Dietary Fat Reduces Odd-Numbered and Branched-Chain Fatty Acids in Depot Lipids of Rabbits

Forty eight Californian×New Zealand White rabbits were randomly distributed in three groups of 16 animals each. A control (with no added fat) and two diets enriched at a rate of 30 g fat kg^-1 were used. Olive oil and sunflower oil were used as sources of fat for the fat-supplemented diets. Branched chain (BCFA) and n-odd-numbered carbon fatty acids (ONFA) in the perirenal fat depots of control animals were respectively 5 and 22 mg g^-1 of total fatty acids, while in fat-enriched diets they were around 3 and 16 mg g^-1, respectively. The ratio of unsaturated: saturated fatty acid in perirenal fat was 1·25:1 when the control diet was administered and around 1·80–1·95:1 in fat-enriched diet groups, which represents approximately a 50% increase (P<0·01). However the melting points of the fats showed little difference (NS) between the control group and the group with olive oil addition whilst the sunflower oil-supplemented group showed only a 5·7% lower value (P<0·01). In a second experiment in which diets with equal digestible energy and protein were used, reductions in total amounts of ONFA (P<0·01) and BCFA (P<0·05) were observed in the perirenal fat of animals receiving the fat-enriched diets. The addition of fat depressed the concentrations of ONFA and BCFA, which may act to maintain the consistency of fat in a narrow range, avoiding to some extent the production of undesirable soft and floppy carcasses. © 1997 SCI.     

Barley β-glucan is effective as a hypocholesterolaemic ingredient in foods

Barley contains high levels of soluble dietary fibre, including mixed linked 1→3, 1→4β-D -glucans (β-glucan). An extract of β-glucan from waxy, hulless barley containing 56% total dietary fibre (TDF) was incorporated into flour tortillas, cornstarch pudding and apple granola bars to provide 2 g soluble fibre as β-glucan per serving. The foods were tested for objective functional properties. Flour tortillas with β-glucan were incorporated into rat diets and compared to diets containing an equivalent amount of cellulose, to test the fibre effect on growth and lipid metabolism parameters. Rats fed β-glucan tortillas had lower feed consumption and body weight (P<0·05) compared to those fed the cellulose tortillas, although feed/gain ratios were not different (P>0·05). Plasma LDL-cholesterol of rats fed β-glucan was lower (P<0·05) than cellulose-fed controls, although total cholesterol and triglycerides did not differ (P>0·05). Rats fed β-glucan tortillas had higher (P<0·05) faecal fat excretion, suggesting impairment of intestinal fat absorption. Liver composition data showed lower (P<0·05) levels of total lipid and cholesterol in β-glucan-fed rats. The results suggest that the barley β-glucan concentrate has potential as a food ingredient to provide supplemental soluble fibre which may be beneficial in reducing plasma LDL-cholesterol in humans. © 1998 SCI.     

Effect of Yeast Culture Supplement on Ruminal Microbial Populations and Metabolism in Buffalo Calves Fed a High Roughage Diet

The effect of Saccharomyces cerevisiae yeast culture (YC, Yea-Sacc 1026) as a supplement to the high-roughage diet of buffalo calves on the rumen microbial populations, fermentation pattern and in sacco dry matter disappearance of dietary constituents was examined. A control group was fed a diet consisting of, on a dry matter basis, 2·12 kg bajra (Pennisetum typhoides) hay and 0·45 kg groundnut cake per day per calf, while the treatment group had the same diet plus 5 g YC. After feeding for 6 weeks, inclusion of YC was stopped and both groups were given the control diet for 2 weeks. At week 4 the pH in the rumen fluid (RF) was significantly higher (P<0·05) up to 6 h post-feeding in the treatment group compared with the control group. The concentrations of total, total viable and cellulolytic bacteria were increased by 41·0 (P<0·05), 33·5 and 57·4% (P<0·01), respectively, with YC supplement. The concentration of total volatile fatty acids (P<0·05), particularly at 4 h post-feeding (P<0·01) and acetate (P<0·01) and acetate to propionate ratio (P<0·05) were higher in the treatment compared with the control group. On YC supplementation, the concentration of NH₃-N was decreased (P<0·05) while that of TCA-precipitable protein in RF was marginally but non-significantly increased. Withdrawal of YC from the diet reversed these effects and the rumen variables returned to values close to control levels after 2 weeks. The in sacco dry matter disappearance of dietary components was higher in the treatment compared with the control group, particularly during the first 24 h of incubation. © 1997 SCI.     

