表没食子儿茶素没食子酸酯对鸡胸肉蛋白质理化特性和脂肪氧化的影响

添加0、40、200、1000 mg/kg表没食子儿茶素没食子酸酯(Epigallocatechin gallate,EGCG)腌制置于Fenton氧化体系中的鸡胸肉糜,通过分析鸡胸肉糜的硫代巴比妥酸值(TBARS值)、酸价、色差、感官以及提取后肌原纤维蛋白的溶解度、巯基含量、荧光色谱,探究不同EGCG浓度对鸡胸肉蛋白质理化特性及脂肪氧化的影响。结果表明,肌原纤维蛋白的溶解度和疏水性随EGCG浓度的增加而逐渐下降;与0 mg/kg组相比,添加EGCG后,巯基含量显著降低(P<0.05);随着EGCG浓度的上升,荧光强度逐渐增加;与0 mg/kg组相比,添加EGCG后,TBARS值显著降低(P<0.05);添加40 mg/kg EGCG时鸡胸肉的各项感官指标、可接受性和色泽整体相对较好。表明添加40 mg/kg EGCG能抑制鸡胸肉蛋白质和脂肪氧化,提高肉品质。     

三种天然抗氧化剂对冷鲜兔肉保鲜效果研究

分别利用茶多酚,迷迭香提取物和植酸钠等天然抗氧化剂对冷却獭兔肉进行抗氧化及保鲜。结果表明:0.3g/kg茶多酚(TP),0.3g/kg水溶性迷迭香提取物及0.2g/kg植酸钠均可有效抑制冷鲜兔肉脂肪氧化,延缓氧化酸败异味的产生,从而有效延长冷鲜兔肉货架期,在(4±0.5)℃条件下达到9d左右;而空白对照组兔肉货架期仅为6d。     

铁核桃油的氧化稳定性及抗氧化剂对其影响研究

以低温液压压榨铁核桃油为试验对象,通过Rancimat892油脂氧化稳定性测定仪研究了铁核桃油的氧化稳定性及抗氧化剂对其影响。结果表明:在不添加抗氧化剂、20℃条件下,铁核桃油的货架期为69 d;在添加相同量的单一抗氧化剂情况下,抗氧化效果排序为TBHQPGBHT茶多酚维生素E;在添加复合抗氧化剂的情况下,铁核桃油氧化诱导时间的排序为添加100 mg/kg TBHQ+100 mg/kg PG100 mg/kg TBHQ+200 mg/kg茶多酚100 mg/kg PG+200 mg/kg茶多酚100 mg/kg TBHQ+100 mg/kg BHT100 mg/kg BHT+200 mg/kg茶多酚。     

茶多酚对梅鱼鱼丸保鲜效果的研究

以感官品质、细菌总数、挥发性盐基氮(TVB-N)、硫代巴比妥酸值(TBA)、pH值为质量指标定期取样测定,研究荼多酚在0℃条件下对梅鱼鱼丸的保鲜效果.结果表明:茶多酚具有良好的抗菌作用和抗氧化活性,能有效抑制微生物的生长及延缓脂肪氧化,提高鱼丸的凝胶性能,延长梅鱼鱼丸的货架期.其添加量为200～300mg/kg时保鲜效果显著.     

大蒜素对肉仔鸡脂肪代谢及相关基因表达的影响

探讨大蒜素对肉仔鸡脂类代谢及相关基因表达的影响,为揭示大蒜素调节动物脂肪沉积的机理作依据。试验选取体重相近、体格健壮的1日龄AA肉仔鸡(公)96只,随机分成4组,每组设4个重复,每个重复6只鸡。试验期为42d。在各组基础饲料中分别添加0、200、400、600mg/kg的大蒜素。结果表明,添加400和600mg/kg大蒜素的处理组与对照组比较,肉仔鸡腹脂率和肝脂率显著降低(P0.05);而添加200、400及600mg/kg大蒜素的处理组与对照组比,皮下脂肪厚度和肌间脂肪厚度没有显著的差异(P0.05),但有下降的趋势。400mg/kg组和600mg/kg组的甘油三酯、总胆固醇及低密度脂蛋白的含量显著下降(P0.05);而高密度脂蛋白水平则呈现出显著的提高(P0.05)。各浓度添加大蒜素组的游离脂肪酸的水平与对照组相比而言,有降低的趋势,但差异不显著(P0.05)。添加400mg/kg或600mg/kg大蒜素可显著降低AA肉仔鸡肝脏中的乙酰辅酶A羧化酶、脂肪酸合成酶的mRNA表达水平(P0.05);添加600mg/kg大蒜素组的肉仔鸡肝脏脂蛋白脂酶mRNA水平显著上调(P0.05)。添加600mg/kg大蒜素的肉仔鸡腹脂中乙酰辅酶A羧化酶mRNA表达水平显著低于对照组(P0.05),脂蛋白脂酶mRNA水平则显著上升(P0.05)。大蒜素对肉仔鸡腹脂脂肪酸合成酶mRNA水平无显著影响。     

