Unbalanced omega-6/omega-3 ratio in red meat products in China

Dietary meats play a crucial role in human health. The objective of this survey was to determine the fatty acid content and omega-6/omega-3 polyunsaturated fatty acids （n-6/n-3 PUFA） ratio of fresh red meat （beef and pork） from four cities （Shanghai, Nanjing, Yinchuan and Hohhot） in China. The results showed that the n-6/n-3 PUFA ratio from all the samples ranged from 6 to 23. The total n-6 PUFA concentrations ranged from 290.54 mg/100 g in beef from Nanjing to 1601.48 mg/100 g in pork from Hohhot, whereas the total concentrations of n-3 PUFA ranged from 46.34 mg/100 g in beef from Nanjing to 96.03 mg/100 g in pork from Nanjing. The results indicated that the n-6/n-3 ratio in the red meat from all four regions is unbalanced and is much higher than that （〈 5：1） rec- ommended by the WHO/FAO. The total amount of n-3 PUFA was far lower than the required daily dose. There- fore, potential solutions to increase the n-3 PUFA content in meat products or to provide alternative source of n-3 PUFA should be explored.

Red meat intake and the risk of endometrial cancer:Metaanalysis of observational studies

AIM:To evaluate whether red meat intake is related to the risk of endometrial cancer(EC) using meta-analysis.METHODS:We searched Pub Med,EMBASE,and the Cochrane Library up to June 2013,using common keywords related to red meat and EC.Case-control studies and cohort studies comparing the risk of endometrial cancer among categories by the amount of intake were included.Eleven case-control studies and five cohort studies met our criteria.We performed a conventional and a dose-response meta-analysis of case-control studies using the Der Simonian-Laird method for random-effects.For cohort studies we performed a conventional meta-analysis.Publication bias was evaluated using Egger's test.RESULTS:In the meta-analysis of 11 case-control studies including 5419 cases and 12654 controls,higher red meat consumption was associated with an increased risk of EC [summary relative risk(SRR) = 1.43,95%CI:1.15-1.79;I2 = 73.3% comparing extreme intake categories).In a dose-response analysis,for red meat intake of 100 g/d,SRR was 1.84(95%CI:1.64-2.05).In contrast,in the meta-analysis of five prospective studies including a total of 2549 cases among 247746 participants,no significant association between red meat intake and EC risk(SRR = 0.97,95%CI:0.85-1.11;I2 = 4.9% comparing extreme intake categories) was observed.CONCLUSION:Our meta-analysis found a significantlinear association between red meat intake and EC risk based on case-control studies but this was not confirmed in prospective studies.

Impact of Inflation, Dollar Exchange Rate and Interest Rate on Red Meat Production in Turkey： Vector Autoregressive （VAR） Analysis

In this study, impact of inflation （WPI--Wholesale Price Index）, exchange rate, and interest rate on the production of red meat in Turkey was examined using the vector autoregressive （VAR） model. The model consisting of variables of dollar exchange rate, inflation rate, interest rate, beef, buffalo meat, mutton, and goat meat production amounts has been estimated for the period from 1981 to 2014. It has been detected that there is a tie among the dollar exchange rate, inflation rate, interest rate, and the amount of red meat production in Turkey. In order to determine the direction of this relation, Granger causality test was conducted. A one-way causal relation has been observed between： the goat meat production and dollar exchange rate; the buffalo meat production and the mutton production; and the beef production and the mutton production. To interpret VAR model, the impulse response function and variance decomposition analysis was used. As a result of variance decomposition, it has been detected that explanatory power of changes in the variance of dollar exchange rate, inflation rate, and interest rate in goat meat production amount is more than explanatory power of changes in the variances of mutton, beef, and buffalo meat variables.

