The purposes of this study are (1) to determine the ascorbic acid content of a variety of fruit juices available in Denton, Texas, during March to July, 1943; (2) to ascertain the loss of ascorbic acid when canned grapefruit, orange, pineapple, and apple juices are opened and stored in the home refrigerator for several days' use; and (3) by means of data obtained, to make recommendations as to the most advantageous ways of using one's "points" in purchasing canned fruit juices for their ascorbic acid value.

by Lee Yee Chung, Edmund. / Thesis (M.B.A.)--Chinese University of Hong Kong, 1991. / Bibliography: leaves 14-17. / ACKNOWLEDGEMENTS --- p.ii / ABSTRACT --- p.iii / TABLE OF CONTENTS --- p.v / LIST OF APPENDICES --- p.viii / LIST OF TABLES --- p.ix / PREFACE --- p.xii / Chapter CHAPTER I --- INTRODUCTION --- p.1 / Purpose of This Study --- p.2 / Chapter CHAPTER II --- LITERATURE REVIEW --- p.4 / Food of China --- p.4 / Kinds of Chinese Foods --- p.4 / Chinese Food Concepts --- p.5 / Characteristics of Chinese Foods --- p.7 / Food Trends in Foreign Countries --- p.9 / Consumer Behaviour of Chinese towards Canned Foods in Hong Kong --- p.10 / Canned Food Consumption in the United Kingdom --- p.11 / Responses of Canned Foods Company towards the Changing Food Trend --- p.12 / Healthy Canned Products --- p.12 / Specialty Markets --- p.12 / Other Methods --- p.13 / Bibliography --- p.14 / Books --- p.14 / Reports --- p.14 / Periodicals --- p.15 / Chapter CHAPTER III --- THE CANNED FOOD INDUSTRY --- p.17 / Types of Chinese Canned Foods --- p.17 / Chinese Canned Food Companies in Hong Kong --- p.18 / Major Brands of Chinese Canned Foods Manufactured in Mainland China --- p.19 / Chapter CHAPTER IV --- MARKET SITUATION OF CANNED FOODS IN THE UNITED KINGDOM --- p.22 / General Situation --- p.22 / Canned Meat --- p.23 / Canned Fish --- p.24 / Canned Vegetables --- p.24 / Canned Fruit --- p.24 / Canned Soup --- p.25 / Consumer Profile --- p.25 / Industry Supply --- p.30 / Foreign-Owned Manufacturers --- p.31 / UK-Owned Manufacturers --- p.33 / Other Companies --- p.35 / Distribution --- p.36 / Market Size and Trends --- p.37 / Market Situation of Chinese Canned Foods in London --- p.39 / Place --- p.39 / Product --- p.40 / Pricing --- p.40 / Promotion --- p.41 / Chapter CHAPTER V --- METHODOLOGY --- p.42 / Sources of Primary Data --- p.42 / Districts being Surveyed --- p.42 / Selected districts in London --- p.42 / Selected districts in Hong Kong --- p.42 / Sample Size --- p.43 / Quotas --- p.43 / By Race --- p.43 / By Age --- p.43 / By district --- p.43 / Design of Questionnaire --- p.44 / Criteria for Identifying Target --- p.44 / Method of Survey --- p.45 / Interviewing Procedures --- p.45 / Data Analysis --- p.46 / Chapter CHAPTER VI --- FINDINGS --- p.48 / Key Factors Influencing the Consumption of Chinese Canned Foods --- p.48 / Social Factors --- p.48 / Personal Factors --- p.49 / 4 P's --- p.50 / Chinese and Non-Chinese Female Consumers' Perception towards Chinese Canned Foods --- p.52 / Foreign Chinese and Non-Chinese Female Consumers' Reasons for Buying --- p.52 / Foreign Non-consumers' Reasons for Not Buying --- p.52 / Foreign Chinese and Non-Chinese Consumers' Buying Patterns for Chinese Canned Foods --- p.53 / Where Do the Consumers Buy --- p.53 / How Do They Buy --- p.54 / Who Buys It --- p.54 / What to Buy --- p.55 / Why to Buy --- p.55 / Who Likes It --- p.55 / Chapter CHAPTER VII --- RECOMMENDATIONS --- p.56 / Pricing --- p.56 / Raise Retail Price --- p.56 / Promotion --- p.56 / Chinese Canned Food Exhibition --- p.56 / Chinese Canned Food Cooking Demonstrations --- p.57 / Opinions from Experts --- p.57 / Girls in Traditional Dress --- p.58 / A Whole Shelf of Chinese Canned Foods --- p.58 / Product Sampling Package --- p.58 / Advertising --- p.59 / Food Trials --- p.59 / Promotion by Using Pamphlets --- p.59 / Cents-off coupons and Rebates --- p.60 / Product --- p.60 / Sell Package --- p.60 / Emphasize Medical Values --- p.61 / Put Emphasis on Canned Vegetarian Foods --- p.61 / Emphasize Famous Chinese Dishes --- p.62 / Special Kinds of Canned Fruits --- p.62 / Reduce Additives --- p.62 / Packaging --- p.62 / Distribution --- p.65 / Sell in Major Supermarkets and Groceries --- p.65 / Chinese Canned Foods Specialty Stores --- p.65 / Chapter CHAPTER VIII --- LIMITATIONS OF THE RESEARCH AND SUGGESTIONS FOR FURTHER STUDY --- p.66 / Limitations of the Research --- p.66 / Small Sample Limited to London --- p.66 / Only Urban Population --- p.66 / Recommendations based only on Marketing Research --- p.67 / No Detailed Marketing Plan --- p.67 / Chapter CHAPTER IX --- CONCLUSION --- p.68