Taurine alleviates dyslipidemia and liver damage induced by a high-fat/cholesterol-dietary habit

Eight male hamsters per group were assigned randomly to one of the following diets: chow diet (Control); high-fat/cholesterol diet (HFCD); HFCD supplemented with 1% Tau (HFCD/1% Tau); HFCD supplemented with 2% Tau (HFCD/2% Tau). Tau supplementation improved (P < 0.05) serum lipids and cholesterol profile in the high-fat/cholesterol-dietary hamsters. Although hepatic cholesterol/triacylglycerol in the high-fat/cholesterol-dietary hamsters were not (P > 0.05) changed by Tau supplementation, faecal cholesterol and bile acid outputs were increased (P < 0.05). Two percent Tau supplementation unregulated (P < 0.05) HMG-CoA reductase and cholesterol 7-α hydroxylase (CYP7A1) expressions in the high-fat/cholesterol-dietary hamsters. Besides, Tau supplementation also increased (P < 0.05) LDL receptor mRNA expressions in high-fat/cholesterol-dietary hamsters. Tau supplementation also reduced serum GPT and GOT values and C-reactive protein (CRP) levels in the high-fat/cholesterol-dietary hamsters. Results clearly indicated that Tau could alleviate blood lipids and hepatic damage induced by a high-fat/cholesterol-dietary diet.     

Effects of Roxarsone on Performance,Toxicity, Tissue Accumulation and Residue of Eggs and Excreta in Laying Hens

In this study, we examined the effects of a high dosage of roxarsone in the diet on the performance, liver function, and its residue in liver, eggs and excreta of laying hens. Seventy-five 32-week-old layers were selected and randomly allocated into five dietary treatments with three replications for each treatment. Feeding periods were 4 weeks with an additional week for withdrawal. The experimental diets included 0, 11, 22, 44 or 88 mg kg^-1 arsenic from roxarsone, respectively. Dietary arsenic above 44 mg kg^-1 significantly decreased the egg production and feed intake of the layer (P < 0·05). Layers ceased to produce eggs after two weeks of feeding the 88 mg kg^-1 arsenic supplement diet. Where the enzyme activities in the serum, aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatine kinase (CK) significantly increased. Also, the liver weight did not only significantly decrease (P < 0·05), but was also damaged on histological examination. Moreover, arsenic residues in the liver, eggs and the excreta significantly increased as dietary arsenic level was increased (P < 0·05). The serum enzyme activities of AST, LDH, CK returns to normal after a week of the drug withdrawal. Arsenic residues in liver, egg and excreta also significantly declined in the withdrawal period (P < 0·05). Furthermore, the hepatic cells were vacuolised from layers treated with 88 mg kg^-1 of arsenic. © 1997 SCI.     

Genetic and environmental variability in starch,fatty acids and mineral nutrients composition in cowpea (Vigna unguiculata (L) Walp)

Fifteen cowpea cultivars grown in three locations (Kano (12°00′N 8°31′E), Mokwa (9°17′N 5°04′E) and Ago-Iwoye (6°58′N 4°00′)) between 1993 and 1994 were analysed for genotype, environmental and genotype×environment variability for starch (g kg⁻¹), fatty acids (% of total oil) and mineral nutrients (g kg⁻¹) composition. There were significant environmental as well as genetic effects on these nutritional qualities. The environmental effect accounted largely for the variability observed in starch (60%), palmitic acid (80%), arachidic acid (100%), potassium (100%), phosphorus (81%) and manganese (86%), while the genotypic effect accounted largely for the variability observed in linoleic acid (50%), linolenic acid (50%) and copper (68%) contents. Correlation coefficient (pooled data) from the three locations indicated that starch was positively correlated to palmitic acid (r = 0·21, 0·01< P < 0·05), potassium (r = 0·80, P < 0·001) and phosphorus (r = 0·65, P < 0·001), but negatively correlated to oleic (r = −0·23, 0·01< P < 0·05), linoleic (r = −0·67, P < 0·001) and linolenic acid (r = −0·74, P < 0·001) contents. Starch showed a strong positive correlation with magnesium content (r = 0·75) and a strong negative correlation with copper (r = −0·73) and iron (r = −0·62) at the genetic level. This research established the degree of variability for these characters in cowpea. © 1998 Society of Chemical Industry.     

