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Acid Ratio (acid + ratio)
Kinds of Acid Ratio Selected AbstractsEffects of hydrogenation parameters on trans isomer formation, selectivity and melting properties of fatEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 3 2008Anar Musavi Abstract Effects of hydrogenation conditions (temperature, hydrogen pressure, stirring rate) on trans fatty acid formation, selectivity and melting behavior of fat were investigated. To this aim, soybean oil was hydrogenated under various conditions and fatty acid composition, trans isomer formation, slip melting point (SMP), solid fat content (SFC) and iodine number (IV) of the samples withdrawn at certain intervals of the reactions were monitored. A constant ratio (0.03%) of Nysosel 222 was used in the various combinations of temperature (150, 165 and 180,°C), stirring speed (500, 750 and 1000,rpm) and hydrogen pressure (1, 2 and 3,bar). Raising the temperature increased the formation of fatty acid isomers, whereas higher stirring rates decreased this formation, while changes in hydrogen pressure had no effect or slightly reduced it, depending on other parameters. Results also indicated that the trans fatty acid ratio increased with IV reduction, reached the highest value when the IV was about 70 and decreased at IV < 70 due to saturation. Selectivity values (S21) at that point ranged between 5.78 and 11.59. Lower temperatures and higher stirring rates decreased not only the trans isomer content but also the S21 values at significant levels. However, same effects were not observed with the changes in hydrogen pressure. It was determined that a high SMP does not necessarily mean a high SFC. Selective conditions produced samples with higher SFC but lower SMP, which is possibly because of higher trans isomer formation as well as lower saturation. [source] Potential for protein deposition and threonine requirement of modern genotype barrows fed graded levels of protein with threonine as the limiting amino acidJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 5-6 2004H. T. Thong Summary The study was conducted to estimate the actual genetic potential for daily protein deposition of growing barrows [genotype: Piétrain × (Duroc × Landrace)]. Twenty-four pigs with an average initial body weight (BW) of 43.7 ± 0.7 kg were used in a N-balance study. Semi-purified diets with graded levels of crude protein (45.8, 94.2, 148.0, 198.9, 255.5 and 300.2 g/kg DM) were used, based on a constant mixture of wheat, soya bean protein concentrate and potato protein concentrate as protein sources. The amino acid pattern of the diets was according to the ideal amino acid ratio for growing pigs (Wang and Fuller, 1989), with the exception of threonine (adjusted as limiting amino acid). N-balance data were used to estimate daily N-maintenance requirement (NMR = 446 mg N/BW/day) by regression method and the theoretical maximum of daily N-retention (PDmaxT = 3115 mg N/BW/day) based on N-utilization model of Gebhardt (1966) using program Mathematica 3.0. The results indicate that PDmaxT of pigs under study is much higher than results from earlier studies with older genotypes. In summary, pigs of modern genotype have a very high genetic potential for daily protein deposition and these actual data are important basic informations for estimation of amino acid requirement within the model used. Threonine requirement data depending on threonine efficieny and protein deposition (8.96, 10.45 and 12.22 g/day for 130, 145 and 160 g daily protein deposition; 50 kg body weight) are discussed. [source] EFFECT OF METHOD OF PRESERVATION OF PULP ON THE QUALITY OF CARBONATED AND NONCARBONATED BEVERAGES PREPARED FROM PEACH FRUITJOURNAL OF FOOD QUALITY, Issue 6 2009SHEETU ARORA ABSTRACT Peach pulp preserved by different methods, i.e., processing at 100C for 30 min, potassium metabisulphite (KMS; 2,000 ppm), sodium benzoate (750 ppm) and mixture of KMS and sodium benzoate (1,000 and 375 ppm) had no significant effect on total soluble solids (TSS), acidity, TSS : acid ratio, pH of carbonated as well as noncarbonated beverages. Carbonated beverages prepared from pulp with 750 ppm of sodium benzoate retained significantly (P , 0.05) higher carbon dioxide (CO2) content and CO2 gas : volume during storage. Color