AA 81.2%, Lys 77.69% and Met 81.4%. Lys was generally the least digestible AA. The ruminally degradable CP fraction was in the range from 52.6% to 70.2% for DDGSc. ID of total and essential by-pass AA was very high 96.2% and 96.1%, Lysine 90.9% and Methionine 96.7%. From these data it can be concluded that DDGS from grains are a good source of protein for ruminants.

Nutritional Composition and Topoisomerase Inhibitor Activity of Ethnomedicinal Marine Mollusk Nerita albicilla

DNA topoisomerases （topo） I and II are molecular targets of several potent anticancer agents. Thus, inhibitors of these enzymes are potential candidates for anticancer development. Traditionally, Nerita albicilla had been used in Kei Island, Southern Maluku, Indonesia to treat liver disease including cancer. The paper reports on the chemical composition ofNerita albicilla and its topo I inhibitor ofhexane, ethyl acetate and methanol extracts. Topoisomerase-I inhibitor activity was determined using the method reported by TopoGEN. The proximate analysis described that Nerita albicilla dried powder contained 12.45% ± 0.05% moisture; 9.17% ± 0.03% ash; 62.05% ± 0.10% protein; 5.58% ± 0.08% fat; 6.60% ± 0.02% crude fiber and 4.15% ± 0.24% carbohydrate （by difference）. Furthermore, the protein consisted of 11 essential amino acids and six non-essential amino acids. It contained significant amount of branched-chain amino acids （BCAA） valine, leucine, isoleucine （a total of 187.8 mg g-1 protein） and lower content of aromatic amino acids phenylalanine, tyrosine and histidine （a total of 111.26 mg .g-1 protein）. The protein score was 92.2. The yield of hexane, ethyl acetate and methanol extracts ofNerita albicilla were 2.05% ± 0.05%, 1.56% ± 0.06% and 6.99% ± 0.14%, respectively. All extracts showed topoisomerase-I inhibitor activities. Minimum inhibitory concentration （MIC） of methanol extract was 2.50 ug mL-1. Chemical screening of the extracts showed that they contained steroidal and alkaloid compounds. The investigation revealed that Nerita albicilla contains active compounds that could be potential for nutraceutical or pharmaceutical development.

Effect of germination on the nutritional quality of Pearl millet

Changes in proximate composition, trypsin inhibitor activity, phytic acid, tannins, in vitro protein digestibility and amino acids content of Pearl millet were investigated after germination for 5 days. Germination significantly increased protein content of pearl millet, with a parallel decrease in lipid and carbohydrates. Trypsin inhibitor activity and the phytic acid content showed significant decrease whereas tannin content increased after 5 days germination. In vitro protein digestibility （IVPD） was significantly decreased with germination, suggesting that tannins may be responsible for enzymes inhibition. Amino acid analysis revealed significant increase in essential amino acids and none essential amino acids.

THE ROLE OF BACTERIAL SYMBIONTS IN AMINO ACID COMPOSITION OF BLACK BEAN APHIDS

To evaluate the role of bacterial symbionts ( Buchnera spp. ) in the black bean aphids ( Aphis craccivora Koch), the aphids were treated with the antibiotic, rifampicin, to eliminate their intracellular symbiotic bacteria. Analysis of protein and amino acid concentration in 7-day-old of aposymbiotic aphids showed that the total protein content per mg fresh weight was significantly reduced by 29 %, but free amino acid titers were increased by 17% . The ratio of the essential amino acids was in general only around 20% essential amino acids in phloem sap of broad bean, whereas it was 44% and 37% in symbiotic and aposymbiotic aphids, respectively,suggesting that the composition of the free amino acids was unbalanced. For example, the essential amino acid,threonine represented 21. 6% of essential amino acids in symbiotic aphids, but it was only 16.7% in aposymbiotic aphids. Likewise, two nonessential amino acids, tyrosine and serine, represented 8.9% and 5.6% of total amino acids in symbiontic aphids, respectively, but they enhanced to 21.1% and 13.6% in aposymbiotic aphids. It seems likely that the elevated free amino acid concentration in aposymbiotic aphids was caused by the limited protein anabolism as the result of the unbalanced amino acid composition.