Ma Wing-chi, Joyce. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 131-148). / Abstracts in English and Chinese. / Abstract (in English) --- p.i / Abstract (in Chinese) --- p.iv / Acknowledgement --- p.vi / Contents --- p.viii / Abbreviation --- p.xii / List of Tables --- p.xiii / List of Figures --- p.xv / Chapter 1. --- Introduction --- p.1 / Chapter 2. --- Literature review --- p.5 / Chapter 2.1 --- Fisheries in Hong Kong --- p.5 / Chapter 2.2 --- Flavor of seafood --- p.6 / Chapter 2.2.1 --- Lipid-derived volatile aroma compounds --- p.7 / Chapter 2.2.2 --- "Alcohols, aldehydes and ketones" --- p.8 / Chapter 2.2.3 --- Enzymatic conversion of sulfur- and nitrogen-containing precursors --- p.9 / Chapter 2.2.4 --- Thermally generated compounds --- p.9 / Chapter 2.2.5 --- Bromophenols --- p.10 / Chapter 2.2.5.1 --- General properties of bromophenols --- p.11 / Chapter 2.2.5.2 --- Threshold of bromophenols --- p.14 / Chapter 2.2.5.3 --- Toxicity of bromophenols --- p.17 / Chapter 2.2.5.4 --- Previous studies about bromophenols --- p.19 / Chapter 2.2.5.5 --- Bromophenols in aquacultured seafood --- p.20 / Chapter 2.2.5.6 --- Possible dietary sources of bromophenols --- p.20 / Chapter 2.2.5.7 --- Possibility of increasing bromophenol content in aquacultured fish --- p.23 / Chapter 2.3 --- Criteria for selecting experimental fish model --- p.24 / Chapter 3. --- Distribution of Bromophenols in selected Hong Kong seafoods --- p.27 / Chapter 3.1 --- Introduction --- p.27 / Chapter 3.2 --- Materials and methods --- p.28 / Chapter 3.2.1 --- Sample collection and preparation --- p.28 / Chapter 3.2.2 --- Simultaneous steam distillation-solvent extraction (SDE) --- p.30 / Chapter 3.2.3 --- Gas chromatography / mass spectrometry (GC/MS) --- p.30 / Chapter 3.2.4 --- Compound identification and quantification --- p.31 / Chapter 3.2.5 --- Recoveries --- p.33 / Chapter 3.2.6 --- Moisture determination --- p.34 / Chapter 3.2.7 --- Statistical analysis --- p.34 / Chapter 3.3 --- Results and discussion --- p.34 / Chapter 3.3.1 --- Distribution of bromophenols in seafoods --- p.34 / Chapter 3.3.1.1 --- Bromophenols in marine fishes --- p.49 / Chapter 3.3.1.2 --- Bromophenols in mollusks --- p.49 / Chapter 3.3.1.3 --- Bromophenols in crustaceans --- p.50 / Chapter 3.3.2 --- Seasonal variations of TBCs --- p.51 / Chapter 3.3.3 --- Bromophenols in diet contents --- p.52 / Chapter 3.3.4 --- Bromophenol contents of freshwater fish --- p.53 / Chapter 3.3.5 --- Relationship between the living habitats and bromophenol contents --- p.56 / Chapter 3.3.6 --- Bromophenols as flavor compounds in seafoods --- p.58 / Chapter 3.4 --- Conclusion --- p.59 / Chapter 4. --- Distribution of Bromophenols in selected Hong Kong seaweeds --- p.61 / Chapter 4.1 --- Introduction --- p.61 / Chapter 4.2 --- Materials and methods --- p.62 / Chapter 4.2.1 --- Sample collection and preparation --- p.62 / Chapter 4.2.2 --- Simultaneous steam distillation-solvent extraction (SDE) --- p.63 / Chapter 4.2.3 --- Gas chromatography / mass spectrometry (GC/MS) --- p.64 / Chapter 4.2.4 --- Compound identification and quantification --- p.65 / Chapter 4.2.5 --- Recoveries --- p.66 / Chapter 4.2.6 --- Moisture determination --- p.67 / Chapter 4.3 --- Results and discussion --- p.67 / Chapter 4.3.1 --- Distribution of bromophenols in marine algae --- p.67 / Chapter 4.3.2 --- Seasonal variations --- p.76 / Chapter 4.3.3 --- Functions of bromophenols in marine algae --- p.79 / Chapter 4.3.4 --- Marine algae as sources of bromophenols in marine environment --- p.80 / Chapter 4.4 --- Conclusion --- p.81 / Chapter 5. --- Enhancement of bromophenol contents in aquacultured fish by the development of bromophenol-rich fish feeds --- p.83 / Chapter 5.1 --- Introduction --- p.83 / Chapter 5.2 --- Materials and methods --- p.85 / Chapter 5.2.1 --- Preparation of fish feeds --- p.85 / Chapter 5.2.2 --- Storage conditions of fish feeds --- p.88 / Chapter 5.2.3 --- Experimental animals --- p.88 / Chapter 5.2.4 --- Solvent and chemicals --- p.90 / Chapter 5.2.5 --- Extraction and quantification of bromophenols --- p.90 / Chapter 5.2.5.1 --- Simultaneous steam distillation-solvent extraction (SDE) --- p.90 / Chapter 5.2.5.2 --- Gas chromatography / mass spectrometry (GC/MS) --- p.91 / Chapter 5.2.5.3 --- Compound identification and quantification --- p.92 / Chapter 5.2.5.4 --- Recoveries --- p.93 / Chapter 5.2.6 --- Moisture determination --- p.94 / Chapter 5.2.7 --- Statistical analysis --- p.94 / Chapter 5.2.8 --- Sensory test --- p.95 / Chapter 5.3 --- Results and discussion --- p.96 / Chapter 5.3.1 --- Bromophenol contents in wild-harvested and aquacultured fish --- p.96 / Chapter 5.3.2 --- Development of bromophenol-rich fish feed --- p.99 / Chapter 5.3.3 --- Effect of feeding the fish with the fish feed developed --- p.105 / Chapter 5.3.4 --- Sensory evaluation on the flesh of the fish fed with different fish feeds --- p.121 / Chapter 5.3.5 --- Growth of the fish fed with different fish feeds --- p.124 / Chapter 5.4 --- Conclusion --- p.126 / Chapter 6. --- General conclusion and significance of the study --- p.128 / References --- p.131