茶多酚棕榈酸酯对棕榈油抗冻性和煎炸稳定性的影响

为了对棕榈煎炸油的开发提供参考，以不同茶多酚棕榈酸酯(抗氧化剂)添加量的分提18℃棕榈油为煎炸油，通过10℃和15℃冷冻试验中煎炸油(茶多酚棕榈酸酯含量分别为0、50、80、100、150、200、300 mg/kg)晶体微量析出时间和发朦时间的变化，以及180℃下薯条煎炸过程中煎炸油酸值、p-茴香胺值、总氧化值、色泽、脂肪酸组成、极性组分含量和3-氯丙醇酯含量的变化，分析了茶多酚棕榈酸酯对棕榈油抗冻性和煎炸稳定性的影响。结果表明：棕榈油的发朦时间与抗氧化剂的添加量整体呈阶梯增长的关系，尤其在15℃条件下，其抗冻性在茶多酚棕榈酸酯含量为50 mg/kg和150 mg/kg时明显增强；煎炸油的酸值、p-茴香胺值、总氧化值、脂肪酸组成、极性组分含量与茶多酚棕榈酸酯添加量无相关性；添加茶多酚棕榈酸酯的棕榈油在煎炸后的色泽均比空白组深；3-氯丙醇酯在煎炸初期降解剧烈，后期降解缓慢，最终趋于平缓，与抗氧化剂的添加量无相关性。总之，向棕榈油中添加茶多酚棕榈酸酯可以明显提高其抗冻性，茶多酚棕榈酸酯含量为50 mg/kg或150 mg/kg时，其抗冻性改进效果最为明显，但是并不能有效提升煎炸油的煎炸稳...     

猪腿肉脂肪酸组成及脂肪氧化的研究

本文研究了不同性别英系大白腿肉中肌间脂肪和皮下脂肪含量,并对其脂肪酸组成进行了分析,同时研究了腿肉在(4±0.5)℃避光贮存条件下脂肪氧化程度的变化,结果表明,不同性别猪腿肉肌间和皮下脂肪酸组成及含量均没有显著性差异(p>0.05);在(4±0.5)℃避光贮存期间(0～5d),肌间脂肪氧化程度显著高于皮下脂肪氧化程度(p<0.05),尤其到第5d时,肌间脂肪氧化指标-TBA值接近0.5mg/kg,而皮下脂肪TBA值低于0.2mg/kg。一般来讲,当生肉的TBA值超过0.5mg/kg时,人就能感觉到有氧化异味。因此,控制肌间脂肪氧化保证冷却肉良好品质的关键。     

迷迭香对西式切片火腿色泽和氧化稳定效应的研究

为了考察迷迭香对蒸煮肉制品的护色、抗氧化效应,以牛肉和猪肉切片火腿(SCCH)为材料,在其腌制剂中分别添加500、1000、1500 mg/kg的迷迭香,以添加400 mg/kg Vc的样品和不添加抗氧化剂的样品作为对照,通过定期测定其在冷藏过程中的表观色泽、色素含量、脂肪氧化TBARS值和蛋白质氧化形成羰基值来分析迷迭香的效果。结果表明:迷迭香在实验浓度范围内可以显著抑制猪肉和牛肉SCCH的脂肪氧化和红色素的降解,对蛋白氧化形成的羰基值没有显著抑制效应。迷迭香可以有效提高火腿的表观红色度,但同时也显著地提高了黄色度b*,而且对b*的提高有浓度依赖性。迷迭香在合适的质量分数下可以对SCCH有效地护色和抗氧化,建议在牛肉中的用量应不超过1000 mg/kg,在猪肉中不超过500 mg/kg。     

