Effect of dietary supplementation with olive pomaces on the performance and meat quality of growing rabbits

The aim was to investigate the effects of three types (A, B and C) of stoned and dehydrated olive pomaces (OPs), differing in olive cultivar, on productive performance and meat quality of growing rabbits. The inclusion of OPs (5%) negatively affected the performance of rabbits as it reduced the feed intake, growth rate, carcass weight and dressing out percentage (P<0.05). Compared with the control, the meat of OP rabbits had a greater amount of monounsaturated and a lower amount of polyunsaturated fatty acids (P<0.05), independent of the type of OP used. Oxidative processes in the meat of OPA and OPB were higher (P<0.05), whereas OPC showed the same levels as the control group. This was due to the higher total polyphenol concentration and to the concomitant lower peroxide value of OPC. These results recommend the use of OP in rabbit diet with caution, taking into account the quality of the by-product in terms of oxidative status.     

Anticarcinogenic effect of phytic acid (IP6): Apoptosis as a possible mechanism of action

Several in vivo and in vitro studies provide convincing evidence for the anticarcinogenic properties of phytic acid (PA) (Inositol hexaphosphate, IP₆). The objectives of this investigation were to elucidate the effects of PA on suppression of colonic aberrant crypt foci (ACF) and to study the inhibitory effect of IP₆ on human colon carcinoma, CaCo-2 cell line. Fisher 344 male, weanling rats were divided into 3 groups of 15 each and were fed control diet (AIN 93 G-C) and C+(1 or 2 g/100 g PA in water) for 13 weeks. Rats received 2 s.c. injections of azoxymethane (AOM) in saline at 16 mg/kg body weight at 7 and 8 weeks of age. There was a 36% and 42% reduction in ACF in 1 and 2 g/100 g PA groups compared to control group (P<0.001). Cytotoxic effect of IP₆ was evaluated on Caco-2 cell line at concentrations of 0.25-4 g mol/l using lactate dehydrogenase (LDH) assay (LDH released from the cytosol of damaged cells into the supernatant), histone-associated DNA fragmentation assay using a cell death detection ELISA^® kit and microscopic analysis. The cells were treated with 0.25, 0.5, 1.0, 2.0, 4 g mol/l of IP₆ and incubated for 24 and 48 h. After 24 h of incubation, LDH release ranged from 13.55% to 44.70%. Histone-associated DNA fragmentation (an assay based on the quantitative sandwich-enzyme-immunoassay- principle directed against DNA and histones which allows the specific determination of mono- and oligonucleosomes in the cytoplasmic fraction of cell lysates) was also dose dependent. CaCo-2 cells grown on slide flaskets in the presence of 0.25 g mol/l IP₆ showed membrane blebbing (zeiosis) characteristic of apoptitic activity. Results of this study indicate that IP₆ might exert anticarcinogenic activity through induction of apoptosis.     

复配植酸保鲜剂对荔枝果实的保鲜效果

报道了植酸复配苯甲酸和柠檬酸对荔枝果实的保鲜效果。新鲜荔枝经复配植酸保鲜剂处理5～10min,3±1℃贮藏40d,根据果皮褐变、感官指标、腐烂程度和营养成分的变化评定保鲜效果。结果表明,复配植酸保鲜剂可使荔枝果实保鲜期达到40d左右,果肉品质、风味、果皮色泽保持良好。     

The effect of tenderizing acids on linoleic acid oxidation during marination of pork

The oxidation of lipids in different prefabricated meat products may have detrimental effects on the organoleptic properties and/or safety of meat, and poses a serious health concern. The oxidation processes may be accelerated by acids that are added to some products, e.g., marinated meat. In this work, the oxidation of free polyunsaturated fatty acids during pork marination in the presence of different acidifiers was investigated. It was demonstrated by the measurement of thiobarbituric acid reactive substances (TBARS) and by liquid chromatography - tandem mass spectroscopy that the highest degree of oxidation occurred in acetic acid and lactic acid marinades, whereas the oxidation was significantly suppressed by citric and ascorbic acids. Among the primary products of oxidation, 9,12,13-trihydroxy-10-octadecenoic acid and two isomers of hydroxy-epoxy-octadecenoic acid were dominating. A nearly linear correlation between TBARS values and total content of these two hydroxy-fatty acids was observed.     