Nutrient contents,rumen protein degradability and antinutritional factors in some colour- and white-flowering cultivars of Vicia faba beans

Six colour-flowering (Scirocco, Alfred, Carola, Condor, Tina and Herz Freya) and six white-flowering (Caspar, Albatros, Gloria, Tyrol, Vasco and Cresta) cultivars of Vicia faba were studied. The crude protein contents of colour- and white-flowering cultivars were 267±13·6 and 283±18·8 g kg⁻¹, respectively, which did not differ significantly at P<0·05. The levels of lipids, crude fibre, starch and ash varied from 14 to 22 g kg⁻¹, 88 to 143 g kg⁻¹, 407 to 485 g kg⁻¹ and 32 to 42 g kg⁻¹, respectively. The calculated organic matter digestibility (OMD) and metabolisable energy (ME) of the white-flowering cultivars were significantly higher (P<0·001) than those of the colour-flowering cultivars (OMD: 889·1±26·6 g kg⁻¹ vs 797·5±17·1 g kg⁻¹; ME: 13·97±0·49 vs 12·30±0·34 MJ kg⁻¹). In all cultivars, sulphur amino acids were lower than adequate concentration when compared with recommended amino acid pattern of FAO/WHO/UNO reference protein for a 2–5-year-old child. The in vitro rumen nitrogen degradability of colour-flowering cultivars was significantly lower (P<0·01) compared to that of white-flowering cultivars (71·4±9·3% vs 88·0±11·1%). Amongst colour-flowering varieties, the contents of total phenols (TP), tannins (T) and condensed tannins (CT) were highest in Alfred (28·3, 21·0 and 35·4 g kg⁻¹, respectively). The contents of TP and T were similar (about 15 and 10 g kg⁻¹, respectively) in Carola, Tina and Herz Freya, and the CT were in the order: Condor>Herz Freya>Carola. The CT were not detected in white-flowering varieties, T were virtually absent and TP were extremely low (4·0–4·9 g kg⁻¹). The activities of other antinutritional factors (white- and colour-flowering cultivars, respectively: trypsin inhibitor activity 3·05±0·34 and 1·85±0·09 mg trypsin inhibited g⁻¹; lectin 27·2±9·4 and 27·1±5·1 mg ml⁻¹ assay medium producing haemagglutination; phytate 15·0±2·7 and 16·6±2·3 g kg⁻¹) were very low. A strong negative correlation (r=-0·92, P<0·001) between tannins and in vitro rumen protein degradability was observed which suggested that tannins have adverse effect on protein degradability. Similarly negative correlations between tannin levels and metabolisable energy (r=-0·89; P<0·001) and organic matter digestibility (r=-0·89; P<0·001) were observed. The correlation coefficient between trypsin inhibitor activity and tannins was negative and highly significant (r=-0·88, P<0·001), whereas between tannins and saponins it was significantly positive (r=0·96, P<0·001). ©1997 SCI     

The Nutritional Value of High-Lysine Barley Determined in Rats,Young Pigs and Growing Pigs

Three experiments, the first with rats, the second with young pigs and the third with growing pigs, were carried out to compare the nutritional value of cv Lysimax, a newly developed high-lysine barley, to cv Lami, a conventional barley grown in Denmark. In the diets for rats and growing pigs the barleys were the sole protein source while in the experiment with young pigs the barleys made up to 649 g kg^-1 of the respective diets. The lysine content of cv Lysimax was 52·6% higher than that of cv Lami; 4·99 g 16 g N^-1 compared to 3·27 g 16 g N^-1. The contents of threonine, tryptophane, methionine and cystine of cv Lysimax were 3·80, 1·41, 1·80 and 2·27 g 16 g N^-1, respectively; being 18·4, 8·5, 9·8 and 5·1% higher than in cv Lami. Conversely, the contents of glutamic acid and proline in cv Lysimax were 15·79 and 7·40 g 16 g N^-1, respectively, being 36·1 and 40·0% lower than in cv Lami. In the experiment with rats, the higher lysine content and the lower content of glutamic acid and proline in cv Lysimax resulted in a 34·8% increase (P<0·05) in biological value (BV); 0·867 for cv Lysimax compared to 0·643 for cv Lami. True protein digestibilities and energy digestibilities in rats fed cv Lysimax were 0·019 and 0·010 units lower (P<0·05) than for cv Lami. For young pigs the increased lysine content and the lower content of glutamic acid and proline of cv Lysimax increased (P<0·05) nitrogen (N) retention from 10·9 to 12·4 g day^-1, respectively, and increased (P<0·05) apparent BV from 0·690 to 0·734, respectively. The digestibility of energy was 0·030 units lower (P<0·05) for the diets with cv Lysimax than for the diets with cv Lami. Likewise, with growing pigs the increased lysine content and the lower content of glutamic acid and proline increased (P<0·05) N retention from 6·4 to 10·8 g day^-1 and apparent BV from 0·271 to 0·495, respectively. The apparent ileal digestibilities of lysine, threonine, tryptophane, methionine and cystine were similar (P>0·05) between the barleys. It is concluded that the development of high-lysine barley varieties could be beneficial for meeting the requirements of essential amino acids for monogastrics. Moreover, N excretion into the environment was substantially reduced due a reduction in the prolamine fraction which is rich in glutamic acid and proline. © 1997 SCI.     