Thesis (MBA (Business Management))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: The vegetable unit of Tiger Brands annually is responsible for the canning of approximately 115,200,000 cans of a variety of vegetables, of which baked beans constitute approximately seventy percent. The canning of baked beans is subject to a number of challenges with regard to the raw materials and equipment used. The challenges involve the approved raw materials, the storage thereof and the condition and age of the equipment in the plant. The baked beans are produced throughout the year and inconsistencies in the final product are a major cause for concern. The primary aim of this study was to determine which cultivar of beans is the most suitable for use in the canning industry and whether other cultivars can be used with some adjustments to the production processes to eliminate the current inconsistencies. A further aim was to make recommendations on how to create more capacity and to increase the quality of the final product. The problem was addressed by analysing the production processes for the three different bean cultivars over a period of approximately three months and determining the behaviour of the different cultivars. It is clear from the data collected that the different cultivars behave differently during the production processes and yield different results at the final stage of inspection. Human intervention during the production processes also played an important role in the quality of the final product of the different bean cultivars. Human interventions are currently necessary due to the age of the equipment, poor maintenance over the years and modifications made to the equipment to try to increase capacity and the quality of the product. Further studies could be conducted in some of the areas excluded from this study, to determine the suitability of other bean cultivars for the canning industry. / AFRIKAANSE OPSOMMING: Die groente-eenheid van Tiger Brands is jaarliks verantwoordelik vir die inmaak van omtrent 115,200,000 blikkies groente van verskillende soorte waarvan gebakte bone omtrent sewentig persent van die volume behels. Die inmaak van die bak bone is onderhewig aan unieke uitdagings ten opsigte van die rou materiaal en masjinerie wat in produksieprosesse gebruik word. Die unieke uitdagings behels die verskille in die goedgekeurde bonekultivars, die opberging daarvan en die toestand en ouderdom van die masjinerie in die aanleg. Die inmaak van die bak bone vind regdeur die jaar plaas en die wispelturige resultate in die finale produk is 'n groot rede tot kommer. Die primêre doelwit van die studie was om te bepaal watter bonekultivar die mees geskikte kultivar vir gebruik in die inmaakbedryf is en of die ander kultivars meer aanvaarbare resultate sal lewer as sekere verstellings in die proses aangebring word om die kwaliteit te verbeter en die teenstrydige resultate uit te skakel. 'n Verdere doelwit was om aanbevelings te maak oor hoe om die kapasiteit van die aanleg te verhoog, sowel as om die kwaliteit van die produk te verbeter. Die probleem is aangespreek deur die data wat oor 'n tydperk van drie maande oor die produksie prosesse vir die drie verskillende kultivars ingesamel is, te analiseer, en die gedrag van die drie verskillende bonekultivars in elke proses te bepaal. Dit is duidelik te sien in die verskeidenheid van ingesamelde data dat die verskillende bonekultivars verskillend reageer gedurende die produksieprosesse en dus verskillende resultate gedurende die finale inspeksieproses lewer. Menslike ingrype in die produksieprosesse speel 'n belangrike rol in die uitkoms van die finale produk se kwaliteit by die verskillende bonekultivars. Die menslike ingrype is tans krities belangrik in die produksieprosesse as gevolg van die ouderdom van die masjinerie, die swak instandhouding wat oor die jare uitgevoer is, asook die wysigings wat aan die masjinerie aangebring is in 'n poging om die kapasiteit van die aanleg te verhoog en om die produk se kwaliteit te verbeter. Verdere studies kan uitgevoer word in sekere van die ander areas wat by hierdie studie uitgesluit is, om te bepaal of ander bonekultivars ook in die inmaakbedryf gebruik kan word.