酵母细胞液处理对白鲢鱼鱼糜脂肪氧化和风味的影响

研究酵母细胞液脱除鲢鱼肉的腥味,以水洗鱼糜为对照,采用化学分析、感官评定、气相色谱- 质谱-嗅闻(GC-MS-O)研究酵母细胞液对白鲢鱼鱼糜脂肪氧化和风味的影响。结果表明：葡萄酒酵母细胞液能显著抑制鱼肉脂肪氧化,并快速消除鱼肉的硫代巴比妥酸反应物(TBARS),在2h 内从2.4 mg/kg 降低到0.8mg/kg,速率约为0.8mg/(kg·h) (25℃)。水洗鱼糜鱼腥味残留较重,葡萄酒酵母细胞液处理鱼糜的鱼腥味大部分被脱除。鱼糜中具有鱼腥味的2- 葵烯醛、2, 4- 葵二烯醛在经葡萄酒酵母细胞液处理后已检测不到,而水洗鱼糜中有部分2- 葵烯醛残留(0.48mg/kg)。所以,葡萄酒酵母细胞液对白鲢鱼鱼糜具有很好的脱腥效果。     

烤翅加工过程中亚硝酸盐对其品质的影响

研究了不同亚硝酸盐添加量(0、50、100和150 mg/kg)对肉鸡翅根腌制和烘烤过程中及杀菌后成品色泽、TBA值、菌落总数及感官特性的影响。烤翅加工过程中鸡翅根内外表面色泽变化,亚硝酸盐添加量越大,鸡翅根内外表面的L*值和a*值越大,但添加量对b*值影响不显著(p0.05);亚硝酸盐能够抑制烤翅加工过程中的脂肪氧化,在腌制和烘烤过程中随着亚硝酸盐添加量增大,样品TBA值逐渐减小(p0.05),杀菌后添加亚硝酸盐的样品TBA值(0.961~0.990 mg/kg)显著(p0.05)低于对照样(1.223mg/kg),但不同添加量之间差异不显著(p0.05);不添加亚硝酸盐的烤翅色泽黯淡、表面发黄,感官色泽评分和总体可接受度低(p0.05);添加亚硝酸盐的样品具有更加明亮的红色,但不同添加量之间的辨识度较低,在口感、滋味和风味方面的感官评分差异不显著;亚硝酸盐对烤翅加工过程中菌落总数无影响。     

Addition of tea catechins and vitamin C on sensory evaluation, colour and lipid stability during chilled storage in cooked or raw beef and chicken patties

The effects of addition of tea catechins (TC) and vitamin C (VC) on sensory evaluation, colour and lipid stability in cooked or raw beef and chicken meat patties during refrigerated storage were studied. Fresh beef striploin and chicken breast muscles were minced, following removal of external fat and connective tissue. Following mincing, beef and chicken were assigned to one of the following five treatments: control (meat treated with no antioxidant); TC200, meat plus 200 mg TC/kg muscle; TC400, meat plus 400 mg TC/kg muscle; VC200, meat plus 200 mg VC/kg muscle, VC400, meat plus 400 mg VC/kg muscle. Sodium chloride (1%) was added to all samples. Patties (125 g portions), formed from the above-treated minced meat, were oven cooked, cooled, and packaged in 30% CO₂:70% N₂. Fresh raw beef and chicken patties were packaged in 80% O₂:20% CO₂. All samples were stored for up to 7 days under fluorescent lighting at 4 °C. Sensory parameters (colour, flavour, taste, tenderness and overall acceptability) were evaluated on cooked beef and chicken patties after 1, 3 and 6 days of storage. Surface colour (Hunter L, a and b values), and lipid oxidation (2-thiobarbituric acid reactive substances) were measured on days 1, 3 and 6 of storage for cooked meats and on days 2 and 7 for raw beef and chicken. Tea catechins addition (200 or 400 mg/kg) to minced meat caused (P < 0.05) discolouration in cooked beef and chicken meat patties and significantly reduced (P < 0.001) lipid oxidation in cooked or raw beef patties compared to the control. Beef, either raw or cooked, was more susceptible (P < 0.01) to oxidation compared to chicken. Raw meat stored in high oxygen conditions was more susceptible to lipid oxidation than cooked meat stored in anaerobic conditions. Tea catechins treatments (TC200 and TC400) inhibited (P < 0.05) lipid oxidation in raw beef to a greater extent than vitamin C treatments (VC200 and VC400). These results indicate that tea catechins are potent natural antioxidants and exhibit greater antioxidant efficacy compared to vitamin C.     