of the beverages prepared from peach pulp containing KMS was better but the beverages prepared from peach pulp preserved by processing and addition of sodium benzoate were organoleptically more acceptable. Both carbonated and noncarbonated drinks remained organoleptically acceptable throughout storage. Suspension of carbonated beverages was significantly (P , 0.05) higher during storage as compared with noncarbonated beverages. PRACTICAL APPLICATIONS Peaches are valued as a table fruit for a short period of time from end of April to end of May. The acceptability and utilization of this fruit can be increased by processing it into delicious carbonated and noncarbonated beverages. This will provide nutritious drink to the consumers and also help in increasing the fruit cultivation resulting in good returns to the growers. This study will also help to give a fillip to the establishment of a peach beverage industry world wide. [source] Effects of selected lactic acid bacteria on the characteristics of amaranth sourdoughJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2010Mario Jekle Abstract BACKGROUND: As the processing of amaranth in baked goods is challenging, the use of sourdough fermentation is a promising possibility to exploit the advantages of this raw material. In this study the fermentation properties of Lactobacillus plantarum, Lactobacillus paralimentarius and Lactobacillus helveticus in amaranth-based sourdough were examined in order to validate them as starter cultures. pH, total titratable acidity (TTA) and lactic/acetic acid ratio of the sourdough and sensory properties of the resulting wheat bread were evaluated using fermentation temperatures of 30 and 35 °C. RESULTS: While fermentation pH, TTA and lactic acid concentration showed small variations with the use of L. plantarum and L. paralimentarius, L. helveticus reached the most intensive acidification after initial adaptation to the substrate. Acetic acid production was independent of lactic acid metabolism. Furthermore, the lactic/acetic acid ratio exceeded recommendation by 10,35 times (fermentation quotient 25,82). Sensory evaluation showed no significant differences between the two fermentation temperatures but differences among the three micro-organisms. CONCLUSION: The results provide relevant information on the fermentation properties required of a customised starter for amaranth flour. Copyright © 2010 Society of Chemical Industry [source] The post harvest sensory and chemical characteristics of cold-stored pineapples pretreated with different Fruitone concentrationsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2006Zaulia Othman Abstract The effects of Fruitone CPA [2-(3-chlorophenoxy)propionic acid] (0-44 ppm) on post-harvest storage, chemical characteristics and sensory evaluation of pineapples for fresh consumption after storage at 10 ± 1 °C were studied. Pre-harvest Fruitone treatment beneficially affected the physical characteristics of pineapples, namely increased fruit weight, reduced texture loss, reduced crown size and delayed ripening, but adversely affected their chemical characteristics. Almost all parameters analysed (total soluble solid, titratable acidity, pH and sugars) showed that Fruitone concentrations between 35.2 and 44 ppm were most effective in delaying the ripening of pineapples compared to other concentrations. At these concentrations, Fruitone significantly (P < 0.05) reduced the total soluble solid and pH, but significantly (P < 0.05) increased the titratable acidity. Fruitone treatment was effective in maintaining the TSS and reduced the fluctuation of sugar and the sugar,acid ratio during storage and between fruits. Sensory scores showed that there was a slight increase in the score for odour after 3 weeks of storage between Fruitone-treated pineapples and control pineapples, while all other sensory attributes (sourness, sweetness, flavour and overall acceptability) were insignificantly different. All sensory attributes correlated positively with pH and sucrose at low concentrations of Fruitone (0,8.8 ppm and 0,26.4 ppm, respectively); with glucose at intermediate Fruitone concentration (17.6,26.4 ppm); with total soluble solid at higher Fruitone concentrations (35.2,44 ppm); and with sugar,acid ratio at all concentrations (except at 