造纸湿部化学参数的测量及控制技术的新进展

本文主要对近几年来湿部化学参数测量及控制技术的新进展进行了综合介绍.着重介绍了BTG脱水分析仪,白水浓度,电荷以及铝离子的最近在线测量仪器及方法.并介绍了两种重要的湿部化学参数控制系统WIC以及Kajaani湿部控制系统.     

Identification of meat species by TaqMan-based real-time PCR assay

In this study, a convenient, sensitive and specific real-time PCR assay was described for the species identification and their quantification in raw and cooked meat products. Specific primers and TaqMan probes were designed on the mitochondrial ND2, ND5 and ATP 6-8 genes for donkey, pork and horse, respectively, and the performance of the method was tested. In the results, no cross-reaction was observed between the donkey and pork species specific primer-probe systems and non-target species (bovine, ovine, chicken and turkey). Only one cross reaction was observed between the horse species specific primer-probe set and 100 ng pork DNA at the ct 33.01 level (corresponding to 0.01 ng horse DNA). The real-time quantitative assay used in this study allowed the detection of as little as 0.0001 ng template DNA from pure meat for each species investigated and experimental meat mixtures. In conclusion, it can be suggested that the TaqMan probe assay used in this research might be a rapid and sensitive method for the routine meat species identifications studies in raw or cooked meat products.     

桑果醋挥发性成分的顶空固相微萃取-气质联用分析

采用顶空固相微萃取法提取桑果醋挥发性成分,用气相色谱.质谱联用方法进行分析,共分离鉴定出35种成分,主要包括有机酸类、酯类、醇类、烯类、酮类、噻唑等.     

Identification of Lactic Acid Bacterial Strains with High Conjugated Linoleic Acid-Producing Ability from Natural Sauerkraut Fermentations

ABSTRACT:  Natural sauerkraut fermentations contain a great number of lactic acid bacteria. The aim of this study was to identify lactic acid bacterial strains with high conjugated linoleic acid (CLA)-producing ability from natural sauerkraut fermentations. Fifteen CLA-producing lactic acid bacterial strains were isolated in the study. One of these strains, designated as NCUL005, showed the highest CLA-producing ability (0.623 mg/mL). The transformation efficiency of converting linoleic acid into CLA by NCUL005 was 26.67%. The CLA produced by NCUL005 comprised a mixture of 32.2% cis9, trans11-C18:2 isomer and 67.8% trans10, cis12-C18:2 isomer. NCUL005 was identified as Lactobacillus plantarum , based on its cell morphology, characteristics of lactic acid production, and analysis result from Biolog Microbial Identification System (BMIS).     

Hydrolysis of grape monoterpenyl glycosides by Candida molischiana and Candida wickerhamii β-glucosidases

The exocellular β-glucosidases of Candida molischiana and Candida wickerhamii are able to hydrolyse geranyl, neryl, citronellyl, linalyl and α-terpinyl-β-D -glucopyranosides. The nature of the aglycone residue greatly affects the rate of hydrolysis. Glucosides with a tertiary alcohol as aglycone residue are more slowly hydrolysed than those with a primary alcohol. The β-glucosidase from C molischiana is also able to hydrolse α-L-arabinofuranosides. This results in the release of monoterpenols from a glycoside extract from grape juice.     

Studies on non-enzymic browning in orange juice using a model system based on freshly squeezed orange juice

An orange juice based model system was set up wherein variables such as the addition of glucose, lysine, sorbitol and L -ascorbic acid and changes in pH and storage temperature were introduced to study their effects on L -ascorbic acid degradation and on browning. The addition of glucose, lysine and sorbitol did not have a significant effect on L -ascorbic acid degradation, whereas added L -ascorbic acid acted solely as a reserve material. In terms of browning, a change in pH and storage at elevated temperature produced a synergistic effect in the development of brown colour which was enhanced by the introduction of additives. Based on the results obtained, L -ascorbic acid appears to be the precursor in the non-enzymic browning occurring in this type of sample due to the formation of reactive carbonyl compounds produced upon its degradation which tend to polymerise, or to react with nitrogenous compounds, to give brown pigments.     

MODELLING OF MICROSTRUCTURE EVOLUTION AND PROPERTIES OF LOW-CARBON STEELS

1.IntroductionMicrostructureprocessmodelsareincreasinglyonhotstriprollingofste.l[1--7].Thesemodelsfrequentlyincorporateagreatdealofempiricismwithcomparativelytightprocessrangesofapplicability.Morefundamentallybasedprocessmodelsarerequiredtodeveloppredictivetoolstooptimizetheproductionforawiderangeofmilldesignsandprocessingconditions.Theprocessofhotstriprollingoflow--carbonsteelscanbesubdividedintothreeprin-cipalstages:(i)reheating,(n)rollingand(iii)cooling(watercoolingontherun--outtableandsubs…     

Tenderness of major muscles from three breed-types of cattle at different times-on-feed

Seventy-five steers (9 to 12 months of age) of Angus (n = 25), Brahman (n = 25) and Brahman × Angus (n = 25) breed-types of known history were fed a high-energy diet and five steers from each breed-type were slaughtered after 0, 56, 112, 168 and 224 days on test. At seven days post mortem, the left side of each carcass was fabricated and eight major primals or subprimals were obtained. Steaks were removed from the shoulder clod, strip loin, tenderloin, top sirloin, knuckle, top round, bottom round and eye of round for Warner-Bratzler shear (WBS) determinations and from the strip loin and bottom round for sensory panel evaluations. Steaks from Angus and Brahman × Angus steers were generally more tender than steaks from Brahman steers. Tenderness of steaks from steers of the three breed-types responded to time-on-feed differently: (a) steaks from Brahman steers improved (P < 0·05) in tenderness with increasing time-on-feed for all muscles except the M. psoas major (tenderloin); (b) with the exception of the M. longissimus muscle (strip loin), the tenderness of steaks from Angus steers did not change (P > 0·05) as time-on-feed increased and (c) for the Brahman × Angus steers, five of the ten muscles studied improved (P < 0·05) in tenderness with increasing time-on-feed. 'Acceptable' tenderness (WBS values of less than 4·5 kg) for most of the muscles was achieved at feeding periods from 112 to 224 days for Brahman, from 0 to 56 days for Angus and from 56 to 168 days for Brahman × Angus.