电子束辐照对新疆干果品质的影响及其最高耐受剂量的确定

目的 探究电子束辐照对4种新疆干果品质的影响,确定干果辐照工艺的最高耐受剂量。方法 采用0、2、4、6、8和10 kGy不同剂量电子束处理枸杞干、红枣干、无花果干、小白杏干,研究不同辐照剂量对水分、维生素C、总酸、总糖4种理化指标及色度、外观、风味、色泽和口感等5种感官品质的影响。结果 仅8 kGy辐照处理对枸杞干口感指标有不良影响,其他3种干果的感官指标几乎不受辐照处理的影响; 10 kGy以内的辐照处理对红枣干的品质无不良影响;无花果干的总酸含量在辐照剂量>6kGy时有所上升,维生素C含量在10 kGy处理时显著低于对照;辐照剂量≥6 kGy时,小白杏干维生素C含量显著降低。结论 通过对电子束辐照新疆干果的品质影响及最高耐受辐照剂量的研究,确定枸杞干、红枣干、无花果干和小白杏干的最高耐受剂量分别是8、10、6和6 kGy。为电子束辐照在新疆干果灭菌工艺中的应用提供了理论基础。     

拉曼光谱法快速检测猪肉脯中的掺伪鸡肉

目的 建立拉曼光谱法快速、准确、无损地检测猪肉脯样品中掺假鸡肉的方法。方法 制备33份猪肉中掺入不同比例鸡肉的肉脯样品,采集拉曼光谱数据,分别采用标准正态变换、多元散射校正、卷积平滑、归一化、一阶导数等5种不同预处理方法,对原始光谱数据进行预处理,采用连续投影算法、竞争性自适应重加权算法及随机蛙跳算法对光谱数据进行特征波长筛选,建立偏最小二乘法(partial least squares,PLS)模型对猪肉脯进行定性定量判别。结果 拉曼光谱数据经过多元散射校正处理的效果最佳,竞争性自适应重加权算法竞筛选效果更佳,构建猪肉脯中猪肉含量的PLS定量模型,其预测集决定系数和预测均方根误差分别为0.9762、7.2998。建立的PLS判别模型的校正集和预测集总判别正确率分别为100.00%和98.33%。结论 拉曼光谱分析技术可有效用于定性鉴别猪肉脯是否掺伪及定量分析猪肉肉脯中掺入鸡肉的比例,为肉脯掺假的快速无破坏性检测的应用提供支持。     

重组香菇鸭肉脯的配方和加工工艺优化

以鸭肉为主要原料,以香菇为特色风味原料,通过单因素试验和正交试验优化重组香菇鸭肉脯的配方和加工工艺。结果表明：重组香菇鸭肉脯辅料的最佳添加量为食盐0.8%,鱼露4%,料酒6%,香菇4%,此时感官评分为96.8。黏合剂的最佳添加量为鸡蛋清3%、玉米淀粉3%、卡拉胶1.0%,此时重组香菇鸭肉脯的拉伸力为12.8 N。最佳加工工艺参数为烘干时间30 min、烘干温度60 ℃、烘烤时间6 min、烘烤温度190 ℃,此时的感官评分为97。     

不同产地辣椒挥发性成分的对比研究

为探究火锅常用干辣椒及其籽、皮的品质及香气的差异,采用理化分析结合气相色谱-质谱联用的方法,对6个不同品种干辣椒及其皮、籽的品质及挥发性成分进行比较分析。结果表明,脂肪（14.50%~24.50%）和蛋白质（12.20%~17.10%）在辣椒籽中含量更高,而辣椒皮的水分（9.80%~16.50%）和总糖（7.87%~16.70%）含量更高;在色泽方面,‘子弹头’、‘艳椒’和‘新一代’的颜色较为鲜红,‘艳椒’的色价（15.12）最高;在辣度方面,‘印度椒’辣度（892度）最高,‘灯笼椒’辣度（43度）最低,辣椒皮的辣度高于辣椒籽。在6个品种干辣椒及其皮、籽中共检测到80种挥发性成分,不同品种干辣椒的挥发性成分具有一定差异,包括D-柠檬烯、4-甲基-1-戊醇、苯乙醛、乙酸、川芎嗪等;干辣椒皮与籽对其整体香气的贡献也不同,D-柠檬烯、芳樟醇、苯乙醛、丙酮、乙酸等在辣椒皮中相对含量较高,主要呈花果香、木香和辛辣气息,而辣椒籽中D-柠檬烯、2,3-丁二醇、4-甲基-1-戊醇、乙酸、二甲醚等的相对含量较高,主要贡献花果香味。研究可为复合使用不同品种干辣椒生产不同风味火锅底料提供理论参考。     