Comparative composition of aerial and subterranean potato tubers (Solanum tuberosum L)

The composition of aerial and subterranean tubers of two potato genotypes cvs Desiree (red skin) and Epicure (white skin) was compared immediately after harvest using a range of analytical methods. Irrespective of genotype, aspartic acid, arginine, glycine, glutamic acid, histidine, leucine, serine, threonine and total amino acid concentrations were significantly higher (P<0·05) in aerial compared with subterranean tuber tissue. Significant increases (P<0·05) in valine in aerial tubers, but no significant differences in alanine, tyrosine and iso-leucine, when compared with subterranean tubers of cv Desiree, were found. In cv Epicure, alanine, tyrosine and iso-leucine were significantly higher in aerial tubers (P<0·05); however, no significant differences in valine were recorded. There was no significant increases in lysine and phenylalanine between tuber types. Regardless of genotype α-solanine, α-chaconine, chlorogenic acid, chlorophyll and crude protein concentrations were significantly higher in aerial tubers compared with subterranean ones (P<0·01). No significant increases in total lipids between tuber types were found. In cv Desiree, ascorbic acid content was not significantly different between aerial and subterranean tuber tissue, but in cv Epicure concentrations were significantly higher (P<0·01) in aerial tubers. Starch concentrations were significantly higher in subterranean tubers of both cultivars (P<0·05). Sugar content was significantly higher in aerial tubers of cv Epicure (P<0·01), but not significantly different between aerial and subterranean tubers of cv Desiree. Regardless of genotype, phosphorus, magnesium, potassium, zinc, manganese and sodium concentrations were significantly higher (P<0·05) in aerial tubers. Iron and copper concentrations were significantly higher in aerial tubers of cv Desiree (P<0·01), but significantly less in cv Epicure compared with subterranean tubers (P<0·01, P<0·05). Calcium concentrations were not significantly different between aerial and subterranean tubers of cv Desiree, but significantly higher in aerial tuber tissue of cv Epicure (P<0·01). Total gross energy (mJ kg⁻¹ FW) was higher in aerial tubers of cv Desiree compared with subterranean tubers (P>0·05), but not significantly different between aerial and subterranean tubers of cv Epicure. The potential applications of aerial tubers for industrial purposes are discussed. © 1997 SCI.     

The variation of oxidative stability and sensory attributes of sunflower oil induced by essential oil from Magnolia liliflora Desr. during high-temperature storage

Essential oils are considered one of the most prominent natural antioxidants in vegetable oils. Herein, sunflower oil was flavoured by the essential oil extracted from the flowers of Magnolia liliflora Desr. (MLEO), and its oxidative stability and sensory properties during the high-temperature storage at 65 °C were explored. After the storage for 30 days, MLEO at 1600 mg kg⁻¹ could significantly suppress the increase for acidity value, peroxide value, ρ-anisidine value and total oxidation values (P < 0.05 or P < 0.01). In the meantime, the elevation for thiobarbituric acid reactive substances, conjugated dienes and trienes was significantly suppressed as well (P < 0.05 or P < 0.01). Additionally, MLEO at 1600 mg kg⁻¹ was able to restrict the transformation for the fatty acid composition of sunflower oil, and the sensory attributes of sunflower oil could be obviously improved. Consequently, MLEO could be employed as one potential natural antioxidant for sunflower oil.     