44 ppm Fruitone). Copyright © 2006 Society of Chemical Industry [source] Use of Cyclopoid Copepod Apocyclops dengizicus as Live Feed for Penaeus monodon PostlarvaeJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2009Omidvar Farhadian In this study, the suitability of cyclopoid copepod Apocyclops dengizicus as a live food for black tiger shrimp, Penaeus monodon, postlarvae was investigated. After 14 d, P. monodon postlarvae (PL1) had survival rates of 41.7 ± 2.9% (mean ± SE), 28.7 ± 1.2%, 56.3 ± 3.7%, 4.4 ± 1.9%, and 2.8 ± 1.0% when fed A. dengizicus (CC), Artemia nauplii (AN), mixture of A. dengizicus and Artemia nauplii (CC + AN), artificial shrimp feed (SF), and microalga Tetraselmis tetrathele (TT), respectively. Specific growth rates (SGRs) of P. monodon were maximum (14.2 ± 0.6%/d) in CC + AN, followed by CC (11.0 ± 0.4%/d), AN (9.3 ± 0.7%/d), SF (6.1 ± 0.2%/d), and TT (6.0 ± 0.5%/d). The total n-3 fatty acids of postlarvae increased from 20.6 to 25.8% when fed with CC, 28.8% with AN, and 29.0% with CC + AN. Better survival and SGRs of P. monodon postlarvae could be attributed to docosahexaenoic acid : eicosapentaenoic acid : arachidonic acid ratio of CC (10.2:3.2:1) diet. The results of this study showed that A. dengizicus has a potential to be used as a substitute live feed for P. monodon postlarvae because of better survival, growth, and high polyunsaturated fatty acids. [source] Arachidonic acid, arachidonic/eicosapentaenoic acid ratio, stearidonic acid and eicosanoids are involved in dietary-induced albinism in Senegal sole (Solea senegalensis)AQUACULTURE NUTRITION, Issue 2 2008M. VILLALTA Abstract Senegal sole larvae were fed live prey enriched with different amounts of arachidonic acid (ARA, 20:4n-6) and eicosapentaenoic acid (EPA, 20:5n-3) to re-evaluate the effect of these two fatty acids on flatfish pigmentation. Echium oil, a plant-derived oil rich in gamma-linolenic acid (18:3n-6) and stearidonic acid (18:4n-3) was also used as a component of one of the enrichment emulsions. Although ARA content did not have any effect on growth there was a clear influence on pigmentation that correlated clearly with prostaglandin production. Inclusion of Echium oil, on the contrary, exerted a positive effect on pigmentation rate even though dietary ARA levels were as high as in the other emulsions. The relationships between dietary ARA levels and dietary ARA/EPA ratio, prostaglandin production and pigmentation are discussed. [source] Stratigraphic and Morphologic Constraints on the Weichselian Glacial History of Northern Prins Karls Forland, Western SvalbardGEOGRAFISKA ANNALER SERIES A: PHYSICAL GEOGRAPHY, Issue 4 2000Torbjörn Andersson Uncertainty remains if ice,free marginal areas existed on the west coast of Svalbard during the Late Weichselian. Field mapping and correlation to well dated raised beach sequences on nearby Brřggerhalvřya reveal the existence of two generations of raised beach deposits on northern Prins Karls Forland. Distinct beach ridges rise up to the inferred Late Weichselian marine limit at 18 m a.s.l. Discontinuous pre,Late Weichselian beach deposits rise from the Late Weichselian marine limit up to approximately 60 m a.s.l. Expansion of local glaciers during the Late Weichselian is indicated by the limited distribution of a till that overlies parts of the older beach sequence. Stratigraphic data and chronological control indicate deposition in a shallow marine environment before 50 ka bp. Correlation to stratigraphic sites on western Svalbard suggests deposition at c. 70 ±10 ka. Glaciotectonic structures disclose expansion of local glaciers into the For,landsundet basin during stage 4 or late stage 5 high relative sea level. Palaeotemperature estimates derived from amino acid ratios indicate that during the time interval c. 70 to 10 ka the area was exposed to cold subaerial temperatures with low rates of racemization. Pedogenesis and frost,shattered clasts at the contact between c. 70 ka deposits and Holocene deposits further indicate a prolonged period of subaerial polar desert conditions during this time interval. The evidence suggests that the Barents Sea ice sheet did not extend across northern Prins Karls Forland during the Weichselian. It is inferred that during the Late Weichselian, ice was drained throughout the