Juliana Cortes Nunes

Intake of butter naturally enriched with cis9,trans11 conjugated linoleic acid reduces systemic inflammatory mediators in healthy young adults

A conjugated linoleic acid (CLA) depletion-repletion study was carried out to investigate the effects of dietary c9,t11 CLA on C-reactive protein, transcription factor NFκB, metalloproteinases 2 and 9, inflammatory mediators (adiponectin, TNFα, IL-2, IL-4, IL-8, IL-10), body composition, and erythrocyte membrane composition in healthy normal-weight human adults. CLA depletion was achieved through an 8-week period of restricted dairy fat intake (depletion phase; CLA intake was 5.2±5.8 mg/day), followed by an 8-week period in which individuals consumed 20 g/day of butter naturally enriched with c9,t11 CLA (repletion phase; CLA intake of 1020±167 mg/day). The participants were 29 healthy adult volunteers (19 women and 10 men, aged 22 to 36 years), with body mass index between 18.0 and 29.9 kg m(-2). Blood samples were collected at baseline and at the end of both depletion and repletion phases. The content of CLA in erythrocytes decreased during CLA-depletion and increased during CLA-repletion. Intake of CLA-enriched butter increased the serum levels of anti-inflammatory IL-10 but reduced transcription factor NFκB in blood and serum levels of TNFα, IL-2, IL-8 and inactive metalloproteinase-9. Moreover, reduced activity of metalloproteinases 2 and 9 in serum was observed during the CLA-repletion period. In contrast, intake of CLA-enriched butter had no effects on body composition (DXA analysis) as well as on serum levels of adiponectin, C-reactive protein, and IL-4. Taken together, our results indicate that the intake of a c9,t11 CLA-enriched butter by normal-weight subjects induces beneficial changes in immune modulators associated with sub-clinical inflammation in overweight individuals.

Effective stabilization of CLA by microencapsulation in pea protein.

CLA was microencapsulated by spray drying in ten varied wall systems (WS) consisting of pea protein isolate or pea protein concentrate (PPC) alone at varied core:WS ratios (1:2; 1:3 and 1:4), or blended with maltodextrin (M) and carboxymethylcellulose at a pea protein:carbohydrate ratio of 3:1. The physical-chemical properties of the CLA microparticles were characterised by core retention, microencapsulation efficiency (ME), particle size and moisture. CLA:M:PPC (1:1:3) showed the most promising results, thus we evaluated the effect of M addition in the WS on other physical-chemical characteristics and oxidative stability (CLA isomer profile, quantification of CLA and volatile compounds by SPME coupled with CG-MS) during two months of storage at room temperature, CLA:PPC (1:4) was selected for comparisons. CLA:M:PPC (1:1:3) microparticles demonstrated better morphology, solubility, dispersibility and higher glass-transition temperature values. M addition did not influence the oxidative stability of CLA, however its presence improved physical-chemical characteristics necessary for food applications.

Effect of drying method on volatile compounds, phenolic profile and antioxidant capacity of guava powders.

We studied the chemical composition of oven and freeze dried guava powders for future use as antioxidant-rich flavour enhancers. Among thirty-one volatiles in guava powders, terpenes were predominant, even after both drying processes. In contrast, esters and aldehydes, volatiles characteristic of fresh guava fruit, appeared to have been decreased by drying. Insoluble phenolics were predominant and among the sixteen compounds identified, quercetin-3-O-rutinoside and naringenin corresponded to 56% of total phenolics. Drying processes decreased total phenolics contents by up to 44%. Oven drying promoted the release of insoluble flavonoids, generating mainly quercetin. Antioxidant capacity also decreased due to both drying processes, but guava powders still presented similar antioxidant capacity in comparison to other tropical fruit powders. Our results suggest that oven drying is a viable option for the production of a functional ingredient that would improve the phenolic content of cereal foods while adding desirable guava flavour.

Bread formulated with guava powder was enriched in phenolic and aroma compounds, and was highly acceptable by consumers

Guava powder (GP) was used as source of aroma and phenolic compounds to fortify wheat bread 10% (GB10) and 20% (GB20), substituting for wheat flour. Phenolic compounds, antioxidant capacity, volatile compounds profile, and sensory acceptability of control bread (CB; without GP) and guava breads (GB) were evaluated. Incorporation of GP increased roughly 2-to-3-fold the phenolic compounds contents of bread. Ten phenolic compounds were identified in GB20, and quercetin-3-O-rutinoside was the major compound, while in CB, ferulic acid was the major among the six phenolic compounds in CB. Bread making seemed to promote the release of phenolic compounds from structural components. Breads incorporated with GP presented a richer volatile profile than CB, especially due to the presence of terpenes. GB improved aroma profile of bread. GP added aroma compounds and phenolic antioxidants, and seemed to be an interesting approach to enhance bread bioactivity and acceptability.