O mangarito (Xanthosoma mafaffa Schott) ou mangará, é uma das espécies da família Araceae, e está entre inúmeras plantas rústicas encontradas nas regiões tropicais. A grande maioria dessas espécies são amiláceas, classificadas como calóricas e consideradas alimentos de subsistência, porém, não há muitos dados sobre esses alimentos não-convencionais, e o estudo deles, pode ter um papel importante na suplementação da alimentação de populações desnutridas e de baixo poder aquisitivo. Dessa forma, o presente trabalho teve como objetivos avaliar composição centesimal, fibras solúveis e insolúveis, minerais, &#945;-tocoferol e o perfil de carotenóides, no mangarito cru (CR) e cozido (CZ). Foram avaliadas cinco colheitas do mangarito provenientes de um único cultivar no interior do Estado de São Paulo entre os anos de 2005 e 2007. Sua composição centesimal foi de aproximadamente 71,93% de umidade; 1,23% de cinzas; 1,43% de lipídeos e 2,11 % de proteínas e houve perdas estatisticamente significativas após o cozimento. Dessa forma, o valor calórico total do mangarito foi de aproximadamente 103,11 kcal/100g. Os valores de fibras alimentares foram de 3,5% (CR) e 3,62% (CZ), não havendo diferença estatisticamente significativa entre eles. O resultado da análise de minerais revelou valores elevados de cálcio (CR=290,60 e CZ=330,0mg/100g), ferro (CR=3,90 e CZ=1,8mg/100g), potássio (CR=1408,70 e CZ=1300,4mg/100g) e zinco (CR=4,2 e CZ=5,20mg/100g). Foram encontrados 72,04&#181;g/g de &#945;-tocoferol e a perda pelo cozimento foi de 14,28%. Os carotenóides encontrados nas amostras foram &#945;-caroteno (1,26&#181;g/g), &#950;-caroteno (3,41&#181;g/g) e traços de mutatocromo e micronona e cozimento ocasionou perda de 20 a 66% para &#945;-caroteno e de 6 a 60% para &#950;-caroteno. Apesar da identificação de um carotenóide com atividade pró-vitamínica (&#945;-caroteno), as quantidades encontradas no mangarito não foram suficientes para que o alimento recebesse a designação de fonte dessa vitamina. / Tannia (Xanthosoma mafaffa Schott) is characterized as a rustic plant found in tropical countries such as Brazil. Vegetables are sources of carotenoids that could be used in prevention of vitamin A deficiency. Considering the generally higher cost of animal foods, the provitamin A from vegetables should be considered as an expressive and easily obtainable source of vitamin A in developing countries Although tannia are popularly c1assified as a source of carotenoids, studies on its chemical composition are rare. Thus, because of the absence of the cultivation, tannia as well as others non-traditional vegetables may become extinct and still be classified as potential source of nutrients. Therefore the goal of the present study is to characterize the chemical composition and carotenoids profile of raw (RT) and cooked tannia (CT). It was analyzed 5 different crops of tannia from the countryside of Sao Paulo state harvested between years 2005 and 2007. When compared to RT, CT presented less (p<0.05) water, protein and fat. Regarding the total amount of energy, RT presented values between 95,12 to 143,60 Kcal/100g while CT presented values between 100,96 to 142,91 Kcal/100 g. In both RT and CT it was found great quantity of calcium (RT =290,60 mg/100 g; CT =330,0 mg/100 g), iron (RT =3,90 mg/100 g; CT = 1,8 mg/100 g), potassium (RT = 1408,70 mg/100 g; CT = 1300,4 mg/100 g) and zinc (RT = 4,2 mg/100 g; CT = 5,20 mg/100 g). Moreover, in RT it was found 72,04 &#181;g of &#945;-tocopherol while CT presented 14,28 % less. It was found &#945;-carotene and &#950;-carotene, mutatochrome and micronone in both RT and CT; however CT presented smaller (p<0.05) concentration of these carotenoids. In conclusion, tannia can not be considered a good source of provitamin A because of the small concentration of &#945;-carotene. Although the great quantity of important minerals, more studies are necessary to elucidate their bioavailability in tannia.

