Bio-nutritional evaluations of three tropical leaf vegetables (Telfairia occidentalis, Amaranthus cruentus and Talinum triangulare) as sole dietary protein sources in rat assay

The bio-nutritional potentials of three tropical vegetable leaf meals (Telfairia occidentalis leaf meal, TOLM; Talinum triangulare leaf meal, TTLM and Amaranthus cruentus leaf meal, ACLM) were investigated using albino rat as the test animal. Some protein quality evaluation indices were measured when the three vegetable leaf meals (VLMs) were used as sole protein sources in diets fed to the experimental animals and results were compared with data obtained for a basal nitrogen free diet (diet 1) and another reference diet (diet 2) in which the protein was solely supplied by nutritional casein (pure protein). The weight gain value recorded over a 10 day experimental period for the test animals on the reference (casein) diet 2 was consistently higher (P < 0.05) than the weight gain value obtained for the animals on the 3 VLMs diets (diets 3–5). Feed intake values recorded for the rats on the VLMs were similar (P > 0.05) and significantly higher (P < 0.05) than the value obtained for rats on the reference (casein) diet. Nitrogen excreted in faeces (feacal nitrogen) was lowest (P < 0.05) for the animals in reference diet 2. However, the nitrogen excreted in urine (urinary nitrogen) was highest (P < 0.05) for the animals on reference diet 2 and lowest for animals on diet 3 (TOLM diet) (P < 0.05). The nitrogen retention (NR) value obtained for the test animals on the reference diet 2 was similar (P > 0.05) to the value obtained for animals on diet 3 (TOLM). These values were significantly higher (P > 0.05) than NR values obtained for animals on diets 4 (TTLM) and 5 (ACLM). Expectedly, the apparent nitrogen digestibility (AND), protein efficiency ratio (PER), net protein ratio (NPR), true digestibility (TD), biological value (BV) and net protein utilization (NPU) all indicated higher and better values (P < 0.05) than the corresponding values obtained for the 3 VLMs diets (diets 3–5).     

The effect of palm oil or canola oil on feedlot performance,plasma and tissue fatty acid profile and meat quality in goats

Twenty-four entire male Kacang kid goats were fed diets containing 3% canola (n = 12) or palm oil (n = 12) supplements for 16 weeks. The goats had an initial live weight of 14.2 ± 1.46 kg and were fed a mixed ration ad libitum (10.4 MJ/ME and 14% crude protein). There was no difference in feedlot performance due to diet. Inclusion of canola oil reduced (P < 0.05) kidney fat weight and increased (P < 0.05) linolenic acid (18:3n − 3) concentration in the blood plasma, m. longissimus lumborum (LL), liver, and kidney. The palm oil diet increased (P < 0.05) myristic (14:0) and palmitic (16:0) acid content in the blood, but this did not alter these fatty acids in the LL muscle. Lipid oxidative substances in the liver and LL from palm oil fed kids were higher (P < 0.05) than those from canola supplemented kids. The incorporation of canola oil into the goats' diet increased muscle omega-3 fatty acid content, but lipid oxidation was lowered in the blood and muscle LL.     

Effects of feeding flaxseed or sunflower-seed in high-forage diets on beef production,quality and fatty acid composition

Yearling steers were fed 70:30 forage:concentrate diets for 205 d, with either grass hay (GH) or red clover silage (RC) as the forage source, and concentrates containing either sunflower-seed (SS) or flaxseed (FS), each providing 5.4% oil to diets. Feeding diets containing SS versus FS significantly improved growth and carcass attributes (P < 0.05), significantly reduced meat off-flavor intensity (P < 0.05), and significantly increased intramuscular proportions of vaccenic (t11-18:1), rumenic (c9,t11-CLA) and n − 6 fatty acids (FA, P < 0.05). Feeding diets containing FS versus SS produced significantly darker and redder meat with greater proportions of atypical dienes (P < 0.05). A significant forage × oilseed type interaction (P < 0.05) was found for n − 3 FA, α-linolenic acid, and conjugated linolenic acid, with their greatest intramuscular proportions found when feeding the RC-FS diet. Feeding GH versus RC also significantly improved growth and carcass attributes, sensory tenderness (P < 0.05) and significantly influenced intramuscular FA composition (P < 0.05), but overall, forage effects on FA profiles were limited compared to effects of oilseed.     

