Effect of Cheese pH and Temperature on Serum Phase Characteristics of Cream Cheese During Storage

Three 13.6‐kg blocks of cultured cream cheese manufactured on different days were obtained from a commercial source within 2 wk of manufacture. Blocks were sectioned into samples that were randomly assigned to 3 treatments. A model system was used to change cheese pH. One group of samples was exposed to volatile ammonia to increase the pH to about 5.3. A 2nd group was exposed to volatile acetic acid to decrease the pH to about 4.5. A 3rd group served as a control (pH about 4.8). Samples from each pH treatment were vacuum‐packaged and randomly assigned to 1 of 2 storage temperatures: 4 °C and 20 °C. Samples were randomly chosen for analysis after 4, 8, 12, 16, 20, 24, and 28 d of storage and centrifuged at 12500 ±g for 75 min at 25 °C to obtain expressible serum (ES). The ES was analyzed for viscosity at 25 °C. Effects of pH treatment, storage time, and storage temperature were evaluated by analysis of variance (ANOVA) according to a split split‐plot design. The amount of ES increased significantly during storage and was affected by storage temperature and cheese pH. Significantly more ES was obtained at higher temperature and higher pH. Viscosity of ES decreased significantly during storage and was affected by storage temperature and cheese pH. Viscosity decreased more rapidly at higher temperature and higher pH. The data suggest that higher temperature and higher pH resulted in accelerated loss of stabilizer function during storage, possibly due to microbiological degradation of the stabilizer.     

Critical micelle concentration of an ammonium salt through DPD simulations using COSMO‐RS–based interaction parameters

In order to determine the critical micelle concentration (CMC) of aqueous dodecyltrimethylammonium chloride (DTAC), a screening of the DTAC gathering process at different molalities by performing dissipative particle dynamics (DPD) simulations over mesomolecules whose beads interact via repulsive conservative forces was performed. Conductor‐like screening model for real solvent quantum methodology, applied to molecular segments that describe the DTAC chemistry and were mapped onto the DPD beads, allows us the computing of activity coefficients at infinite dilution to obtain thermodynamic Flory–Huggins interaction parameters, from which we calculated the maxima repulsive conservative forces, that is, the DPD interaction parameters. Results indicate that at room temperature the CMC is 0.0217 mol/kg, the aggregation number ranges from 46 to 54 molecules, and the aggregate radius varies from 19.58 to 22.02 Å; all values are in excellent agreement with literature reported experimental ones of 0.0213 mol/kg, 47 5 molecules, and 20.1 Å. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4413–4423, 2013     

Application of the TRIZ creativity enhancement approach to design of passively compliant robotic joint

The essence of the conceptual design is getting the innovative projects or ideas to promise the products with best performance. It has been proved that the theory of inventive problem solution (TRIZ) is a systematic methodology for innovation. The design of a passively compliant robotic joint as an engineering example is illuminated in this paper to show the significance and approaches of applying TRIZ into getting the creative conceptual design ideas. In the robotic joints with passively compliance, the joints are composed of mechanical components such as springs and dampers as internal elements, which absorb the excessive collision force. Passive compliant joints with springs and dampers ensure a smooth contact with the surroundings, especially if robots are in contact with humans, but the passive compliant joints cannot determine precisely the position of the members of the joint or direction of the collision force. The main aim of this work is to show a systematic methodology for innovation as an effective procedure to enhance the capability of developing innovative passive compliant robotic joint and to overcome the main design problems. The TRIZ method will be utilized in order to eliminate the technical contradictions which appear in the passively compliant robotic joint.     

The role of distillation on the quality of tequila

The role of a batch rectification on the quality of tequila, a traditional Mexican beverage, was studied. It was shown that the official tequila standard composition, particularly the size of the slop cuts and the correct balance of flavour constituents, can be determined by monitoring the concentration of the regulated compounds (ethanol, methanol, higher alcohols, ethyl acetate, acetaldehyde and furfural) throughout the rectification process. It was found that these regulated compounds are produced over the same time scales when either stainless steel or copper alembics are used. When distillations were done in copper alembics, however, it was found that the copper content of the rectified product exceeded the amount permitted in the official tequila standards. Finally, we report a comparison of sensory properties of tequila distillates obtained in both copper and stainless steel alembics.     