Effects of dietary flaxseed oil on cholesterol metabolism of hamsters

High-fat/cholesterol diets (HFCD) formulated by addition of butter (BU), coconut oil (CO), or flaxseed oil (FX) enhanced (P < 0.05) serum lipids of hamsters compared to the low-fat/cholesterol diet (Control). However, FX groups showed a hypocholesterolaemic effect compared to CO and BU groups. Lower (P < 0.05) hepatic triacylglycerol and cholesterol contents were measured in FX groups than those of CO and BU groups; whereas, higher (P < 0.05) faecal triacylglycerol and cholesterol contents were observed in FX groups. HMG-CoA reductase mRNA expression was upregulated (P < 0.05) by HFCD, whilst FX groups showed no (P > 0.05) influence on LDL-receptor mRNA expression compared to that of Control groups; however, higher (P < 0.05) than those of CO and BU groups. Meanwhile, there was a tendency towards higher CYP7A1 expression in the CO or FX group than the BU group. Thus, the hypocholesterolaemic effect of FX might result from increases of LDL-receptor mRNA expression, and cholesterol catabolism/output.     

Genetic and Environmental Variation for Seed Yield,Protein, Lipid and Amino Acid Composition in Cowpea (Vigna unguiculata (L) Walp)

The genetic and environmental variability for seed yield (kg ha^-1), protein content (g kg^-1 DM), lipid content (mg g^-1 DM) and essential amino acid composition (g per 16 gN) of cowpea seeds using 15 cultivars grown in three locations (Kano (12°00′ N 8°31′ E), Mokwa (9°17′ N 5°04′ E) and Ago-Iwoye (6°58′ N 4°00′ E)) that differ markedly in climate was studied. The environmental effect accounted largely for the variability observed in yield (93%), protein (71%), lipid (100%), threonine (96%), cystine (80%) and arginine (81%) while the genotypic effect accounted largely for the variability observed in methionine (56%) and lysine (51%) contents. Correlation coefficients (pooled data) from the three locations indicated that yield was negatively correlated to protein content (r=-0·87, P<0·001) and positively correlated to lipid content (r=0·73, P<0·001). Protein content was negatively correlated to lipid content (r=-0·67, P<0·001) and positively correlated to threonine (r=0·66, P<0·01), cystine (r=0·69, P<0·001) and methionine (r=0·88, P<0·001) contents. Similarly, yield was positively correlated to threonine (r=0·22, 0·01<P<0·05), cystine (r=0·38, 0·001<P<0·01) and methionine (r=0·67, 0·001<P<0·01). Yield showed a strong negative correlation with protein content (r=-0·81) and a strong positive correlation with lipid content (r=0·97) at the environmental level. Cystine, methionine and to some extent, threonine were the limiting amino acids in the three environments. This research established the degree of variability for these characters in cowpea and indicated that concurrent selection for yield, lipid content, threonine and sulphur amino acids compositions is feasible. © 1997 SCI.     

Hypolipidemic effect of enzymatically extracted sunflower seed protein fraction

An attempt was made to enzymatically extract the protein fraction (PF) from sunflower seeds and investigate its dietary effect on the growth, plasma and tissue lipid profiles, plasma protein content, erythrocyte membrane lipid profile and organ weights of rats. Extraction of dehulled sunflower seeds in an aqueous medium in the presence of the enzyme pectinase at 50 ± 1 °C and pH 4.5 yielded a protein fraction with low residual chlorogenic acid and fibre contents. Rats fed the sunflower seed protein fraction showed a similar body weight gain and food efficiency ratio as rats fed casein. However, the different dietary proteins had different effects on plasma total cholesterol and triglyceride contents. The rats fed the sunflower seed protein fraction showed a significant decrease in plasma cholesterol (p < 0.02) and triglyceride (p < 0.02) concentrations compared to the casein‐fed rats. The PF‐fed rats also exhibited a significant difference in erythrocyte membrane phospholipids and phosphatidylcholine/phosphatidylethanolamine ratio. Rats fed the different dietary proteins did not show much variation in plasma protein content, liver and brain lipids and organ weights. These results demonstrate the hypolipidemic action of the sunflower seed protein fraction and that it can be considered a suitable edible protein like casein. © 2000 Society of Chemical Industry     