This thesis aims to assess the human health impact of exposure to estrogenic compounds from the diet. A multi-disciplinary approach is taken to address various aspects of this issue. An introduction to xenoestrogens, including international research priorities, wildlife and human health effects, mechanisms of action, structure activity relationships and additivity of estrogenic effects is provided as background information. An assessment of exposure to a range of naturally occurring and synthetic estrogenic compounds found in food is derived in Chapter 2. The assessment combines new and existing data on food concentration, food consumption and serum levels for each xenoestrogen. Exposure is combined with relative estrogenic potency data from published bioassasy data to estimate risk relative to normal circulating levels of estradiol. Assuming additivity of xenoestrogens, for an average New Zealand male and for post-menopausal women, xenoestrogens in the diet contribute an additional 12-90% of estrogenicity above normal circulating levels. For a pre-menopausal female, the contribution from the diet represents in the order of an additional 2%. The level of exposure determined in this thesis would seem to be of pharmacological relevance, especially for men with low levels of estrogen and for post-menopausal women. Bisphenol A (BPA) is an important monomer used in the manufacture of epoxy resins for internal food can linings. A survey of the BPA content of a range of 80 canned foods available to the New Zealand consumer was undertaken and the results used in the exposure and risk assessments. BPA was detected in all foods analysed except soft drinks, at concentrations ranging from <10-29 µg/kg, except for individual samples of tuna, corned beef and coconut cream that were 109, 98 and 191 µg/kg respectively. None, of over 4000 individual exposure scenarios, exceeded the temporary Tolerable Daily Intake (TDI) of 10 µg/kg body weight per day set by the Scientific Committee on Food in 2002. Intestinal microflora influence the bioavailability of the naturally occurring xenoestrogens genistein and daidzein that contribute significantly to total estrogenicity from the diet. The degradation of genistein and daidzein by the faecal microfloral of 5 human subjects was variable and unpredictable between individuals and within an individual. These findings have important implications for the promotion and prescription of soy foods and supplements for disease prevention and health benefits. The "yeast assay" is one of a number of methods available to measure estrogenicity. This assay was established and validated. In utero exposure to estrogenic compounds at critical periods of sexual differentiation and endocrine development may imprint for health effects observed later in life. Placental transfer of estrogenicity, from 17β-estradiol was studied using the human placental perfusion model and the yeast assay. The placenta provides a protective barrier to the transfer of estrogenicity. Experiments with genistein showed that 5-15% placental transfer occurred, suggesting that in utero exposure might be in the order of 10% of maternal exposure. The thesis concludes with consideration of a genomic approach to substantiate, or refute, the mechanistic link between exposure to xenoestrogens and claimed human health effect. Such an approach offers exciting opportunity to clarify the mode of action of the synthetic versus the naturally occurring xenoestrogens, to confirm or dispute additivity of effect that is an important premise of the exposure assessment, to identify key genes involved in the many possible health effects and thence risk to the individual from dietary exposure to xenoestrogens.

