发酵温度对高盐稀态酱油原油品质的影响

研究了不同发酵温度(35、25℃、自然)对高盐稀态酱油原油品质的影响。结果表明,高盐稀态酱油在25℃下发酵品质最好,发酵60d后总氮含量为1.23g/100mL,氨基酸态氮为0.74g/100mL,总酸和还原糖分别为2.03、3.37g/100mL,pH为4.60。25℃下发酵酱油的氨态氮含量与35℃和自然发酵的酱油相比,分别高出了11.68%和8.55%,而且25℃发酵的酱油其游离氨基酸总量也最高,为55.67mg/mL,其中必需氨基酸占43.97%,鲜味氨基酸占29.20%,甜味氨基酸占22.06%,均高于35℃和自然发酵的酱油。25℃发酵酱油的赖氨酸含量为3.91mg/mL,分别比35℃和自然发酵酱油高出16.37%和15.69%。     

鮸鱼肌肉和副产物营养组成分析及评价

对鮸鱼肌肉和副产物营养成分进行测定,鮸鱼肌肉和副产物水分含量分别为79.65%与69.15%,蛋白质含量分别为18.65%与19.36%,粗脂肪含量分别为0.24%与3.90%,灰分含量分别为1.15%与3.75%。鮸鱼肌肉和副产物的氨基酸总量(TAA)分别为18.58%与15.47%,必需氨基酸(EAA)质量分数分别为7.65%与5.52%,但只有鮸鱼肌肉的EAA/TAA(41.17%)与EAA/非必需氨基酸(69.99%)符合FAO/WHO优质蛋白质标准。氨基酸评分和化学评分的结果表明鮸鱼肌肉和副产物的第一限制性氨基酸均为蛋氨酸。鮸鱼肌肉必需氨基酸指数(EAAI)为89.07,副产物的EAAI为61.78。鮸鱼肌肉和副产物都含有丰富的丁酸、棕榈油酸、油酸、神经酸、二十二碳六烯酸、Mg、Ca、K和Fe。鮸鱼肌肉和副产物是高蛋白质、低脂肪、富含矿物质的食品源。     

两种微生物水解脱淀粉小麦中蛋白效果的比较研究

为研究枯草芽孢杆菌（Bacillus subtilis）和米曲霉（Aspergillus oryzae）对脱淀粉小麦中蛋白质的水解效果,采用前发酵和后发酵获得发酵液,比较两种微生物培养过程中性蛋白酶活力和发酵液的pH值、可溶性无盐固形物、氨基酸态氮含量、氨基酸组成,并对其发酵液进行感官评价。结果表明,在最适前发酵工艺的条件下,枯草芽孢杆菌和米曲霉中性蛋白酶活力分别为1 060.82 U/g和908.02 U/g;两种微生物最终发酵液pH值为7.08和5.37,可溶性无盐固形物为15.60%和18.98%,氨基酸态氮含量为0.73 g/100 mL和0.75 g/100 mL,总游离氨基酸含量为4.35 mg/mL和9.04 mg/mL,蛋白质水解度为55.99%和59.71%。枯草芽孢杆菌发酵液中必需氨基酸的组成和比例更符合氨基酸模式谱,必需氨基酸与总游离氨基酸的比值（EAA/TAA）、必需氨基酸与非必需氨基酸（EAA/NEAA）的比值也高于米曲霉。感官评价结果显示,米曲霉发酵液好于枯草芽孢杆菌。     