Oxidative stability of camelina oil in salad dressings,mayonnaises and during frying

Oxidative stability of omega‐3 rich camelina oil in food products and during frying was evaluated and compared with sunflower oil. Camelina oil‐based salad dressings were of similar oxidative stability to those prepared with sunflower oil, as indicated by predominantly insignificant (P > 0.05) differences in peroxide values (PV), ρ‐anisidine values (AV), total oxidation values (TOTOX), conjugated diene levels (CD) and conjugated triene levels (CT). However, thiobarbituric acid reactive substances (TBARS) were significantly higher (P < 0.05) for camelina oil and salad dressings throughout storage. Camelina and sunflower oils, alone and in salad dressings or mayonnaises, were acceptable to a sensory analysis panel with slightly lower scores for camelina oil. PV, AV and TOTOX values were similar for camelina and sunflower oil during deep frying but while PVs remained low (<10 meq kg^?1), AV and TOTOX values increased quickly. TBARS values were significantly higher in deep‐frying camelina oil and ‘fishy’ odours were observed.     

Glycaemic responses and hypocholesterolaemic effects of high-amylose barley diets on broiler chicks

The glucose and lipid responses of barley diets were investigated with chicks based on either flour or red dog (RD) from each of three barley cultivars, Glacier, covered high-amylose Glacier (HAG) and hull-less high-amylose Glacier (HHAG), with two maize control diets. Mean time interval blood glucose levels were higher (P<0·05) for chicks fed uncooked barley flour or RD, compared with controls. Total and LDL plasma cholesterol were lower (P<0·05) for chicks fed the HAG and HHAG flour and all barley RD diets. HDL cholesterol values for chicks fed Glacier and HHAG flour and HHAG RD diets were higher than controls. The LDL/HDL cholesterol ratios for chicks fed HAG and HHAG flour and all barley RD diets were lower (P<0·05) than controls. Lower body weights were observed in all chickens fed barley diets. The results suggest that the soluble fibre, mainly β-glucan and starch structures, in barley may be responsible for the hypocholesterolaemic effect. © 1998 SCI.     

Instrumental Assessments of Japanese White Salted Noodle Quality

Strong correlations were found between some sensory evaluation results and instrumentally (Instron, Model 4301) assessed quality parameters for Japanese white salted noodles made from 32 Australian wheats. The sensory texture parameter, softness, had a strong negative correlation (r=-0·74, P<0·001) with the instrumental texture parameter, cutting force peak area divided by time. Other sensory texture parameters, smoothness and elasticity, showed significant correlations with another instrumental parameter, compression force peak area divided by time (r=-0·58, P<0·001 and r=0·52, P<0·01 respectively). Brightness, yellowness and discolouration of both raw and cooked noodles were measured using a colorimeter (Minolta, Model CR310). Strong correlations were observed between yellowness and discolouration of raw noodles and CIELAB b* (r=-0·79, P<0·001) and L*a* (r=-0·63, P<0·001) values, respectively. Similar relationships were found for cooked noodles (r=-0·74, P<0·001 for yellowness and r=-0·53, P<0·01 for discolouration). Both flour pasting properties including the flour swelling test and mixograph dough properties showed strong correlations with instrumental measures of noodle texture. Protein and ash content significantly affected noodle colour. In an attempt to simplify objective noodle quality measurements instrumental texture tests were carried out on flour gels. Textural measurements of flour gels showed that sensory softness of cooked noodles was correlated with an instrumental parameter, cutting peak force divided by time (r=-0·46, P<0·01). However, in this study no strong correlations were found between the smoothness and elasticity of noodles and any parameters of compression force-time profiles derived from gels. Yellowness of flour gels measured by a colorimeter showed a significant correlation with that of cooked noodles (r=-0·68, P<0·001). © 1997 SCI.     

