Doutoramento em Ciências Farmacêuticas / PhD in Pharmaceutical Sciences

The tea plant, Camellia sinensis, is a fluoride (F) accumulator. Upon brewing, tea releases large amounts of F. Excessive amounts of F can cause dental fluorosis (DF) and skeletal fluorosis (SF). This study aims to determine the F levels in 4 brands of green tea and 4 brands of black tea. F was measured using an ion selective electrode (ISE) in 3 analyses: i) standard tea infusion, ii) infusion over time with spectrophotometric determination, and iii) microwave digestion. By considering the existing literature and the results of this study, the health risk associated with consuming these 8 brands of tea is evaluated. In accordance with the literature, black tea infusions have significantly higher F than green tea infusions (p < 0.01). As the brew with the significantly highest F concentration (4.07 mg L-1 ), Tetley was chosen to demonstrate the relationship between infusion time and F concentration. As expected, both F concentration and absorbance increase with infusion time. The microwave digestion results are less conclusive. There is no significant difference between the dry mass of F (mg kg-1 ) in green and black tea. Across all samples, approximately 10-31% of the total F is released after 2 minutes of infusion. These results suggest that chronic tea consumption could cause DF and SF. A cup of Tetley tea contains 0.81 mg of F. Only 7.4 or 2.2 cups of Tetley tea would need to be consumed by an adult or child, respectively, to exceed the daily upper limit at which symptoms of SF can arise. Considering the multiple other dietary fluoride sources and the increased susceptibility of children, F in tea should be more closely monitored.

The effect Leuconostoc mesenteroides and Lactobacillus plantarum has on the physical and chemical properties of fresh and dehydrated sauerkraut was tested. Sauerkraut inoculated with L . plantarum was slower in fermenting and significantly lower in acidity and higher in pH. Dehydration of sauerkraut by freeze-conventional hot-air and micro-wave processes produced a significant loss in volatile components, ascorbic acid , lactic acid and an increase in pH. Each of the dehydration processes caused browning of the sauerkraut . These changes were less with freeze-drying and increased with conventional hot-air drying and microwave drying. Gas-liquid chromatography confirms the loss of volatile components and the production of a new peak, occurring at 9 to 10 minutes , in the conventional hot-air dried and microwave dried. Sensory evaluation scores of freeze-dried and conventional hot-air dehydrated sauerkraut compared favorably with that of a canned commercial product.

The purpose of this study is to collect and organize all data available to the investigator on the subject of calcium and phosphorus requirements for normal children. Since it is the business of nutrition to maintain health and prevent disorders, leaving the cure of disorders to the medical profession, this study deals with the calcium and phosphorus metabolism of normal children and avoids going into the pathological phases, taking up rickets and tetany only in so far as prevention is concerned. If this study has any value it lies in the fact that the findings of investigators seem to be scattered throughout a great many books and scientific journals, and it was thought that the collection and organization of these findings would serve as useful purpose in making this research more readily available to nutrition students. The bibliography for the study was made up from references given by such recognized authorities and sources as Sherman, McLester, Starling, Lusk, Van Slyke and Peters, Bogert, Rose, Child Development Abstracts, British Nutrition Abstracts, and Chemical Abstracts. From this bibliography were chosen those books and articles which seemed to the writer to be most promising as to reliability, amount of information, and variety of information. Part of the work has of necessity been adapted to children from experiments on adults. The importance of calcium and phosphorus in the diet of little children is emphasized by Sherman as follows: "The effect of an insufficient intake of calcium is natural more serious with growing than with full grown animals. The young need more calcium because during growth and development the body in increasing not only the amount but the percentage of calcium which it contains. *** growing children whose height, weight, and appearance are normal may have a calcium-poor condition of the body*** Since this is largely a matter of the deposition of calcium phosphate in the developing bones, the phosphorus content of the body tends to remain low when the calcium is low and to rise to normal with the calcium when the calcium content of the food is increased.

A study of the adaptive changes of some enzyme activities to the dietary protein intake was made in the liver, kidney, and pancreas of rats and serum of humans. The rats fed the 40 per cent casein diet had a higher rate of weight gain and the weights of the liver and kidney were higher than in the rats fed the 10 per cent casein diet. Three enzymes involved in the elimination of excess nitrogen from the body were found to show a similar response to increased dietary protein intake. These enzymes were: D-amino acid oxidase in the kidneys, arginase in the liver and kidneys, and glutamic-pyruvic transaminase in the liver of rats. The rate of enzyme induction was detectable the second day, being high during the first four days and reaching the maximum value on the fourth day. Thereafter, the enzymatic activity did not change much. The alkaline phosphatase activities in the liver and kidneys of the rats did not show significant change during consumption of the diets containing 10 per cent or 40 per cent casein. Samples of pancreatic trypsinogen and chymotrypsinogen of the rats were not collected during the appropriate time to note any significant changes caused by the diets . A more appropriate experimental design, including proper timing for feedings and dissections, for the study of the adaptation of the proteolytic enzymes in the pancreas of the rats is desirable and recommended. The values for the circulating enzymes of the human serum, 0-amino acid oxidase, glutamic-pyruvic transaminase, and alkaline phosphatase were not found to be affected significantly by the diets containing 12 per cent and 30 per cent protein calories.