An Assessment of Barriers to MSMEs’ Adoption of CSA in Livestock Red Meat Value Chain, Kajiado County, Kenya

Climate change poses great risks to poverty alleviation, food security and livelihoods sustainability in sub-Saharan Africa, declining crop yields and livestock productivity, especially in ASALs that suffer from fragile ecosystems characterized by frequent droughts and low rainfall. Climate-Smart Agriculture (CSA) objectives of improving productivity and incomes, adaptation, resilience to climate change and mitigation on GHGs emissions, are responses to these climate risks. CSA technologies, innovation and management practices (TIMPs) in general do exist, however they are concentrated in crop farming neglecting livestock production and especially in marginalized areas such as ASALs, which forms 85% of Kenyan land mass and is dominated by pastoral and nomadic livestock production. Most CSA practices are mainly at the production level and hardly extend to the entire value chain, and diffusion is slow due to several barriers. A mixed method approach was used to evaluate barriers to actors’ adoption of CSA in the pastoral Livestock red meat value chain starting from input suppliers, producers, to consumers (pasture to plate). This study used six broad perspectives to examine the barriers: 1) Knowledge and institutional;2) Market and financial;3) Policy and incentives;4) Networks and engagement platforms;5) Cultural and social;6) Physical infrastructure barriers. These barriers can be surmounted with concerted efforts from the government, development partners, pastoral communities, value chain actors and public private partnership among others. Efforts such as modernization of the pastoral red meat value chains, integration of MSMEs into the livestock systems, access to affordable financing, availability of context based, affordable CSA TIMPs, incentives, policies and institutional support, which currently remains inadequate. Institutional barriers like lack of capacity, coupled with knowledge and behavioral barriers hinder adoption. Financial institutions and cooperative societies can be enablers, however, their reluctance to invest in the sector is a barrier too.

Association of Red Meat Usual Intake with Serum Ferritin and the Risk of Metabolic Syndrome in Chinese Adults: A Longitudinal Study from the China Health and Nutrition Survey

Objective The present study aimed to investigate the association of red meat usual intake with metabolic syndrome(Met S),and explore the contribution of red meat usual intake to serum ferritin.Methods Based on the data from the longitudinal China Health and Nutrition Survey(CHNS),2,797 healthy adults aged 18–75 years without hypertension,diabetes,and Met S were selected in 2009 as subjects and follow-up studies were carried out till 2015.We used the National Cancer Institute(NCI)method to estimate the usual intake of foods.Multivariable logistic regressions were performed to evaluate the association between red meat usual intake and the risk of Met S.Quantile regression analysis was used to study the relationship between red meat consumption and serum ferritin levels.Results After adjusting for potential confounders,red meat,and fresh red meat were positively associated with the risk of Met S(RR=1.41,95%CI:1.05–1.90 and RR=1.37,95%CI:1.02–1.85,respectively).These relationships showed increasing trend(P<0.05).The level of serum ferritin increased significantly with the number of Met S components(P<0.05).The quantile regression analysis showed that red meat and fresh red meat usual intake had a significant positive association with serum ferritin levels across the entire conditional serum ferritin distribution(P<0.05).Processed red meat did not exhibit a similar association.Conclusion Higher red meat usual intake was associated with an increased risk of Met S and elevated serum ferritin levels.

Natural radioactivity measurements of frozen red meat samples consumed in Iraq

Purpose In the present study,the activity concentrations of long-lived gamma-ray emitters(^(238)U,^(232)Th and ^(40)K)in ten dif-ferent types of frozen red meat samples selected from markets in Iraq were measured.Methods The technique of gamma spectrometer equipped with scintillation detector NaI(Tl)was used.Results The annual effective dose was estimated in adults and kids.The results showed that the concentrations of ^(238)U,^(232)Th and ^(40)K were found in the range of permissible limits of 30,32 and 400 Bq kg−1,respectively.On the other hand,the maximum values of ^(238)U and ^(232)Th in beef samples are higher than in lamb meat samples.The annual effective dose of adults and kids was observed to be below the limit(1.0 mSv)recommended by ICRP.Conclusion The frozen red meat samples are safe for human consumption and have gamma-ray emitter concentrations lower than the maximum permissible levels.