major fjords on the west coast of Svalbard and that relatively large marginal areas experienced polar desert conditions and minor expansions of local glaciers. [source] SEASONAL VARIATIONS IN FATTY ACID COMPOSITION OF OIL IN DEVELOPING COCONUTJOURNAL OF FOOD QUALITY, Issue 2 2009S. NARESH KUMAR ABSTRACT Studies on seasonal variation in oil and fatty acid profile of developing solid endosperm of two cultivars, West Coast Tall (WCT) and Chowghat Orange Dwarf (COD), and their hybrids indicated that oil percentage increased from 30% in 6-month-old nuts to 63% in matured nuts (12 months old). Nuts sampled during July from different levels of maturity had high oil percentage and followed by those sampled during April, October and January. During nut development to maturity, the percentages and contents of medium and long chain saturated fatty acids increased except that of palmitic and myristic acids. Concentration of long chain unsaturated fatty acids (LCUFAs) in developing coconut kernel were high at 5 and 6 months after fertilization and then decreased toward maturity. The LCUFAs were high in nuts developing during October; consequently, saturated to unsaturated fatty acid ratios were low during October. Results indicated that nuts matured during October had better nutritional quality for human consumption and those matured during January are more suitable for industrial purpose due to higher medium chain fatty acid concentrations. PRACTICAL APPLICATIONS Coconut is consumed either as the tender nut (5,6 months after fertilization) or as the kernel from mature nut (12 months after fertilization). Recent technologies of making snowball tender nut use the nuts aged 7,8 months old. Kernel also is consumed in this product. Apart from this, the coconut is being increasingly used for making different kernel-based value-added products. This information is useful, as the value-added products are being developed using different maturities of coconut. Hence, it is of paramount importance that the fatty acid profile of coconut kernel is known in detail for assessing the safety of food consumption from the human health point of view. Apart from this, information on the seasonal variation in fatty acid profile of developing endosperm gives an integrated knowledge so as to optimize the usage of coconut kernel for both human consumption and industrial exploitation. [source] Inclusion of Blended Lipid Solutions as Functional Ingredients to Alter the Fatty Acid Profile of Beef PattiesJOURNAL OF FOOD SCIENCE, Issue 7 2010A.C. Lowder Abstract:, Beef patties formulated to contain beef fat, plant oil, and a rosemary extract to increase unsaturated fatty acid content and maintain desirable sensory attributes were compared to control beef patties formulated without plant oils. Treatment patties were formulated to a fat content of 10% or 20% by combining beef trimmings (6% fat) with 4% or 14% addition of a lipid blend. Blends contained 57% beef tallow, 0.3% rosemary extract, and 43% of high oleic safflower oil (SO), olive oil (OO), or corn oil (CO). Lipid oxidation, as measured by TBA values, of treatment patties were similar to control patties after 0 and 3 d of refrigerated (2 °C) storage and up to 56 d of frozen (,10 °C) storage. Cooked lipid blend patties having a fat content of 10% or 20% were similar to or higher than control patties for juiciness and were no different for other sensory attributes evaluated. At fat levels of 10% or 20%, oleic acid (18: 1) in cooked SO patties (46.1% and 50.3%, respectively) and OO patties (43.8% and 48.1%, respectively) was higher than the control (37.3% and 37.6%, respectively). Unsaturated to saturated fatty acid ratios at the 10% or 20% fat levels were higher in SO (1.37 and 1.60, respectively) and CO (1.40 and 1.48, respectively) patties than the control (0.97 and 0.94, respectively). Beef patties manufactured with varying lipid blends increased unsaturated fatty acid content and were similar in physical characteristics and sensory attributes of all beef patties formulated without lipid blends. Practical Application:, The development of healthier beef products that will be more appealing to consumers has long been an industry goal. The authors believe that lipid blends such as the one used in this study could be used to create such