刺鲃鱼皮和鱼鳞营养成分的分析与评价

为了开发利用刺鲃(Spinibarbus caldwelli)鱼皮和鱼鳞,对网箱养殖刺鲃鱼皮和鱼鳞营养成分进行测定。结果表明:鱼皮和鱼鳞(鲜样)中分别含粗蛋白质(23.80%、40.77%)、粗脂肪(13.24%、2.70%)、水分(49.21%、53.53%)、粗灰分(0.38%、9.05%);鱼皮和鱼鳞均含有16种氨基酸,其中必需氨基酸(EAA)7种,非必需氨基酸(NEAA)9种,其氨基酸总量(TAA)分别为11.91%和50.64%。鱼皮中EAA/TAA为20.91%,EAA/NEAA为26.43%,鱼鳞EAA/TAA为16.71%,EAA/NEAA为20.06%,其鲜味氨基酸(DAA)/TAA均较高,分别达46.23%和48.42%。鱼皮和鱼鳞均检测到11种主要脂肪酸,其中饱和脂肪酸总量(∑SFA)分别为23.20%和25.01%,单不饱和脂肪酸总量(∑MUFA)分别为53.59%和53.95%,多不饱和脂肪酸总量(∑PUFA)分别为23.21%和21.04%;鱼皮和鱼鳞5种微量元素中,均是Zn含量最高,分别达64.62 mg/kg和32.96 mg/kg,Se含量最低0.03 mg/kg和0.27 mg/kg。研究表明,刺鲃鱼皮和鱼鳞均是味道鲜美且富含胶原蛋白和微量元素的保健食品源,同时也是一种良好的动物性饲料原料。     

苦荞芽苗茶饮料发酵前后营养、风味及抗氧化活性的变化

采用植物乳杆菌发酵苦荞芽苗茶饮料,通过对发酵前后苦荞芽苗茶饮料中芦丁、槲皮素、山奈酚-3-O-芸香糖苷、总黄酮、氨基酸、挥发性化合物、DPPH和ABTS自由基清除率等指标进行测定,研究发酵前后营养、风味及抗氧化活性的变化规律。结果表明,发酵后芦丁含量基本保持不变,槲皮素和山奈酚-3-O-芸香糖苷含量有稍许降低,总黄酮含量从(120.6±1.9)μg/mL微降至(114.6±1.7)μg/mL。苦荞芽苗饮料中包含6种必需氨基酸(EAA)和11种非必需氨基酸(NEAA),发酵后必需氨基酸/总氨基酸(EAA/TAA)为38.32%,EAA/NEAA为62.13%,显著高于发酵前。分离鉴定出8类54种挥发性物质,发酵前含有46种,发酵后含有43种,通过发酵,阈值较低的芳香性风味物质含量明显提升。发酵后DPPH和ABTS自由基清除率均升高,乳酸菌发酵可以提高苦荞芽苗茶饮料的抗氧化活性。     

鱼皮低聚肽氨基酸组成及抗氧化活性研究

以还原型谷胱甘肽和抗坏血酸为对照,采用DPPH·法和邻二氮菲-Fe~(2+)氧化法分别测定鱼皮低聚肽清除DPPH·和·OH活性能力;并利用GB/T5009.124-2003《食品中氨基酸的测定》方法测定鱼皮低聚肽的氨基酸组成,进行营养价值评价及抗氧化能力与氨基酸组成关系的初步分析。结果表明,在优选的反应体系中,鱼皮低聚肽、谷胱甘肽和抗坏血酸对·OH的IC_(50)值分别为2.482、0.357、0.100mg/mL,对DPPH·的IC_(50)值分别为0.635、0.030、0.003 mg/mL,鱼皮低聚肽必需氨基酸含量为24.43%,EAA/TAA值为24.19%,EAA/NEAA值为32%,CS均大于100,EAAI为352,含硫氨基酸含量为3.8%,除蛋氨酸外的疏水性氨基酸占氨基酸总量的26.7%,具有抗氧化活性的氨基酸总量为30.5%,与鱼皮低聚肽的抗氧化活性一致。     

明月草营养成分的分析及评价

对明月草的氨基酸、矿质元素及其他营养成分进行了分析测定,并进行了营养评价。结果表明,明月草中水分、蛋白质、粗脂肪、总糖、粗纤维、灰分、维生素C与总黄酮的含量为92.70%、1.99%、0.35%、0.21%、0.68%、1.40%、0.08 mg/g与4.79 mg/g;含有氨基酸15种,氨基酸总量(TAA)为20.01%。EAA/TAA为43.83%,EAA/NEAA为78.02%,各种人体必需氨基酸种类齐全,且比例均衡,比值系数分(SRC)为65.10。在各种人体必需氨基酸中,第一限制氨基酸为蛋氨酸+胱氨酸;P、K、Ca、Mg、Fe、Zn、Cu、Mn矿质元素的含量为322、4210、1441、478、38、2.36、1.14、55.70 mg/kg,经分析明月草氨基酸、矿质元素及其他营养成分含量丰富,具有很好的开发与利用价值。     