Red Meat Is Strongly Linked to Cancer

营养学家认为,人们应减少红肉和加工肉类(如香肠、腊肉、火腿、腌肉 等)的摄入量,因为大量食用红肉容易导致肠癌,他们建议人们用白肉(鱼肉、鸡 肉、鸭肉)代替红肉(牛肉、猪肉、羊肉等)。

Consumption of red and processed meat and esophageal cancer risk:Meta-analysis

To summarize the evidence about the association between red and processed meat intake and the risk of esophageal cancer,we systematically searched the PubMed and EMBASE databases up to May 2012,with a restriction to English publications,and the references of the retrieved articles.We combined the studyspecific relative risks(RRs) and 95%CI,comparing the highest with the lowest categories of consumption by using a random-effects model.A total of 4 cohort studies and 23 case-control studies were included in the meta-analysis.The combined RRs(95%CI) of the cohort studies comparing the highest and lowest categories were 1.26(1.00-1.59) for red meat and 1.25(0.83-1.86) for processed meat.For the case-control studies,the combined RRs(95%CI) comparing the highest and lowest categories were 1.44(1.16-1.80)for red meat and 1.36(1.07-1.74) for processed meat.Findings from this meta-analysis suggest that a higher consumption of red meat was associated with a greater risk of esophageal cancer.

性别对红骨绵羊肌肉食用和营养品质的影响

为探究盐源县不同性别红骨绵羊的肉质特性,本试验以该绵羊的背最长肌为材料,测定其肉质理化指标和营养指标,研究性别对红骨绵羊肉品质特性的影响。结果表明盐源红骨绵羊肉的pH值、熟肉率、剪切力和色差等指标在公母之间均无显著性差异(P>0.05),营养指标中常规营养成分、氨基酸、重金属等指标在公母之间均无显著性差异(P>0.05),矿物质含量中钙元素在公母之间具有显著性差异(P<0.05),表明性别对红骨绵羊肉除矿物质元素钙以外的pH值、嫩度、熟肉率、常规营养成分、氨基酸及重金属含量等指标均没有显著的影响。

高红肉饮食通过铁死亡通路促进小鼠溃疡性结肠炎

目的探讨铁死亡在高红肉饮食促进溃疡性结肠炎(Ulcerative colitis,UC)发生中的作用机制。方法36只雄性Balb/c小鼠中随机选取18只,给予标准饲料,另外18只小鼠给予含60%红肉饲料。8周后,给予标准饲料的18只小鼠分为对照组、UC模型组和UC模型+铁死亡抑制剂(Fer-1)组,每组各6只;给予含60%红肉饲料的18只小鼠分为高红肉组、高红肉+UC模型组和高红肉+UC模型+Fer-1组,每组各6只。除对照组、高红肉组外,其余组予小鼠3%葡聚糖硫酸钠(Dextran sodium sulfate,DSS)构造UC小鼠模型,UC模型+Fer-1组和高红肉+UC模型+Fer-1组造模同时给予铁死亡抑制剂(Ferrostatin-1,Fer-1)腹腔注射,连续9 d。比较UC小鼠疾病活动指数(DAI)评分和HE染色评价小鼠UC严重程度,Elisa、RT-qPCR和透射电镜检测小鼠亚铁离子(Ferrous ion,Fe 2+)、活性氧(Reactive oxygen species,ROS)、丙二醛(Malondialdehyde,MDA)、谷胱甘肽(Glutathione,GSH)、谷胱甘肽过氧化物酶4(Glutathione peroxidase 4,GPX4)、铁蛋白重链1(Ferritin heavy chain1,FTH1)和酰基辅酶A合成酶长链家族成员4(Acyl-CoA synthetase long-chain family member 4,ACSL4)的铁死亡以及肿瘤坏死因子α(Tumor necrosis factor-α,TNF-α)和白介素6(Interleukin 6,IL-6)等炎症相关因子的表达,并观察小鼠结肠肠上皮细胞线粒体形态的变化。结果与UC模型组相比,高红肉+UC模型组小鼠DAI评分显著升高(P<0.05),结肠黏膜结构被完全破坏,结肠肠上皮细胞线粒体空泡化严重且线粒体膜破裂、嵴消失;小鼠结肠中Claudin1、Occludin和ZO-1mRNA表达水平明显降低(P<0.05);在小鼠血清中Fe 2+、ROS、MDA、TNF-α及IL-6表达水平明显升高,GSH表达水平明显降低(P<0.05);在小鼠结肠组织中GPX4和FTH1 mRNA的表达水平明显降低,ACSL4 mRNA的表达水平明显升高(P<0.05)。Fer-1干预后,结肠炎小鼠铁死亡及炎症相关指标降低,抗氧化指标上升(P<0.05)。结论高红肉饮食可加重UC模型小鼠肠道炎症,其机制可能是通过调控铁死亡通路,增加结肠炎症的表达,促进UC的发生发展,Fer-1对高红肉饮食诱导的铁死亡和炎症有显著的改善作用。