The research in this dissertation focused on determining antioxidant effects of various natural antioxidants in cooked meat systems. Milk mineral (MM), spices, and raisin paste were used in cooked meat systems to verify their potential antioxidant properties. The MM study determined the antioxidant activity of 1.5% MM added to uncured cooked beef meatballs, and possible additive effects of MM in combination with 20-ppm or 40-ppm sodium nitrate in cooked beef sausages . There was no additive inhibition of lipid oxidation in samples containing 20-ppm or 40-ppm sodium nitrite plus 1.5% MM. Cooked meat yield was not different between control meatballs and those containing MM. As expected, treatments containing nitrite had higher redness (a*) values than samples without nitrite. The MM at 1.5% was a very effective antioxidant as compared to controls. The Garam Masala (GM) study determined the antioxidant effects and sensory attributes of the individual spices in an Indian spice blend GM in cooked ground beef, and possible additive antioxidant effects between Type I and Type II antioxidants. All spices had antioxidant effects on cooked ground beef, compared to controls without spices, with cloves being the most effective. All spices at their lowest effective recommended level effectively lowered the perception of rancid odor and rancid flavor in cooked ground beef as compared to control samples. As expected, most spices also imparted distinctive flavors to the cooked ground beef. Type II antioxidants (iron binding phosphate compounds) were more effective than individual Type I antioxidants (spices and butylated hydroxytoluene; BHT) in cooked ground beef. There was a positive additive antioxidant effect seen with rosemary + MM and rosemary + sodium tripolyphosphate (STPP) treatments as compared to individual rosemary treatment. There was no additive antioxidant effect observed for other combinations of spices with phosphate antioxidants. The raisin study was done to determine the antioxidant activity of raisin paste added to cooked ground beef, pork, and chicken. Thiobarbituric acid (TBA) values were measured using the distillation method, on the distillates, to avoid interference from sugar in the raisins. Beef, pork, and chicken flavor intensity, rancid flavor intensity, and raisin flavor intensity were evaluated by a trained sensory panel (n = 6). Addition of 2% raisin paste effectively inhibited rancid flavor development for 14 days after cooking in cooked ground beef, pork, and chicken. Sugar added at levels equivalent to that contributed by the raisins inhibited rancidity, probably due to antioxidant effects of Maillard browning products, suggesting that the antioxidant effect of raisins was due to their sugar content.

Many objective chemical tests have attempted to correlate with organoleptic evaluation of oxidative rancidity. Major chemical tests used to detect oxidative rancidity of lipids measure nonvolatile high molecular weight carbonylic substances which make no considerable contribution to rancid flavors. High molecular weight carbonyls are present at much greater concentrations than volatile low molecular weight carbonyls. Peroxides and other unknown substances also react in these chemical tests to give at best an empirical evaluation. A 3-methyl-2-benzothiazolinone hydrazone chemical test is proposed which corrected some deficiencies of earlier procedures, and was correlated with organoleptic evaluation of rancid turkey samples. The proposed test measures oxidative rancidity in terms of milligrams of acetaldehyde per kilogram of sample. A comparison of the 3-methyl-2-benzothiazolinone hydrazone method with a widely used chemical test was conducted. The thiobarbituric acid test was selected because it is used most often as an indicator of rancidity. The thiobarbituric acid test values increased followed by a definite leveling off as formation of malonaldehyde reached a maximum even though rancid flavor continued to increase. The 3-methyl-2-benzothiazolinone hydrazone test measured a continuing increase of volatile aliphatic aldehydes as rancid flavor increased .