Calcium-supplemented goat milk does not interfere with iron absorption in rats with anaemia induced by dietary iron depletion

The short-term effects of Ca-supplemented goat or cow milk on the nutritive utilization of Fe were evaluated in a metabolic balance study of rats with nutritional ferropenic anaemia (NFA). Control and Fe-deficient rats were fed for 14 d with goat or cow milk diets containing high-Ca content (10,000 mg/kg diet). The consumption of diets containing high levels of Ca for 14 d had no adverse effects on Fe absorption when the goat milk-based diet was provided, whereas for the cow milk-based diet, there was a significant fall in the apparent digestibility coefficient (ADC) of Fe. Moreover, the ADC and Fe retention/intake ratio (R/I) were higher in the anaemic rats fed the goat milk diet than among those fed the cow milk diet. These results suggest that despite a high dietary Ca content, goat milk minimizes Ca–Fe interactions and has no adverse effects on Fe absorption in rats with NFA.     

Effect of sugarcane diets and a high fibre commercial diet on fresh meat and dry-cured ham quality in local Caribbean pigs

The effects sugar cane (SC) diets and a milling by product diet on meat quality characteristics of fresh meat and dry-cured ham were studied on a total of 48 Creole (CR) pigs. Pigs were fed with a control soya-bean meal corn diet (C1), a soya-bean meal wheat diet (C2), a SC fresh juice diet (SC-J), or a ground cane diet (SC-G). Average BW gain was 657, 530, 546, and 200 g/d for diets C1, C2, SC-J and SC-G, respectively. Lean cuts (i.e., ham and loin) were significantly higher in SC-G than in C1 pigs (472 vs. 424 g/kg; P < 0.01); intermediate values were found for C2 and SC-J pigs (427 and 412 g/kg, respectively). The ultimate pH in LD muscle was lower in SC-J than the other groups (5.44 vs. 5.65; P < 0.01). The intra muscular fat (IMF) content in LD was significantly higher in SC-J diet and lower in SC-G diet (1.9% and 1.0%, respectively); intermediates values were found for C1 and C2 diets (1.4% on average). Ham weight losses during 6 months drying period were lower for SC-G fed pigs (9.7% vs. 12.4%; P < 0.05) whereas weight losses during the 12 months drying period were not affected by diet. The TBA value in dry-cured ham was not affected by diet (P > 0.05) whereas the fatty acids profiles of subcutaneous fat in SC-J and SC-G pigs contained more mono-unsaturated and less polyunsaturated fatty acids than in C1 and C2 groups. Significant effects of dietary treatment were found for dry-cured ham sensory quality parameters.     

Beef quality attributes as affected by increasing the intramuscular levels of vitamin E and omega-3 fatty acids

In order to investigate the effects of increasing beef n-3 fatty acid content and the protective effects of vitamin E antioxidant activity on meat quality characteristics, 80 feedlot steers were fed 4 different diets (control, high vitamin E, 10% ground flaxseed or high vitamin E-10% ground flaxseed). While dietary treatments had no effect (P > 0.05) on meat composition or tenderness values, the increase in oxidation products was lower (P = 0.046) in meat from vitamin E supplemented steers and higher (P = 0.006) in meat from flaxseed fed animals. The increase in α-tocopherol tissue levels (P < 0.001) in meat from animals fed flaxseed and increased dietary vitamin E resulted in the lowest drip loss values (P = 0.013). As expected, display time had a large effect on retail traits in both steaks and patties (P < 0.001). While retail traits of steaks were not affected by the dietary treatments (P > 0.05), feeding flaxseed decreased (P < 0.05) ground beef retail scores, which were not corrected by higher levels of dietary vitamin E. Finally, although no effect (P > 0.05) was observed among treatments for sensory attributes in steaks, the correlations of a combined n-3:α-tocopherol ratio against retail and sensory attributes (P < 0.05) suggest that increased n-3 fatty acids levels require increased dietary antioxidants, such as vitamin E to avoid negative effects on meat quality from a loss in oxidative stability.     