by Sum Kwok-fong, Louisa [and] Wong Wai-ling, Jacqueune. / Bibliography: leaf 63 / Thesis (M.B.A.)--Chinese University of Hong Kong, 1985

High pressure (HP) sterilization of low acid foods is a process involving HP at elevated temperatures. Data available on HP destruction kinetics of pressure resistant pathogenic, spoilage-causing and surrogate bacterial spores are limited, but essential for establishing such a process. While compression heating could be employed to provide the elevated temperature, accurate data gathering under such conditions is difficult due to rapid heat loss during the treatment. The objectives of this research were to first standardize the set up carrying out HP tests at elevated and stabilized temperatures, and subsequently to evaluate HP destruction kinetics of selected bacterial spores under HP elevated temperature processing conditions. / The set-up consisted of a thick insulated chamber for holding samples during the test. A relationship was established for the adiabatic temperature rise milk which was used as the main low acid food medium: DeltaTP = -0.306 + 0.0224Ti + 0.0423P + 4.49x10-4T i2 + 1.31x10-4TiP -- 1.24x10 -5P2 (R2 =0.999, n = 50, SE = 0.20&deg;C, p&lt;0.05). Initial temperatures at 83.5, 91.7, 95.8&deg;C and 80.7, 88.9, 93.0&deg;C provided operating process temperature 121, 130, 135&deg;C, at 800, 900MPa, respectively. / Destruction kinetics tests were carried with two strains of Clostridium sporogenes (11437, 7955) and Geobacillus stearothermophilus 10149 spores suspended in milk at 700-900 MPa and 70-100&deg;C. These strains were selected for their relatively high pressue and thermal resistance. The survival counts were well fitted by first order linear models. The D values C. sporogenes 11437 varied from 0.73 min at 900 MPa 100&deg;C to 17.0 min at 700 MPa 80&deg;C HP treatments while they ranged from 6.0 to 833 min at 80-100&deg;C under thermal processing conditions. The D values associated with of C. sporogenes 7955 spores were higher and varied from 1.3 min at 900 MPa 100&deg;C to 38.2 min at 700 MPa 80&deg;C HP treatments, and from 12.1 to 156 min at 80-100&deg;C during thermal treatments. The D values of Geobacillus stearothermophilus 10149 spores varied from 0.6 min at 900 MPa 90C to 20.9 min at 500 MPa 70&deg;C HP treatments with 6.3 to 49.4 min for thermal treatments at 110-120&deg;C. Hence C. sporogenes 7955 spores were the most resistant among those studied. The HP destruction kinetics of C. sporogenes 7955 spores were also studied in salmon and were lower than in milk. / Pressure resistance screening of selected group I C. botulinum spores was carried out at 800-900 MPa at 90-100&deg;C. Nominal D values of each strain were evaluated which demonstrated that PA9508B, H09504A and CK2-A were the more resistant spores (PA9508B > HO9504A > CK2-A). HP destruction kinetics of C. botulinum PA9508B spores in milk were evaluated in detail at 700-900 MPa at 90-100&deg;C and parallel thermal treatment at 90-100&deg;C. The survival counts were again described by first order linear models (R2 >0.86). The D values varied from 0.35 min at 900 MPa 110&deg;C to 38.9 min at 700 MPa 90&deg;C for HP treatments and 14.4 to 273 min at 90-100&deg;C for thermal treatments. These demonstrated that HP processing combined with elevated temperatures will accelerate the spore destruction rate. However, the associated D values of C. botulinum PA9508B spores in milk were more resistant than those of C. sporogenes 7955 at 90, 100&deg;C, which indicated that the surrogate may not be very effective for using as a target for verification HP at elevated temperature processing conditions. / Overall, this work has demonstrated several findings. The non-pathogenic C. sporogenes 7955 spore was the most resistant surrogate but the pathogenic C. botulinum PA9508B spore was even more resistant. D values associated with HP at elevated temperatures were higher than under conventional thermal treatments, and hence provide accelerated destruction kinetics at least for the non-pathogenic spores and hence better spoilage control. However, from safety point of view the conventional thermal sterility requirements would still persist even under HP processing conditions. Milk as a low acid food medium provided more resistance for HP destruction than fish.

