THERMOSTABLE AND THERIVIOLABILEISOFORMS IN COMMERCIAL ORANGE PEEL PECTINESTERASE1

Thermostable and thermolabile pectinesterase isoforms in commercial Valencia orange peel pectinesterase (Sigma Chemical Co., St. Louis, MO) were separated by affinity chromatography on a Heparin‐Sepharose CL‐6B column. Among the seven putative PE isoforms separated, three (P1, P2 and P3 with 70 kDa, 60 kDa and 27 kDa, respectively)‐were thermostable and four [P4, P5, P6 (35 kDa) and P7 (35 kDa)]‐were thermolabile, according to the qualitative and quantitative studies of thermal stability. The commercial PE showed 83.4% and 98.3% inactivation after heat treatment at 70C for 5 min and at 90C for 1 min, respectively. P2 was the most heat stable, with 85.5% inactivation at 70C for 5 min and 93.0% inactivation at 90C for 1 min. The thermolabile P6 and P7 could be inactivated at 70C for 5 min or at 90C for 1 min. Thermostable PE activity was 16.6% of total activity of the commercial PE based on heat treatment at 70C for 5 min, but only 1.5% based on heating at 90C for 1 min. The 90C for 1 min heat treatment might be better than the 70C for 5 min heat treatment to distinguish thermostable PE and thermolabile PE isoforms in Valencia oranges.     

Multiple instruments to change energy behaviour: The emperor’s new clothes?

Over the last few decades, several instruments have evolved to deal with similar energy and environmental challenges. For instance, the economic literature prescribes separate tax or cap-and-trade systems to internalize negative environmental externalities and subsidies to internalize positive externalities such as research and development. However, policy is not straightforward because of the influence on cost and competition and concerns for regional employment, economic activity within certain industries and any distributional effects. Tax discrimination, subsidies and regulations then undermine the efficiency of energy instruments. To balance any environmental concerns, other instruments, including green and white certificates, have been created. While innovative, these work as simple combinations of taxes and subsidies. While the extant literature thoroughly analyzes the partial effects of these instruments, there has been little focus on their basics and the effects of aggregate taxes and subsidies. This complexity calls for research on the efficiency of each instrument, including the administration and transaction costs associated with holding a large set of instruments. We should consider the coordination and simplification of policy tools before complicating the system further by introducing new, primarily equivalent, instruments.

Combined Effect of High Hydrostatic Pressure and Lysine or Cystine Addition in Low-Grade Surimi Gelation with Low Salt Content

The aim of this study was to reduce the sodium chloride (NaCl) level in surimi-based products by adding lysine or cystine in combination with high hydrostatic pressure (HHP). For experiments, Alaska pollock surimi was used to prepare gels in a factorial design (3?×?3?×?2) using three additive levels (no additive, lysine, and cystine), three NaCl levels (0, 0.3, and 3 %), and two HHP levels (0 and 300 MPa/10 min/10 °C). After blending, the pastes, consisting of surimi, additives, and different levels of salt, were stuffed into casings, high pressure treated, and stored at 5 °C for 24 h (suwari gel). Subsequently, samples were heated at 90 °C for 30 min (kamaboko-type gel). To assess the degree of protein denaturation prior to gelation at 90 °C, suwari gels were analyzed by differential scanning calorimetry to determine myosin denaturation enthalpy. Kamaboko-type gels were characterized by lightness properties, water binding capacity, and mechanical properties (by puncture test). Results showed that the pressure treatment at 300 MPa and/or the addition of lysine or cystine (0 and 0.1 %) to low-sodium-chloride samples (0 and 0.3 %) resulted in gels with similar quality characteristics to those with the regular 3 % sodium chloride addition, most likely due to the protein unfolding induced by both HHP treatment and the additives used.     