天然虾青素对鸭肉品质和脂质氧化稳定性的影响

研究天然虾青素对肉鸭的感官、肉质和储藏稳定性的影响。试验选择108只出壳健康商品樱桃谷肉鸭,随机分为2组,分别饲喂添加0mg/kg(对照组)和10mg/kg虾青素(试验组)的饲粮。结果表明:饲喂虾青素可显著改善肉鸭胫掌、喙的颜色,并可在肝脏、胸肌和腿肌中沉积,可显著降低胸肌鲜样和冰冻样中的丙二醛(MDA)含量。     

Phage inactivation of foodborne pathogens on cooked and raw meat

Phages infecting Salmonella Typhimurium PT160 and Campylobacter jejuni were added at a low or high (10 or 10(4)) multiplicity of infection (MOI) to either low or high (<100 or 10(4)cm(-2)) densities of host bacteria inoculated onto raw and cooked beef, and incubated at 5 and 24 degrees C to simulate refrigerated and room temperature storage. Counts of host bacteria were made throughout the incubation period, with phages being counted at the first and last sampling times. Host inactivation was variable and depended on the incubation conditions and food type. Significant host inactivations of the order of 2-3 log(10)cm(-2) at 5 degrees C and >5.9 log(10)cm(-2) at 24 degrees C were achieved compared to phage-free controls using the Salmonella phage under optimal conditions (high host cell density and MOI). These results alongside those already published indicate that phages may be useful in the control for foodborne pathogens.     

Effects of kimchi ethanolic extracts on oxidative stability of refrigerated cooked pork

The antioxidant effect of different kimchi extracts in cooked ground pork during storage for 14 days at 4°C was studied. Cooked ground pork was treated with ascorbic acid, BHT, baechu kimchi (BK), got kimchi (GK), puchu kimchi (PK), and white kimchi (WK) and compared to cooked ground pork without antioxidant. Radical scavenging and chelating activities of kimchi extracts were in the order: GK>PK>BK>WK. Total phenolic contents and flavonoid contents ranged from 32.52 to 46.73 mg of GAE/g and 5.87 to 25.58 mg quercetin/g, respectively. Significantly (P<0.05) lower values of TBARS, peroxide values, and hexanal contents were obtained for GK treated samples compared with cooked pork without antioxidant during refrigerated storage. GK showed good antioxidant activity and was significantly different (P<0.05) from the other treatments. Based on these findings, the natural antioxidants examined may have applications in the development of nutritionally enhanced meat products with enhanced shelf life.     

The effect of the change from a herbage- to a concentrate-based diet on the oxidative stability of raw and cooked lamb meat

Over 89 days, 10 lambs (S) were fed concentrates and hay in stall, while 9 lambs (P) grazed at pasture. Two groups of 9 animals grazed at pasture until switching to a concentrate-based diet for 14 or 37 days before slaughter (P-S14 and P-S37). The fat content of longissimus dorsi muscle (LM) increased with increasing duration of concentrate feeding (P = 0.05). As a consequence, the concentration of polyunsaturated fatty acids (PUFA) and of the highly peroxidisable (HP) PUFA in the polar lipids was similar between treatments. Lipid oxidation in fresh LM over 8 days of storage was affected by the diet (P < 0.0005) with the P-S37 and P treatments producing, respectively, the highest and the lowest TBARS values. The P treatment reduced TBARS in cooked minced LM over 2 days of storage and no difference was found between the P-S14, P-S37 and S treatments. Colour stability of fresh LM was not noticeably affected by the dietary treatment.     

