Os adesivos \"hot melt\" são blendas poliméricas aplicadas no estado fundido para fechamento de embalagens. Neste trabalho, procedemos à análise térmica e ensaios de adesão de alguns adesivos \"hot melt\" desenvolvidos para embalagens de alimentos congelados, buscando as formulações de melhor estabilidade térmica na temperatura de aplicação (180 ºC) e desempenho de colagem na temperatura do freezer. Estes adesivos contêm diferentes matérias-primas, tais como copolímeros de etileno e acetato de vinila (EVA), resinas promotoras de adesão e ceras. As técnicas utilizadas para as análises térmicas foram a termogravimetria (TG) e a calorimetria exploratória diferencial (DSC). Para avaliação das colagens, foi utilizado um dinamômetro. Das análises de calorimetria exploratória diferencial foi possível concluir que a miscibilidade da resina nas blendas estudadas pode ser monitorada pelo maior ou menor deslocamento da Tg do EVA. Os ensaios mecânicos de colagem a -18 ºC mostraram que a miscibilidade destes sistemas, que tem impacto direto sobre sua Tg, é responsável pela melhor ou pior performance adesiva. A blenda contendo uma resina terpênica-fenólica (TP 2040), altamente imiscível, apresentou o melhor resultado de tração de descascamento a -18 ºC. Já a blenda contendo um éster de pentaeritritol (RE 100 L), de alta miscibilidade, foi a que teve resultado menos satisfatório neste teste. A calorimetria exploratória diferencial, assim como a termogravimetria, se mostraram importantes ferramentas para avaliação da estabilidade térmica dos adesivos. A blenda contendo EVA, um oligômero de ciclopenteno e uma cera sintética foi a que apresentou maior estabilidade térmica. / The \"hot melt\" adhesives are polymeric blends applied in the molten state for case and carton sealing. In the present work, we carried out the thermal analysis and bonding evaluations of some hot melt adhesives for freezer grade carton sealing. These adhesives contained different raw materials, such as ethylene / vinyl acetate copolymers (EVA), tackfying resins and waxes, and we pursued the formulations with the best pot life in the application temperature (180 ºC) and bonding performance in the blast freezer temperature (-18 ºC). The techniques used for the thermal analysis were the thermogravimetric analysis (TGA) and the differential scanning calorimetry (DSC). For the bonding assessments, a dynamometer was used. From the DSC curves it was possible to figure out that the miscibility of the resin in the blends can be monitored by the EVA\'s Tg displacement. The bonding force analysis at -18 ºC showed that the miscibility of these systems is responsible for the adhesive performance. The blend containing a terpene-phenolic resin (TP 2040), highly imiscible, had the best result of peeling resistance whereas the blend containing a pentaerythritol ester of rosin (RE 100 L), a very miscible resin, was the one with the less satisfactory result. The thermogravimetry and the differential scanning calorimetry were important tools for the evaluation of the thermal stability of the adhesives. The blend containing an oligomer of cyclopentene presented the best thermal stability.

<div> <p>Proper understanding of materials science is critical in understanding the functionality of ingredients in food products, as well as their behavior in these products over time. Amorphous materials are metastable, eventually rearranging to the thermodynamically stable crystalline state. Amorphous materials have properties which are beneficial in some food products: they are softer in texture and dissolve more rapidly. The amorphous state of sucrose might provide an increase in quality in applications like powdered beverages where rapid dissolution is preferred. A number of classes of compounds have been shown to delay the crystallization of amorphous sucrose; however, polyphenols, particularly their glycosylated forms, have been little explored. Glycosylated polyphenols contain two distinct structural regions: a more hydrophilic sugar unit(s) and a more hydrophobic polyphenol backbone. While the sugar unit should be able to easily associate with sucrose molecules, the polyphenolic backbone may not and might provide hindrance to crystal nucleation and growth.</p> <p> </p> <p> Thiamine is an essential nutrient that is found naturally in foods such as whole grains and pork. The processing of grains removes nearly the entirety of the natural thiamine content; thus, foods are often enriched with synthetic thiamine. Two salts of thiamine are used commercially: thiamine mononitrate and thiamine chloride hydrochloride. The two forms have specific applications driven by their specific properties, specifically their aqueous solubility and hygroscopicity. While these two salts provide adequate functionality, it is possible new salts may have properties beneficial in certain food applications. A method making use of silver nitrate was developed to produce new salt forms. An intermediate in this reaction, TCl·H₂O, was characterized including measurements of stability in aqueous solutions and solid state properties.</p> </div> <br>