This thesis aims to assess the human health impact of exposure to estrogenic compounds from the diet. A multi-disciplinary approach is taken to address various aspects of this issue. An introduction to xenoestrogens, including international research priorities, wildlife and human health effects, mechanisms of action, structure activity relationships and additivity of estrogenic effects is provided as background information. An assessment of exposure to a range of naturally occurring and synthetic estrogenic compounds found in food is derived in Chapter 2. The assessment combines new and existing data on food concentration, food consumption and serum levels for each xenoestrogen. Exposure is combined with relative estrogenic potency data from published bioassasy data to estimate risk relative to normal circulating levels of estradiol. Assuming additivity of xenoestrogens, for an average New Zealand male and for post-menopausal women, xenoestrogens in the diet contribute an additional 12-90% of estrogenicity above normal circulating levels. For a pre-menopausal female, the contribution from the diet represents in the order of an additional 2%. The level of exposure determined in this thesis would seem to be of pharmacological relevance, especially for men with low levels of estrogen and for post-menopausal women. Bisphenol A (BPA) is an important monomer used in the manufacture of epoxy resins for internal food can linings. A survey of the BPA content of a range of 80 canned foods available to the New Zealand consumer was undertaken and the results used in the exposure and risk assessments. BPA was detected in all foods analysed except soft drinks, at concentrations ranging from <10-29 µg/kg, except for individual samples of tuna, corned beef and coconut cream that were 109, 98 and 191 µg/kg respectively. None, of over 4000 individual exposure scenarios, exceeded the temporary Tolerable Daily Intake (TDI) of 10 µg/kg body weight per day set by the Scientific Committee on Food in 2002. Intestinal microflora influence the bioavailability of the naturally occurring xenoestrogens genistein and daidzein that contribute significantly to total estrogenicity from the diet. The degradation of genistein and daidzein by the faecal microfloral of 5 human subjects was variable and unpredictable between individuals and within an individual. These findings have important implications for the promotion and prescription of soy foods and supplements for disease prevention and health benefits. The "yeast assay" is one of a number of methods available to measure estrogenicity. This assay was established and validated. In utero exposure to estrogenic compounds at critical periods of sexual differentiation and endocrine development may imprint for health effects observed later in life. Placental transfer of estrogenicity, from 17β-estradiol was studied using the human placental perfusion model and the yeast assay. The placenta provides a protective barrier to the transfer of estrogenicity. Experiments with genistein showed that 5-15% placental transfer occurred, suggesting that in utero exposure might be in the order of 10% of maternal exposure. The thesis concludes with consideration of a genomic approach to substantiate, or refute, the mechanistic link between exposure to xenoestrogens and claimed human health effect. Such an approach offers exciting opportunity to clarify the mode of action of the synthetic versus the naturally occurring xenoestrogens, to confirm or dispute additivity of effect that is an important premise of the exposure assessment, to identify key genes involved in the many possible health effects and thence risk to the individual from dietary exposure to xenoestrogens.