Antioxidant and free radical scavenging potential of Achillea santolina extracts

The antioxidative activities of hydroalcoholic extract of Achillea santolina were investigated employing various established in vitro systems including total antioxidant activity in linoleic acid emulsion system, 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide and hydroxyl radicals scavenging, reducing power, and inhibitory effect on protein oxidation as well as the inhibition of Fe²⁺/ascorbate induced lipid peroxidation in rat liver homogenate. Total phenolic and flavonoid content of A. santolina extract (ASE) was also determined by a colorimetric method. The results revealed that ASE has notable inhibitory activity on peroxides formation in linoleic acid emulsion system along with concentration-dependent quenching of DPPH and superoxide radicals. Furthermore, the extract showed both nonsite-specific (Fe²⁺ + H₂O₂ + EDTA) and site-specific (Fe²⁺ + H₂O₂) hydroxyl radical scavenging suggesting potent hydroxyl radical scavenging and chelating ability for iron ions in deoxyribose degradation model. A linear correlation between ASE and the reducing power was also observed (r² = 0.9981). ASE prevents thiobarbituric acid reactive substances formation in Fe²⁺/ascorbate induced lipid peroxidation in rat liver tissue in a dose-dependent manner. Moreover, free radical induced protein oxidation was suppressed significantly by the addition of ASE over a range of concentration. These results clearly demonstrated that A. santolina extract possess a marked antioxidant activity.     

Effect of processing methods on product characteristics,lipid, fatty acid composition and oxidative stability of smoke-dried beef

Smoke-dried beef was pre-processed with water or by pressure cooking, weight losses were 50 and 54% respectively, with the rate of drying faster in the latter. There was a greater loss of total lipid and triglycerides in pressure cooked samples but the reverse was true for the phospholipids. The proportions of saturated and monoenoic fatty acids were slightly higher in the water cooked products although total unsaturation was slightly lower, the values being 37 and 39%, respectively. The fatty acid composition of the phospholipids was similar for both treatments except that the levels of polyenoic fatty acids were 16.4 and 14.43%, respectively in water and pressure cooked samples. Of the polyenes C20:4 accounted for about 75% of the fatty acids in the water cooked samples, compared with 40% with pressure cooking. After 60 weeks of storage at room temperature, pressure cooked samples were found to be more stable oxidatively: malonaldehyde was the principal oxidative by-product in both treatments.     

甘蓝型油菜籽粒油酸、亚油酸、亚麻酸和蛋白质含量变异及相关性分析

对现有种质资源进行分析,有利于甘蓝型油菜品质育种亲本选配及种质创新.本研究对312份甘蓝型油菜种质资源进行近红外光谱检测,通过相关性分析和聚类分析探究油菜籽粒中油酸、亚油酸、亚麻酸和蛋白质含量及它们间的相关性.结果 表明:油酸含量与亚油酸及蛋白质含量呈极显著负相关,亚油酸含量与蛋白质含量呈极显著正相关;在阈值为2时,可...     

Dietary Spirulina (Arthrospira platensis) and Thyme (Thymus vulgaris) supplementation to growing rabbits: Effects on raw and cooked meat quality,nutrient true retention and oxidative stability

The study evaluated the effect of Spirulina and Thyme dietary supplementation on rabbit meat quality, nutrient true retention and protection against oxidative stress. Rabbits in the control group (C–C) received a non-supplemented pellet throughout the experiment (5–11 weeks of age). In the other groups, the pellet contained 5% Spirulina (S), 3% Thyme (T), or both (ST) for either the entire (groups S–S, T–T, ST–ST) or only the final part of the growing period (8–11 weeks: groups C–S, C–T, C–ST). Spirulina supplementation increased the γ-linolenic acid content of rabbit meat, whereas Thyme improved the oxidative stability of raw and freeze-dried meat.     