CHAPTER 1:The Chemistry of Selenium

Selenium is a chalcogen element found in nature as numerous allotropic forms, six stable isotopes, several radioactive isotopes and four oxidation states. Although selenium and sulfur have equivalent electronic configurations and therefore similar chemical and physical properties, in biological systems selenium tends to be reduced, whereas sulfur is usually oxidized. Organoselenium compounds, especially selenols (e.g. selenocysteine) and selenides (e.g. selenomethionine), are of great biological relevance due to their presence in peptides and proteins. Other classes of organoselenium compounds include diselenides, selenoxides, selenones, selenium acids, selenium halides and selenaheterocyclic compounds and are chemically similar to their sulfur analogs. In food, selenium is found at trace levels and depends mainly on soil characteristics such as selenium content (i.e. seleniferous, low selenium or selenium deficient) and pH. Moreover, plant species may be classified according to their ability to accumulate selenium into nonaccumulators, secondary selenium accumulators and selenium accumulators.

ATIVIDADES ANTIOXIDANTE E ANTIMICROBIANA DE POLPA E RESÍDUO DE TAMARILLO (Solanun betaceum)

O Brasil destaca-se como grande produtor de frutas, incluindo frutas exóticas como o tamarillo (Solanun betaceum). O tamarillo apresenta cultivo crescente em algumas regiões do país e possui rica composição em fenólicos, com destaque para antocianinas. Ressalta-se, no entanto, que ainda são escassos estudos acerca da atividade antioxidante e antimicrobiana deste fruto e de seus co-produtos. O objetivo desse trabalho foi avaliar o teor de compostos fenólicos totais (CF) e as atividades antioxidante (AA) e antimicrobiana do fruto de tamarillo e de suas frações (polpa e resíduo), bem como o efeito da pasteurização da polpa sobre as variáveis de interesse. Os frutos de tamarillo, adquiridos na região serrana do Rio de Janeiro, foram selecionados, higienizados e processados em centrífuga Juicer para obtenção da polpa e do resíduo. Parte da polpa foi armazenada a -20 °C até as análises e outra parte foi pasteurizada (60 °C por 15 min.). O teor de CF foi determinado pelo método espectrofotométrico de Folin-Ciocalteau (Singleton et al., 1999). A AA foi avaliada pelos métodos espectrofotométricos FRAP (Benzie & Strain,1996) e TEAC (Re et al., 1999). Os resultados foram expressos em base seca. A atividade antimicrobiana foi determinada pelo Teste de Suscetibilidade aos Antimicrobianos (TSA) (Bauer e Kirby, 1966). Dentre as frações da fruta, foi observado maior teor de CF (g EAG/100 g) no fruto in natura (5,2 ± 0,01) quando comparado à polpa in natura (2,8 ± 0,09) e ao resíduo (1,0 ± 0,02). Consistentemente, a atividade antioxidante (TEAC; mmol trolox/100 g e FRAP; mmolFe/100 g) do fruto in natura (16,3 ± 0,09 e 1622,7 ± 5,1) foi maior quando comparada a polpa in natura (6,8 ± 0,06 e 12,0 ± 0,3) e ao resíduo (2,2 ± 0,07 e 747,0 ± 2,4). O tratamento térmico promoveu redução de 32%, 25% e 21%, respectivamente, no teor de CF e nos valores de TEAC e FRAP. Tal redução pode estar associada a termolabilidade dos compostos fenólicos que também impactou na redução da atividade antioxidante. Foi observado a formação de halos de inibição contra bactéria Gram negativa de 3 mm para a polpa in natura, 2 mm para o resíduo e não houve formação de halo de inibição para a polpa pasteurizada, indicando que o fruto do tamarillo não apresenta atividade antimicrobiana pelo método investigado. Por fim, nossos resultados demonstram o potencial do fruto de tamarillo como fonte de antioxidantes naturais e contribuem para estudos futuros acerca do desenvolvimento de produtos elaborados a partir do fruto tamarillo, bem como da investigação de sua bioatividade.

Seasonal Variation in Fat Quality and Conjugated Linoleic Acid Content of Dairy Products from the Tropics: Evidence of Potential Impact on Human Health

Seasonal variation in conjugated linoleic acid (CLA) content and atherogenicity index (AI) of retail dairy products (whole milk, butter, and prato, a soft yellow cheese) from Brazil was investigated. CLA content of dairy products ranged from 0.55 to 1.53 g CLA/100 g fatty acids and was on average 25% higher during the rainy season compared to the dry season. Dairy products from the rainy season also had lower AI levels, indicating a lower risk of causing cardiovascular disease in consumers. This seasonality led to estimated seasonal variations of milk fat quality consumed by the population of southeastern Brazil, meaning 15% and 19% variation in daily intake of CLA and AI values, respectively. Dietary consumption of CLA (g/day) was greater in the rainy season, despite higher intake of dairy products during the dry season. We show that dairy products produced during the rainy season in Brazil are expected to be more beneficial to human health than are those produced during the dry season.