Effect of garlic powder on the performance,egg traits and blood parameters of laying hens

This study was conducted to investigate the effects of garlic powder on the performance, egg traits and blood parameters of laying hens. One hundred and sixty‐two SHSY‐type brown layers aged 21 weeks were chosen at random from a large flock. They were allocated to three dietary treatments. Each treatment comprised six replicates of nine layers in groups of three. The diets were supplemented with 0, 5 and 10 g kg^?1 garlic powder. The experimental period lasted 22 weeks. Garlic powder addition did not significantly affect body weight, egg production, feed consumption, feed efficiency, egg shell index, egg breaking strength, egg shell thickness, egg albumen index, egg yolk index, egg Haugh unit, egg yolk weight and serum protein concentration. Egg weight increased (P < 0.01) with garlic powder supplementation. There was a significant (P < 0.01) reduction in egg cholesterol concentration as mg g^?1 yolk when the dietary level of garlic powder was increased from 0 to 10 g kg^?1. Hen serum triglyceride (P < 0.05) and total cholesterol (P < 0.01) concentrations decreased with garlic powder supplementation. This study demonstrated that garlic powder addition increased egg weight and decreased egg yolk cholesterol concentration (mg g^?1 yolk) and serum triglyceride and cholesterol concentrations without adverse effects on performance and egg traits. Copyright © 2006 Society of Chemical Industry     

Could the Dumas Method Replace the Kjeldahl Digestion for Nitrogen and Crude Protein Determinations in Foods?

Increased demand for determinations of nitrogen (N), and hence crude protein (CP), has led to wider use of the Dumas method in place of the traditional Kjeldahl methods. Although Kjeldahl N (KN) and Dumas N (DN) represent different N fractions, published studies on infant formula, animal feed and meat products have indicated that DN could replace KN with little practical impact on the reliability of the N values obtained. This study was conducted to establish whether DN determination could replace that of KN in a broader range of foods for CP calculation. Statistical analysis was performed on in-house assayed KN and DN values together with published KN and DN values for selected food products. In the range 0·05–6·8% N, KN may be estimated from DN with the equation: KN=1·00^(P<0·01)×DN-0·09^(P=0·50) (n=101, R²=0·98, P-regression<0·01). Because N levels in individual groups of food did not span the entire range of N contents, KN: DN ratios were calculated for each food group. KN: DN ratios differed significantly (R²=0·25, P<0·01) from group to group. Ratios of 1·01 for dairy, 1·00 for oilseeds, 0·99 for feed, 0·98 for infant formulas, 0·95 for cereals, 0·94 for meats, 0·89 for vegetables, 0·80 for fish and 0·73 for fruits were valid for the estimation of KN and CP using DN data. CP was independently calculated as CP1=H×KN or CP2=H×KN: DN×DN, where H is the nitrogen to protein conversion factor for the food group. Mean differences between CP1 and CP2 values were 0% for dairy, oilseeds, feed, infant formulas and baby foods, cereals, meat and meat products, vegetables and vegetable products and fruit, and 1% for fish. These results suggest that DN may replace KN for the determination of N and CP in selected food groups when appropriate coefficients are used. © 1997 SCI.     

Effect of high-fat cholesterol enriched diets on hypolipemic action of Oenothera paradoxa oil in rats. Part 2. Blood serum and liver fatty acids

The effect of Oenothera paradoxa oil on blood serum and liver fatty acids composition in rats was studied. Rats were fed high-fat diets containing 15% of lard or sunflower oil with or without 0.5% of cholesterol. Soybean protein isolate (27%) was the source of proteins. Intake of Oe. paradoxa oil resulted in increase of levels of gamma-linolenic acid (GLA) and linoleic acid (LA) in blood serum and liver of experimental animals. The effect of Oe. paradoxa oil on blood serum and liver fatty acids composition depended mainly on the type and to the lower degree on the amount of fat in a diet. The addition of cholesterol did not change the influence of examined oil on the composition of fatty acids.     

Hypolipidemic study of xylanase-modified corn bran fibre in rats

In order to understand the regulatory effect of xylanase-modified corn bran fibre (XMF) on lipid homeostasis, detailed influences, following the ingestion of XMF and its original form (corn bran dietary fibre, CDF), on serum, liver and faecal lipids were studied in Sprague–Dawley rats. In both CDF and XMF groups, serum total cholesterol (TC), triacylglycerol (TG) and low-density lipoprotein cholesterol (LDL-C) were significantly lowered after 4 weeks (p < 0.05). By the end of week 6, data in the XMF group showed that serum LDL-C was lowered further and high-density lipoprotein cholesterol (HDL-C) was significantly increased (p < 0.05); liver TC, TG and fat were significantly lower (p < 0.05), while the excretions of faecal fat, TC and bile acids were significantly higher (p < 0.05). The decrease of liver and serum lipids in the XMF group was consistent with the improved excretion of faecal lipids and bile acids. Other related mechanisms are also considered.