Chitosan films are an excellent media for binding metal ions due to the electrostatic nature of the chitosan molecules. Addition of cross-linking or plasticizing agents alters texture of the films, but their effect on metal-binding capacity has not been fully characterized. The objective of this research was to determine effects of plasticizers and cross-linkers on physical and metal-binding properties of chitosan films and coatings prepared by casting and by spincoating. Chitosan films were prepared using 1% w/w chitosan in 1% acetic acid with or without (control) additives. Plasticizing agents were tetraethylene glycol (TEG) and glycerol while citric acid, ethylenediamine tetraacetic acid (EDTA), and tetraethylene glycol diacrylate (TEGDA) were used as cross-linkers. The additives were applied in concentrations of 0.10%, 0.25%, and 0.50% w/w of film-forming solution. The films were prepared by casting and by spincoating. Films were cast at ambient conditions for tests within one week (fresh films) and eight weeks (aged) after casting. The cast films were evaluated for thickness, residual moisture (by the Karl Fischer method), Cr(VI) binding capacity, puncture strength, and puncture deformation while the chitosan coatings were tested for thickness, Cr(VI) binding capacity, solubility in aqueous solution, and surface morphology (using atomic force microscopy). Cast films with cross-linkers showed an increase in resistance to puncture while plasticized films become more elastomeric. Control films bound 97.2% Cr(VI) ions from solution (0.56 mg Cr(VI)/g film), and addition of plasticizers did not affect chromium binding, tying up to 96.7% Cr(VI) ions from solution (0.56 mg Cr(VI)/g film). Films containing cross-linkers yielded binding capabilities ranging from 42.3% to 94.3% bound Cr(VI) ions (0.26-0.52 mg Cr(VI)/g film). Ultrathin coatings also possess the ability to bind Cr(VI) from solution, though only a maximum of 7.4% of Cr(VI) ions could be bound from solution, the thin films had the ability to bind up to 224 mg Cr(VI)/g ultrathin film. These coatings use less chitosan, but they display greater binding per mass. Overall, plasticizers do not alter, while cross-linkers may reduce, the binding capacity of chitosan films, but physical properties of the films can be controlled by inclusion of additives.

Roasting is an important processing step for developing cocoa flavor, color, and aroma. Cocoa beans contain polyphenolic compounds, which can be desirable antioxidants. Oxygen Radical Absorbance Capacity (ORAC) values can be used as an indicator of health benefits of antioxidants in foods. ORAC values measure total antioxidant capacity of different foods by measuring antioxidant scavenging activity against peroxyl radical induced by 2,2’-azobis (2-amidinopropane) dihydrochloride (AAPH). This measurement of total antioxidant capacity gives a complete assessment during which the inhibition time and inhibition degree are measured as the reaction comes to a completion. ORAC values were determined as Trolox Equivalents (TE). Cocoa beans were also measured for antioxidants using Total Phenolics assay and DPPH assay and measured as gallic acid equivalents (GAE). Cocoa beans from the Ivory Coast were roasted at varying times (10-40 minutes) and temperatures (100ºC -190ºC). It was determined that cocoa beans from the Ivory Coast, roasted at 130ºC for 30 minutes resulted in an ORAC value of 522,789 μmol (micromoles) TE/g, GAE value of 2.46 mg/L as determined by Total Phenolics, and GAE value of 1.48 mg/L as determined by DPPH assay. The analyzed values tended to decrease at the highest temperatures and times of roasting. Cocoa beans from different countries were roasted at 130ºC for 30 minutes and antioxidants were analyzed. It was determined that Dominican Republic and Ecuador had the highest TE values (487,913 and 463958 μmol (micromoles) TE/g respectively). GAE differed and Total Phenolic assay found Haiti had the highest GAE (3.26 mg/L) and DPPH assay found Ivory Coast and Dominican Republic had the highest (0.623 and 0.610 mg/L respectively). If an acceptable flavor, color, and aroma of cocoa can be developed at a roasting temperature closer to 130ºC than to 160ºC, then a greater antioxidant content should occur in dry cocoa powder.

Applesauce prepared for the US military is processed as MRE (meals-ready-to-eat) in several forms including Type VI - Applesauce with raspberry puree, and Type VII - Carbohydrate enriched applesauce. Production of MRE applesauce starts with commercially prepared and thermally processed applesauce that is further processed by a military contractor. The further processing includes adjusting pH, ºBrix, and ascorbic acid level, packaging into pouches, and again thermally processing. Both types of the MRE applesauce are very much liked by troops, but under stress storage applesauce darkens and its consumption is drastically reduced. The overall goal of this project was to identify additives to be used during further processing in order to slow darkening when exposed to elevated temperatures during shipping and storage. The specific objective was to determine whether different types of ascorbic acid, calcium salts, or addition of chelators can reduce deterioration under stress storage. Applesauce (AS), applesauce with raspberry puree (RPAS), MRE AS (Type VII) and MRE RPAS (Type VI) for all experiments were provided by Sopakco, Bennettsville S.C. The research was carried out in three phases. From the Phase 1, we learned that Type VII and Type VI darkened at faster rates at the beginning of the storage, but the effects of storage at 50°C for more than 2 weeks overcame any differences caused by further processing. Phase 2 helped us determine the formulations for the processing on the industrial scale. The formulations were: 0.15% L-ascorbic-acid (AA), and 0.15% AA with 300 ppm EDTA for both AS and RPAS, with 0.83% calcium lactate gluconate (CLG) for AS, and 0.15% ascorbyl-palmitate for RPAS. The results from the Phase 3 indicated that AS with addition of CLG and RPAS with total of 0.18% AA had the least total color change. In all samples, accumulation of HMF was related to amount of ascorbic acid with exception of samples with Pal which had the lowest HMF content. Our results indicate that current MRE Types VI and VII may have better stability at stress storage if the level of AA is limited to 0.18% and 0.83% CLG is added to the AS formulation.