茶多酚和维生素C对腌制猪肉亚硝酸盐残留量和脂肪氧化的影响

以腌制猪肉模型为材料,研究不同含量的茶多酚和维生素C对色泽、残留亚硝酸盐含量以及脂肪氧化TBARS值的影响。结果表明,茶多酚和维生素C都在一定程度上降低了腌制模型中亚硝酸钠的残留量,维生素C的作用效果要显著强于茶多酚(p<0.05)。腌制过程中TBARS值呈逐渐增加的趋势,茶多酚和维生素C有降低TBARS值的作用,茶多酚的作用效果要强于维生素C。在腌制过程中,维生素C组的色泽显著高于茶多酚组(p<0.05),而蒸煮后各组之间色泽差异不显著(p>0.05)。      

Antioxidant and protective properties of six Tanacetum species against hydrogen peroxide-induced oxidative stress in K562 cell line: A comparative study

The antioxidant activities of ethanolic extract of six species of Tanacetum (T. budjnurdense, T. hololeucum, T. chiliophyllum, T. sonboli, T. tabrisianum, T. kotschyi) from Iran were examined by employing various established in vitro assay systems. The results showed that all Tanacetum extracts displayed antioxidant activities, with IC₅₀ values ranging from 59.55 to 157.24 μg/ml, using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The extract of T. hololeucum, with an IC₅₀ value of 59.55 μg/ml was nearly two or three times more active than the other used Tanacetum extracts. The amounts of total phenolics and total flavonoids were also determined by spectrophotometer. A similar order of the amounts of phenolics and flavonoids in all plant extracts were found. The results showed that the extent of antioxidant activities is in accordance with the amounts of phenolics and flavonoids existing in all plant extracts. Regarding high performance liquid chromatography (HPLC) data, caffeic acid, ferulic acid, luteolin, apigenin and rutin were detected as major phenolic compounds in all the species investigated. Pretreatment of K562 cells with various concentrations of Tanacetum extracts (10–100 μg/ml) for 16 h prevent cell damage and enhanced activity of antioxidant enzymes induced by a treatment with H₂O₂. Moreover, lower level of glutathione caused by hydrogen peroxide in K562 cells were partly recovered by a pretreatment of cells with various Tanacetum species extract. These results may show the significant protection effect of Tanacetum sp. against oxidation of the cells.     

响应面法优化麦麸中植酸的提取条件及植酸抑菌效果分析研究

以麦麸为原料,采用盐酸提取麦麸中植酸。在单因素实验的基础上,选择提取时间、提取温度、酸浸液浓度和料液比为自变量,植酸含量为指标,通过响应面法优化植酸提取的工艺条件,建立了植酸提取的二次多项式数学模型,并得到最佳工艺条件。采用牛津杯法研究了其对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌和沙门氏菌的抑菌谱及最小抑菌浓度;探讨了不同浓度、金属阳离子及浓度、温度和有机溶剂对其抑菌效果的影响。结果表明:麦麸中植酸提取的最佳工艺条件为:提取时间2.2h,提取温度40℃,酸浸液浓度1.2mol/L,料液比1∶22(g/m L)。经验证在最佳提取工艺下,植酸的含量为1.215%。植酸提取液对四种细菌均有较好的抑制效果,最小抑菌浓度依次为2.17、2.89、3.61、3.61μg/m L;随着植酸提取液浓度增大,抑菌效果增强;分别与100、200、300mmol/L的氯化钠、氯化钾、氯化镁、氯化钙溶液混合,抑菌效果减弱;与10%(v/v)乙醇、丙二醇、丙三醇等有机溶剂混合后,其抑菌效果明显下降;经0、65、121℃处理后的植酸提取液的抑菌效果无明显变化。      

Inhibitory effect of organic acid salts on spoilage flora in culture medium and cured cooked meat products under commercial manufacturing conditions

