氯化钙处理对牛肉系水力影响的研究

试验采用2因素有重复试验设计,研究对宰后8h的牛肉分别注射肉重3%的浓度为200mmol/L、250mmol/L、300mmol/L的CaCl2溶液,然后将处理样品在4℃下腌制12h、24h、48h,通过对其煮熟率的测定,分析注射CaCl2溶液及腌制时间对牛肉系水力的影响。试验结果表明:与对照组相比,不同浓度的CaCl2溶液处理对牛肉煮熟率影响差异不显著(P>0.05);不同腌制时间对牛肉煮熟率的影响差异亦不显著(P>0.05)。注射CaCl2溶液对牛肉的系水力无显著影响。     

注射氯化钙和 Vc对牛肉品质的影响

将宰后 8 h 的牛肉分别注射0、100、200 mmol/L 的氯化钙溶液和 0%、1%、2%的 Vc 溶液(注射量为肉质量的 5%),然后将肉样在 4 ℃下分别放置2、4、6 d,通过对其剪切力、pH、总色素进行测定,以研究注射氯化钙和 Vc 对牛肉嫩度、pH、总色素的影响.结果表明:氯化钙溶液处理显著影响牛肉的嫩度(P<0.05),但对pH和色泽的影响不显著(P>0.05);Vc 溶液处理显著影响牛肉的 pH(P<0.05),但对嫩度、色泽的影响不显著(P>0.05);Vc 和氯化钙对牛肉品质的影响没有互作效应.     

牛肉嫩化机制的初步研究

对牛肉分别注射300mmol／LCaCl2溶液、EDTA溶液、ZnCl2溶液（注射量为肉重的5％），然后将处理样品在4℃下分别腌制24h、48h，通过对其剪切力值、MFI的测定，初步研究牛肉嫩化的机制。结果表明，注射CaCl2能促进肌原纤维的分解，进而加速肉的嫩化；而注射EDTA和ZnCl2却抑制肌原纤维的分解，阻止肉的嫩化。牛肉的嫩化是Ca^2＋通过促进肌原纤维的分解而实现的。     

CaCl_2处理对羊肉嫩度和系水力的影响

选用宰后8h的羊背最长肌,注射占肉质量3%的浓度分别为0、150、200和250mmol/L的CaCl2溶液,将样品放在4℃左右冷藏24h后,测定其剪切力和煮熟率,以此分析不同浓度CaCl2处理对羊肉嫩度和系水力的影响。研究结果显示,CaCl2处理能显著降低羊肉的剪切力(P<005),但对煮熟率影响不显著(P>005)。注射CaCl2在改善羊肉嫩度同时,不影响羊肉的系水力。     

应用蛋白酶进行牛肉嫩化的研究

以牛肉为材料,研究不同嫩化液及重组等处理对牛肉的持水力值、pH值及色泽等指标变化的影响,旨在阐明牛肉嫩化机理,寻找适于对牛肉生产的嫩化方法和最佳物质组合,确定牛肉的最佳加工工艺。主要研究结果如下:在4℃条件下,不同嫩化液对牛肉嫩化的单因素试验显示:各种嫩化液都可不同程度地提高肉的嫩度,以0.03?Cl2溶液、40%木瓜液、60%苹果梨汁20 mL/100 g嫩化效果较好,对牛肉色泽均有显著影响;CaCl2溶液对pH值没有显著影响,但木瓜液和苹果梨汁对pH值均有一定影响。优化试验表明:牛肉嫩化效果的主次顺序为CaCl2溶液>木瓜液>苹果梨汁>腌渍时间,3种嫩化液组合注射,其CaCl2溶液、木瓜液、苹果梨汁浓度分别为0.03%、40%、20%,在4℃条件腌制时间为12 h,牛肉嫩化效果最佳。     

不同注射处理对牛肉剪切力和肌原纤维小片化指数的影响

本文研究了不同注射处理对牛肉在成熟过程中剪切力,肌原纤维小片化指数(MFI)的影响。3头改良黄牛(鲁西黄牛×犁木赞)在屠宰厂按照标准的屠宰工艺屠宰并预冷20h后取样,将样品给予7个不同的处理,每个处理分别按样品重10%注射蒸馏水(作为对照)、200mmol/L CaCl2、200mmol/L EGTA、200mmool/L ZnCl2、0.2mg/ml亮肽素、0.2mg/ml亮肽素 1%Triton X-100、1%Triton X-100,处理后将样品分别成熟3、8、16d后测一些指标变化。结果发现注射外源性钙激活酶抑制剂(亮肽素,ZnCl2)显著降低了牛肉的成熟速度,使牛肉剪切力增加,MFI降低;而注射CaCl2则相反,且注射CaCl2后牛肉成熟4d时的剪切力和对照组成熟16d时的差异不显著(p>0.05)。     

