Renata Galhardo Borguini

Tomatoes and Tomato Products as Dietary Sources of Antioxidants

Tomatoes, as an agricultural product, represent an important commodity worldwide and comprise a significant part of the human diet. They are one of the most versatile and widely used fruits, being consumed in the raw state and used for the preparation of a wide range of products. Tomatoes and tomato products are rich in antioxidant compounds such as carotenoids (particularly lycopene), ascorbic acid and phenolic compounds. The regular consumption of tomatoes and tomato products has been correlated to a reduction in risk of contracting various types of cancer and cardiovascular diseases. This positive effect is attributed to the antioxidants present in tomatoes.

Antioxidant potential of tomatoes cultivated in organic and conventional systems

The objective of the study was to compare the effect of organic and conventional cultivation on the antioxidant compound content and antioxidant activity of the Carmen tomato cultivar. Tomatoes were analyzed regarding ascorbic acid, phenolic compounds, lycopene content and antioxidant activity. Organic tomatoes presented higher content of ascorbic acid and total phenolics (641.39 and 4466.66 mg/100 g EAG on dry wt basis) than did the conventional tomatoes (510.16 and 3477.50 mg/100 g EAG on wt dry basis, respectively). There was no difference in lycopene concentrations between the organic and conventional. The ether, alcohol and aqueous extracts obtained from the tomatoes were subjected to the DPPH test and the β-carotene/linoleic acid system assay. The alcohol and aqueous extracts from organic tomatoes presented higher antioxidant activity in the DPPH test (25.43 and 14.28%, respectively) than the conventional tomatoes (19.52 and 11.33%, respectively). Organic tomatoes had higher antioxidant potential probably due to its higher ascorbic acid and total phenolic values.

Microscale extraction method for HPLC carotenoid analysis in vegetable matrices

In order to generate simple, efficient analytical methods that are also fast, clean, and economical, and are capable of producing reliable results for a large number of samples, a micro scale extraction method for analysis of carotenoids in vegetable matrices was developed. The efficiency of this adapted method was checked by comparing the results obtained from vegetable matrices, based on extraction equivalence, time required and reagents. Six matrices were used: tomato (Solanum lycopersicum L.), carrot (Daucus carota L.), sweet potato with orange pulp (Ipomoea batatas (L.) Lam.), pumpkin (Cucurbita moschata Duch.), watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) and sweet potato (Ipomoea batatas (L.) Lam.) flour. Quantification of the total carotenoids was made by spectrophotometry. Quantification and determination of carotenoid profiles were formulated by High Performance Liquid Chromatography with photodiode array detection. Microscale extraction was faster, cheaper and cleaner than the commonly used one, and advantageous for analytical laboratories.

SELEÇÃO ELETRÔNICA PELA COR NA DESCONTAMINAÇÃO DE AMENDOIM CONTAMINADO COM AFLATOXINAS

Quarenta e dois lotes comerciais de 300 kg de amendoim descascado, produzidos em 1997 e contaminados com aflatoxinas, foram submetidos a selecao eletronica pela cor para verificar a eficiencia desse processo na melhoria da qualidade de lotes de amendoim quanto a diminuicao da contaminacao com aflatoxinas. Os lotes de amendoim foram classificados pelo tamanho como normalmente utilizados pela cerealista, sendo 22 lotes de amendoim graudo (7,5 a 7,9mm) e 20 lotes de amendoim miudo (6,4 a 7,1mm), nos quais os niveis de contaminacao inicial variaram de 7 a 3.763 mg/kg e de 76 a 3.309 mg/kg, respectivamente. Nos 42 lotes, nao foram detectadas aflatoxinas em dois lotes de amendoim graudo e 1 de amendoim miudo. Este trabalho demonstrou que o processo de selecao eletronica retirou graos altamente contaminados, concentrando-os na porcao rejeito. Apesar disso, nao houve uma melhora substancial nos niveis iniciais medios de contaminacao dos lotes indicando que a distribuicao das aflatoxinas estava generalizada, uma vez que, os graos selecionados tambem estavam contaminados. Em lotes com menor contaminacao pode funcionar. Novos estudos serao realizados.

Chemical characterization of Myrciaria floribunda (H. West ex Willd) fruit

M. floribunda fruit was studied to characterize its chemical composition. The chemical composition, bioactive compounds, antioxidant activity and volatiles of the fruit were determined. The chemical composition was determined according to AOAC and AOCS, the bioactive compounds by HPLC, the volatiles by GCMS and the antioxidant activity by ABTS+ and DPPH methods. The chemical composition of the freeze-dried fruit was 1.89 g·100 g-1, 2.43 g·100 g-1, 4.78 g·100 g-1 and 90.89 g·100 g-1 of ashes, lipids, proteins and total carbohydrates on a dry base, respectively. The concentration of the carotenoids was 52.22 mg·100 g-1 and for the flavonoid rutin was 78.56 mg·100 g-1. The gallic and ellagic acid contents were 5.45 mg·g-1 and 2.21 mg·g-1, respectively. The cis-β-ocimene corresponded to 50.90% of the volatiles. The antioxidant activity by ABTS+ method was 550.14 µmol Trolox·g-1 and by the DPPH method the EC50 was 85.68 g·g-1. The fruits presented relevant antioxidant activity, a high concentration of carotenoids and of rutin.