皮山红羊肉用性状的研究分析

试验旨在探究皮山红羊的背膘厚度、眼肌面积和眼肌深度等肉用性状指标与体重的相关性,为皮山红羊的生产和选育提供参考。试验选择饲养管理均相同的506只6月龄皮山红羊,利用便携式B超诊断仪测量背膘厚度、眼肌深度和眼肌面积等肉用性状指标和体重,采用SAS 9.2进行影响因素的分析,采用SPSS 25.0软件进行相关性分析。结果显示,产羔类型、性别和群别分别对背膘厚度、眼肌深度和眼肌面积有显著或极显著影响(P<0.05或P<0.01)。单羔的眼肌深度极显著高于三羔(P<0.01),且双羔眼肌深度显著高于三羔(P<0.01),单羔眼肌面积极显著高于多羔(P<0.01),双羔眼肌深度显著高于三羔(P<0.05),且显著高于四羔(P<0.05)。性别对于3个肉用性状指标具有极显著影响(P<0.01),其中公羔在背膘厚度、眼肌深度和眼肌面积方面均高于母羔。眼肌面积与体重的相关性最高,其次为眼肌深度和背膘厚度,眼肌面积对于皮山红羊直接作用最大,其次是眼肌深度和眼肌面积。研究表明:6月龄羔羊的背膘厚度、眼肌深度和眼肌面积三个肉用性状受到羔羊出生类型、性别及其饲养管理方式的影响,在绵羊饲养管理和选种选育时应考虑它们对6月龄羔羊上述性状的影响,提高对上述肉用性状选育及遗传评估准确性。

基于生物技术的红肉鱼副产物高值化利用研究进展

青皮红肉鱼是一类产量高却利用率低的低值海产品,将其加工副产物利用生物技术进行高值化利用成为研究重点。有研究证明海洋生物活性肽是一类极具开发潜力的新型药物来源。目前,对红肉鱼生物活性肽制备技术和生物应用方面的研究较少。综述了以青皮红肉鱼加工副产物为原料制备生物活性肽,以及体内体外的生物活性表征。介绍了红肉鱼生物活性肽的抗氧化、抗糖尿病、降血压、抗菌等功能活性,以便为开发新型海洋药物提供理论依据。

三种天然红色素在素肉肠中的应用比较研究

为探究天然红色素在素肉制品中的着色效果,比较了番茄红、红曲红、高粱红在素肉肠熟化前后,不同光照、真空度、贮藏温度及反复冻融条件下的着色稳定性,以感官评分为指标评价了3种色素在素肉肠中应用效果。结果表明,番茄红素肉肠在熟化前后,不同光照、真空度、贮藏温度及反复冻融条件下的稳定性优于红曲红及高粱红。

