Energy Landscape and Global Optimization for a Frustrated Model Protein

The three-color (BLN) 69-residue model protein was designed to exhibit frustrated folding. We investigate the energy landscape of this protein using disconnectivity graphs and compare it to a Go model, which is designed to reduce the frustration by removing all non-native attractive interactions. Finding the global minimum on a frustrated energy landscape is a good test of global optimization techniques, and we present calculations evaluating the performance of basin-hopping and genetic algorithms for this system.Comparisons are made with the widely studied 46-residue BLN protein.We show that the energy landscape of the 69-residue BLN protein contains several deep funnels, each of which corresponds to a different β-barrel structure

Comparative Analysis of the Volatile Fraction of Fruit Juice from Different Citrus Species

The volatile composition of fruit from four Citrus varieties (Powell Navel orange, Clemenules mandarine, and Fortune mandarine and Chandler pummelo) covering four different species has been studied. Over one hundred compounds were profiled after HS-SPME-GC-MS analysis, including 27 esters, 23 aldehydes, 21 alcohols, 13 monoterpene hydrocarbons, 10 ketones, 5 sesquiterpene hydrocarbons, 4 monoterpene cyclic ethers, 4 furans, and 2 aromatic hydrocarbons, which were all confirmed with standards. The differences in the volatile profile among juices of these varieties were essentially quantitative and only a few compounds were found exclusively in a single variety, mainly in Chandler. The volatile profile however was able to differentiate all four varieties and revealed complex interactions between them including the participation in the same biosynthetic pathway. Some compounds (6 esters, 2 ketones, 1 furan and 2 aromatic hydrocarbons) had never been reported earlier in Citrus juices. This volatile profiling platform for Citrus juice by HS-SPME-GC-MS and the interrelationship detected among the volatiles can be used as a roadmap for future breeding or biotechnological applications

Flavor characterization of three mandarin cultivars (Satsuma, Bodrum, Clemantine) by using GC/MS and flavor profile analysis techniques

WOS: 000229755800005The flavor characteristics of three mandarin cultivars: Satsuma (Citrus unshi), Bodrum (Citrus deliciosa) and Clemantine (Citrus reticulata) from the Aegean region of Turkey and changes throughout storage were investigated by using GC/MS and descriptive flavor profile analysis techniques. The key aroma impact compounds were detected as limonene, gamma-terpinene, p-cymene, myrcene, alpha-pinene, beta-pinene and alpha-terpinolene in all samples. Limonene and gamma-terpinene accounted for approximately 88% in all three cultivars. An off-flavor character was developed during storage by increase of limonene and decrease of gamma-terpinene percentages. Flavor of mandarins consisted of sweet, sour, floral, lemon, orange and cellulose characters. Dimethyl anthranilate, which was found to be specific to Clemantine mandarins, contributed to the floral orange blossom character

A consumer survey on food additives

Consumers knowledge and opinions on food additives were evaluated by using a combined questionnaire and interview study. A total of 400 consumers living in the metropolitan area of zmir from 8 groups covering medical doctors, housewives, students and academic personelle of Food Engineering Department of Ege University, other university students and kindergarten teachers were chosen as respondents. There weren't much differences between the groups related to opinions on food additives while students and academic personelle from Food Engineering Department seemed to have better knowledge on the subject. Major findings of the study were unawareness of most of the consumers about the functions and advantages of food additives and concerns about their health hazards. Some respondents described them as unnatural, toxic or carcinogenic substances, and suspicions about additives like MSG and food colors, were mentioned. Most of the consumers recognized additives on food labels and this effected their decision of buying the food negatively. Control programs on additives were found insufficient by majority of consumers and some respondents did not have any information about these activities. Data showed that consumer education on functions advantages, safety issues, label declaration and control programs of food additives is necessary. © 1995 Elsevier B.V