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-11-22T16:49:47Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) ana_claudia_silveira_alexandre.pdf: 1522170 bytes, checksum: ecd371ab3f6777103dd99573de2bf35a (MD5) / Made available in DSpace on 2018-11-22T16:49:47Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) ana_claudia_silveira_alexandre.pdf: 1522170 bytes, checksum: ecd371ab3f6777103dd99573de2bf35a (MD5) Previous issue date: 2018 / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / A melancia (Citrullus lanatus) ? um fruto refrescante que apresenta versatilidade de consumo e consider?vel potencial nutricional; entretanto, ? respons?vel por uma grande gera??o de res?duos, sendo o mesocarpo (entrecasca), o principal destes. Este res?duo agr?cola subutilizado ? uma boa alternativa para aproveitamento e desenvolvimentos de novos produtos. O presente estudo relata a possibilidade de agrega??o de valor ao mesocarpo de melancia por meio do desenvolvimento de picles acidificados e fermentados. A efici?ncia do emprego de culturas starters, cultura aut?ctone isolada e cultura de Lactobacillus acidophilus foram avaliados e comparados em rela??o ? fermenta??o natural do mesocarpo de melancia. As fermenta??es foram acompanhadas por meio de an?lises f?sico-qu?micas e microbiol?gicas, e os produtos foram caracterizados quanto ? composi??o centesimal, f?sico-qu?mica, qualidade microbiol?gica e sensorial. Inferiu-se que a exist?ncia de bact?rias l?ticas durante os processos fermentativos do mesocarpo de melancia afetou a comunidade microbiana presente, resultando no consumo de carboidratos, produ??o de ?cidos org?nicos e acidifica??o do meio fermentativo. Nas fermenta??es adicionadas de culturas starters, foram alcan?ados menores valores de pH ao final dos processos fermentativos, sendo atingidos pH 3,52 (cultura starter aut?ctone isolada) e pH 3,68 (cultura starter L. acidophilus). A fermenta??o do mesocarpo de melancia resultou em produtos com maior valor nutricional, mais seguros e est?veis. Determinou-se que os picles desenvolvidos foram seguros do ponto de vista microbiol?gico, al?m de apresentarem maior potencial bioativo que o mesocarpo in natura. Os melhores resultados sensoriais foram encontrados para os picles n?o fermentados. / Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Ci?ncia e Tecnologia de Alimentos, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2018. / The watermelon (Citrullus lanatus) is a refreshing fruit that presents versatility for consumption and considerable nutritional potential; however, it is responsible for a large generation of residues, the mesocarp (inner rind) being the principal residue. This underutilized agricultural residue is a good alternative for the use and development of new products. The present study reports the possibility of increasing the value to the watermelon mesocarp through the development of acidified and fermented pickles. The efficiency of the use of starter cultures, isolated autochthonous culture and a culture of Lactobacillus acidophilus were evaluated and compared to the natural fermentation of the watermelon mesocarp. The fermentations were accompanied by physicochemical and microbiological analyses, and the products were characterized with regard to the proximate composition, physicochemical characteristics and the microbiological and sensorial qualities. It was inferred that the existence of lactic bacteria during the fermentative processes of the watermelon mesocarp affected the microbial community present, resulting in the consumption of carbohydrates, production of organic acids and acidification of fermentative media. In the fermentations to which starter cultures were added, lower pH values were reached at the end of the fermentation process, reaching pH 3.52 (native starter culture isolated) and pH 3.68 (L. acidophilus culture starter). The fermentation of the watermelon mesocarp resulted in products with higher nutritional value, being more secure and stable. The pickles developed were found to be safe from a microbiological point of view, in addition to having a greater bioactive potential than the fresh mesocarp. The best sensory results were obtained for the unfermented pickles.

Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2014-10-21T14:15:47Z No. of bitstreams: 1 Tese - Dannuza Cavalcante.pdf: 1879788 bytes, checksum: 0fd9cc5ca387348e35095d0c92a17183 (MD5) / Approved for entry into archive by Ana Hilda Fonseca (anahilda@ufba.br) on 2014-10-29T17:23:53Z (GMT) No. of bitstreams: 1 Tese - Dannuza Cavalcante.pdf: 1879788 bytes, checksum: 0fd9cc5ca387348e35095d0c92a17183 (MD5) / Made available in DSpace on 2014-10-29T17:23:53Z (GMT). No. of bitstreams: 1 Tese - Dannuza Cavalcante.pdf: 1879788 bytes, checksum: 0fd9cc5ca387348e35095d0c92a17183 (MD5) / CNPq / Neste trabalho que está no âmbito do PRONEX, foram desenvolvidas estratégias analíticas para a determinação de arsênio e selênio em amostras de alimentos por HG AFS. Foram realizados três trabalhos distintos. O primeiro consistiu no emprego da amostragem e m suspenção para determinação de arsênio em amostras de arroz. Procedimentos de amostragem de suspensão foram avaliados para determinação de As por geração de hidreto acoplado a AFS, usando HNO 3 e sonicação por 30 min. As amostras foram preparadas com KI e m ácido ascórbico e com HCl 6 mol L - 1 , para determinação As total. A exatidão foi confirmada por análise do material de referência certificado NIES SRM 10b de farinha de arroz, a precisão foi confirma com valores de RSD abaixo de 5,9 % e limites de detecçã o e quantificação de 0,91 e 3,04 ng L - 1 , respectivamente. Este método foi utilizado para determinar o teor de arsênio em 24 amostras de arroz que foram adquiridas em supermercados da cidade de Salvador, Bahia, Brasil. O conteúdo de arsênio nos três tipos de arroz (branco, parbolizado e integral) variou de 0,12 a 0,47 μg g - 1 . O segundo trabalho foi o desenvolvimento de método analítico para determinação de selênio em ovos. Três tipos de ovos foram adquiridos (codorna, galinha e pata) em feiras e supermercad os de Salvador. A digestão foi realizada mediante adição de HNO 3, H 2 O 2 30% v v - 1 e HCl 6 mol L - 1 , utilizando o bloco digestor com dedo frio. As condições para a pré - redução e geração do hidreto de selênio foram otimizadas empregando o planejamento fatorial e a matriz de Doehlert. As condições ótimas foram: concentração de HCL 5,3 mol L - 1 , concentração do borohidreto de sódio 2,6 % (m/v), volume de KBr 10% 1,0 mL e tempo de pré - redução de 30 min. O método apresentou limites de detecção e quantificação de 0,22 e 0,77 ng L - 1 , respectivamente. O RSD ficou abaixo de 4,7 % demonstrando boa repetibilidade. A exatidão foi comprovada através da análise do CRM de tecido de ostra e também através de comparação com resultados obtidos e m análise no ICP - MS. O método foi aplicado em quatro diferentes grupos de amostras, na clara e na gema separadas e na mistura dos dois, sendo que as concentrações mínimas e máximas foram de 0,35 ± 0,01 a 0,88 ± 0,03 μg g - 1 . O terceiro trabalho foi o desenv olvimento de método para determinação de arsênio em atum e sardinha enlatados. As amostras foram submetidas a 3 procedimentos de preparo de amostra (bloco digestor, forno de micro - ondas e forno mufla). As condições para a pré - redução e geração do hidreto d e arsênio foram otimizadas empregando o planejamento fatorial e a matrix de Doehlert e as condições encontradas foram: tempo de pré - redução de 21 min, volume de pré - redutor KI 10 % (m v - 1 ) em ácido ascórbico 2% (m v - 1 ) de 1,0 mL, concentração de HCl 4,7 mo l L - 1 e concentração de NaBH 4 de 2% (m v - 1 ). O método mostrou - se preciso, com valores de RSD abaixo de 7,0 %. Um material de referência certificado de tecido de ostra (NIST SRM 1566b) foi analisado para avaliar a exatidão do método. O material foi submetid o a três