Water extracts of saffron, a spice derived from the plant Crocus Sativus L. obtained from India and Iran, were analyzed by liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS). The components in the extracts were separated on four different solid phase extraction cartridges with four different solvents and by silica gel column. Analysis was done by GC-MS, LC-MS and UV-Vis spectroscopy. The extracts separated into three distinct bands (two bright yellow and one orange) on the silica gel column. Based on GC-MS, the extracted compounds show many structural similarities. Using both extraction techniques, several compounds were identified that were not previously reported to be in saffron. Picrocrocin, safranal, and crocins presence in the extracts were evidenced by absorbance bands at wavelengths of 250 nm, 310 nm and 440 nm, respectively, in their UV-Vis spectra. The LC-MS analysis revealed several high molecular weight compounds that were not observed by GC-MS.

Os produtos obtidos a partir da cana-de-açúcar possuem, além de altas concentrações de sacarose, flavonóides que podem atuar como quimiopreventivos e antioxidantes. Neste estudo foram elucidadas as estruturas dos flavonóides e dos ácidos cinâmicos mais abundantes no caldo de cana, sendo apresentadas duas novas substâncias, uma flavona, tricina-7-&#927;-&#946;-(6\"-p-metoxicinamato)-glucosideo e uma lignana, 3-hidroxi-1-[4,5-dihidroxi-3-metoxifenil]-2-[4-(3-hidroxi-1-(E)-propenil)-2,6-dimetoxifenoxi]-propil-&#946;-D-glucopiranosídeo. Entre as flavonas analisadas, o derivado de tricina apresentou maior abundância. Foi também confirmada neste estudo a perda de compostos fenólicos durante o processamento industrial do açúcar. Nos colmos de cana-de-açúcar evidenciamos altas concentrações de ácidos clorogênico e cumárico, e baixos teores de flavonóides. No decorrer do processamento verificaram-se perdas significativas de ácidos cinâmicos e aumento nos teores de flavonóides. Os maiores teores foram verificados no xarope e os menores no açúcar VHP. Entretanto, a proporção dos compostos fenólicos teve pouca alteração durante o processamento. As flavonas encontradas na cana in natura se mantiveram durante todo o processamento, enquanto que não se detectou ácido ferúlico nas variedades e ácido caféico nos produtos. A atividade antioxidante dos produtos obtidos durante as etapas do processamento do açúcar foram avaliadas. As maiores atividades foram encontradas no xarope e melaço, enquanto que as menores, no caldo misto e açúcar VHP. Uma avaliação sobre o perfil dos compostos fenólicos de amostras de rapadura e caldo de cana obtidos no comércio local mostrou que a rapadura apresenta altos teores de luteolina, enquanto no caldo, prevalece tricina. Nas amostras de rapadura destacam-se altos teores de ácido clorogênico, composto que se mostrou ausente nas amostras obtidas durante as etapas do processamento industrial do açúcar. As atividades antioxidantes dos extratos de rapadura mostraram que mesmo em baixas concentrações a atividade é moderada. O caldo apresentou atividade semelhante, mas em concentrações mais elevadas. Quanto à atividade antiproliferativa, o extrato de rapadura apresentou atividades citostáticas para todas as linhagens e citocida para as linhagens de células cólon (HT-29), de mama (MCF-7), de mama resistente (NCI-ADR), de pulmão (NCI-460), de ovário (OVCAR), de rim (786-0) e de melanoma (UACC-62). O derivado de tricina, isolado a partir do caldo de cana, apresentou atividade antioxidante moderada. Suas atividades antiproliferativas foram mais pronunciadas para as linhagens de células de mama resistente (NCI-ADR) e de cólon (HT-29), com atividade citostática e citocida para as linhagens de pulmão (NCI-460), de mama (MCF-7), de ovário (OVCAR), de rim (786-0) e de melanoma (UACC-62). / Sugar cane products have high sucrose concentration and flavonoids that can function with chemopreventive and antioxidant. In this study have been elucidated flavonoids and cinnamic acids structures most abundant in sugar cane juice and were presented two new substances, one flavone, tricin-7-&#927;-&#946;-(6-methoxycinnamic)-glucoside and one lignan, 3-hydroxy-1-[4,5-dihydroxy-3-methoxyphenyl]-2-[4-(3-hydroxy-1-(E)-propenyl)-2,6-dimethoxyphenoxy]-propyl-&#946;-D-glucopyranoside. Among the flavones analyzed, tricin presents high concentration. In this study was corroborated the loss of phenolic compounds during the processing industrial of sugar. In culm of sugar have been evidenced high concentrations of the chlorogenic and coumaric acids, and low flavonoid contents. During the processing has been proved significant loss of cinnamic acids and increase of flavonoids. The highest contents have been proved in the syrup and the smallest in the sugar VHP. However, the profile of the phenolic compounds had little alteration during the processing. The flavones finded in sugar cane in natura were remaining during all the processing and, are not find ferulic acid in the varieties and caffeic acid in the products. The antioxidant activities in products obtained during processing stage of sugar cane were evaluated. The highest activities were finded in the syrup and molasses and the smallest in sugar cane juice and sugar VHP. Assessment about the profile of the phenolic compounds in rapadura and sugar cane juice acquired in local commerce showed that the rapadura presents high contents of the luteolina, while in sugar cane juice, predominate tricin. In the sample of rapadura stand out high chlorogenic acid contents, compound that showed absent in sample from during the processing industrial stages of sugar. The antioxidants activities of rapadura extracts showed the in spite of in low concentration the activity is moderate. The sugar cane juice presented similar activity but, in high concentration. As for the antiproliferative activity, the rapadura extract presented cytostatic effect for ali lines and cytocidal for the colon cell lines (HT-29), of breast (MCF-7), of multi-drug resistant breast cells (NCI-ADR), of lung (NCI-460), of ovary (OVCAR), of kidney (786-0), and of melanoma (UACC-62). Tricin, isolated from sugar cane juice, presented moderate antioxidant activity. The antiproliferative effects of tricin were more pronunciated for multi-drug resistant breast cells (NCIADR) and of colon (HT-29), with cytostatic effect and cytocidal for lung lines (NCI460), of breast (MCF-7), ovary (OVCAR), of kidney (786-0), and of melanoma (UACC-62).