火龙果果皮红色素抑菌活性及对鳙鱼肉新鲜度的指示效应

本研究通过超声波辅助乙醇浸提法提取火龙果果皮红色素,采用药敏试纸抑菌圈检验法、DPPH自由基清除法比较两种果皮红色素的抑菌活性和总抗氧化能力,同时结合果皮红色素提取物对pH变化的响应和色差值评估指标,优选红色素提取物浓度制作指示卡。通过检测常温放置过程中鱼肉的pH、脂质过氧化值变化评估指示卡对鳙鱼鱼肉新鲜度的指示效果。结果表明,红肉红皮火龙果果皮红色素对大肠杆菌(Escherichia coli)和金黄色葡萄球菌(Staphylococcus aureus)的抑菌活性和总抗氧化能力均显著高于白肉红皮火龙果果皮红色素(P<0.05),且其红色素提取物水溶液对pH2~13具有较灵敏的呈色变化反应。应用10 g/L红肉火龙果果皮红色素提取物制备的指示卡,评估鳙鱼鱼肉变化可知,25℃常温放置12 h过程中鱼肉的pH先微降后上升,TBA脂质过氧化值持续升高为0 h的1.96倍,揭示鱼肉的新鲜度下降;同期,放置鱼肉的指示卡色差值ΔE也从起始时1.40(0 h)上升到18.30(12 h),指示卡外围呈色从淡红色向玫红色及土黄色转变,对放置的鲜切鳙鱼肉新鲜度的衰减表现出较为直观的指示效应。本研究为火龙果果皮天然红色素的综合利用提供前期的科学依据,也为水产类预制菜行业的新型食品包装应用提供初步参考。

不同能量水平玉米秸秆青贮饲料对郏县红牛表观消化率、血清生化指标、屠宰性能及肉品质的影响

为研究不同能量水平玉米秸秆青贮饲料对郏县红牛表观消化率、血清生化指标、屠宰性能及肉品质的影响,选取体重、月龄相近的健康郏县红牛60头(公母各半),按照单因素完全随机区组设计分成A(低能组)、B(中能组)、C(高能组)共3组,每组20个重复,每个重复1头试验牛。试验分成7 d预试期、120 d正试期,其中正试期包括40 d前期、40 d中期和40 d末期三个阶段。前期A、B、C组饲粮粗蛋白(CP)水平均为12.0%,综合净能(NE_(mf))分别为6.21、6.52、6.83 MJ/kg。中期A、B、C组饲粮CP水平均为11.58%,NE_(mf)分别为7.14、7.45、7.76 MJ/kg。末期A、B、C组饲粮CP水平均为11.02%,NE_(mf)分别为8.07、8.38、8.69 MJ/kg。结果显示,B组平均日增重、干物质采食量最高,均显著高于C组(P<0.05),料重比最低,但组间无显著差异。B组粗脂肪、粗蛋白、酸性洗涤纤维、中性洗涤纤维、钙、总磷含量最高,组间差异不显著。C组胆固醇、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇含量均显著高于A组(P<0.05)。屠宰率、胴体产肉率、眼肌面积和背膘厚度随着能量水平提高而增加,组间无显著差异,C组背膘厚度显著高于A组(P<0.05)。能量水平对pH、蒸煮损失、失水率、剪切力和肉色均无显著影响,能量水平增加有改善牛肉品质的趋势。增重经济效益以B组最高。说明适宜的饲粮能量水平可以提高郏县红牛生产性能、改善肉品质、增加经济效益;中能量的郏县红牛生产性能、养分表观消化率、血清生化指标和肉品质效果最佳,且养殖经济效益最高。

The significance of N‑carbamoylglutamate in ruminant production

Improving the efficiency and production of grazing ruminants to support food and fiber production,while reducing the environmental footprint and meeting the welfare needs of the animals,is important for sustainable livestock production systems.Development of new technologies that can improve the efficiency of nitrogen(N)utilization in ruminants,and that are effective and safe,has important implications for ruminant livestock production.N-carbomoylglutamate(NCG)is a functional micronutrient that stimulates endogenous synthesis of arginine,which can improve survival,growth,lactation,reproductive performance,and feed efficiency in mammals.There is a growing body of evidence to support the potential of dietary NCG supplementation to improve the productive capacity and N utilization efficiency of ruminants.This review summarizes the current literature on the effects of dietary supplementation with NCG in ruminants and impacts on production and potential to reduce the environmental footprint of farmed ruminant livestock.The current literature highlights the potential for commercial application in ruminant livestock to improve productivity and N utilization efficiency.

