A comparative study of innovation rennets from Swedish ruminants: calves, kids, and lambs

The study aimed to examine Swedish innovation rennets (lamb and kid) and bovine rennets (pepsin and chymosin) in combination with species-specific milk from goat, sheep, and cow. This was accomplished by evaluating the gross composition, casein and whey protein content, casein number of the milk types, as well as rheological properties, such as curd yield, coagulation time, and gel firmness. The milk composition showed that sheep milk had the highest levels for all investigated milk components but the lowest pH, which was 3% lower for cow and goat milk. Comparing the effect of milk type on curd yield using the different rennets, the sheep milk in combination with chymosin resulted in 9% and 35% higher curd yield compared to cow and goat milk, respectively (p=0.001). Pepsin in combination with goat milk resulted in 28% and 30% lower curd yield than for cow and sheep milk, respectively (p=0.001). The lamb rennet with sheep milk showed 12% and 24% higher curd yield than with cow and goat milk, respectively (p=0.001), and the kid rennet with goat milk had a 37% lower curd yield than with cow and sheep milk, respectively (p=0.001). Comparing the effects of the rennets on the curd yield for each milk type, cow milk with chymosin and lamb rennet resulted in a 5% higher curd yield than with kid rennet (p=0.021). Kid rennet with goat milk showed 15% and 29% lower curd yield compared to chymosin and lamb rennet, respectively (p=0.001). The curd yield from sheep milk with lamb rennet was 10% and 17% higher compared to pepsin and kid rennet (p=0.001). The effect of milk type on coagulation time showed that cow milk with chymosin was 50% and 60% longer than in goat and sheep milk (p=0.001). Pepsin with cow milk displayed 44% and 54% higher coagulation time than with goat and sheep milk, respectively (p=0.001). Sheep milk with lamb rennet had 46% and 53% shorter coagulation times than with goat and cow milk, respectively (p=0.001). Within the milk types, the effects of rennets showed that lamb rennet, compared to chymosin, pepsin, and kid rennet, resulted in the longest coagulation time, 9%, 26%, and 54% longer, respectively, in combination with cow milk (p=0.001). Goat milk with lamb rennet showed a 48%, 52%, and 72% longer coagulation time compared to chymosin, pepsin, and kid rennet, respectively (p=0.001). Kid rennet with sheep milk resulted in 47%, 51%, and 61% shorter coagulation time than with pepsin, chymosin, and lamb rennet, respectively (p=0.001). Comparing the effect of milk type on gel firmness showed that chymosin in sheep milk resulted in 84% and 80% higher gel firmness than in cow and goat milk, respectively (p=0.001). Pepsin with sheep milk displayed the highest gel firmness, 83% and 81% higher than for cow and goat milk, respectively (p=0.001). Lamb rennet with sheep milk resulted in 82% higher gel firmness compared to cow and goat milk, respectively (p=0.001). Kid rennet with goat milk showed 49% and 78% lower gel firmness than cow and sheep milk (p=0.001). Within the milk types, the effects of rennets on gel firmness showed that when kid rennet was used in cow milk, gel firmness was 31%, 39%, and 41% higher compared to when pepsin, lamb rennet, and chymosin, respectively, were used (p=0.001). Kid rennet with goat milk showed the lowest gel firmness, 32% lower than for chymosin and pepsin Abstract (p=0.002). Sheep