INFLUENCE OF UNIAXIAL COMPRESSION RATE ON RHEOLOGICAL PARAMETERS AND SENSORY TEXTURE PREDICTION OF COOKED POTATOES

The effect of uniaxial compression rate (20–1000 mm/min) on the parameters: Stress (σ_ftrue), strain (ε_fHencky) and work to fracture (W_f), modulus of deformability (E_d), maximum slope before fracture (E_max) and work during 75% compression (W_total) was investigated for ten potato varieties. Multivariate data analysis was used to study the correlation between and within the sensory and nonsensory measurements by Principal Component Analysis (PCA) which showed σ_ftrue, E_max, W_f, and W_total to explain the same type of information in the data, and ε_fHencky versus E_d another type of information in the data. The deformation rate had a large effect on ε_fHencky. Nine sensory texture attributes covering the mechanical, geometrical and moistness attributes were evaluated. Relationships between uniaxial compression data at various deformation rates and the sensory texture attributes were studied by Partial Least Squares Regression (PLSR). A minor effect of deformation rate on the correlation with the sensory texture properties was obtained. Mechanical properties were predicted to a higher extent than the geometrical attributes and moistness. The prediction of the mechanical, geometrical and moistness attributes increased largely by using uniaxial compression supplemented by chemical measures such as dry matter and pectin methylesterase, but here no relevant effect of deformation rate was obtained.     

Genesis of the Barium Titanate Butterfly Twin

It has been discovered that the formation of the butterfly twin in barium titanate depends on both the average particle size and the particle-size distribution of the starting material. Maximum twin yields occur when the particles have an average size near 1μ with a rather sharp cutoff in the distribution in the large-particle region. All impurities act to decrease twin yield, principally because they interfere with stacking-fault formation which also is necessary for twinning to occur.     

Kairomone response inThanasimus predators to pheromone components ofIps typographus

Thanasimus formicarius (L.) responds to racemic ipsdienol and ipsenol and less to (S)-cis-verbenol. All three are pheromone components in several bark beetles of the genusIps. Synergistic effects appeared when the components were combined. Methylbutenol alone, the specific pheromone component ofIps typographus, elicited no response, but synergestic effects appeared when methylbutenol was combined withcis-verbenol and ipsdienol. The sympatric speciesThanasimus femoralis (Zett.) responds to (S)-cis-verbenol, while ipsdienol and ipsenol synergize the response.     

EFFECT OF SOYBEAN STORAGE ON TOFU AND SOYMILK PRODUCTION1

Century 84 and Century -L₂L₃ (lacking lipoxygenase isozymes 2 and 3) near isogenic soybean varieties were stored at five temperature and relative humidity conditions for up to three months. At one-month intervals, soybeans were retrieved from storage and processed into soymilk and tofu. Chemical and physical characteristics of the soybeans, soymilk, and tofu were analyzed. In general, soybean storage above 25C and 50% relative humidity adversely affected the characteristics of the soymilk (reduced pH and solids content) and tofu (decreased yield and moisture content, and darker color) produced. Century -L₂L₃ soybeans were more resistant to changes during adverse storage than were Century 84 soybeans.     

Production and Evaluation of Pea Protein Isolate

Laboratory and pilot plant processes were developed for producing pea protein isolate from field peas. Sodium proteinate and isoelectric products containing up to 90% protein were obtained by alkaline extraction and precipitation at the isoelectric point. Drying was carried out by freeze, spray and drum processes. Chemical analysis, functional properties, color and flavor of the dried isolates compared favorably with their soy counterparts. Generally, the sodium proteinates exhibited more functionality than isoelectric isolates. Drum drying decreased the nitrogen solubility index and increased water absorption. Freeze- and spray-drying resulted in isolates with the highest emulsification and water absorption values. Spray drying produced the best foaming, color and flavor properties.     

Welfare effects of emission taxes in Norway

The welfare effects of introducing taxes on emissions of carbon dioxide is analysed within an empirical general equilibrium model of the Norwegian economy. A CO₂ tax regime where we aim at stabilizing the CO₂ emissions at the 1990 emission level in 2020 is compared to a reference scenario without such taxes. In the simulations introduction of CO₂ taxes reduces gross domestic product, but increases net national real disposable income, private consumption and money metric utility. This difference in sign is due to a positive terms of trade effect; some of the CO₂ taxes will be paid by foreigners through exports. The welfare effects differ from household to household depending on the composition of their total consumption. Poor households are less favourably affected than rich households, due to smaller budget shares for the rich households on consumer goods which imply relatively much CO₂ emissions.