O mangarito (Xanthosoma mafaffa Schott) ou mangará, é uma das espécies da família Araceae, e está entre inúmeras plantas rústicas encontradas nas regiões tropicais. A grande maioria dessas espécies são amiláceas, classificadas como calóricas e consideradas alimentos de subsistência, porém, não há muitos dados sobre esses alimentos não-convencionais, e o estudo deles, pode ter um papel importante na suplementação da alimentação de populações desnutridas e de baixo poder aquisitivo. Dessa forma, o presente trabalho teve como objetivos avaliar composição centesimal, fibras solúveis e insolúveis, minerais, &#945;-tocoferol e o perfil de carotenóides, no mangarito cru (CR) e cozido (CZ). Foram avaliadas cinco colheitas do mangarito provenientes de um único cultivar no interior do Estado de São Paulo entre os anos de 2005 e 2007. Sua composição centesimal foi de aproximadamente 71,93% de umidade; 1,23% de cinzas; 1,43% de lipídeos e 2,11 % de proteínas e houve perdas estatisticamente significativas após o cozimento. Dessa forma, o valor calórico total do mangarito foi de aproximadamente 103,11 kcal/100g. Os valores de fibras alimentares foram de 3,5% (CR) e 3,62% (CZ), não havendo diferença estatisticamente significativa entre eles. O resultado da análise de minerais revelou valores elevados de cálcio (CR=290,60 e CZ=330,0mg/100g), ferro (CR=3,90 e CZ=1,8mg/100g), potássio (CR=1408,70 e CZ=1300,4mg/100g) e zinco (CR=4,2 e CZ=5,20mg/100g). Foram encontrados 72,04&#181;g/g de &#945;-tocoferol e a perda pelo cozimento foi de 14,28%. Os carotenóides encontrados nas amostras foram &#945;-caroteno (1,26&#181;g/g), &#950;-caroteno (3,41&#181;g/g) e traços de mutatocromo e micronona e cozimento ocasionou perda de 20 a 66% para &#945;-caroteno e de 6 a 60% para &#950;-caroteno. Apesar da identificação de um carotenóide com atividade pró-vitamínica (&#945;-caroteno), as quantidades encontradas no mangarito não foram suficientes para que o alimento recebesse a designação de fonte dessa vitamina. / Tannia (Xanthosoma mafaffa Schott) is characterized as a rustic plant found in tropical countries such as Brazil. Vegetables are sources of carotenoids that could be used in prevention of vitamin A deficiency. Considering the generally higher cost of animal foods, the provitamin A from vegetables should be considered as an expressive and easily obtainable source of vitamin A in developing countries Although tannia are popularly c1assified as a source of carotenoids, studies on its chemical composition are rare. Thus, because of the absence of the cultivation, tannia as well as others non-traditional vegetables may become extinct and still be classified as potential source of nutrients. Therefore the goal of the present study is to characterize the chemical composition and carotenoids profile of raw (RT) and cooked tannia (CT). It was analyzed 5 different crops of tannia from the countryside of Sao Paulo state harvested between years 2005 and 2007. When compared to RT, CT presented less (p<0.05) water, protein and fat. Regarding the total amount of energy, RT presented values between 95,12 to 143,60 Kcal/100g while CT presented values between 100,96 to 142,91 Kcal/100 g. In both RT and CT it was found great quantity of calcium (RT =290,60 mg/100 g; CT =330,0 mg/100 g), iron (RT =3,90 mg/100 g; CT = 1,8 mg/100 g), potassium (RT = 1408,70 mg/100 g; CT = 1300,4 mg/100 g) and zinc (RT = 4,2 mg/100 g; CT = 5,20 mg/100 g). Moreover, in RT it was found 72,04 &#181;g of &#945;-tocopherol while CT presented 14,28 % less. It was found &#945;-carotene and &#950;-carotene, mutatochrome and micronone in both RT and CT; however CT presented smaller (p<0.05) concentration of these carotenoids. In conclusion, tannia can not be considered a good source of provitamin A because of the small concentration of &#945;-carotene. Although the great quantity of important minerals, more studies are necessary to elucidate their bioavailability in tannia.