Overview of Sourdough Technology: from Production to Marketing

Sourdough is a type of dough fermented by yeast and lactic acid bacteria (LAB) used as sponge dough in bread making. Sourdough may have four classifications according to the fermentation type and the technological process used. On sourdough type I, the fermentation of yeasts and LAB present in the flour occurs spontaneously whereas in type II, fermentation occurs after the inoculation of a starter culture. Type III is simply type II sourdough dehydrated and type IV is a mixture of type I and type II sourdough, produced on laboratory scale. With LAB’s growth during fermentation, pH decreases with subsequent hydrolysis of starch and protein, favoring the growth of yeasts. The yeast in turn, releases amino acids during autolysis, contributing to the growth of LAB. Due to this synergistic growth of LAB and yeasts, the products obtained from sourdough show more concentration of flavor, more elastic dough, and a longer shelf life than bread fermented only by yeast. Although, the benefits of this technology, using sourdough, is present just in a few countries, where it is also possible to obtain the dehydrated sourdough starters, for domestic use, in local supermarkets. Due to its fermentative process complexity, this paper presents updated information about the fabrication process of sourdough, main factors affecting this process, benefits of sourdough use for bakery products, and the varieties of dehydrated sourdough commercially available throughout the world.     

Influence of Macromolecular Brushes with Polyimide Backbones and Poly(methyl methacrylate) Side Chains on Structure,Physical, and Transport Properties of Polyphthalamide

Composite films based on polyamide (poly(m-phenylene-iso-phthalamide)) (PA) and a brush-like polymer with polyimide (PI) backbone and side poly(methyl methacrylate) chains (PI-PMMA) were prepared by mixing individual solutions of PA and PI-PMMA and subsequent film casting. Macromolecular brushes with the same backbone length and density of side chains but with various lengths of side PMMA chains were synthesized via activator generated by electron transfer atom transfer radical polymerization. Interactions between PA and PI-PMMA, as well as distribution of PI-PMMA filler inside the PA matrix, were studied by viscometry, dynamic light scattering, differential scanning calorimetry, scanning electron microscopy, and IR spectroscopy. The mechanical properties of polymer samples were also investigated. Microphase separation was revealed in PA/PI-PMMA films. The length of side chains influences interactions between PA and PI-PMMA. At the same time, the degree of reduction in the rigidity parameters and in the elasticity parameter depends on the side chain length. Diffusion membranes were prepared on the basis of compositions with the best mechanical properties; these membranes proved to be highly efficient in pervaporation of methanol–hexane mixture. It was established that the fluxes and separation factors of the studied membranes are several times higher as compared to the corresponding characteristics of known commercial membranes. POLYM. ENG. SCI., 60:481–490, 2020. © 2019 Society of Plastics Engineers     

High‐Temperature Neutron Diffraction,Raman Spectroscopy,and First‐Principles Calculations of Ti3SnC2 and Ti2SnC

Herein, we report—for the first time—on the additive‐free bulk synthesis of Ti₃SnC₂. A detailed experimental study of the structure of the latter together with a secondary phase, Ti₂SnC, is presented through the use of X‐ray diffraction (XRD), and high‐resolution transmission microscopy (HRTEM). A previous sample of Ti₃SnC₂, made using Fe as an additive and Ti₂SnC as a secondary phase, was studied by high‐temperature neutron diffraction (HTND) and XRD. The room‐temperature crystallographic parameters of the two MAX phases in the two samples are quite similar. Based on Rietveld analysis of the HTND data, the average linear thermal expansion coefficients of Ti₃SnC₂ in the a and c directions were found to be 8.5 (2)·10^?6 K^?1 and 8.9 (1)·10^?6 K^?1, respectively. The respective values for the Ti₂SnC phase are 10.1 (3)·10^?6 K^?1 and 10.8 (6)·10^?6 K^?1. Unlike other MAX phases, the atomic displacement parameters of the Sn atoms in Ti₃SnC₂ are comparable to those of the Ti and C atoms. When the predictions of the atomic displacement parameters obtained from density functional theory are compared to the experimental results, good quantitative agreement is found for the Sn atoms. In the case of the Ti and C atoms, the agreement is more qualitative. We also used first principles to calculate the elastic properties of both Ti₂SnC and Ti₃SnC₂ and their Raman active modes. The latter are compared to experiment and the agreement was found to be good.     