基于不同方法评价坚果与果干复配物的抗氧化能力

为科学评价坚果与果干复配物的健康功效,本实验通过化学提取法、体外消化模型、小鼠模型评价多种坚果与果干复配后的抗氧化能力变化。化学提取法分析结果表明,坚果与果干复配后富含酚类物质、脂肪酸和蛋白等营养物质,且1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力、2,2-联氨-双-3-乙基苯并噻唑啉-6-磺酸（2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic?acid),ABTS）阳离子自由基清除能力和铁离子还原能力（ferric?ion?reducing?antioxidant?power,FRAP）比坚果组总体显著提高（P<0.05）;体外消化模型分析结果表明,与坚果和果干组相比,胃肠道消化后坚果与果干复配物中酚类物质的含量提高了2.90%～60.38%,两种自由基清除率提高了1.23%～18.60%,且坚果与果干适当配比时（6∶4,m/m）抗氧化协同效果最好;小鼠模型实验分析结果表明坚果与果干复配物在体内消化后提高了小鼠血清和肝脏中过氧化氢酶、超氧化物歧化酶活力及总抗氧...     

陈皮中黄酮类化合物的抗氧化性

目的研究陈皮中黄酮类化合物的抗氧化性。方法用茜素紫作显色剂,分光光度法测定黄酮类化合物对Co2 H2O2体系所产生的羟基自由基的消除作用。利用连苯三酚自氧化法测定陈皮中黄酮类化合物对超氧阴离子自由基的消除作用。结果陈皮中黄酮类化合物对羟基自由基和超氧阴离子自由基有消除作用。结论陈皮中黄酮类化合物具有良好的抗氧化活性。     

Nitrogen utilization,whole-body urea-nitrogen kinetics,omasal nutrient flow,and production performance in dairy cows fed lactose as a partial replacement for barley starch

The objective of this study was to determine whether the partial replacement of barley starch with lactose (fed as dried whey permeate; DWP) affects N utilization, whole-body urea kinetics, and production in dairy cows. Eight lactating Holstein cows were used in a replicated 4 × 4 Latin square design with 28-d periods. Four cows in one Latin square were ruminally cannulated and used to determine dietary effects on whole-body urea kinetics and N utilization. Cows were fed a barley-based diet that contained 3.6% (dry matter basis) total sugar (TSG; designated control), or diets that contained 6.6, 9.6, or 12.6% TSG. Dietary TSG content was increased by the replacement of barley grain with DWP (83% lactose). Diets were isonitrogenous (～17.3% crude protein), and starch contents of the control, 6.6, 9.6, and 12.6% TSG diets were 24.3, 22.2, 21.2, and 19.1%, respectively. Whole-body urea kinetics were measured using 4-d infusions of [¹⁵N¹⁵N]-urea with concurrent total collections of feces and urine. Dry matter intake (mean = 26.7 kg/d), milk yield (mean = 34.9 kg/d), and milk protein and fat contents were unaffected by diet. Ruminal ammonia-N concentration decreased linearly as TSG content increased, whereas ruminal butyrate concentration increased linearly as TSG content increased. Urinary excretion of total N and urea-N changed quadratically, whereas urinary excretion of total N (% of N intake) tended to change quadratically as TSG content increased. Fecal N excretion linearly increased as TSG content increased. A quadratic response was observed for total N excretion as TSG content increased. Milk N and retained N were not affected by diet. As TSG content increased, we observed quadratic responses in the omasal flow of fluid-associated and total bacterial nonammonia N, endogenous production of urea-N, urea-N recycled to the gastrointestinal tract, and urea-N returned to the ornithine cycle. Dietary TSG content did not affect the anabolic utilization of recycled urea-N or the proportion of recycled urea-N that was used for bacterial growth. Our results indicate that feeding DWP did not influence dry matter intake, milk yield, or milk composition. Feeding DWP decreased ruminal ammonia-N concentration, but this did not result in positive responses in milk protein secretion or N balance. The quadratic response in omasal flow of total bacterial nonammonia N indicated that including TSG beyond 9.6% of diet dry matter might depress ruminal microbial protein synthesis.     