Effect of concentrate feeding on instrumental meat quality and sensory characteristics of fallow deer venison

Venison from twenty four hybrid fallow deer does, 36 months old with an initial body condition score (BCS) of 2, was tested to determine the influence of feed type on meat quality. Feeding with concentrates increased BCS (P < 0.01) but did not affect ultimate pH (P > 0.05). BCS 4 animals had higher intra muscular fat (IMF) (P < 0.01), and more tender meat (P < 0.05). Venison from does fed over 24 weeks exhibited less redness (P < 0.01) than those fed for 19 weeks regardless of feed type.Panellists evaluated samples for colour, flavour, tenderness, juiciness and overall liking. They detected significantly (P < 0.05) stronger flavour in meat from animals fed concentrates. Male panellists detected flavour differences within meat from animals fed concentrates (P < 0.05), with longer feeding periods resulting in stronger flavour. There was no difference in overall liking, therefore finishing fallow deer on grain-based concentrate feeds prior to slaughter provided little commercial advantage.     

Cholesterol-lowering effect of phytosterol-containing lactic-fermented milk powder in hamsters

Male hamsters were fed six different diets for 4 weeks. Group 1, fed with control diet of regular rodent chow. Group 2, fed with high-fat-high-cholesterol diet containing cholesterol and corn/coconut oil mixture. Group 3, the positive control fed with high-fat-high-cholesterol diet containing 0.74% (w/w) phytosterols. Groups 4–6 were the high-fat-high-cholesterol diet mixed with phytosterol-containing lactic-fermented milk powder (PSFMP) which contains 0.37%, 0.74% and 1.85% (w/w) of phytosterols, respectively. Results demonstrated that PSFMP could significantly decrease (P < 0.05–P < 0.001) the levels of total cholesterol (serum cholesterol), serum triacylglycerol, liver lipids and atherogenic index (LDL-C/HDL-C), while it could also significantly (P < 0.001) increase the level of fecal cholesterol. The pronounced hypolipidemic effects of PSFMP might be attributed to its ability to enhance cholesterol excretion. These results suggest that PSFMP could be used as a potential cholesterol-lowering ingredient in the management of hypercholesterolemia.     

Influence of calcium fortification on sensory, physical and rheological characteristics of fruit yogurt

There has been great demand of calcium fortified dairy products as they can serve as an ideal vehicle for carrying extra calcium to fulfill the nutritional needs but there is need to generate information on the effect of fortification of calcium on the physical properties of these products. In the present study, the calcium enriched mango yogurt was prepared after fortification of pasteurized yogurt mix with 50 mg Ca/100 ml of calcium lactate, this level selected from a preliminary study of sensory evaluation. Fortification of yogurt with calcium lactate at this level significantly (P<0.005) increased the water holding capacity (WHC) by 2.99% on 1st day of storage. WHC of calcium fortified fruit yogurt was higher than control fruit yogurt on 7th and 14th day of storage. Measurements performed on slowly stirred samples (flow curves and final apparent viscosity) showed that calcium-enriched fruit yogurt had stronger structures. Calcium fortified fruit yogurt showed less shear thinning behavior as compared to control. Also, apparent viscosity measurements at constant shear rate showed a significantly (P<0.05) less decrease in initial apparent viscosity in calcium fortified fruit yogurt. However, no statistically significant (P>0.05) difference was observed in tan δ values of control and calcium fortified fruit yogurt indicating similar nature of bonds involved in the gel structure formation of both the yogurt samples. The more firm structure of the calcium fortified fruit yogurt is thus attributed to the higher extent of colloidal calcium phosphate cross-linking between casein micelles due to increased calcium content by fortification. Also flavor, color, and body and texture scores of control and calcium fortified fruit yogurt did not show any significant difference (P>0.05).     

Conjugated linoleic acids content in M.longissimus dorsi of Hanwoo steers fed a concentrate supplemented with soybean oil,sodium bicarbonate-based monensin,fish oil

We hypothesized that increasing ruminal pH would lead to enrichment of adipose tissue with conjugated linoleic acid (CLA). Twenty-four Korean native (Hanwoo) steers were used to investigate the additive effects of monensin (30 ppm, SO-BM) and/or fish oil (0.7%, SO-BMF) in the diets along with soybean oil (7%) and sodium bicarbonate (0.5%, SO-B) on cis-9, trans-11 and trans-10, cis-12 CLAs in adipose tissue. The steers were assigned to randomly four groups of six animals each based on body weight. The control group (CON) was fed a commercial concentrate for the late fattening stage. Supplementation of oil and sodium bicarbonate reduced feed intake and daily gain, and fish oil further decreased feed intake (P < 0.001) and daily gain (P < 0.087) compared to steers fed other diets. Total CLA and CLA isomers in M.longissimus dorsi were not affected when steers were fed SO-B and SO-BM diets compared with those of steers fed CON and SO-BMF diets. However, total poly unsaturated fatty acids were higher (P = 0.03) in steers fed SO than in CON steers.     