On multiobjective combinatorial optimization and dynamic interim hedging of efficient portfolios

A dynamic portfolio policy is one that periodically rebalances an optimally diversified portfolio to account for time‐varying correlations. In order to sustain target‐level Sharpe performance ratios between rebalancing points, the efficient portfolio must be hedged with an optimal number of contingent claim contracts. This research presents a mixed‐integer nonlinear goal program (MINLGP) that is directed to solve the hierarchical multiple goal portfolio optimization model when the decision maker is faced with a binary hedging decision between portfolio rebalance periods. The MINLGP applied to this problem is formed by extending the separable programming foundation of a lexicographic nonlinear goal program (NLGP) to include branch‐and‐bound constraints. We establish the economic efficiency of applying this normative approach to dynamic portfolio rebalancing by comparing the risk‐adjusted performance measures of a hedged optimal portfolio to those of a naively diversified portfolio. We find that a hedged equally weighted small portfolio and a hedged efficiently diversified small portfolio perform similarly when comparing risk‐adjusted return metrics. However, when percentile risk measures are used to measure performance, the hedged optimally diversified portfolio clearly produces less expected catastrophic loss than does its nonhedged and naively diversified counterpart.     

Psychological services to Spanish-speaking populations: A model curriculum for training competent professionals.

The competent delivery of mental health services to Spanish-speaking clients requires knowledge of Latino cultures, racial and ethnic identity development, variables that impact service delivery, and the Spanish language. We present the Psychological Services for Spanish Speaking Populations (PSSSP) program as a model for training mental health professionals to deliver services to Spanish-speaking clients. The goals for the program were to improve participants' oral and written Spanish language proficiency in work-related contexts and to improve multicultural competence in service delivery to Latino clients. Recommendations for those who wish to offer similar programs include (a) grouping trainees according to Spanish language proficiency, (b) using Spanish language instructors with expertise in teaching heritage language learners, and (c) developing criterion references or measures to assess program outcomes. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Route instructions in map-based human–human and human–computer dialogue: A comparative analysis

When conveying information about spatial situations and goals, speakers adapt flexibly to their addressee in order to reach the communicative goal efficiently and effortlessly. Our aim is to equip a dialogue system with the abilities required for such a natural, adaptive dialogue. In this paper we investigate the strategies people use to convey route information in relation to a map by presenting two parallel studies involving human–human and human–computer interaction. We compare the instructions given to a human interaction partner with those given to a dialogue system which reacts by basic verbal responses and dynamic visualization of the route in the map. The language produced by human route givers is analyzed with respect to a range of communicative as well as cognitively crucial features, particularly perspective choice and references to locations across levels of granularity. Results reveal that speakers produce systematically different instructions with respect to these features, depending on the nature of the interaction partner, human or dialogue system. Our further analysis of clarification and reference resolution strategies produced by human route followers provides insights into dialogue strategies that future systems should be equipped with.     

Heat of Wetting the Surface of Very Fine Particles of Iron and Its Composites with Ag,Pt, Au,Cu, and Zn with Water

The heat of wetting for very fine iron powder and its composites with Ag, Pt, Au, Cu, and Zn prepared by a thermochemical method is measured. It is established that their surface is hydrophilic. This makes it possible to modify the surface of powders with different substances and create new materials intended for medicine and technics.

     

美国塑料再生需跟上世界步伐

最近从洛杉矶迁居东京的一位朋友几天前打电话给我，说她对新居住地的塑料回收规定甚感惊讶。     

Interpretation of phase diagrams of ternary reciprocal systems by complete conversion points

A new classification of ternary reciprocal systems is proposed taking into account the number of thermal effects in the thermograms of complete conversion points. The classification is useful for general evaluation of the liquid surface of the systems.     

Identity and overall acceptance of two types of sour rye bread

Response surface methodology was employed to study the influence of four recipe variables (wheat: rye flour ratio, bread acidity, ash content of rye flour and sodium chloride content) on the identity and overall acceptance of two rye bread types (soft and crisp rye bread). The subjects ( n = 79) rated attribute intensities, the extent to which the salient sensory properties and the overall sample corresponded to their expectations of rye bread, and the overall acceptance (pleasantness and purchase intentions). The acidity and ash content contributed the most to the extent to which a sample met subjects' expectations. The NaCl content was not critical. Consumer acceptance was affected by ash content, and by the interactions, NaCl content × acidity and wheat:rye ratio × ash content. The non-significance of NaCl content should encourage the baking industry to put low-salt rye products on the market.