红肉及肉制品摄入与炎性肠病相关性的研究进展

炎性肠病(IBD)是一种慢性复发性疾病,其病因及发病机制复杂,至今尚未明确。饮食习惯与IBD的相关性是近年研究的热点,红肉及肉制品摄入过多与IBD的患病风险增加显著相关。该饮食习惯可通过改变肠道菌群、破坏肠道黏膜完整性、减少肠道内有益短链脂肪酸的含量、产生有害气体促进肠道内各种免疫反应产生,进而导致肠道炎症。因此,深入研究红肉及肉制品摄入与IBD的关系及其发病机制,并优化饮食结构,可为预防和治疗IBD提供新策略。

平凉红牛生长性能、胴体及肉质性状分析

【目的】通过研究平凉红牛的生长性能、胴体性状和肉质性状,深入挖掘平凉红牛的肉用特征和遗传特性,为平凉红牛新品种选育提供参考。【方法】试验选取24头平凉红牛阉牛,经强度育肥180 d后屠宰,年龄在24-36月龄,对其体尺、屠宰性能、胴体指数进行测定,并选取其中3头的外脊和大黄瓜条进行肉质测定分析。【结果】经育肥后的成年平凉红牛体重、体高、十字部高、胸围、管围相较于2019年测定的22-28月龄的平凉红牛分别增长6.96%、4.61%、4.43%、4.28%、7.90%,体斜长减少3.52%;胴体重为(417.01±56.94)kg、净肉重为(372.48±54.60)kg、屠宰率为61.56%±1.86%、净肉率为54.92%±2.60%,相较于2010年测定的24月龄平凉红牛数据分别增长12.61%、19.16%、-1.91%、3.82%,肉骨比为8.65±2.00,相较于2012年测定的22-27月龄数据增长27.96%;此外高档肉块重(里脊、外脊、眼肉、上脑)为(51.59±7.92)kg,优质肉块重(臀肉、霖肉、米龙、大黄瓜条、小黄瓜条、辣椒条、肩肉)为(62.62±5.56)kg,分别占净肉重的13.91%±1.45%和17.07%±2.24%,平凉红牛的生长性能和产肉性能良好。在肉品质方面,外脊和大黄瓜条的剪切力分别为2.72 kg和4.43 kg,比市场购买的A3级雪花牛肉分别低19.58%和64.82%,但差异不显著(P>0.05);外脊和大黄瓜条的粗蛋白含量均达到了20%以上,且平凉红牛外脊的粗蛋白含量显著高于雪花牛肉(P<0.05)。外脊和大黄瓜条的EAA/NEAA比值分别为71%和68%,较高于FAO/WHO的标准值(60%);EAA/TAA比值分别为42%和41%,略高于FAO/WHO的标准值(40%)。相较于市场购买的A3级雪花牛肉,平凉红牛外脊和大黄瓜条的必需氨基酸和呈味氨基酸含量高;对外脊和大黄瓜条肉块进行氨基酸评分分析,平凉红牛外脊和大黄瓜条的赖氨酸均高于FAO/WHO氨基酸评分标准模式;此外,大黄瓜条中硒含量极显著较高(P<0.01),铁、锌、PUFA含量、n-6/n-3和PUFA/SFA比值均显著较低(P<0.05);外脊中EPA含量显著较高(P<0.05)。【结论】经过改良和选育,平凉红牛的体格增大、胸围增长,体躯紧凑,肉用性能提高;平凉红牛肉质具有细嫩鲜美、风味浓厚、营养价值高的特点,极具开发利用价值。