Effect of Processing on Bioactive Compounds, Physicochemical and Rheological Characteristics of Juçara, Banana and Strawberry Smoothie

This study aimed to evaluate the effect of processing steps on bioactive compounds and physicochemical and rheological characteristics of a juçara, banana and strawberry smoothie. The product was obtained by mixing the pulps of these fruits in previously defined proportions. The mixture was standardized in a pilot disintegrator, homogenized at 60 MPa in continuous mode and pasteurized at 90 °C for 35 s. The homogenization step increased the concentration of cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside, major anthocyanins in the smoothie. However, these anthocyanins, as well as perlagonidin-3-O-glucoside, have been reduced (p<0.05) after the pasteurization step. The pasteurization also affected the instrumental color of the smoothie, expressed by Hue angle (p<0.05). Regarding to the rheological behavior, the smoothie, in all processing steps, presented a non-Newtonian fluid behavior with pseudoplastic characteristics (n<1). After homogenization, the smoothie became more fluid and homogeneous. Thus, despite the negative impact of pasteurization on the smoothie’s color, the pasteurized product preserves the bioactive compounds such as flavonoids and phenolic acids that are of great importance to human health. Furthermore, the development of this product contributes to add value to the juçara agro-chain and Atlantic Forest preservation.

QB009 - FRUTOS DE Myrciaria glazioviana COMO FONTE DE VITAMINA C

Myrciaria glazioviana (Kiaersk.) G. M. Barroso ex Sobral, conhecida popularmente como cabeludinha, cultivada em pomares domésticos, pertence à família Myrtaceae. Seus frutos são subglobosos (2,5 a 3 cm), de casca amarelo-alaranjada, com polpa suculenta. A família Myrtaceae apresenta espécies bastante conhecidas. Seus frutos estão presentes na alimentação, como a pitanga e a goiaba; outros apresentam grandes concentrações de vitamina C como o camu-camu e a acerola. A vitamina C ou ácido ascórbico é uma importante substância hidrossolúvel, termolábil e antioxidante, encontrada em plantas. Sua ingestão diária recomendada para adultos é de 45 mg por dia de acordo com a Agência Nacional de Vigilância Sanitária, exercendo funções como as de participar de reações de oxirredução em células, atuar na imunidade do organismo contra infecções e na formação de fibras colágenas, presentes na maioria dos tecidos do corpo humano. O objetivo do trabalho foi determinar o teor de vitamina C em frutos de Myrciaria glazioviana por cromatografia líquida de alta eficiência. Os frutos foram coletados em Guaratiba, no município do Rio de Janeiro. Para a extração da vitamina C, foi realizada a separação das partes do fruto em casca, polpa e semente. As amostras foram maceradas e foi adicionado 10 mL de solução de ácido sulfúrico 0,05 mol.L -1 . Após agitação por 10 minutos em banho ultrassônico, filtrou-se uma alíquota de 1,5 mL em papel de filtro, diretamente no vial para injeção em cromatógrafo líquido de alta eficiência. Utilizou-se uma coluna de troca iônica para a separação dos analitos e detector de arranjo de diodos. A quantificação foi realizada por padronização externa. Os frutos apresentaram os seguintes teores médios de vitamina C: casca (355,13 mg.100g -1 ), polpa (577,64 mg.100g -1 ), não sendo detectada na semente. A polpa dos frutos de Myrciaria glazioviana, parte comestível, apresentou teor de vitamina C elevado em relação ao da laranja pera (53,70 mg.100g -1 segundo a tabela brasileira de composição de alimentos), fruto conhecido como fonte de vitamina C mais consumido no Brasil, de acordo com a Pesquisa de Orçamentos Familiares de 2008-2009. Assim a polpa de Myrciaria glazioviana apresenta teor aproximadamente 10 vezes maior do que o da laranja pera e pode ser considerada uma excelente fonte dessa vitamina.

Teor de carotenoides em nutricosméticos: análise da adequação e qualidade do produto

The present study analyzed the nutricosmetics adequacy referring to the carotenoids contents, such as β-carotene, lutein, lycopene and zeaxanthin, and these findings were compared with the contents declared by the manufacturers. Nineteen carotenoids-containing nutricosmetics were purchased at retail market in Rio de Janeiro city in 2012. Two methodologies of extraction were used according to the type of shell (capsules), carriers (excipients) and carotenoids. Quantification and determination of carotenoids profile were performed in a High Performed Liquid Chromatograph (HPLC) with validated and accredited methodology. Of 19 analyzed samples, four were within the limits established by the Good Manufacturing Practice specification (90 to 110 %), and the others were out of this range, revealing an inadequacy in the carotenoids contents and failures in the quality control of nutricosmetics production. This study demonstrated that the nutricosmetics production sector should receive a special attention from the health surveillance, and it needs a specific legislation to regulate the manufacture, labeling and advertising of these products.