Comparison of wheat- versus corn-based dried distillers’ grains with solubles on meat quality of feedlot cattle

A considerable amount of information has been generated on the feeding value and impact of corn dried distillers’ grains with solubles (DDGS) on meat quality, whereas little is known about the effects of wheat DDGS on meat quality, and no direct comparison of these two sources of DDGS has been completed. The current study was conducted to examine the objective and subjective carcass and meat quality traits of cattle fed diets containing corn or wheat (20% or 40%) DDGS (DM basis) as compared to a standard barley-based finishing diet (control). In general, meat obtained from animals fed the barley-based control diet was slightly darker in colour (lower chroma and hue at 24 h, P < 0.01) and less tender (highest proportion of tough shears at 2 d and lowest proportion of tender shears at 20 d). Meat from corn DDGS was rated as more tender and palatable than control samples (P < 0.05), and 20% corn samples were rated better for beef flavour intensity (P < 0.01) and desirability (P < 0.05) than 40% corn DDGS samples. In contrast, meat from steers fed wheat DDGS showed intermediate characteristics between steers fed control and corn DDGS diets. Hence, feeding wheat DDGS had no negative effects, and feeding corn DDGS had some positive effects on meat quality characteristics of beef.     

Anti-oxidant effect of extracts of kinnow rind,pomegranate rind and seed powders in cooked goat meat patties

To overcome the disadvantages of using synthetic anti-oxidants in meat products, an investigation was carried out to evaluate the anti-oxidant effect of extracts of fruit by-products viz., kinnow rind powder (KRP), pomegranate rind powder (PRP) and pomegranate seed powder (PSP) in goat meat patties. Total phenolics content, DPPH radical scavenging activity and effect of these extracts on instrumental color, sensory attributes and TBARS values during storage (4 ± 1 °C) of goat meat patties were evaluated. Results showed that these extracts are rich sources of phenolic compounds having free radical scavenging activity. Hunter Lab L value significantly (P < 0.05) lowered in PRP followed by PSP and KRP patties. Sensory evaluation indicated no significant differences among patties. Further, a significant (P < 0.5) reduction in TBARS values (lipid oxidation) during storage of goat meat patties was observed in PRP, PSP and KRP as compared to control patties. Average TBARS values (mg/kg meat) during refrigerated storage (4 ± 1 °C) were significantly lower in PRP, followed by PSP and KRP as compared to control. The overall anti-oxidant effect was in the order of PRP > PSP > KRP. It was concluded that extracts of above fruits by-product powders have potential to be used as natural anti-oxidants in meat products.     

In vitro and in vivo protein hydrolysis of beans (Phaseolus vulgaris) genetically modified to express different phaseolin types

Experiments were conducted to study whether phaseolin type could influence proteolysis susceptibility and nutritional value of total bean protein. The DOR-390 bean cultivar was genetically modified to express different phaseolin types (S, T or I). Beans were soaked and autoclaved. A sequential hydrolysis was carried out in vitro with pepsin and pancreatin. Differences in the degree of protein hydrolysis among bean lines started at 30 min and remained until 240 min, with the S bean proteins presenting lower values (P < 0.05). Subsequently, rats were fed with diets containing beans expressing different phaseolin types as the only source of protein for N digestibility and nutritional value determination. No differences (P > 0.05) in ileal protein digestibility and rat growth were observed. In conclusion, the differences in in vitro hydrolysis between bean lines expressing different phaseolin types had no consequences on growth and N retention in rats.     