Effect of dietary α-tocopherol supplementation and gamma-irradiation on α-tocopherol retention and lipid oxidation in cooked minced chicken

The effects of dietary α-tocopherol supplementation and gamma-irradiation on α-tocopherol retention and lipid oxidation in cooked minced chicken during refrigerated storage were studied. Minced breast and thigh meat from broilers fed diets supplemented with 100, 200 or 400 mg α-tocopheryl acetate/kg feed was irradiated at 2.5 or 4.0kGy. Cooked irradiated and unirradiated meat was stored at 4 °C for 5 days. α-Tocopherol concentrations increased with increasing dietary supplementation. Concentrations decreased during storage, but retention was not affected by irradiation. Lipid stability was determined by measuring the formation of thiobarbituric acid-reacting substances (TBARS) and cholesterol oxidation products (COPs) during storage. TBARS and COPs increased during storage and were reduced by increasing levels of dietary α-tocopheryl acetate supplementation. Irradiation accelerated TBARS formation during storage, but this was prevented by supplementation with 200 mg α-tocopheryl acetate/kg feed. Irradiation tended to increase COPs during storage, although no consistent effects were observed. In general supplementation with over 400 mg α-tocopheryl acetate/kg feed may be required to control cholesterol oxidation in minced chicken. The results suggest that, overall, irradiation had little effect on lipid stability in α-tocopherol-supplemented meat following cooking and storage.     

Effect of different dietary levels of natural-source vitamin E in grow-finish pigs on pork quality and shelf life

Improving pork quality and shelf life is important in today’s swine industry because higher levels of DDGS are incorporated into pig diets. Relatively high level of poly-unsaturated fatty acids (PUFA) in DDGS may increase pork susceptibility to lipid oxidation and thus reduce pork shelf life. Antioxidants such as vitamin E may delay the onset of pork lipid oxidation when used as an ingredient in the diet. This experiment examined carcass characteristics, meat quality, shelf life, and color stability in pork from pigs (n = 150) fed five levels of a natural vitamin E (Nova-E) and one level of synthetic vitamin E. Natural vitamin E and synthetic vitamin E had no effect on carcass characteristics or meat quality. Increasing dietary natural vitamin E from 10 to 200 mg/kg decreased lipid oxidation. Lipid oxidation of pork chops and ground pork was similar between pigs fed 40 mg/kg and higher levels of natural vitamin E, indicating no additional benefits from supplementing beyond 40 mg/kg natural vitamin E. Supplementing 200 mg/kg synthetic vitamin E decreased pork lipid oxidation when compared to supplementing 10 mg/kg natural vitamin E. High levels of natural vitamin E or synthetic vitamin E, however, did not prevent discoloration of loin chops. These data indicate that natural vitamin E was effective to help reduce lipid oxidation and the effective minimal level of dietary supplementation appeared to be 40 mg/kg.     

Effects of Rosemary Extract and Sodium Lactate on Quality of Vacuum-packaged Ground Ostrich Meat

ABSTRACT Vacuum‐packaged ground ostrich meat patties containing 2% sodium lactate (SL), 0.2% rosemary extract as oleoresin (RE), or their mixture (MIX) were evaluated and compared with control for their storage stability at 3 ± 1 °C in the dark by measuring pH, 2‐thiobarbituric acid‐reactive substance (TBARS) values, sample color (CIE L*, a*, b*, Hue and Chroma), and microbiological content. The pH values of ostrich patties, ranging from 6.03 to 6.13, were not affected by treatment (P < 0.05). At 9 d of storage, TBARS concentration for control samples containing no additives was 1.64 mg malonaldehyde/kg meat. Addition of RE to the ground ostrich meat inhibited lipid oxidation during storage at 3 ± 1 °C (P < 0.05). TBARS values of SL‐added samples were lower than control samples (P < 0.05); addition of SL also delayed the oxidation. It was found that RE had a protective effect on color, whereas addition of SL decreased CIE a* values (P < 0.05). SL, either alone or with RE, was effective in inhibiting total aerobic bacteria (TAB), coliforms, lactic acid bacteria (LAB), and Brochothrix thermosphacta in ostrich patties (P < 0.05) and provided a 2‐log reduction in microbial population during storage. In addition, RE did not have a significant effect on microbial growth at the concentration used in this study.     