甘薯渣发酵乙醇的工艺研究

研究了甘薯渣同步糖化发酵乙醇的最佳工艺条件,考察了不同酵母接种量、水料比、发酵时间和 pH 对甘薯渣发酵乙醇的影响。通过单因素、正交试验,最终确定同步糖化发酵乙醇的最佳条件为：接种量1.4%,水料比25：1,发酵时间108h,pH 5.5。在此条件下乙醇得率为34.78%,糖利用率为73.76%。     

Moisture absorption effects on the thermal and mechanical properties of wood flour/linseed oil resin composites

The thermal and mechanical behavior of new natural polymeric composite materials after exposure to humid environments must be well known and understood in order to predict their performance in final applications. For this reason, composites made from unsaturated polyesters based on linseed oil and filled with wood flour were exposed to environments of different relative humidities and their final properties were measured. In general, the equilibrium moisture content increased as the wood flour percentage increased. Dynamic mechanical tests performed in temperature scan mode were carried out in order to monitor the changes resulting from moisture absorption on the main transition temperature of the matrix (T_α). The temperature of this transition decreased as the amount of absorbed water increased, but the effect was partially reversible by re‐drying the samples. The mechanical properties were also strongly affected by moisture. The flexural modulus and ultimate stress of the composites decreased after equilibration in humid environments. Copyright © 2006 Society of Chemical Industry     

Relating graph and term rewriting via Böhm models

Dealing properly with sharing is important for expressing some of the common compiler optimizations as source-to-source transformations, such as common subexpressions elimination, lifting of free expressions and removal of invariants from a loop. Term graph rewriting is a computational model to accommodate these concerns. In this paper we are interested in defining a term model for term graph rewriting systems, which allows us to prove total correctness of those optimizations. We introduce the notion of Böhm tree, and show that for orthogonal term graph rewriting systems, Böhm tree equivalence defines a congruence. Total correctness then follows in a straightforward way from showing that if a programM contains less sharing than a programN, then bothM andN have the same Böhm tree. Using Böhm trees we also show that orthogonal term graph rewriting systems are a correct implementation of orthogonal term rewriting systems. This boils down to showing that the behavior of a term graph can be deduced from its finite approximations, that is, graph rewriting is a continuous operation. Our approach differs from that of other researchers which is based on infinite rewriting.     

Use of ultrafiltration and supercritical fluid extraction to obtain a whey buttermilk powder enriched in milk fat globule membrane phospholipids

Whey buttermilk, a by-product from whey cream processing to butter, is rich in milk fat globule membrane (MFGM) constituents, which have technological and potential health properties. The objective of this work was to produce a dairy ingredient enriched in MFGM material, especially phospholipids, from whey buttermilk. Whey buttermilk was concentrated by ultrafiltration (10×) and subsequently diafiltered (5×) (10 kDa molecular mass cutoff membrane) at 25 °C and the final retentate was spray-dried. The whey buttermilk powder was submitted to supercritical extraction (350 bar, 50 °C) using carbon dioxide. The membrane filtration removed most of the lactose and ash from the whey buttermilk, and the supercritical extraction extracted exclusively non-polar lipids. The final powder contained 73% protein and 21% lipids, of which 61% were phospholipids. This ingredient, a phospholipids-rich dairy powder, could be used as an emulsifier in different food systems.     

Design of carbon fiber reinforced boron nitride matrix composites by vacuum-assisted polyborazylene transfer molding and pyrolysis

In the present study, the vacuum-assisted polyborazylene transfer molding (VAPTM) followed by pyrolysis at 1450 °C under nitrogen was successfully applied to prepare C/BN composites with a relative density of 94.7%, and an open porosity of 5.1 vol%. Rheology measurements combined with TG experiments and measurement of the weight gain of the composites after each polymer impregnation pyrolysis (PIP) cycles allowed fixing elaboration parameters (10 PIP cycles using two types of polyborazylene) to generate C/BN composites as high temperature vacuum compatible materials which demonstrate potentialities for vacuum technology and space applications. Scanning electron micrographs of composites demonstrated that the BN matrix appropriately filled the space between the fibers with a low fiber-matrix bonding which affects the compressive modulus. The thermal diffusivity and electrical conductivity of the BN matrix have been measured and showed that carbon fibers have poor effects on the intrinsic properties of BN.     

The Brazilian sugarcane innovation system

Ethanol has recently been of great interest worldwide because it is a viable economic alternative to petroleum products and it is a renewable source of energy that mitigates the emission of greenhouse gases. Brazilian bioethanol from sugarcane is the most successful case at the world level because of its low cost and low level of greenhouse gas emissions. Brazil’s success with sugarcane cannot be understood as based solely on a natural comparative advantage, but as a result of efforts that culminated in a positive trajectory of technological learning, relying mostly on incremental innovations. The purpose of this article is to analyze the key aspects of the innovation system built around the Brazilian sugarcane industry. It is based on the national innovation systems approach according to which innovation results from the interaction of different institutional actors. Institutional arrangements are analyzed as the basis for the innovative process, in particular R&D and the innovation policies and strategies of the main players in the sugarcane sector, including sugar and ethanol mills, industrial goods suppliers, public and private research institutions, and governmental agencies.