Effects of feeding a single or sequence of beta-adrenergic agonists on cull cow meat quality

Sixty cull cows were implanted and assigned to four treatments: C = concentrate ration only; RH = supplemented with ractopmaine-HCl (8.33 mg/kg of feed) for 25 d; ZH = supplemented with zilpaterol-HCl (ZH) (200 mg head ^– 1d^– 1) for the last 20 d; and RH + ZH = supplemented with RH for 25 d followed by ZH for 20 d. All cows were fed a concentrate ration for 74 d. Infraspinatus steaks from cows supplemented with RH and/or ZH had lower (P < 0.05) shear force than steaks from C cows. Longissimus (LM) steaks from the 6–8th rib section of ZH and RH + ZH cows had decreased (P < 0.0001) desmin degradation at 10 and 21 d postmortem compared to steaks from C and RH cows. Collagen solubility of the LM was increased (P < 0.05) by ZH and RH + ZH compared to C. There were no treatment differences in 12th rib LM tenderness when enhanced with calcium lactate. Color and sensory traits of meat from RH + ZH cows were not different from C but flavor intensity was greater and off-flavor less than for C cows.     

Colour changes of fillets of rainbow trout (Oncorhynchus mykiss W.) fed astaxanthin or canthaxanthin during storage under controlled or modified atmosphere

Rainbow trout were fed diets containing two levels of lipids (9 g/100 g and 24 g/100 g) associated with two keto-carotenoid pigments (80 mg of astaxanthin or of canthaxanthin/kg of diet) for 4 months. After slaughter colour stability of fillets was studied during a 4-week storage at +4 °C under controlled (CA) and modified (MA) atmospheres under 100% air, 60:40 N₂-CO₂ mix and 60:40 air-CO₂ mix. Fillets from fish fed high fat level diets showed higher chroma and higher a^* and b^* colour parameters than those from fish fed low fat level diets. Storage time increased lightness and hue angle in CA but only lightness under MA. After storage at +4 °C lightness of fish fillets stored under MA were lower (P<0.05) than those stored under CA. Carotenoid source resulted in differences in chroma and hue angle of fish fillet stored under CA and MA. Dietary lipid levels resulted in differences in chroma under CA. Under CA the lower (P<0.05) differences between stored-initial values was for N₂-CO₂ and the higher (P<0.05) for air. Under MA, air-CO₂ and N₂-CO₂ gave similar results for L^*, C^* and H(°)_ab. Our experiment demonstrated that colour parameters of fish fillets reacted differently according to gas mixture and storage time.     

Two exotic fruits positively affect rat’s plasma composition

The aim of this investigation was to determine the bioactive compounds and the antioxidant potentials of Snake fruit and Mangosteen and their influence on plasma lipid levels and antioxidant activity in rats fed cholesterol-containing diets. It was found that total polyphenols and antioxidant potentials of Snake fruit were significantly higher than those of Mangosteen (P < 0.05). A cholesterol-containing diet supplemented with the studied exotic fruits showed a positive affect on rat’s plasma lipid levels and on the antioxidant activity during 30 days of feeding. In rat’s plasma of the Chol/Snake diet group, the fibrinogen fraction showed a decrease in the amounts and compositions of electrophoretic protein bands in the range of 110 and 14 kDa. However, all the positive results of this experiment on animals could not be automatically applied to humans.     

Effect of dietary supplementation of gallic acid and linoleic acid mixture or their synthetic salt on egg quality

The effect of a dietary supplementation of gallic acid and linoleic acid mixture (MGL) and their synthetic salt, sodium 2,3-dihydroxy-5-(((9E,12E)-octadeca-9,12-dienyloxy)carbonyl)phenolate (NGL), on egg quality was investigated. A total of 120 laying hens were allotted into five groups over 4 weeks of the experimental period. Birds were fed the following diets: (1) control [commercial diet (CD)], (2) 0.05% MGL (w/w, GA:LA = 1:1, equal molar ratio), (3) 0.1% MGL, (4) 0.05% NGL, (5) 0.1% NGL. The performance of the hen, the anti-oxidative potential of egg albumen and yolk, and the fatty acid composition and cholesterol content of egg yolk were measured. The TBARS value of egg yolk from hens fed 0.1% MGL and 0.05% NGL was lower than that fed control diet after storage for 14 days. The ABTS⁺ reducing activity of egg albumen was significantly improved by MGL and NGL, but only NGL had an effect on yolk (p < 0.05). The dietary supplementation of 0.05% or 0.1% MGL, and 0.05% NGL raised the PUFAs composition in egg yolk. The cholesterol content of egg yolk from hens fed control diet was higher than those fed 0.1% MGL, 0.05% or 0.1% NGL (p < 0.05). In conclusion, a diet consisting of MGL and NGL can improve the antioxidative potential of egg and the fatty acid quality of egg yolk while lowering the cholesterol level.     