In this research project, real natural strawberries bought from different local sources were profiled by gas chromatography-mass spectroscopy (GCMS). These profiles were then used as a reference to compare GCMS profiles of commercial artificial strawberry flavor products such as strawberry flavored Cool Splashers™, Gatorade®, and Aquacal® flavored water. The chromatograms obtained were patterned using simple visual observations, scatter plot designs, Mann-Whitney U Test, and correlation coefficients. The artificially flavored commercial products tend to have simpler chromatograms. The Burger King® milkshake, Gatorade®, and Hi-C® are the most similar to that of the natural strawberry flavor. Their correlation coefficients are 0.972, 0.870, and 0.984 respectively. The Mann-Whitney U Test results also support the conclusions from correlation coefficients. However, the natural products tend to have more constituents including the main flavoring compounds. Thus fresh produce have better flavor and are more nutritious for a good reason.

The overall objective of the study was to investigate different food ingredient conditions and ultrasound treatment on pea protein in terms of surface morphology and thermal characteristics. The motivation of this work was based on previous studies focusing on non-chemical physical modifications of plant proteins and the increasing demand for functional alternative proteins. Ultrasonication time and amplitude, pH, protein concentration, and salt concentration all influenced the thermal and interfacial properties of pea protein. Ultrasound treatment altered the quaternary and tertiary structure of the storage protein and disrupted non-covalent bonds. The structural altercations and a reduction in particle size led to improved functionality. For foams generated at pH 5.0 with 4% (w/v) ultrasound treated protein, the foams had acceptable capacity and stability even when high levels of sugar (5% sucrose) and salt (0.6 M) were incorporated. An acceptable angel food cake simulation can be achieved by replacing egg white with ultrasound treated pea protein. Color and loaf height were different, but similar texture profiles were achieved. Ultrasound treatment significant improved the emulsifying capacity (up to 1.4 fold), emulsion stability, and creaming index compared to control samples (no ultrasound) over two weeks. The ultrasound treated emulsion yielded lower TBARS values, likely due to the change in exposed protein reactive groups. These findings demonstrate that ultrasound processing is an effective nonchemical method to change the structural and physiochemical properties of pea protein. Pea protein processed with this method might allow for the functionality in a bakery, dressings, or beverage products, which is appealing to many consumers and manufacturers.

