Biochemistry & Nutrition

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Browsing Biochemistry & Nutrition by Author "Ammu, K."

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    Biochemical and nutritional changes in fish protein during drying
    (1995) Raghunath, M.R.; Sankar, T.V.; Ammu, K.; Devadasan, K.
    Biochemical and nutritional changes in the muscle proteins of a lean marine fish Nempizerra japordeus during drying at 50, 60 and 70‘t were investigated. Solubility of proteins in water, 0-6 m NaCI, 1-5 M urea, it m urea and 10 g litre-1 sodium dodecyl sulphate (SDS1 decreased as drying progressed at all three temperatures; most of the decrease occurring in the initial 4 h of drying. SDS-polyacrylamide gel electrophoresis of 1.5 M urea, 8 m urea and SOS extracts showed that higher molecular weight (MW) protein fractions were more sensitive to drying and disappeared much earlier from electropherograms than the lower MW protein fractions. Residual Solubility of proteins near the pH range of 4 6 was found to increase during drying, but solubility at acid and alkaline pH was adversely affected. Decrease of solubility by drying was more affected at acid pH, especially at higher temperatures than at alkaline pH. Sulphydryl groups registered a regular and sharp decrease with drying except at 50°C, where initially an increase was observed. Apart from disulphide and hydrophobic bonds, free amino groups also appear to be involved in denaturation reactions during drying. Pepsin digestibility of fish muscle decreased slightly during drying but a clear relationship with drying temperature was not evident. Highly significant differences in proteins between protein efficiency ratio (PER), net protein utilisation (NPU) and biological value were observed between the drying temperatures. The PER and NPU of fish dried at 60°C were significantly higher than those dried at 50 or 70°C.
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    Biochemical investigations on Antarctic krill Euphausia superba
    (Society of Fisheries Technologists (India), 2000) Ragunath, M.R.; Sankar, T.V.; Radhakrishnan, A.G.; Mathew, S.; Ammu, K.
    Antarctic krill (Euphausia superba Dana), caught by the first Indian krill expedition was processed on board into whole krill, peeled tail meat and whole krill mince. These were analysed for trace metals, lipids, cholesterol, fatty acids and amino acids. Autolysis at various pH and temperatures as well as thermal coagulation of krill mince suspended in various media were also studied. Trace metals were below toxic levels while no pesticides were detected. Krill tail meat had small amount of lipids and cholesterol (0.81 and 0.033% respectively). The lipids were rich in C18:1, C20:5, C22:6, fatty acids. Autolytic activity at pH 3-4 and 8-10 was predominant in whole krill at 20 and 40 degree C but autolysis in tail meat was very low. Nearly 80% of the soluble proteins in krill suspension could be precipitated by rapid heating.
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    Carbonyls from some commercially important fishes and shell fishes of tropical waters.
    (Society of Fishery Techonologists (India), 1986) Ammu, K.; Nair, P.G.V.; Devadasan, K.
    Results of a preliminary study of the hexane extractable carbonyls from three fish and one shellfish are reported. Volatile carbonyls that can be isolated from oil sardine (Sardinella longiceps ) by distillation at different temperatures in air or nitrogen atmosphere were also studied. Carbonyls were converted to their 2:4 dinitro phenyl hydrozones. These were fractionated by column chromatography and the different fractions were analysed by capillary gas chromatography. The data show wide variations in the content of different carbonyls in different fishes. Carbonyls in distillates from muscle water homogenates of oil sardine showed some differences from the carbonyls extracted with hexane from the same fish.
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    Changes in protein during drying milk fish (Chanos chanos) at 60 degree C
    (Society of Fisheries Technologists (India), 2001) Thippeswamy, S.; Ammu, K.; Joseph, J.
    Milk fish collected from brackishwater culture ponds was dressed and dried at 60 degree C for 24 h and biochemical changes taking place during drying were studied. Alpha amino nitrogen (AAN) showed a slight increase but total free amino acids (FFA) showed significant reduction during 24 h drying. The variation in individual free amino acid was found to be different for each amino acid. Salt soluble nitrogen and SH group decreased considerably as a result of drying. Electrophoretic study showed a decrease in the number of high molecular weight and low molecular weight protein fractions, but intermediate molecular weight proteins did not show considerable change.
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    Effect of n-3 polyunsaturated fatty acids on the fatty acid profile in rats
    (Society of Fishery Technologists (India), 1998) Nair, P.G.V.; Ammu, K.; Devadasan, K.