杂粮同熟化技术的应用拓展研究

介绍一种用于改善大米中营养缺乏的杂粮米复配方案,复配杂粮饭中必需氨基酸占氨基酸总量（EAA/TAA,E/T）和必需氨基酸与非必需氨基酸比值（EAA/NEAA,E/N）更接近世界卫生组织（WHO）和联合国粮农组织（FAO）提出蛋白质中EAA/TAA应达到40%、EAA/NEAA应大于60%的参考标准,食用口感与大米接近,与精米饭中相比,必需氨基酸营养更合理。     

5种百香果品系间氨基酸组成比较及评价分析

为了比较不同品系百香果中的氨基酸含量及组成,利用氨基酸自动分析仪对5种百香果果汁中氨基酸成分及含量进行检测与营养价值评价,同时对氨基酸组成及含量进行差异分析及聚类分析。结果表明,5个品系百香果均含有17种氨基酸,‘芭乐味黄金果’氨基酸总量TAA (977.03 mg·100 g-1)、必需氨基酸EAA (268.14 mg·100 g-1)和儿童必需氨基酸CEAA (63.26 mg·100 g-1)含量均为最高,和‘实生株系紫果’达差异极显著水平(P<0.01);‘实生株系紫果’EAA/NEAA (42.13%)、EAA/TAA (29.63%)和氨基酸比值系数分SRC (72.61)均最高。百香果的SRC值为64.49~72.61,第一限制氨基酸为甲硫氨酸+胱氨酸(Met+Cys)。以TAA、EAA、呈味氨基酸等指标进行系统聚类分析,将5个品系百香果氨基酸聚类为2类。第1类为‘芭乐味黄金果’,其特征为氨基酸总量、必需氨基酸、儿童必需氨基酸、鲜味氨基酸、苦味氨基酸、药用氨基酸、支链氨基酸和芳香族氨基酸均为最高;第2类为‘台农’、‘紫香’、‘满天星’和‘实生株系紫果’。     

甜酒酿营养成分分析与评价

该文检测分析了用纯根霉酒曲发酵而成的甜酒酿的主要营养成分,着重分析了其氨基酸含量和组成情况,为进一步提高其食用价值及开发利用提供科学依据.对甜酒酿的粗脂肪、粗蛋白、还原糖、氨基酸、总酸和酒精度进行了测定,结果表明:甜酒酿含有19种氨基酸,总量为1100mg/100mL～1700mg/100mL,其中谷氨酸含量最高,为190mg/100mL～320mg/100mL;必需氨基酸总量为390mg/100mL～580mg/100mL,占氨基酸总量的比例为32.00%～35.45%.甜酒酿还原糖35.76g/100mL～37.34g/100mL;总酸0.34g/100mL～0.46g/100mL.甜酒酿含有的氨基酸种类齐全,而且糖度和酸度适中,酒精度低,具有较高的营养价值.     

Nitrogen use efficiency in grain production and the estimated nitrogen input/output balance in China agriculture

BACKGROUND Understanding the nitrogen (N) use efficiency and N input/output balance in the agricultural system is crucial for best management of N fertilisers in China. RESULTS In the last 60 years, N fertiliser consumption correlated positively with grain production. During that period the partial factor productivity of N (PFP_N) declined greatly from more than 1000 kg grain kg^?1 N in the 1950s to nearly 30 kg grain kg^?1 N in 2008. This change in PFP_N could be largely explained by the increase in N rate. The average agronomic efficiency of fertiliser N (AE_N) for rice, wheat and maize during 2000‐2010 was 12.6, 8.3 and 11.5 kg kg^?1 respectively, which was similar to that in the early 1980s but lower than that in the early 1960s. Estimation based on statistical data showed that a total of 49.16 × 10⁶ t of N was input into Chinese agriculture, of which chemical N, organic fertiliser N, biological fixed N and other sources accounted for 58.2, 24.3, 10.5 and 7.0% respectively. Nitrogen was surplus in all regions, the total N surplus being 10.6 × 10⁶ t (60.6 kg ha^?1). CONCLUSION The great challenge is to balance the use of current N fertilisers between regions and crops to improve N use efficiency while maintaining or increasing crop production under the high‐intensity agricultural system of China. © 2012 Society of Chemical Industry     