Microbiological and Chemical Evaluation of Dried Smoked Meat Product

The aim of this study was to determine the chemical and microbiological quality of an artisanal dried smoked meat product, manufactured in a domestic household. At the end of production, the average moisture content was 37.83%, salt 5.07%, while water activity was 0.89. Yeast counts were approximately 1.0 x 10⁷ cfu/g while mould counts were 1.2 x 10⁶ cfu/g. Two commonly present Penicillium species were identified: P. aurantiogriseum and P. commune. Our results suggest that the artisan manufacturers of these types of meat product should take steps to ensure a higher quality of their products.     

Ruminal fermentation,kinetics, and total-tract digestibility of lactating dairy cows fed distillers dried grains with solubles in low- and high-forage diets

The objective of this study was to investigate the effects of concentrations of forages and corn distillers dried grains with solubles (DDGS) on ruminal fermentation, ruminal kinetics, and total-tract digestibility of nutrients in lactating dairy cows. Four lactating Holstein cows with ruminal cannulas were assigned to a 4 × 4 Latin square in a 2 × 2 factorial arrangement of treatments. Diets were formulated to contain low forage [LF; 17% forage neutral detergent fiber (NDF)] or high forage (HF; 24.5% forage NDF) and DDGS at 0 or 18% (0DG or 18DG) of diet dry matter (DM). Intake of DM was not affected by the diets. Daily mean ruminal pH was affected by forage NDF × DDGS interactions, as the lowest ruminal pH was observed among cows fed LF18DG (6.02). Apparent total-tract digestibility for DM, organic matter, crude protein, NDF, acid detergent fiber, and starch was not affected by diets. Cows fed LF diets had a greater total volatile fatty acid concentration compared with cows fed HF (122 vs. 116 mM). Molar proportions of acetate were greater for HF compared with that of LF diets (62.6 vs. 57.5 mmol/100 mmol) and greater for 0DG diet compared with that of 18DG diets (61.3 vs. 58.7 mmol/100 mmol) diets. The molar proportion of propionate was affected by forage × DDGS interaction as the greatest propionate molar proportion was observed with cows fed LF18DG diet (27.7 mmol/100 mmol). Also, molar proportion of butyrate was affected by forage × DDGS interaction, as the greatest butyrate molar proportion was observed in cows fed HF18DG diet (13.5 mmol/100 mmol). Average fractional dilution rate for all diets was 11.9%/h and was not affected by diets. Fractional passage rate of the solid phase was greater for HF than for LF (4.40 vs. 3.76%/h). The ruminal retention time of solid phase was greater for LF compared with HF diets (27.3 vs. 23.3 h). Fractional passage rate of DDGS was affected by forage × DG interaction, as the highest fractional passage rate of DDGS was observed with cows fed HF18DG diet (7.72%/h). Our results demonstrated that concentrations of forage, DDGS, and their interaction influence ruminal degradation and kinetics of diets fed. Diets formulated at 17% forage NDF at 17% (DM basis) can decrease milk fat concentration compared with diets formulated at 25% forage NDF. Additionally, feeding DDGS at 18% DM basis to lactating dairy cows did not affect milk fat concentration or yield.     

Survey of sulfites in wine and various Turkish food and food products intended for export, 2007–2010

Surveys were carried out between 2007 and 2010 to determine the total levels of sulfites in 1245 samples of wines, dried apricots, dried vegetables, nuts, juices and purees, frozen foods and cereals containing dried fruit supplied by food inspectors and by food producers for testing or for export certification. Sulfite analysis of wine was carried out using the Ripper method with an LOQ of 5?mg?l^?1 and for dried and other foods the Monier-Williams distillation procedure was employed with an LOQ of 10?mg?kg^?1. In the survey all wines contained measurable sulfites, but with the exception of one sample of white wine they were otherwise below Turkish Food Codex limits of 160?mg?kg^?1 for red wine, 210?mg?kg^?1 to white wine and 235?mg?kg^?1 for sparkling wine. None of the cereal products, frozen foods, juices or purees contained sulfites above 10?mg?kg^?1. However, all dried apricot samples contained significant levels of sulfite with around 40% having levels exceeding the Turkish limit of 2000?mg?kg^?1. Significant levels of sulfite were found in other samples of dried fruit with even a fruit and nut bar containing 1395?mg?kg^?1 of sulfite, suggesting the dried fruit ingredients contained levels above regulatory limits.