products, not only in the form of beef patties, but any number of processed meat products. Because the materials and equipment used to create the lipid blends in this study are widely available, their incorporation into meat products would represent a small capital investment. This is an important factor in bringing a reasonably priced, healthier product to consumers. [source] FTIR-spectroscopic characterization of humic acids and humin fractions obtained by advanced NaOH, Na4P2O7, and Na2CO3 extraction proceduresJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 4 2007Michael Tatzber Abstract Aim of our study was the development of the methodological basis for the characterization of humic fractions of a long-term field experiment. Humic acids (HAs) were extracted from three layers of a nontilled soil using three different extractants (1 M NaOH, 0.1 M Na4P2O7, 1 M Na2CO3), and the humin fraction was enriched. NaOH as extractant for FTIR analysis of humic substances yields higher resolved IR spectra, especially in the important regions of stretching vibrations including aromatic and aliphatic groups and in the fingerprint area including amides, aliphats, and aromats than the other extractants. The NaOH extraction has lower extraction yields as compared to Na4P2O7 and Na2CO3 and represents a different part of the soil organic matter (SOM). This is reflected by lower C : N ratios and higher E4 : E6 and fulvic acid,to,humic acid ratios as compared to the other extractants. The FTIR band areas of HA fraction obtained by NaOH showed an increase of the aromatic and carbonyl groups and a decrease of amide groups with increasing soil depth. Aliphatic groups showed contradicting results: The bands of the stretching vibrations increased, and the band of the bending vibrations decreased. We assume that band interactions in the bending vibrations were responsible for that phenomenon under the assumption of an increase of aliphatic groups with increasing soil depth. The IR bands of the enriched humin fraction showed a decreasing trend in case of both aliphatic bands deriving from stretching vibrations and an increase of aromatic characteristics with depth. Our study led to the conclusion that HA fractions obtained by 1 M NaOH represent a small and dynamic fraction indicated by the measured yields in combination with values of Nt, C : N, E4 : E6 ratios, and ratios of fulvic acids (FA) to HA. The humin fraction has a high contribution to the total organic C and represents a more stabilized fraction of SOM which still shows changes in its aromatic and aliphatic characteristics with soil depth. [source] Influence of environmental temperature on composition of lipids in edible flesh of rainbow trout (Oncorhynchus mykiss)JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2003Antonella Calabretti Abstract The adaptative changes in the fatty acid composition of the main lipid classes in rainbow trout (Oncorhynchus mykiss) edible flesh in response to environmental variation in water temperature were investigated. The research was carried out on intensively farmed trout sampled at different times of the year. Neutral lipids (NL), phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were separated using flash chromatography. Compared with summer acclimatisation, a decrease in neutral lipids of about 19% was observed in winter, accompanied by increases in phosphatidylethanolamine and phosphatidylcholine of about 41 and 29%, respectively. The metabolic adjustment in cold adaptation caused an increase in the levels of unsaturated fatty acids and monoenes of the oleic acid ,9 family and an increase in the levels of unsaturated fatty acids of the linoleic acid ,3 family. At the same time a reduction in the levels of saturated and monounsaturated fatty acids of the oleic acid ,9 family was observed. This pattern turned out to be particularly evident in phosphatidylcholine. The net result of these changes in composition was a significant increase in the polyunsaturated/saturated and polyunsaturated/monoenic fatty acid ratios in the edible flesh. Copyright © 2003 Society of Chemical Industry [source] LIPID, CHOLESTEROL AND FATTY ACID PROFILE OF SOME COMMERCIALLY IMPORTANT FISH SPECIES FROM SOUTH CASPIAN SEAJOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2010S. PIRESTANI