Effects of a polymer-coated urea product on nitrogen metabolism in lactating Holstein dairy cattle

The purpose of this study was to evaluate the impact of polymer-coated urea on nitrogen retention, rumen microbial growth, and milk production and composition. Coated urea (CU) that is more slowly hydrolyzed to ammonia than unprotected urea could potentially be used more efficiently by rumen microorganisms. Eight cows were offered each of three diets in a randomized crossover design. Each treatment period consisted of a 14-d adjustment period and a 5-d collection period. Diets were formulated to maintain milk production while reducing plasma urea nitrogen concentrations and urinary nitrogen excretion. Diets consisted of corn silage, mixed grass/legume haylage, chopped alfalfa hay, corn meal, protein, vitamin and mineral supplements, in a total mixed ration and fed ad libitum. The diets contained 17.9%, 18.1%, and 16.4% CP and 0, 0.77%, and 0.77% CU (dry matter basis) and are denoted as CP18-CU, CP18+CU, and CP16+CU, respectively. Individual feed intakes were measured, and total fecal, and urine collections were conducted. Cows were milked twice daily at 0500 and 1700 h, and the milk sampled for composition and milk urea N analysis. Dry matter intake averaged 23.5 +/- 0.2 kg/d and was not altered by diet. Also, milk fat and true protein were not altered by diet and averaged 3.72 and 3.07%, respectively. Milk yield was highest for diets CP18-CU and CP18+CU. Significant differences were observed in N intake and excretion in urine, feces, and milk between dietary treatments. Cows fed CP16+CU consumed 11% less N than in CP18-CU. Cows fed CP18+CU showed the highest excretion of N in urine, and together with CP16+CU, the lowest N excretion in feces. Nitrogen excretion in milk was lower for cows fed CP16+CU. Calculated N balance was not significantly different between diets nor was it significantly different from zero. Efficiency of N capture in milk protein as a function of N intake was higher for animals on CP16+CU. Urinary excretion of purine derivatives was not different between diets, and estimated microbial CP was also similar. Coated urea was not effective at reducing nitrogen excretion by dairy cattle.     

液氮冻结技术及其在冰淇淋生产中的应用

为解决冰淇淋生产中的质量问题，浸渍式液氮冰淇淋快速冻结装置和喷雾式液氮冰淇淋快速冻结装置，能有效地提高巧克力脆皮冰淇淋和火炬形冰淇淋的质量。对浸渍式和喷雾式液氮冰淇淋快速冻结装置，和液氮冻结技术及装置进行了的介绍。     

海产动物蛋白的酶曲二步法酿造新型营养酱油

利用蛋白酶水解与成曲酿制相结合的方法，对以鱼粉为主要原料的底物进行充分发酵，生产口味良好、全氮与氨基氮含量高的海味营养酱海，并对相关的主要工艺条件进行了探讨。     

可同化氮含量对赤霞珠葡萄酒发酵和香气成分的影响

选取山西戎子酒庄有限公司不同位置的三个葡萄园(驮腰坡,东廒北,东廒南),对各葡萄园进行土壤含氮量、赤霞珠葡萄及葡萄酒发酵过程中可同化氮(YAN)含量、葡萄酒理化指标与香气成分的检测分析。结果表明,葡萄果实可同化氮含量可能主要与土壤铵态氮含量有关。不同葡萄园的赤霞珠葡萄汁可同化氮的含量不同,均超过了150 mg/L,能保证发酵顺利进行。如果需要添加可同化氮时,应以此时测定的可同化氮含量为依据,避免添加过量。原酒中酯类和醇类相对含量由高到低依次为：驮腰坡＞东廒南助剂＞东廒北＞东廒南,这与葡萄汁中可同化氮含量呈正相关。     

