Modelling the effects of transglutaminase and l-ascorbic acid on substandard quality wheat flour by response surface methodology

Over the past decade, extreme variations in climatic conditions have been observed, which in combination with inadequate agro techniques lead to decreased quality of mercantile wheat, i.e. flour. The application of improvers can optimise the quality of substandard wheat flour. This paper focuses on systematic analysis of individual and interaction effects of ascorbic acid and trans-glutaminase as dough strengthening improvers. The effects were investigated using response surface methodology. Transglutaminase had much higher linear effect on the rheological and fermentative properties of dough from sub-standard flour than L-ascorbic acid. Both transglutaminase and L-ascorbic acid additions had a significant linear effect on the increase of bread specific volume. Effects of transglutaminase and ascorbic acid are dependent on the applied concentrations and it is necessary to determine the optimal concentration in order to achieve the maximum quality of the dough and bread. Optimal levels of tested improvers were determined using appropriate statistical techniques, which applied the desirability function. It was found that the combination of 30 mg/kg of transglutaminase and 75.8 mg/kg of L-ascorbic acid achieved positive synergistic effects on rheological and fermentative wheat dough properties, as well on textural properties and specific volume of bread made from substandard quality flour

Cognitive and affective reactions to success and failure: The quality of feedback as the determinant of self-verifying and self-enhancing motivation

A study was conducted to ascertain what the dominant self motivation is like - selfverifying or self-enhancing? - in a situation when a person is faced with a negative evaluation of a central personality characteristic. Previous research suggested that affective reactions should follow the pattern predicted by self-enhancement theory by which all individuals would react with positive affect to positive evaluation and with negative affect to negative evaluation. On the other side, cognitive reactions are expected to follow the pattern predicted by self-verification theory which suggests that information consistent with the self-concept should be the most convincing (i.e. cognitive reactions should be influenced by interaction of feedback and self-esteem). Ninety female respondents were given a false favorable or extremely unfavorable feedback about their achievement on an intelligence test, after which their cognitive and affective reactions were measured. The results revealed that the respondents demonstrated a self-enhancing motivation both in the affective and the cognitive domain, i.e., regardless of their level of self-esteem, those who had failed experienced more negative affect, rated test more unfavorably, assessed it as less accurate, and claimed they had invested less effort to solve the test, than those who were successful. The research imposes conclusion that cognitive reactions to failure are not conditioned only by the degree of negativity or positivity of global self-views, but also by the quality/intensity of unfavorable feedback. This conclusion provides important methodological implications for future research in this area

Validation of two conceptualizations of fragile self-esteem: Contingent high self-esteem and incongruent high self-esteem

The aim of this research was to validate two aspects of fragile high self-esteem: a combination of contingent and high (explicit) self-esteem and a combination of high explicit and low implicit self-esteem (i.e. incongruent high self-esteem), as well as to examine the relationship between these aspects of fragile self-esteem and narcissism. No convergence was found between contingent high and incongruent high self-esteem. The result was consistent regardless of the technique of measurement of implicit self-esteem. There was a limited evidence that individuals with narcissistic personality characteristics were characterized by high self-esteem contingent upon competences, but not by a combination of high explicit and low implicit self-esteem, as an aspect of fragile self-esteem. Also, individuals with low selfesteem more contingent upon competences showed higher levels of narcissistic characteristics than those who were not contingent in this domain. [Projekat Ministarstva nauke Republike Srbije, br.179034: From encouraging initiative, cooperation and creativity in education to new roles and identities in society i br. 47008: Improving he quality and accessibility of education in modernization processes in Serbia

General causality orientations and defensive attributions of failure on academic exam