milk with kid rennet resulted in 37% and 41% lower gel firmness compared to chymosin and pepsin rennet (p=0.010). This research indicates that the species-specific innovative rennets from Swedish ruminants can potentially contribute to the optimization of the production of Swedish artisanal cheeses, thereby increasing the added value of the final product.Studiens syfte var att undersöka svenskt innovationslöpe från lamm och killing i jämförelse med bovint löpe (pepsin och chymosin) i kombination med mjölk från get, får och ko. I studien utvärderades mjölkens generella sammansättning, innehåll av kasein och vassleproteiner, kaseintal, reologiska egenskaper (koaguleringstid och gelstyrka), samt utbyte av ostmassa. Resultatet av mjölkens sammansättning visar att fårmjölk innehöll högsta mängden för alla undersökta mjölkkomponenter, men dess pH var 3% lägre än för ko- och getmjölk. När effekten av mjölktyp undersöktes avseende utbyte av ostmassa, gav fårmjölk i kombination med chymosin 9% och 35% högre mängd jämfört med ko- och getmjölk (p=0,001). Pepsin med getmjölk resulterade i 28% och 30% lägre utbyte än med ko- och fårmjölk (p=0,001). Lammlöpe med fårmjölk gav 12% och 24% högre utbyte än med ko- och getmjölk (p=0,001), och killinglöpe med getmjölk 37% lägre utbyte än med ko- och fårmjölk (p=0001). Effekterna av löpe inom mjölktyp visade att komjölk med chymosin och lammlöpe resulterade i 5% högre utbyte av ostmassa än med killinglöpe (p=0,021). Killinglöpe med getmjölk gav 15% och 29% lägre utbyte jämfört med chymosin och lammlöpe (p=0,0001). Utbytet av ostmassa från fårmjölk med lammlöpe var 10% och 17% högre jämfört med pepsin och killinglöpe (p=0,001). Effekten av mjölktyp på löpenas koaguleringstiden visade att chymosin med komjölk resulterade i 50% och 60% längre koaguleringstid än med get- och fårmjölk (p=0,001). Pepsin med komjölk uppvisade 44% och 54% längre koaguleringstid än med get- och fårmjölk (p=0,001). Lammlöpe med fårmjölk hade 46% och 53% kortare koaguleringstid än med get- och komjölk (p=0,001). Inom mjölktyp hade lammlöpe, jämfört med chymosin, pepsin och killinglöpe, den längsta koaguleringstiden, 9%, 26% respektive 54%, i komjölk (p=0,001). I getmjölk hade lammlöpe 48%, 52% och 72% längre koaguleringstid jämfört med chymosin, pepsin och killinglöpe (p=0,001). Fårmjölk med killinglöpe resulterade i 47%, 51% och 61% kortare koaguleringstid än med pepsin, chymosin och lammlöpe (p=0,001). I studier av effekten av mjölktyp på gelstyrkan för de olika löpena resulterade chymosin i fårmjölk i 84% respektive 80% högre gelstyrka än i ko- och getmjölk (p=0,001). Pepsin med fårmjölk uppvisade 83% och 81% högre gelstyrka än med ko- och getmjölk (p=0,001). Lammlöpe med fårmjölk resulterade i 82% högre gelstyrka jämfört med ko- och getmjölk (p=0,001). Killinglöpe med getmjölk visade 49% och 78% lägre gelstyrka än med ko- och fårmjölk (p=0,001). Studier av effekterna av löpe inom mjölktyp visade att när killinglöpe användes i komjölk var gelstyrkan 31%, 39% och 41% högre än med pepsin, lammlöpe och chymosin (p=0,001). Killinglöpe uppvisade den lägsta gelstyrkan med getmjölk, 32% lägre än med chymosin och pepsin (p=0,002). Fårmjölk med killinglöpe resulterade i 37% och 41% lägre gelstyrka jämfört med chymosin- och pepsin (p=0,010). Sammanfattning Denna studie indikerar att artspecifikt innovationslöpe från svenska idisslare skulle kunna bidra till ett ökat mervärde i produktionen av svenska hantverksostar