ABSTRACT The fatty acid, lipid, cholesterol and energy contents in five commercially important fish species from South Caspian Sea (common kilka, Caspian kutum, golden gray mullet, common carp and pike perch) were evaluated. The fatty acid compositions of these five fish species ranged from 28.99 to 41.05% saturated fatty acids, 40.99,56.25% monounsaturated fatty acids and 14.22,23.03% polyunsaturated fatty acids. Among these, those occurring in the highest proportions were palmitic acid (20.42,27.9%), palmitoleic acid (11.09,26.26%), oleic acid (16.1,36.94%), eicosapentaenoic acid (3.22,7.53%) and docosahexaenoic acid (3.86,11.36%). The lipid, cholesterol and energy contents ranged from 1.97% to 10.23%, 57,302 mg/100 g and 4365.4,5544.2 cal g/dm, respectively. The obtained Statistical results showed that in these fishes, many of the above mentioned indices had significant differences (P , 0.01) and the cluster analysis results of fatty acid compositions showed that common carp and pike perch had good similarity, followed by the Caspian kutum and golden gray mullet. However, common kilka did not show any similarity to others. PRACTICAL APPLICATIONS Fish consumption has been linked to health benefits such as reduced risk of coronary heart disease. This is largely attributed to the lipid, cholesterol, energy contents, fatty acid compositions and the polyunsaturated fatty acids present in fish oils. The ,-3 : ,-6, polyunsaturated fatty acid/saturated fatty acid and eicosapentaenoic acid + docosahexaenoic acid/C16 ratios are considered to be useful criteria for comparing relative nutritional and oxidation values of fish oils. [source] COMPARISON OF VOLATILE COMPOUNDS AND CHEMICAL AND PHYSICAL PROPERTIES IN ORANGE JUICE FROM DIFFERENT PARTS OF JINCHEN FRUITJOURNAL OF FOOD QUALITY, Issue 2 2010YU QIAO ABSTRACT Jinchen is a native sweet cultivar of Citrus sinensis and one of the most important varieties used in orange juice processing in China. The study of flavor components of Jinchen orange juice has not been carried out before. In this paper, the color characteristics, pH value, total soluble solids, total acids, as well as organic acids and sugars were determined in Jinchen orange juice from different parts of fruit (peeled juice, pulp juice, whole fruit juice). The color characteristics were significantly different among three types of Jinchen orange juice. The level of vitamin C and total soluble solids/total acids ratio (TSS/TA) is higher in whole fruit juice. The organic acids and sugars also changed. Pulp juice is rich in the highest amounts of organic acids and sugars. Volatiles from three juices were studied using the solid phase microextraction (SPME) combined with gas chromatography/mass spectrometry. The whole fruit juice has the highest amount of volatile compounds (53.07 mg/L) followed by peeled juice (51.044 mg/L) and pulp juice (27.107 mg/L). Some differences in the constituents of the volatile compounds of three type juices were observed. These results indicated that volatile compounds and quality properties differed in Jinchen orange juice from different parts of fruit. PRACTICAL APPLICATIONS The peeled orange fruits are usually used for juice processing. Great amounts of aroma components with intensive odor are located in the peel of orange. The aroma of pulp possessing weak fresh citrus odor is different from peel. The different parts of the orange utilized in processing have direct impact on juice quality. It is very essential to obtain the data of chemical and physical properties in juice from different parts of orange fruit. The quality information could be used to modify the orange aroma. [source] Effects of feeding fermented fish on egg cholesterol content in hensANIMAL SCIENCE JOURNAL, Issue 1 2009Teck-Chwen LOH ABSTRACT This study was conducted to investigate the effects of feeding fermented fish (FF) to layers on laying performance, and polyunsaturated fatty acid and cholesterol levels in eggs and plasma. A total of 96, 13-week-old Babcock B380 pullets were used in this study. They were randomly assigned to four numerically equal groups with eight replicates per treatment, three birds per replicate. All the birds were housed in individual cages. The dietary treatments were: Control diet, without FF; FF3 diet containing 