    Effect of a polyunsaturated fatty acid (PUFA) concentrate containing about 80 percentage free acids at a level of 1 percentage of the diet, on the fatty acid profile of the lipids of liver and heart of rats fed on it for a period of three months was investigated. Law levels of dietary PUFA influence fatty acid composition of the lipids in liver and heart. The pattern of changes was different in the two organs, indicating tissue specificity to n-3 PUFA.
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    Effect of preprocessing storage conditions on the carbonyls of oil sardine
    (Society of Fisheries Technologis(India), 1989) Ammu, K.; Devadasan, K.
    Changes in the total as wen as major individual carbonyls of oil sardine muscle during storage at room temperature for 24 hand in crushed ice upto 6 days are reported. Carbonyls extracted with hexane were converted to their 2:4 dinitrophenyl hydrazone (DNPH) derivatives and were separated into major classes by column chromatography on celite/magnesia. Individual carbonyls were then identified by capillary gas chromatography of these derivatives. Though absolute values for carbonyls exhibited wide variations depending upon the degree of freshness, the pattern of changes in the carbonyls during storage of fish under different conditions gave an insight into the influence of carbonyls on flavour. The significance of the findings is discussed.
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    Effects of peroxidised PUFA on tissue defence system in experimentally induced myocardial infraction in rats
    (Society of Fisheries Technologists(India),Cochin, 2003) Anandan, R.; Mathew, S.; Asha, K.K.; Ammu, K.; Nair, P.G.V.
    In the present study, the administration of peroxidised PUFA was found to aggravate the isoproterenol-induced myocardial infraction in rats, which was evident from the increased level protein and enhanced the release of marker enzymes in the serum of rats given PUFA and isoproterenol. It was also observed that oxidized PUFA in the diet resulted in higher levels of peroxidation and lower levels of antiperoxidative enzymes.
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    Hypocholesterolemic effects of poly unsaturated fatty acid concentrate prepared from fish oil
    (Association of Food Scientist and technologists (India), 1998) Nair, P.G.V.; Ammu, K.; Devadasan, K.
    Hypocholesterolemic effects of a concentrate of polyunsaturated fatty acids (pUFA) prepared from commercially available fish oi1were evaluated In albino rats. PUFA concentrate containing about 76% of total polyunsaturated acids (36% of docosahexaenoic acid, (DHA) and 23% of e1cosapent.aenoic acid, (EPA) was Incorporated In a hypercholesterolemic diet at 1% level and fed to rats for two different periods, viz., one month and three months. The results showed that one month was too short a period for the hypocholesterolemic effects to be manifested. Continuation of the same diet for three months resulted in lowering of serum cholesterol level to about 36% of that in the control group. Cholesterol content of the liver of the animals fed on PUFA-supplemented diet was more than two times that of the control group (2.71 and 1.17 g/100g. respectively). Total lipid content of the liver of the animals also showed a sim1iar trend, suggesting that n-3 PUFA probably would lower serum cholesterol levels by effective redistribution of total cholesterol between serum and tissues.
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    Influence of dietary carbohydrates on serum cholestrol levels in albino rats
    (Society of Fisheries Technologists (India), 1994) Ammu, K.; Devadasan, K.; Unnithan, G.R.
    The influence of different carbohydrates like cornstarch, tapioca starch, potato starch, sucrose and rice starch in combination with different dietary proteins (casein, ground nut prraottse ifne da nodn mau slcolwe fparto tdeiient fwraosm srtouhdui e(dL,a boevoe rr oah iptear)i oodn otfh eo nseer ummo ncthhol.e sUtnedreorl tlheevseel sc oinnd ailtbiionnos sucrose was the least atherogenic of all the carbohydrates tried whereas potato starch led to higher levels of serum cholesterol in combination with all proteins used . Rice starch had good cholesterol lowering properties in combination with all proteins . But this could be partially due to the protein content of the rice flour used . The effect of different carbohydrates varied depending upon the level of fat in diet, the protein component and also the length of feeding time and any conclusions drawn should take all these factors into consideration .
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    Influence of dietary proteins on cholesterol levels in albino rats
    (Society of Fisheries Technologists (India), 1989) Ammu, K.; Stephen, J.; Devadasan, K.