Effect of carnosine, salt and dietary vitamin E on the oxidative stability of chicken meat

The effect of carnosine on lipid and cholesterol oxidation in salted chicken thigh meat and its relationship to dietary α-tocopherol supplementation was examined. Broilers (Cobb 500) were fed diets with a basal (30 mg kg(-1)) or supplemental (200 mg kg(-1)) level of α-tocopheryl acetate for 6 weeks. Thigh meat patties were prepared with carnosine (1.5%), salt (1%) or salt plus carnosine. Salt accelerated lipid and cholesterol oxidation following cooking and refrigerated storage. However, carnosine inhibited lipid and cholesterol oxidation in salted patties. Dietary α-tocopherol supplementation also reduced the extent of lipid and cholesterol oxidation in salted patties. The combination of carnosine and dietary α-tocopherol resulted in the greatest lipid and cholesterol stability in salted meat.     

超高压处理对牦牛肉贮藏性能的影响

牦牛肉分别经200、400、600 MPa超高压处理480 s，测定4°C条件下贮藏0、4、8、12、16 d后感官、pH、微生物、色泽、蛋白质与脂质氧化情况，以探讨超高压处理对牦牛肉贮藏期内品质的影响。结果表明：超高压处理可以显著降低贮藏期内牦牛肉的菌落总数、总挥发性盐基氮含量（total volatile basic nitrogen, TVB-N）(P<0.05)，延长保质期，且经贮藏4～8 d后能良好保持牦牛肉的感官品质。经超高压处理后牦牛肉L*值、b*值显著增大（P<0.05）,a*值在400 MPa时显著增大（P<0.05）并在贮藏期内维持在最高水平，且400 MPa组各类肌红蛋白（Myoglobin, Mb）含量也表现出良好的肉色稳定性，但a*值在其他压力处理后显著减小（P<0.05）。但经超高压处理后牦牛肉肌原纤维蛋白（Myofibrillar Protein, MP）羰基含量与表面疏水性增高、巯基含量降低，TBARS值升高。Pearson相关性分析结果也表示超高压处理后牦牛肉品质的变化与压力、蛋白质氧化、脂质氧化和微生物相关（P<0.05...     

儿茶素对鸡肉的抗氧化保鲜作用

通过在肉鸡饲料中添加一定量的儿茶素 ,来研究体内儿茶素对鸡肉的抗氧化保鲜作用效果。体内儿茶素明显提高了鸡肉的氧化稳定性能 ,具有延长保鲜期的潜力 ,鸡腿肉的效果比鸡胸肉的效果更加明显 ,鸡肉的氧化稳定性能随着儿茶素添加量的增多而改善 ,儿茶素 3 0 0mg/kg的抗氧化作用效果与VE2 0 0mg/kg的相近。结果表明 ,儿茶素可以代替VE 作为肉鸡饲料中的抗氧化添加剂 ,以提高鸡肉的氧化稳定性及延长其保鲜期     

Effects of Dietary Rape Seed Oil, Copper(II) Sulphate and Vitamin E on Drip Loss, Colour and Lipid Oxidation of Chilled Pork Chops Packed in Atmospheric Air or in a High Oxygen Atmosphere