The effect of ractopamine hydrochloride (Paylean) on lean carcass yields and pork quality characteristics of heavy pigs fed normal and amino acid fortified diets

Effects of ractopamine hydrochloride (RAC) on carcass parameters in heavy weight (133.24 ± 8.07 kg) finishing pigs (n = 278) given amino acid fortified (AA) or 16% crude protein (CP) diets were evaluated. A total of seven experimental diets were formulated; RAC was added at 0, 5 and 20 ppm to the 16% CP diets (CP0, CP5 and CP20, respectively) and at 0, 5, 10 and 20 ppm to the AA fortified diets (AA0, AA5, AA10 and AA20, respectively). Carcass, tenderloin, and ham weights were heavier (P < 0.05) for RAC AA diets vs. AA0. Loin weight was heavier (P < 0.05) for AA20 vs. AA0 and CP20 vs. CP0. No differences (P > 0.05) were observed for color or firmness scores. Carcass muscle score, ham weight and protein% were greater (P < 0.05) for RAC diets. Moisture was greater (P < 0.05) and fat was lower (P < 0.05) for AA5 and AA20 vs. AA0 and CP5 and CP20 vs. CP0. Feeding RAC to late finishing swine increases carcass yields and protein% with lower fat% for pigs weighing up to 136 kg.     

Effect of dietary olive leaves and/or α-tocopheryl acetate supplementation on microbial growth and lipid oxidation of turkey breast fillets during refrigerated storage

Thirty turkeys were allocated to five groups of six birds each. One group that served as control was fed a basal diet, while the others were fed diets supplemented with olive leaves at 5 or 10 g/kg, or α-tocopheryl acetate at 150 or 300 mg/kg. Following slaughter, fillets from breast were stored at 4 °C in the dark for 12 days, and lipid oxidation and microbial growth were assessed. Results showed that the incorporation of olive leaves in turkey diets increased (P < 0.05) the oxidative stability of raw breast fillets during refrigerated storage. Dietary olive leaves at 10 g/kg were more effective (P < 0.05) in inhibiting lipid oxidation compared to 5 g/kg, but inferior to the supplementation of 300 mg α-tocopheryl acetate/kg. In turn, α-tocopheryl acetate supplementation at 150 mg/kg was equal to olive leaves at 5 g/kg but inferior to olive leaves at 10 g/kg. Total viable counts, lactic acid bacteria, Enterobacteriaceae and psychrotrophic bacteria counts were all increased (P < 0.05) in breast fillets of all groups throughout the refrigerated storage. Diet supplementation with α-tocopheryl acetate had no effect on the bacterial counts recorded in the control group, but diet supplementation with olive leaves resulted in decrease (P < 0.05) of all bacterial counts at day 2 of storage and thereafter; during this period, olive leaves at the level of 10 g/kg were more effective in inhibiting bacterial growth compared to the level of 5 g/kg.     

Influence of on-farm production practices on sensory and technological quality characteristics of pork loin

Quality of pork from pigs raised either traditionally (outdoor access or bedded settings with no sub-therapeutic antibiotics or growth promotants in feed) or conventionally (commercial indoor) was evaluated. Pork loins (m. longissimus thoracis et lumborum, LTL) from four hundred pigs from either traditional or conventional production systems (n = 200) fed commercially formulated diets ad libitum were harvested at slaughter. Intramuscular crude fat content and lean color (L* and b*) values were significantly decreased in conventional pork loins. LTL from conventionally-raised pig carcasses showed increased (P < 0.05) mean pH, moisture content and reduced cooking loss and shear force values and had increased tenderness and juiciness scores compared to those from traditionally-raised pig carcasses. Results indicated that pork from conventionally raised pigs was superior to that from traditionally raised pigs in terms of tenderness and juiciness, suggesting that consumers may value pork from traditionally raised pigs on the basis of factors other than eating quality and appearance.