Defensive behaviour after failure, such as denial of the responsibility for own achievement, reduces person’s openness for further learning and development and, thus, is undesirable in pedagogical practice. General causality orientations success-fully predict defensive behaviours after failure. Autonomous causality orientation implies behaviours motivated by personal growth and development, while controlling orientation purports ego-involved behaviours aimed at proving one's own self-worth. The research was conducted with the aim of testing two hypotheses (additive and synergistic) about the influence of general causality orientations and their combinations on defensive attribution of failure on the exam. After their faculty exam, N=158 psychology students answered questions about the expected grade and they filled out two questionnaires: Attribution of Success on the Test and General Causality Orientation Scale. The results showed that internal attribution of success is related to greater expected grade and higher autonomous causality orientation. External attribution was characteristic for individuals with high controlling causal orientation. It was confirmed that general causality orientations can predict the way a person perceives academic success. Thus, we give recommendations on how to support and encourage autonomous and discourage controlling behaviours of students

The rheological properties of wheat dough containing zeolite residue

The use of natural zeolite - clinoptilolite, to protect wheat grain from storage insects within environmentally-friendly storage techniques can lead to the presence of small amounts of zeolite residues in flour. This study investigated the influence of as-received zeolite clinoptilolite (Z) and sodium-rich clinoptilolite (NaZ) in wheat dough on the dough rheological properties. Zeolites were added to dough at 0.5-1.5 wt% flour basis level, which is a range expected to remain in the grain (flour) after treatment to control storage pests. The effects were studied in two types of wheat, conventional (Triticum aestivum) and spelt (T aestivum spp. spelta) because they initially differ in rheological properties. NaZ was used to discern whether the presence of increased concentration of Na+ in the zeolite was able to exert a higher strengthening effect as compared to as-received zeolite (Z). NaZ exerted the highest dough strengthening effect which was mainly reflected as decreased dough softening and increased water absorption. The fact that the presence of NaZ was the most effective factor in improving the dough rheological profile suggested that the presence of movable cations in the zeolite lattice might have a pronounced role in the mechanism by which zeolite affects dough behaviour

Analiza tretmana pšenice inertnim prašivima sa ciljem zaštite od pirinčanog žiška (Sitophilus oryzae L.) kroz promenu parametara tehnološkog kvaliteta primenom metode glavnih komponenti

Quality parameters of several wheat grain lots (low vitreous and high vitreous grains, non-infested and infested with rice weevils, (Sitophilus oryzae L.) treated with inert dusts (natural zeolite, two diatomaceous earths originating from Serbia and a commercial product Protect-It®) were investigated. Principal component analysis (PCA) was used to investigate the classification of treated grain lots and to assess how attributes of technological quality contribute to this classification. This research showed that vitreousness (0.95) and test weight (0.93) contributed most to the first principal component whereas extensigraph area (-0.76) contributed to the second component. The determined accountability of the total variability by the first component was around 55%, while with the second it was 18%, which means that those two dimensions together account for around 70% of total variability of the observed set of variables. Principal component analysis (PCA) of data set was able to distinguish among the various treatments of wheat lots. It was revealed that inert dust treatments produce different effects depending on the degree of endosperm vitreousness.Cilj istraživanja je ispitivanje uticaja tretmana inertnih prašiva (prirodni zeolit i dve dijatomejske zemlje poreklom iz Srbije, kao i komercijalni preparat Protect-It®) na brašnavu i staklavu pšenicu, infestiranu i neinfestiranu pirinčanim žiškom (Sitophilus oryzae L.), kroz parametre tehnološkog kvaliteta. Primenom metoda analize glavnih komponenti (PCA) zaključeno je da se ukupna varijabilnost (preko 73%) posmatranog skupa može dovoljno objasniti pomoću prve dve dimenzije, ili glavne komponente. Najveći uticaj na formiranje prve glavne komponente imali su procenat staklavosti (0,95) i hektolitarska masa (0,93), dok je druga glavna komponenta najbolje objašnjena kroz parametar tehnološkog kvaliteta, energije na ekstenzogramu (-0,76). Primenjen metod je ukazao na značajan uticaj staklavosti pšenice na efekat inertnih prašiva. Istovremeno, potvrđen je uticaj prašiva na smanjenje stepena infestiranosti i poboljšanje parametara kvaliteta. Takođe, pokazano je da različita inertna prašiva daju slične efekte pri istoj staklavosti endosperma pšenice