The effect of addition of rapeseed oil (canola), CuSO(4) and vitamin E (all-rac-α-tocopheryl acetate) to pig diets on pork meat quality (lipid oxidation, colour and drip loss) was studied. Pigs were reared on ten different diets, either a control diet (no supplementation of rapeseed oil, CuSO(4) or vitamin E) or 6% rapeseed oil diets supplemented with CuSO(4) (0, 35 or 175mg/kg) and vitamin E (0, 100 or 200mg all-rac-α-tocopheryl acetate/kg). The natural content of vitamin E originating from feed ingredients amounted to 9-23mg vitamin E (α-tocopherol) per kg feed. Muscle vitamin E levels reflected the dietary intake and pigs fed the control diet had significantly lower levels than pigs fed rapeseed oil diets. The quality of fresh pork chops packed in air or in 80% O(2):20% CO(2) was followed during chill storage for 8 and 13 days, respectively. Colour, as measured by tristimulus colorimetry of pork chops packed in 80% oxygen atmosphere, was significantly improved with respect to redness when compared to chops packed in air, regardless of dietary treatment. The low vitamin E content in pigs fed the control feed significantly decreased a values and the oxidative stability of pork chops during chill storage compared to the other feeding groups. Packing of chops in a high-oxygen atmosphere increased lipid oxidation, especially in chops with low levels of vitamin E. Supplementation of rapeseed oil diets with 100 or 200mg vitamin E significantly decreased lipid oxidation of chill stored chops. Supplementation with CuSO(4) did not influence meat quality attributes (drip loss, colour stability and lipid oxidation) for any of the storage conditions.     

Effect of different dietary levels of natural-source vitamin E in grow-finish pigs on pork quality and shelf life

Improving pork quality and shelf life is important in today’s swine industry because higher levels of DDGS are incorporated into pig diets. Relatively high level of poly-unsaturated fatty acids (PUFA) in DDGS may increase pork susceptibility to lipid oxidation and thus reduce pork shelf life. Antioxidants such as vitamin E may delay the onset of pork lipid oxidation when used as an ingredient in the diet. This experiment examined carcass characteristics, meat quality, shelf life, and color stability in pork from pigs (n = 150) fed five levels of a natural vitamin E (Nova-E) and one level of synthetic vitamin E. Natural vitamin E and synthetic vitamin E had no effect on carcass characteristics or meat quality. Increasing dietary natural vitamin E from 10 to 200 mg/kg decreased lipid oxidation. Lipid oxidation of pork chops and ground pork was similar between pigs fed 40 mg/kg and higher levels of natural vitamin E, indicating no additional benefits from supplementing beyond 40 mg/kg natural vitamin E. Supplementing 200 mg/kg synthetic vitamin E decreased pork lipid oxidation when compared to supplementing 10 mg/kg natural vitamin E. High levels of natural vitamin E or synthetic vitamin E, however, did not prevent discoloration of loin chops. These data indicate that natural vitamin E was effective to help reduce lipid oxidation and the effective minimal level of dietary supplementation appeared to be 40 mg/kg.     

The effects of dietary oregano essential oil and α-tocopheryl acetate on lipid oxidation in raw and cooked turkey during refrigerated storage

The effects of dietary oregano essential oil and α-tocopheryl acetate supplementation on the susceptibility of raw and cooked turkey breast and thigh meat to lipid oxidation during refrigerated storage for 9 days were examined. Thirty 12-week-old turkeys were divided into five groups and fed a basal diet containing 30 mg α-tocopheryl acetate kg(-1) feed as control, or basal diet plus 200 mg α-tocopheryl acetate kg(-1), or basal diet plus 100 mg oregano oil kg(-1), or basal diet plus 200 mg oregano oil kg(-1), or basal diet plus 100 mg oregano oil and 100 mg α-tocopheryl acetate kg(-1), for 4 weeks prior to slaughter. Lipid oxidation was assessed by monitoring malondialdehyde formation in raw and cooked meat at 0, 3, 6 and 9 days of refrigerated storage, through use of a third-order derivative spectrophotometric method. Results showed that all dietary treatments significantly (P<0.05) increased the stability of both raw and cooked turkey meat to lipid oxidation compared with the control. Oregano oil at 200 mg kg(-1) was significantly (P<0.05) more effective in delaying lipid oxidation compared to the level of 100 mg kg(-1), equivalent to α-tocopheryl acetate at 200 mg kg(-1), but inferior (P<0.05) to oregano oil plus α-tocopheryl acetate at 100 mg kg(-1) each, which in turn was superior (P<0.05) to all dietary treatments, indicating a synergistic effect. Thigh muscle was more susceptible to oxidation compared with breast muscle in all treatments, although it contained α-tocopherol at significantly (P<0.05) higher levels.