超声结合氯化钙溶液处理对牛肉品质的影响

探讨超声波结合氯化钙处理在不同成熟期对牛肉色泽、系水力、蒸煮损失及嫩度的影响。选择对宰后12h成年母黄牛的臀肉注射300mmol/L 氯化钙(注射量分别为肉质量的5%、10%),样品再分别在强度为133W/m2 的超声波中处理6、12min,即4 个处理组(Ⅰ组注射量5%、处理6min,Ⅱ组注射量5%、处理12min,Ⅲ组注射量10%、处理6min,Ⅳ组注射量10%、处理12min),对照组未作任何处理。各组分别在4℃成熟1、2、3、4、5、7d时检测肉块的色泽、系水力、蒸煮损失及嫩度(剪切力)。结果表明：注射10% 氯化钙结合超声波处理12min 对牛肉的色泽、系水力、蒸煮损失改善效果最好,注射5% 氯化钙结合超声波处理6min 对改善嫩度效果最显著(P ＜0.05),剪切力平均降低了28.41%。所以超声波结合氯化钙处理牛肉能明显改善牛肉品质。     

焦磷酸钠处理对牛肉嫩度和系水力影响的研究

向牛肉切块中注入10mmol／L、20mmol／L、30mmol／L3种不同浓度的焦磷酸钠（注射量占肉重0．3％）．然后在0～4℃条件下腌制24h，通过测定剪切力、煮熟率。分析不同浓度焦磷酸钠对牛肉嫩度和系水力的影响。结果表明，焦磷酸钠对牛肉剪切力影响极显著（P〈0．01）。牛肉嫩度有显著的改善作用；焦磷酸钠的适宜浓度为20mmol／L。焦磷酸钠处理对牛肉煮熟率的影响无显著差异（P〉0．05），焦磷酸钠处理对牛肉系水力无影响。     

可溶性胶原蛋白含量、肌原纤维小片化指数和粗钙激活因子活性的测定及其与牛肉嫩化效果之间的关系研究

本试验采用宰后向牛的股二头肌注射CaCl2溶液和木瓜蛋白酶来嫩化牛肉，并于后熟24h进行了肌原纤维小片化指数（MFI），粗钙激活因子活性（CAF）和可溶性胶原蛋白含量等指标的测定。实验结果表明，宰后注射CaCl2溶液和木瓜蛋白酶，显著降低了股二头肌的剪切力。3?Cl2溶液导致CAF活性比对照组显著增强。试样的可溶性胶原蛋白含量与剪切力相关性（r=-0.96)。对照组MFI与相应的剪切力相关显著（r=-0.736)。因此，MFI可作为量常规方法后熟或注射CaCl2牛肉的嫩度的方法。对于采用注射植物蛋白酶嫩化的牛肉，测量其可溶性胶原蛋白含量对于预测嫩度具有重要意义，而CAF活性的测定则可衡量常规方法后熟或注射CaCl2溶液的牛肉后熟的程度及其嫩度。     

注射CaCl2对猪半腱肌品质的影响

选用宰后48 h的猪半腱肌,注射占肉重5%、浓度分别为0和300mmol/L的CaCl2溶液,放在4℃左右条件下冷藏72 h后,测定其剪切力、煮熟率、pH和总色素,以此分析CaCl2处理对猪半腱肌品质的影响.结果显示,注射CaCl2能显著降低猪半腱肌的剪切力（P＜0.05）,但对煮熟率、pH和总色素影响均不显著（P＞0.05）.可见,注射CaCl2能通过改善猪半腱肌的嫩度而提高其品质,而对系水力、pH和色泽没有影响.     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of     

The Latest Data about Development of Chinese Printing Industry in 2013

In the 2014 China（Shanghai）International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan;     

The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)"

正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly     

China textile machinery: taking off in progress

正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing,     

Top Ten News of China's Paper Industry 2013

On December 24th, 2013, the meeting on the selection of top 10 news of China＇s paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation.     

National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the "13~(th) Five-Year Plan"

In Apri Commi major p Plan＂ （h 2014, the National Development and Reform ssion issued an announcement for selection of reliminary research projects for the ＂13th Five-Year ereafter referred to as ＂The Announcement＂）     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the latest scientific     

Contamination of animal feed and food from animal origin with mineral oil hydrocarbons

Oils and fats used for the production of animal feed can become contaminated with mineral oil material originating from gas oils (C₁₈-C₃₅) or synthetic oils (poly alpha olefins, C₂₅ to beyond C₄₅). An important cause is assumed to be the discharge of waste oils, such as motor oil and hydraulic oils. Mineral oil material was analysed by on-line LC-GC-FID directly in the fat or in a raw extract from animal feed or foodstuffs. In Switzerland in summer/autumn 1999 concentrations in oils and fats for feed production were often found to be between 100 and 1000mg/kg. In the feeds, the average concentration was around 100mg/kg with values ranging up to a maximum of 1000mg/kg; few samples were free of contamination. In animal body fat, the average concentration determined in summer 1999 was 25mg/kg, with a maximum of 150mg/kg, although in samples from December 1999, contamination was substantially lower. In the fat phase of eggs, the average concentration was 30mg/kg, with a maximum of 80mg/kg. Paraffin oil is used for feed production, which may account for part of the contamination problem (e.g. eggs).