procedimentos de digestão. Através da análise dos resultados pode - se observar que o valor obtido no forno de micro - ondas e no bloco digestor foi cerca de metade do valor certificado, pois a arsenobetaina só é convertida a arsênio inorgânico a temp eraturas acima de 300 º C. O método foi aplicado para 20 amostras de atum e sardinha enlatados e os valores de concentração variaram de: 0,63 ± 0,10 a 3,28 ± 0,20 μg g - 1 / In this work is under PRONEX , strategies for analytical determination of arsenic and selenium in food samples by HG AFS were developed. Three diferent studies were conducted. The first one consisted in the use of sampling in suspension for determination of arsenic in rice procedures were evaluated to As by hydride generation coupled to AFS using HNO 3 and sonication for 30 min. The samples were prepared with KI in ascorbic acid and 6 mol L - 1 HCl to determine total As . The accuracy was confirmed by analysis of certified reference material NIES SRM 10b rice flour , precision was confirmed with % RSD values lower than 5.9% and limits of detection and quantification of 0. 91 and 3.04 ng L - 1 , respectively. This method was used t o determine the content of arsenic in 24 rice samples purchased at supermarkets in the city of Salvador , Bahia , Brazil . The content of arsenic in the three types of rice ( white, parboiled and integral ) ranged from 0.12 to 0.47 μ g g - 1 . In the second study we developed a method for determination of selenium in eggs. Three types of eggs were purchased ( quail, chicken and paw) at fairs and supermarkets of Salvador . The digestion was performed by adding HNO 3 , 30% H 2 O 2 ( v v - 1 ) , 6 mol L - 1 HCI and , using the block digester cold finger. The conditions for the pre - reduction and hydride generation of selenium were optimized using factorial design and Doehlert matrix, the optimal conditions were : HCl concentration of 5.3 mol L - 1 , the 2.6 % ( w v - 1 ) sodium borohydride concentration , 1.0 mL volume of 10% ( w v - 1 ) KBr and pre - reduction time 30 min. The method has limits of detection and quantification of 0.2 2 and 0.7 7 ng L - 1 , respectively. The % RSD was below 4.7 showing good repeatability . The accuracy was confirmed by analysis of CRM oyster tissue and also by comparison with results obtained for analysis by ICP - MS. The method was applied to four different groups of samples , in clear and separate yolk and mix of the two , the minimum and maximum concentrations were 0.35 ± 0.01 to 0.88 ± 0.03 mg g - 1 . The third work was the development of a method for determination of arsenic in canned tuna and sardines . The samples were subjected to three procedures for sample preparation ( digestion block, microwave and oven muffle ). The co nditions for the pre - reduction and hydride generation of arsenic were optimized using factorial design matrix and Doehlert , the conditions were: pre - reduction time of 21 min, volume of 1.0 mL of 10% KI ( w v - 1 ) (pre - reducing) in 2% a scorbic acid, HCl concentration of 4.7 mol L - 1 and NaBH 4 - in 2% ( v m - 1 ). The method was precise, with RSD values below 7.0 %. A certified reference material of oyster tissue ( NIST SRM 1566b ) was analyzed to assess the accuracy of the method . The material was subjected to the three digestion procedure. From t he analysis of the results it can be seen that the value obtained in the microwave oven and the digester block was about half the value of the certificate , as the only arsenobetaine is converted to inorganic arsenic at temperatures above 300 °C. The method was applied to 20 samples of canned tuna and sardines and concentration values ranged from 0.63 ± 0.1 0 to 3.28 ± 0.2 0 mg g - 1