Lactobacillus curvatus, isolated from a spoiled vacuum-packaged 'pariza' type meat product, was used to inoculate modified MRS broth containing sodium lactate, sodium acetate and potassium sorbate in different concentrations, alone or in inter se combinations. Two commercial preparations (MIX 1 and MIX 2) were also used containing combinations of the above antimicrobials. Results from the preservatives addition to the culture medium showed highest antimicrobial activity in the case of the sodium lactate (2%, 3% or 4%), sodium acetate (0.5%) and potassium sorbate (0.15%) combination. Results from the preservatives addition to two types of thermally processed meats showed that sodium lactate and the combination of sodium lactate, sodium acetate and potassium sorbate were the most effective; extending the products shelf life an additional 10 days. Finally, MIX 1 and MIX 2 suppressed the lactic acid bacteria (LAB) growth in the culture medium but not in the final product.     

Effect of dietary antioxidant and fatty acid supply on the oxidative stability of fresh and cooked pork

The effect of dietary oil (linseed or soybean oil) and antioxidant treatment (α-tocopheryl acetate (AT; 40ppm) versus a cocktail (AOC; 200ppm): α-tocopheryl acetate+rosemary+citric acid+gallic acid) on colour, lipid and protein oxidation of fresh and processed pork was investigated. No effect of oil source on different parameters of oxidation was seen. No effect of antioxidant treatment on colour stability of fresh longissimus thoracis (LT) or cooked cured ham (CCH) was observed. For both antioxidant treatments, lipid oxidation in fresh LT and CCH was well controlled during display. However, lipid oxidation increased significantly in pre-frozen uncured cooked meat under aerobic conditions. No unambiguous effect of antioxidant treatment on protein oxidation was observed. There seemed to be no clear link between colour, protein and lipid oxidation. At the dose used in this study, no additional or synergistic effects of the extra components of the AOC on the different oxidation parameters was found.     

Comparison of solvent and microwave extracts of cranberry press cake on the inhibition of lipid oxidation in mechanically separated turkey

Cranberry press cake, an under utilized by-product of the cranberry processing industry is a potential source of food antioxidants. The objective of this research were (1) to prepare extracts from cranberry press cake using solvent extraction (SE) and microwave assisted solvent extraction (MASE), and (2) to test the ability of these extracts to inhibit lipid oxidation in mechanically separated turkey (MST). Water, ethanol and acetone were used as extraction solvents. Heating press cake prior to extraction with 70% ethanol increased antioxidant efficacy compared to extracting unheated press cake. Water extracts were least effective in inhibiting lipid oxidation. The most effective extracts were obtained by SE with 100% acetone or MASE with 100% ethanol. A poor correlation of 0.69 was obtained between the total phenols in the extracts and their ability to inhibit thiobarbituric acid reactive substances (TBARS) formation in MST. The correlation coefficient between the amount of quercetin in the extracts and the number of days of TBARS inhibition in MST was 0.87. This indicates that although quercetin may be good inhibitor of lipid oxidation, polyphenols other than quercetin are likely have a role in the inhibition of TBARS in MST. For a similar yield of the extracts, MASE extract using 100% ethanol was a better inhibitor than 100% ethanol SE extract of lipid oxidation in MST. In terms of choice of solvent, based on their flammability and toxicity, MASE with 100% ethanol would be a more likely a choice over SE with 100% acetone, for inhibiting oxidation in MST.     

Evaluation of antioxidant and immune activity of Phellinus ribis glucan in mice

The potential protective effects of Phellinus ribis glucan (PRG) administration against immune injury due to free radical formation were evaluated in mice. The results showed that glucan administration significantly increased thymus and spleen indices, spleen lymphocyte proliferation and NK cells activity, as well as CD8 T cell numbers, and decreased CD4+/CD8+. In accordance with a previous study, glucan administration significantly enhanced plasma glutathione peroxidase, superoxide dismutases activity and reduced plasma thiobarbituric acid reactive species level. In conclusion, our results indicate that glucan administration improve immune function by its free radicals scavenging activity and reducing oxidative stress in mice.