北京地区孕早期孕妇膳食蛋白质摄入与妊娠期糖尿病的关系

目的了解北京地区孕早期孕妇膳食蛋白质摄入情况,探讨膳食蛋白质摄入频率与妊娠期糖尿病(gestational diabetes mellitus,GDM)的关系。方法本研究数据来自北京出生队列研究(Beijing Birth Cohort Study),最终纳入10320例于2018年9月至2020年12月在首都医科大学附属北京妇产医院门诊进行常规产检的孕6~16周健康单胎孕妇,通过食物频率法了解孕早期孕妇膳食蛋白质摄入情况。于孕24~28周行75 g口服葡萄糖耐量试验,根据国际糖尿病与妊娠研究组(International Association of the Diabetes and Pregnancy Study Groups,IADPSG)标准诊断GDM。采用χ^(2)检验分析研究对象基线特征与GDM发病率的关系,采用多因素Logistic回归分析方法探讨膳食蛋白质摄入频率与GDM发病率的关系。结果①本研究纳入的10320例孕妇中确诊为GDM的有1585例,发病率为15.4%。②单因素分析结果显示,总蛋白质类食物、动物蛋白、红肉的摄入频率与GDM的发生风险有关(P<0.05),每周摄入频率越高,GDM发病率越高;而植物蛋白、白肉摄入频率与GDM的发生风险无关(P>0.05)。进一步分析显示,猪肉的摄入频率与GDM的发生风险有关(P<0.05),摄入频率越高,GDM发病率越高。③多因素Logistic回归分析结果显示,在控制了年龄、学历、产次、孕前体质量指数(body mass index,BMI)、糖尿病家族史后,孕早期蛋白质类食物总摄入频率增加会增加GDM的发生风险(OR=1.504,95%CI:1.138~1.988);其中动物蛋白摄入频率对GDM发生有影响(OR=1.429,95%CI:1.122~1.984),而未发现植物蛋白摄入频率对GDM发生有影响。进一步分析显示,红肉的摄入频率增加会增加GDM的发生风险(OR=1.288,95%CI:1.072~1.547),而未发现白肉摄入频率对GDM发生有影响。在红肉类别中,猪肉的摄入频率增加会增加GDM的发生风险(OR=1.025,95%CI:1.007~1.044)。结论北京地区孕早期孕妇膳食蛋白质的主要来源为动物蛋白中的肉类。较高的动物蛋白摄入频率,特别是以猪肉为主的红肉,是GDM发生的危险因素,而白肉和植物蛋白摄入频率与GDM发生无关。妇幼保健人员应该开展孕早期,甚至备孕期的营养宣教,以利于GDM的预防。

基于顶空-气相色谱-离子迁移谱分析蒸制过程中草鱼肉挥发性成分的变化

为提高蒸制草鱼的风味品质,通过顶空-气相色谱-离子迁移谱(headspace-gas chromatography-ion mobility spectroscopy,HS-GC-IMS)结合主成分分析(principal component analysis,PCA)及感官评定研究了草鱼白肉和红肉在蒸制过程中挥发性成分的变化。在鱼肉中共鉴定出40种化合物,其中白肉(34种)和红肉(37种)共有的挥发性化合物有30种,主要是醛类、醇类、酮类和酯类。蒸制处理会促进鱼肉中挥发性化合物(异丁醛、戊醛、己醛、庚醛、2-乙基己醇和2-戊酮)的形成;蒸制后,红肉中挥发性成分的数量和相对含量都高于白肉。PCA结果表明,在蒸制过程中,红肉的风味变化较白肉更为丰富。在蒸制时间到达9 min时,鱼肉整体的风味趋于稳定,鱼肉中的挥发性成分可以代表熟草鱼肉的风味。感官评定的结果也显示,蒸制9 min的草鱼肉具有较好的风味和整体可接受度。综上,HS-GC-IMS和PCA的组合可以较好地描述不同蒸制时间的草鱼白肉和红肉挥发性化合物的变化,并为确定草鱼适宜的蒸制时间提供依据。