Actors and interpretations in an environmental controversy: the Swedish debate on sewage sludge use in agriculture

This study examines the Swedish debate on the sustainability of using sewage sludge as fertiliser in agriculture. Although the use of sludge as fertiliser presents potential resource and environmental advantages, it can have negative effects on people and soil productivity. Both proponents and opponents of agricultural application of sludge use environmental arguments to support their positions. By 1990, the Swedish parliament stressed the importance of recycling nutrients from wastewater; however, despite low levels of contamination, compared to other countries, little sludge is used in agriculture today. During the last few decades, a large amount of research has addressed the risks and benefits of using sludge as fertiliser, but the central actors have not been able to reach lasting agreements. This study, which is based on document analysis, direct observations, and interviews, analyses the beliefs, preferences, and arguments of major actors in the national debate on sludge. The study investigates how actors define problems and interpret the risks and benefits of sludge use. Specifically, the study concentrates on the role of science in the sludge controversy. Two distinct ways of thinking - a precautionary frame and a proof-first frame - are identified. These frames are shown almost immune to factual claims and arguments from opponents. It is concluded that actors in the controversy need to address explicitly value judgements and beliefs that go beyond scientific information. In addition, the study concludes that there is a need for policy makers to further develop process leadership skills. \ua9 2004 Elsevier B.V. All rights reserved

Insektsinvasion i klimatförändringens spår

Under evolutionens gång har insekter erövrat större delen av jordklotet. De finns i nästan alla klimatzoner och biotoper och kan förhållandevis snabbt anpassa sig till ändrade klimatförhållanden

Attractive plant volatiles as a control method against apple fruit moth (Argyresthia conjugella Zell.)?

Apple fruit moth, Argyresthia conjugella Zell. (Lepidoptera: Argyresthiidae), is the most important pest of apples in Scandinavia. In years when its primary host, rowan (Sorbus aucuparia L.), has little or no berries for egglaying, female A. conjugella fly into apple orchards to lay their eggs. In some years the entire apple crop can be destroyed. Volatiles from apples and rowan have been collected and identified. In GC-EAD tests females have responded to several compounds found in both rowan and apple. Some of these compounds were used in field trapping tests during 2002, and a mixture of two compounds trapped significantly more females and males compared to control traps. However, field trapping results from 2003 indicate that the two-compound blend seem to trap insects too late in the season to prevent egglaying in apples. Several new compounds were also tested in 2003, and some of these gave promising results. The results will be discussed in relation to use attractive plant volatiles as a control method against A. conjugella females

Local ethnic composition and Natives’ and Immigrants’ geographic mobility in France, 1982-1999

This article provides empirical results on patterns of native and immigrant geographic mobility in France. Using longitudinal data, we measure mobility from one French municipality (commune) to another over time and estimate the effect of the initial municipality’s ethnic composition on the probability of moving out. These data allow us to use panel techniques to correct for biases related to selection based on geographic and individual unobservables. Our findings tend to discredit the hypothesis of a “white flight” pattern in residential mobility dynamics in France. Some evidence does show ethnic avoidance mechanisms in natives’ relocating. We also find a strong negative and highly robust effect of co-ethnics’ presence on immigrants’ geographic mobility

Stat och kommun i makt(o)balans : En studie av flyktingmottagandet

Already from the title of this dissertation can two important points be made. The first is that the dissertation is about the relationship between central and local government, more specifically in Sweden today. The second point is that this relationship is seen from a balance of power perspective, where the relative power of the actors is an empirical question rather than derived from a given hierarchical structure. Such a perspective is based on analysing the actors as interdependent. The central government can thus be dependent on the local government, as well as the other way around, and this interdependence can vary over time and between policy areas. This perspective differs from that of most studies, which often see the relationship either in terms of steering (that local governments are executing centrally determined policies) or local self-government (that the Swedish local governments has a constitutionally protected right to handle their own affairs within certain legal limits). I argue that both these perspectives take a hierarchical point of departure and are, to a large degree, static in their approaches, which means that they risk not discovering, or have problem explaining, changes in the relation between central and local government. To view the relationship between central and local government as interdependence leads to a focus on the resources that the actors possess. For public organisations the most relevant resources are: authority-related resources, financial resources, political resources, informational resources, and organisational resources. The central government has a power advantage concerning authority and financial and political resources while local governments generally have an advantage in terms of informational and organisational resources. The policy area chosen is Swedish refugee policy. The basic paradox within this area is that the central government grants the refugees asylum but cannot give them a place to live without the permission of the local government. This permission is accomplished through voluntary agreements signed between the National Integration Office and the local governments. It is then the local governments that integrate the refugees to Swedish society by providing housing, education, healthcare and so on while the central government is giving the local government a grant to cover the expenses. The central government has lacked political, informational and authority-related resources. The resource used to compensate for this has been the financial resource. By economic incentives the central government has encouraged local governments to increase their refugee reception. This has been the central government’s universal weapon and has been used to reduce its vulnerability as well as its sensitivity. For local governments, authority-related and financial resources have been lacking. The resource that the local governments have had, all the way through the time period studied here, is the organisational resource. This is something that the central government simply cannot provide and this is why there is a relationship of interdependence – just as only the central government has authority in its power base, the local level is the only one with organisational resources