3% (w/w) FF, FF6 diet containing 6% (w/w) FF and FF9 diet containing 9% (w/w) FF. The study was carried out for 16 weeks inclusive of two weeks of adjustment. Weekly feed intake and egg production were recorded. Blood plasma cholesterol and fatty acid profiles were assayed at the end of the experiment. FF did not enhance (P > 0.05) egg mass but (P < 0.05) decreased egg weight slightly. However, egg yolk cholesterol and plasma cholesterol concentrations were reduced (P < 0.05) by FF. The n-6:n-3 fatty acids ratio in the egg yolk (Control = 7.9, FF9 = 6.2) and plasma (Control = 10.6, FF9 = 6.2) were decreased by feeding FF. Moreover, FF was able to increase (P < 0.05) the docosahexaenoic acid (DHA) concentrations in egg yolk and plasma. In conclusion, this study demonstrated that FF increased DHA and reduced egg yolk cholesterol in poultry eggs. [source] Changing of fat content and fatty acid profile of reared pike (Esox lucius) fed two different dietsAQUACULTURE RESEARCH, Issue 1 2006Balázs Kucska Abstract Fat content and fatty acid profile of two pike yearling groups grown on two different diets were compared. The groups originated from culture on artificial feed. One group (cultured pike fed first pellet then prey-fish (PF)) was fed with natural food, live prey-fish, while the other one (cultured pike fed exclusively pellet (PP)) by trout feed through a 3-month experimental period. Growth of pike was lower with PP than with PF. The trout feed resulted in an increase of the fat content of fillet and the formation of abdominal fat depots. Feeding of natural food decreased the fat content. The proportion of the saturated fatty acids in fillet was higher in the (PF) group. The n-6 fatty acids (arachidonic C20:4n-6 and docosatetraenic C22:4n-6 acids) were lowest in PP-fed pike. Regarding total n-3 fatty acids ratio there was no significant difference between the groups, but the level of ,-linolenic (C:18:3n-3) acid showed significant difference among groups. [source] Numerical calculations of the pH of maximal protein stabilityFEBS JOURNAL, Issue 1 2004The effect of the sequence composition, three-dimensional structure A large number of proteins, found experimentally to have different optimum pH of maximal stability, were studied to reveal the basic principles of their preferenence for a particular pH. The pH-dependent free energy of folding was modeled numerically as a function of pH as well as the net charge of the protein. The optimum pH was determined in the numerical calculations as the pH of the minimum free energy of folding. The experimental data for the pH of maximal stability (experimental optimum pH) was reproducible (rmsd = 0.73). It was shown that the optimum pH results from two factors , amino acid composition and the organization of the titratable groups with the 3D structure. It was demonstrated that the optimum pH and isoelectric point could be quite different. In many cases, the optimum pH was found at a pH corresponding to a large net charge of the protein. At the same time, there was a tendency for proteins having acidic optimum pHs to have a base/acid ratio smaller than one and vice versa. The correlation between the optimum pH and base/acid ratio is significant if only buried groups are taken into account. It was shown that a protein that provides a favorable electrostatic environment for acids and disfavors the bases tends to have high optimum pH and vice versa. [source] QUALITY OF FRESH-CUT TOMATOESJOURNAL OF FOOD QUALITY, Issue 3 2004ABDUL HAKIM ABSTRACT Tomato fruit at pink or light-red stages of ripening were cut into slices, rinsed with water containing 50 ,L.L,1 sodium hypochlorite and drained. They were stored in perforated polyethylene package at 1C in air or controlled atmosphere for five and ten days. Weight loss, chlorophyll and lycopene contents, seed discoloration, fungal infection, total soluble solids content, titratable acidity, sugar/acid ratio, pH, flavor and taste, firmness, ascorbic acid content, rate of respiration and ethylene production, and electrolyte leakage were evaluated after each storage period. The overall quality of controlled atmosphere-stored slices was better than that of air stored slices. Slices from light-red fruit had lower weight loss, minimum seed discoloration, lower [source] | ||||||||||||||||