    Albino rats (6 groups) were fed diets identical except for their protein sources for 60 days. The protein sources used were fat-free casein, defatted groundnut cake, and defatted fish powders from three spp. of fishes, namely, the fresh water fish Labeo rohita, the marine fishes Rastrelliger kanagurta and Otolithus argenteus, and marine prawns Parapenaeopsis stylifera. After 60 days, cholesterol levels in serum, liver and heart of the rats were estimated. The casein-fed group recorded the highest cholesterol level. Compared with casein, groundnut protein was distinctly hypocholesterolaemic. The fish proteins had an even greater cholesterol lowering ability. The proteins of prawns had the max. hypocholesterolaemic effect. An attempt is made to correlate the cholesterol-lowering effects of proteins with their respective amino acid compositions.
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    Influence of Vitamin E supplementation of dietary fish oils on lipid profile and blood glucose levels in albino rats
    (Association of Food Scientist and Technologists of India, 1996) Ammu, K.; Sankar, T.V.; Devadasan, K.
    Vitamin E supplementation of dietary sardine oil and shark liver oil was found to enhance the hypocholesterolemic properties and other favourable effects like reduction in serum triglycerides and increase in the percentage of HDL cholesterol in albino rats. The effect of diets having these oils with or without added vitamin E (1.5 IU/g) was compared to a sunflower oil diet and a commercial feed. The increase in the blood sugar levels in rats fed with polyunsaturated fatty acid (PUFA)-rich fish oil was insignificant. Influence of dietary fatty acids on the fatty acid composition of the lipids of heart, liver and adipose tissue of the rats fed on these diets is also reported
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    Lipase activity in different tissues of four species of fish: rohu (Labeo rohita Hamilton), oil sardine (Sardinella longiceps Linnaeus), mullet (Liza subviridis Valenciennes) and Indian mackerel (Rastrelliger kanagurta Cuvier)
    (Wiley, 2003) Nayak, J.; Nair, P.G.V.; Ammu, K.; Mathew, S.
    Lipase activity in stomach and pyloric caeca, liver, intestine and red muscle of rohu (Labeo rohita Hamilton), oil sardine (Sardinella longiceps Linnaeus), mullet (Liza subviridis Valenciennes) and Indian mackerel (Rastrelliger kanagurta Cuvier) was studied. Distinct differences in lipolytic activity in different tissues of these fish were observed. Rohu showed the highest activity in all tissues in comparison with the other three species of fish. Among the three size groups of mullet, medium-sized mullet showed higher activity than the other two groups in all tissues except intestine. Rohu hepatopancreatic lipase exhibited more hydrolytic activity on fish oil than rohu intestinal lipase.
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    Nutritional evaluation of fish solubles
    (Society of Fisheries Technologists (India), 1986) Ammu, K.; Stephen, J.; Antony, P.D.
    this paper reports the results of a preliminary study on the biochemical composition and nutritional charactersitics of fish solubles from oil sardines (Sardinella longiceps) and white tailed pink perch (Nemipterus japonicas) ., The nutritional quality of sardine solubles has been evaluated by feeding trials using albino rats also . The studies have shown that compared to a control group of rats whose diet had casein as the sole source of protein, a group of rats in whose diet dried sardine solubles replaced half of the casein, had a noticeably higher growth rate . This higher growth rate was not prominent in the early stages of growth (4-7 weeks) . But, during later stages (7-10 weeks), solubles incorporated diet supported a distinctly higher growth rate . This effect was more pronounced in female rats (17% over the control group) compared to the male rats (4% over the control group) . Fish solubles are found to be poor sources of essential amino acids . Thus, the observed increase in growth rate is higher than the rate expected from the amino acid make up. This probably supports the view expressed by workers elsewhere that fish solubles contain some unidentified growth factors .
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    A study on the intestinal lipase of Indian major carp Labeo rohita
    (Asian Fisheries Society, Manila, Phillipines, 2004) Nayak, J.; Nair, P.G.V.; Mathew, S.; Ammu, K.
    Lipase from rohu(Labeo rohita, Cyprinidae) intestine was extracted, fractionated with ammonium sulphate and purified on Sephadex G100 column. It was found that the specific activity increased 3.6 times after ammonium sulphate precipitation and Sephadex G-100 Chromatography of crude extract. Lipase activity at different levels of ammonium sulphate showed lower activity. Fractions precipitated with 80% saturated ammonium sulphate has the maximum activity and no activity was detected in the filtrate from this fraction. Lipase was found to have optimum activity at temperature 45 degree C and at pH 7.0. The amino acid composition of the enzyme showed that lipase had high amount of polar amino acids than non polar amino acid content.