Xylose reductase from Pichia stipitis with altered coenzyme preference improves ethanolic xylose fermentation by recombinant Saccharomyces cerevisiae

<p>Abstract</p> <p>Background</p> <p>Xylose reductase (XR) and xylitol dehydrogenase (XDH) from <it>Pichia stipitis </it>are the two enzymes most commonly used in recombinant <it>Saccharomyces cerevisiae </it>strains engineered for xylose utilization. The availability of NAD⁺for XDH is limited during anaerobic xylose fermentation because of the preference of XR for NADPH. This in turn results in xylitol formation and reduced ethanol yield. The coenzyme preference of <it>P. stipitis </it>XR was changed by site-directed mutagenesis with the aim to engineer it towards NADH-preference.</p> <p>Results</p> <p>XR variants were evaluated in <it>S. cerevisiae </it>strains with the following genetic modifications: overexpressed native <it>P. stipitis </it>XDH, overexpressed xylulokinase, overexpressed non-oxidative pentose phosphate pathway and deleted GRE3 gene encoding an NADPH dependent aldose reductase. All overexpressed genes were chromosomally integrated to ensure stable expression. Crude extracts of four different strains overexpressing genes encoding native <it>P. stipitis </it>XR, K270M and K270R mutants, as well as <it>Candida parapsilosis </it>XR, were enzymatically characterized. The physiological effects of the mutations were investigated in anaerobic xylose fermentation. The strain overexpressing <it>P. stipitis </it>XR with the K270R mutation gave an ethanol yield of 0.39 g (g consumed sugars)^-1, a xylitol yield of 0.05 g (g consumed xylose)^-1and a xylose consumption rate of 0.28 g (g biomass)^-1h^-1in continuous fermentation at a dilution rate of 0.12 h^-1, with 10 g l^-1glucose and 10 g l^-1xylose as carbon sources.</p> <p>Conclusion</p> <p>The cofactor preference of <it>P. stipitis </it>XR was altered by site-directed mutagenesis. When the K270R XR was combined with a metabolic engineering strategy that ensures high xylose utilization capabilities, a recombinant <it>S. cerevisiae </it>strain was created that provides a unique combination of high xylose consumption rate, high ethanol yield and low xylitol yield during ethanolic xylose fermentation.</p

Pheromone races of Cydia splendana (Lepidoptera,Tortricidae) overlap in host plant association and geographic distribution

Identification of the sex pheromone of Cydia splendana (Lepidoptera, Tortricidae) by pheromone gland analysis followed by field trapping with synthetic compounds shows the occurrence of two pheromone races. Acorn moth females from Sweden, where oak Quercus robur is the only host plant, use a blend of the E,Z and E,E isomers of 8,10-dodecadien-1-yl acetate. In Central and Southern Europe, where C. splendana feeds on chestnut Castanea sativa and several species of oak, males respond to another isomer blend, E,E and Z,E. The distribution of the two pheromone races of C. splendana overlaps in Northern France, where they share oak as plant host. Differences in sex communication signals between these populations of C. splendana corroborate the role of specific mate recognition in speciation events