The formation of green trihydroxy benzacridine (TBA) derivatives when chlorogenic acid (CGA) quinones and amino acids react can be visually unappealing in some applications where CGA containing ingredients are used. Cysteine was studied as an amino acid anti-greening strategy, because cysteine-CGA conjugates are colorless. Buffered CGA: lysine: cysteine solutions at pH 8.0 and 9.0 were prepared and incubated for a maximum of 48 h at ambient temperature. Color intensity was periodically monitored using a UV-Vis spectrophotometer. Quantification and identification of conjugate formation were conducted by HPLC and LC-MS, while Antioxidant capacity was assessed by Trolox Equivalent Antioxidant Capacity and Folin-Ciocalteu reagent reducing capacity assays. More intense greening was detected at higher pH. Lysyl amine- CGA conjugates were identified as the predominant precursor of green TBA. Concentration-dependent cysteine inhibition of CGA-lysine greening was primarily by redox diphenol regeneration when pH was below cysteinyl thiol pKa 8.3 while primarily by forming cysteinyl-CGA conjugates when pH was above 8.3. Visible greening was fully inhibited with a cysteine: lysine 1:1 molar ratio in pH 9 CGA: Lys: Cys solutions, indicating that cysteinyl thiol was a stronger nucleophile than ε-lysyl amine to react with CGA o-quinones. Mono- and di-cysteine-CGA conjugates contributed to antioxidant capacity. Cysteine concentration, pH and incubation time all significantly affected color intensities and antioxidant capacity (p

The common tomato of our garden belongs to the natural order Solanaceae and the genus Lycopersicum. The name from lykos, a wolf, and persica a peach, is given to it because of the supposed aphrodisiacal qualities, and the beauty of the fruit. By culture and use it is a vegetable, botanically it is a fruit and among the fruits, it is a berry being indehiscent, pulpy, with one or more seeds that are not stones. Though the tomato was not recognized as a valuable food until about a century ago, its merit is now universally accepted. Often it is referred to as "the poor man's orange" for it is rich in vitamins and in malic and citric acids, possessing besides, a fine appetizing flavor. The popularity of the tomato in man's diet is due to the fact that it is a most rewarding crop for the home garden. It grows well practically everywhere, affording high nutritional values. The demand for and acceptance of fresh tomato fruit is based largely on its nutritional value, flavor, aroma, taste, and other characteristics, such as color and texture. These quality criteria are dependent primarily on the structure and chemical composition of the fruit. The importance of quality in tomatoes beyond that which can be expressed in calories per gram, or even in vitamin content, is generally accepted in the United States. In order to meet this increasing demand throughout the year tomatoes often have to be grown in the greenhouses. Therefore, in commercial greenhouses, the tomato has replaced lettuce as the principal crop and it is likely to remain as an important underglass crop. Flavor is a composite of taste and odor. Odor is produced by many aromatic substances which are present in fruit. Flavor itself is a very complex sensation. The physiological basis of flavor perception is extremely complex and not clearly understood. Flavor chemistry is a comparatively new field of research. Tomato fruit quality is determined mainly by the sugar acid ratio, pectins, color, and flavor. Among these color and flavor are probably the most useful criteria for estimating maturity of tomato fruit. Higher quality is associated with redness of color and prominence of flavor. The flavor of a fruit becomes pronounced when the sugar content is at its maximum and the color of the skin acquires the richest shade. Isolation of volatile components from natural products is often difficult. Typical flavor and aroma of tomato fruit is primarily due to its volatile components. Neither complete analysis for nor synthesis of tomato flavor has been accomplished due to the marathon of problems associated with the extraction, separation, and identification techniques. The primary aim of this investigation was to separate and identify some of the major flavor and aroma components in the developing tomato fruit and also to assess the influence of certain physiological and biochemical changes on the biosynthesis of these components during fruit growth.

The extent and nature of biochemical changes that take place in canned fruits during storage temperatures above freezing have been reviewed and discussed by Pederson, et al. (1947). These changes include loss in nutritive value, e.g. ascorbic acid, thiamine (Brenner, et al., 1948) and deterioration of color (Tressler, et al., 1955). Bauernfeind (1953) reported that canned peaches, apricots, and sweet cherries, after a few months of storage at 70° F, frequently undergo changes such as destruction of anthocyanin and carotenoid pigments with the subsequent formation of brown colored compounds. Darkening of fruit-color eventually results in their unacceptability at consumer level. Preference for fruit is mainly based upon the attractive appearance of the products. Thus, color is an important factor governing the quality of fruits and fruit products. In earlier studies, conducted elsewhere, emphasis was placed on effects of low storage temperatures on the quality of canned apricots and cherries. Paucity of scientific literature on the stability of processed apricots and cherries gave impetus to a study of the comparative influence of high storage temperatures and their duration, as such tests will have considerable economic bearing upon storing and shipping processed products to tropical countries. This thesis presents the effects of storage temperatures (40, 70, 100, and 120° F) and their duration (16 weeks) on colors (anthocyanins and carotenoids), total titratable acidity, pH, viscosity, carbohydrates (total 2 and free reducing sugars, pectins), volatile reducing substances, hydroxymethyl furfural, and organoleptic quality of canned apricots and cherries .

