外加酶制备麦汁的研究

以燕麦为辅料制备麦芽汁,采用正交试验设计,探讨它们对麦芽汁品质的影响。方差分析结果表明:NSP酶的添加量对麦汁的过滤时间、糖化时间、α-氨基氮量、还原糖量和收得率均有显著性影响(p<0.05),NSP酶的添加阶段和燕麦添加量均只对麦汁中α-氨基氮量有显著性影响(p<0.05),而NSP酶的作用时间对测定的理化指标均无显著性影响(p>0.05)。因此,在本试验条件下,确定的最佳工艺条件为:NSP复合酶添加量0.24%,燕麦添加量为30%,NSP复合酶在蛋白质休止阶段(45℃~50℃)添加、保温23min。     

加酶制备燕麦麦汁的正交试验研究

以燕麦为辅料制备麦芽汁，采用正交试验设计研究酶的添加量、添加阶段、作用时间、辅料添加量对麦芽汁品质的影响。结果表明，NSP酶的添加量对麦汁的过滤时间、糖化时间、α-氨基氮含量、还原糖量和收得率均有显著性影响（p〈0．05），NSP酶的添加阶段和燕麦添加量均只对麦汁中仅一氨基氮含量有显著性影响（p〈0．05），而NSP酶的作用时间对测定的理化指标均无显著性影响（p〉0．05）。最佳工艺条件为NSP复合酶添加量为0．24％，燕麦添加量为30％，NSP复合酶在蛋白质休止的第一阶段（45℃）添加，保温23min。     

荞麦啤酒的研制

以荞麦为辅料制备麦芽汁,以酶的添加量、添加阶段、作用时间和辅料添加量为影响因素进行正交试验,得到最佳麦汁制备条件。在此条件下制成10oP和14oP的麦汁,进行发酵,得到荞麦啤酒,并对其理化指标进行分析。最终得到:在酶的添加量为0.30%,添加阶段为低温浸渍(45℃),作用时间20min,荞麦添加量30%的条件下制成10oP的麦汁所发酵的啤酒感官指标和理化指标最好。     

超声波协同复合嫩化剂对生鲜猪肉嫩度的影响

采用超声波协同氯化钙及复合磷酸盐(三聚磷酸钠、六偏磷酸钠)对生鲜猪肉进行嫩化后,以植物蛋白酶(木瓜蛋白酶、菠萝蛋白酶)对其进行酶法嫩化,在单因素试验基础上通过正交试验,以剪切力为考察指标,探讨生鲜猪肉最优嫩化工艺条件。结果表明:超声功率、超声时间、复合磷酸盐添加量、植物蛋白酶添加量、酶作用温度影响显著,氯化钙添加量及水浴时间影响不显著,各因素对剪切力影响的主次关系为超声时间植物蛋白酶添加量超声功率酶作用温度复合磷酸盐添加量氯化钙添加量水浴时间。功率150 W条件下超声处理25min、1.0%氯化钙、0.20%复合磷酸盐、0.03%植物蛋白酶、酶作用温度20℃、水浴30 min,生鲜猪肉剪切力最小,肉最嫩。     

谷氨酰胺转氨酶对鸡蛋全蛋液热凝固性的影响

通过物性测定仪分析的方法,探讨NaCl添加量、pH值、谷氨酰胺转氨酶(TGase)添加量、酶作用温度、酶作用时间对鸡蛋全蛋液热处理后的凝胶硬度的影响,旨在拓展TGase在蛋品行业的应用,为传统蒸蛋的工业化生产提供一定的数据支持。结果表明:TGase处理全蛋液提高了全蛋液在加热后的凝胶硬度。且在NaCl添加量为2%,pH值为7.00,TGase添加量为1.2U/mL·全蛋液,酶作用温度为30℃,酶作用时间为4h时,所得全蛋液在加热后凝胶硬度达到最大(52.375g)。     

高效β-葡聚糖酶对麦汁过滤速度的影响

对添加高效β-葡聚糖酶对麦汁过滤速度的影响进行了研究。结果表明,添加β-葡聚糖酶可提高过滤速度2～3倍;添加木聚糖酶对过滤速度也有提高;β-葡聚糖酶的最适用量为110g,木聚糖酶用量为20g,两种酶复合应用效果较好;添加酶制剂对啤酒的外观及口味无不良影响,不会影响啤酒的风味;添加β-葡聚糖酶可缩短麦汁生产时间,提高生产效率。（孙悟）     

转谷氨酰胺酶在淡水鱼制品中的应用

试验研究了添加转谷氨酰胺酶对鱼肉蛋白凝胶强度以及色差的影响,试验先采用单因素分析了转谷氨酰胺酶不同的添加量、不同的作用温度以及不同的作用时间对淡水鱼制品的凝胶强度、色差的影响,然后又经3因素3水平正交设计确定了转谷氨酰胺酶的最适添加量、最适作用温度及最最佳作用时间。经试验证明,转谷氨酰胺酶的最适的添加量为6%,最适的作用温度和作用时间分别为40℃和1.5h。     

酶解法制备薏米汁的工艺优化

以薏米为原料,采用α-淀粉酶和木瓜蛋白酶酶解薏米制备薏米汁。以还原糖含量和氮溶解指数(NSI)为检测指标,研究酶添加量、酶解时间、酶解温度3个因素对淀粉酶与木瓜蛋白酶酶解作用的影响。结果表明,α-淀粉酶酶解时间3.5 h,酶解温度65℃,酶添加量300 U/g;木瓜蛋白酶酶解时间为6 h,酶解温度为50℃,酶添加量为100 U/g。在此优化条件下,薏米汁中还原糖含量达23.26 mg/m L,氮溶解指数达到79.58%。     

转苷酶在低醇啤酒酿造中的应用

本文采用跳跃式糖化与加转苷酶相结合的方法来调整发酵度，通过对转苷酶的加量、时间、pH值、温度进行正交实验，选择最佳工艺条件：煮沸之前把麦汁温度调到55℃、pH调到5．5、添加量为0.1％、添加时间50min，从而生产出优质的低醇啤酒。     

酶促酯化制备DAG过程中的酰基转移研究

采用Sn-1,3特异性脂肪酶Lipozyme RM IM,以油酸和甘油的酶促酯化制备甘二酯(DAG)为模型,探讨酯化时间、酯化温度、底物(油酸与甘油)摩尔比和酶添加量对体系酰基转移的影响。结果表明:底物摩尔比对反应体系的酰基转移影响不大;酯化时间和酯化温度是影响酰基转移的最主要因素,酯化时间越长、酯化温度越高,酰基转移越严重,65℃酯化10 h时的酰基转移率达26. 1%,75℃酯化2 h时的酰基转移率达15. 1%;酶添加量在油-水反应界面达到饱和(界面饱和的酶添加量为6%)之前,酶添加量的变化对酰基转移的影响不大,达到饱和之后,进一步增加酶添加量,明显加剧体系的酰基转移。     

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).