Non-protein nitrogen in infant cereals affected by industrial processing

The effects of industrial processing on non-protein content in four varieties of infant cereals, so-called ‘Multicereal' and ‘Wheat' as gluten infant cereals, and ‘Growth' and ‘Rice and carrot' as gluten-free infant cereals were determined. Samples were classified according to their industrial stage of treatment: (1) mixture of raw flours; (2) mixture of roasted flours; (3) mixture of enzymatically hydrolysed and drum-dried flours (film); (4) commercial infant cereals. Total nitrogen (TN), protein nitrogen (PN) and non-protein nitrogen (NPN) contents were higher in gluten infant cereals than in gluten-free infant cereals. NPN content was always higher than PN content in all cereals. Industrial processing led to a significant increase in NPN (P<0.01) and free amino acid contents (P<0.001), whereas TN and PN contents decreased significantly (P<0.05). Although non-amino acid nitrogen components remained stable with the industrial processing, a high content of ammonium was found in gluten-free infant cereals as a consequence of taurine and asparagine degradation.     

Updating analysis of nitrogen balance experiments in dairy cows

Nitrogen balance (NB) experiments allow calculation of N retention in the body by subtracting N excreted in feces (NF), urine (NU) and milk (NM) from N intake (NI). In a previous study, we found that NB data from experiments with lactating dairy cows were generally high and, in the current meta-analysis, we update our earlier study with experiments from the last 2 decades and investigate probable causes of error. A total of 83 publications, with 86 experiments and 307 dietary treatments, were selected from top-ranked scientific journals that reported all NB components. The NB and NB components were analyzed by linear regression with a model that used NI as an independent variable and experiment as a random effect. The NF, NU and NM each represented 27 to 34% of NI, and the remaining N accumulated in the body was equal to 38.5 g/d (overall SD = 43.2 g/d). Retained N (as g/d or % of NI) increased linearly with NI, and this led to unlikely high N retentions, especially at high NI. Both NF and NU (g/d) increased with increasing NI, and we assume that some N in feces and urine were unaccounted. Only ~22% of experiments measured N in wet feces samples and, when analysis used dry samples, no mention of corrections due to potential volatile N losses during drying were reported. No experimentalists preserved feces immediately to prevent volatilization during collection. Moreover, ~27% of experiments estimated urine volumes by concentration of creatinine in spot samples, and in these experiments, NU was ~12% lower than those where total urine was collected (168 vs. 191 g/d). Only 40 experiments reported the volume and concentration of acids used for urine preservation, 33 furnished incomplete information, and the remainder did not describe the urine preservation method. In conclusion, the results of NB experiments using lactating dairy cows overestimate N retention, and the losses of N from feces and urine are the most probable reason.     

麦汁、发酵液、成品酒隆丁区分之间的相互关系和检验准确性的探讨

隆丁区分值又叫蛋白质区分值,是对 .芽蛋白质分解情况进行检查的一个量值.在一定程度上反映了麦芽蛋白溶解度,隆丁区分值对于麦芽干燥过程中凋萎休止阶段的控制和在制麦汁过程中蛋白质体止温度和时间的控制都有一定的指导意义,对啤酒质量也有很大的影响.     

尿素改性木素磺酸钙制备缓释氮肥的工艺研究

对尿素改性木素磺酸钙合成缓释有机氮肥的工艺条件进行了研究,通过正交实验确定了反应pH值、时间、温度、尿素用量等工艺条件对改性反应的影响程度,测定了改性后木素磺酸钙中的总氮和铵态氮含量。结果表明,pH值为3、温度85℃、时间4 h、m尿素∶m木素=(1-1.6)∶1是较为理想的反应条件,改性木素磺酸钙产品的总氮含量最高达9.84%、铵态氮含量为0.60%。