The objectives of this investigation have been to characterize black gram (Phaseolus Mongo L.) and rice (Oryza sativa L.) proteins and to study changes in their nutritional value due to fermentation. black gram, the legume chosen for this work, is one of the most important legume crops throughout a large part of the tropics. The protein content of 60 mesh, dehydrated, defatted black gram meal was 28.5 percent. Sodium carbonate (0.5- 1.0 percent), tetra-sodium pyrophosphate (0.5 percent), and sodium dodecyl sulfate (SDS) (0.5-5 percent) proved to be the potential protein solubilizers as they extracted more than 76 grams of Lowry's protein per 100 grams Kjeldahl protein. On the considerations of contaminating residue in the final product and disruption of native structure of the proteins, these chemical agents were unsuitable. Sodium sulfate at the 10 percent level was judged to be the best protein solubilizer. Proteins separated on polyacrylamide gel using a phenol-acetic acid-mercaptoethanol-urea (PAMU) system were run on the flat bed gel containing SDS. The proteins were separated in 13 constituents and the molecular weights of the major ones were 140,000 and 55,000. Solubilized proteins contained 81 percent globulins, 13 percent albumins, 4 percent prolamins, and 2 percent glutelins . Sulfur containing amino acids and threonine were deficient in total proteins xv of the seeds with 27. 6 and 78.8 as their respective chemical scores . Chemical scores of the albumin, globulin, prolamin, and glutelin fractions were 64, 0, 56, and 70.7, respectively. The predicted biological values in human nutrition varied from O for globulins to 110 for glutelins, and was 14.9 for total proteins in the seeds. The constituents of the protein fractions were isoelectrically focused in the acidic pH range with the exception of two globulins for which the isoelectric points were 8.42 and 8.65. The trypsin inhibitor from black gram was isolated using affinity chromatography gel with 19. 5 fold purification. The inhibitor had 75 amino acid residues and contained one disulfide bridge. Chemical studies assigned an important role for the hydrogen bonds and demonstrated vital importance of the disulfide bridge in retaining the inhibiting activity. The inhibitor was stable and retained 35 percent of the activity when heated at 100°C for 60 minutes at pH 11. Chemical modification of amino acid residues suggested the involvement of lysine and arginine residues at the active site of the inhibitor. Lysine and arginine moieties at the active site have been proposed to be present as alanyllysine and histidylarginine. Inhib i tion of bovine pancreatic trypsin by the inhibitor was kinetically studied . The kinetic constants Km and Vm ax were 2.7 x l0- 5M and 6 x l0 - 3M/min, respectively. The dissociation constant for the enzyme-inhibitor complex (Ki) was 4 x l0- 7M, whereas that for the enzyme-inhibitor-substrate complex (K. 1 , ) was 1.89 x l0- 6M. The inhibition was a mixture of partial competitive and pure-noncompetitive systems. Rice and black gram form the integral parts of a fermented snack food of the Indian subcontinent~idli. Amino acid composition of black gram and rice were complementary. Leucine, lysine, and sulfur containing amino acids were the most limiting amino acids in rice with 65. 1, 66.3, and 67.9 as their respective scores. The estimates of biological values of rice proteins in human nutrition qualified albumins as superior and prolamins as inferior proteins. The PAMUsy stem in polyacrylamide gel electrophoresis was more efficient in resolving protein subunits than the SOS gel system. The PAMUsy stem was not sensitive to the ionic strength of the sample. Mobilities of rice and black gram proteins in SOS and PAMUsy stems were based on the related parameters. In the PAMUsy stem, the mobilities of most proteins seemed to depend on their molecular size. The PAMUsy stem on gel electrophoresis was judged superior to the SOS system. Fermentation of the black gram-rice blend was kinetically studied for changes in physicochemical characteristics and nutritional functionality. Trypsin inhibiting activity was unaffected, but chymotrypsin inhibiting activity was reduced to 3 percent after 20 hours fermentation , Significant increases were noted in the contents of sulfur containing amino acids during fermentation . These amino acids seemed to be bioavailable. In vitro digestion with pepsin and pancreatin indicated improvement in digestibility of proteins after fermentation. The digestibility was further enhanced by steaming.