Effect of rosemary (Rosmarinus officinalis) extracts on the oxidative stability and sensory acceptability of soybean oil

Background: Plant extracts have b een used as an alternative to the use of synthetic antioxidants in order to preserve oils fromoxidative degradation. Additionally, these extracts add special flavors and aromas to the food. Thus, the objective of this studywas to evaluate the effect of hydroethanolic extracts of fresh and freeze-dried rosemar y in the oxidative stability of soybean oilunder accelerated storage in an oven. Results: The application of the extracts in the oil showed that that freeze-dried extract was better in reducing the formation ofoxidation products, showing 8.6 meq kg−1of peroxides after 20 days of storage. On the other hand, the mixture of the naturalextract with t-butylhydroquinone conferred better oxidative stability index until the 20th day, 9.7 h. Both extracts prevented theloss of tocopherol, not d iffering between each other (P > 0.05), and present approximately 505 mg kg−1of residual tocopherols.The sensory evaluation revealed that consumers accepted equally the oils added and not added of the rosemary extracts. Conclusion: The extracts are therefore potential sources of natural antioxidants and they would be well accepted by consumersif applied by the food industry to replace synthetic antioxidants.

Antifungal activity of extracts and isolated compounds from Buchenavia tomentosa on Candida albicans and non-albicans

Aim: This study aimed to evaluate the antifungal activity of Buchenavia tomentosa extract and bioactive compounds on six Candida species. Materials & methods: The antimicrobial activity of extract was evaluated using standard strains and clinical isolates. Cytotoxicity was tested in order to evaluate cell damage caused by the extract. Extract was chemically characterized and the antifungal activity of its compounds was evaluated. Results: Extract showed antifungal activity on Candida species. Candida non-albicans were more susceptible than Candida albicans. Low cytotoxicity for extract was observed. The isolated compounds presented antifungal activity at least against one Candida spp. and all compounds presented antifungal effect on Candida glabrata. Conclusion: Extracts from Buchenavia tomentosa showed promising antifungal activity on Candida species with low cytotoxicity. Gallic acid, corilagin and ellagic acid showed promising inhibitory activity on Candida glabrata.

Bioprospecção de fungos endofílicos Camarops sp., Periconia atropurpurea e Pseudofusicoccum stromaticum e avaliação epigenética de Phoma sp

Pós-graduação em Química - IQ

Caracterização do potencial inseticida e capacidade antioxidante de Spathodea campanulata (Bignoniaceae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antioxidant, anti-acetylcholinesterase and cytotoxic activities of ethanol extracts of peel, pulp and seeds of exotic Brazilian fruits Antioxidant, anti-acetylcholinesterase and cytotoxic activities in fruits

Ethanol extracts of powdered genipap (Genipa americana L), umbu (Spondia tuberosa A.) and siriguela (Spondia purpurea L) prepared from separate pulp, seeds and peel were investigated for their (i) antioxidant capacity, which was evaluated by various known methods; (ii) acetylcholinesterase (AChE) inhibitory activity; and (iii) cytotoxic effect on corneal epithelial cells of sheep. The highest values of total phenolic content were obtained with peel and seed extracts. Siriguela and umbu (seeds and peel) extracts displayed the highest antioxidant activities. Lipid peroxidation assays using mimetic biomembranes and mouse liver homogenates indicated that genipap pulp is a promising antioxidant. The investigation of phenols and organic acid contents revealed the presence of quercetin, citric and quinic acids, chlorogenic acid derivatives, among others, in several extracts, with the highest amount found in siriguela seeds. Genipap pulp and siriguela seed ethanol extracts presented an AChE inhibition zone similar to that of the positive control, carbachol. AChE inhibition assay with chlorogenic acid, one of the main constituents of siriguela seeds, revealed that this acid showed activity similar to that of the control physostigmine. These data suggest that these extracts are potentially important antioxidant supplements for the everyday human diet, pharmaceutical and cosmetic industries. (C) 2012 Elsevier Ltd. All rights reserved.

Evaluation of rhamnolipid and surfactin to reduce the adhesion and remove biofilms of individual and mixed cultures of food pathogenic bacteria

Biofilms represent a great concern for food industry, since they can be a source of persistent contamination leading to food spoilage and to the transmission of diseases. To avoid the adhesion of bacteria and the formation of biofilms, an alternative is the pre-conditioning of surfaces using biosurfactants, microbial compounds that can modify the physicochemical properties of surfaces changing bacterial interactions and consequently adhesion. Different concentrations of the biosurfactants, surfactin from Bacillus subtilis and rhamnolipids from Pseudomonas aeruginosa, were evaluated to reduce the adhesion and to disrupt biofilms of food-borne pathogenic bacteria. Individual cultures and mixed cultures of Staphylococcus aureus, Listeria monocytogenes and Salmonella Enteritidis were studied using polystyrene as the model surface. The pre-conditioning with surfactin 0.25% reduced by 42.0% the adhesion of L monocytogenes and S. Enteritidis, whereas the treatment using rhamnolipids 1.0% reduced by 57.8% adhesion of L monocytogenes and by 67.8% adhesion of S. aureus to polystyrene.Biosurfactants were less effective to avoid adhesion of mixed cultures of the bacteria when compared with individual cultures. After 2 h contact with surfactin at 0.1% concentration, the pre-formed biofilms of S. aureus were reduced by 63.7%, L. monocytogenesby 95.9%, S. Enteritidis by 35.5% and the mixed culture biofilm by 58.5%. The rhamnolipids at 0.25% concentration removed 58.5% the biofilm of S. aureus, 26.5% of L monocytogenes, 23.0% of S. Enteritidis and 24.0% the mixed culture after 2 h contact. In general, the increase in concentration of biosurfactants and in the time of contact decreased biofilm removal percentage. These results suggest that surfactin and rhamnolipids can be explored to control the attachment and to disrupt biofilms of individual and mixed cultures of the food-borne pathogens. (C) 2011 Elsevier Ltd. All rights reserved.

Effect of enzymatic treatment on the cross-flow microfiltration of acai pulp: Analysis of the fouling and recovery of phytochemicals

This study aimed to investigate the effects of pectinase enzyme treatment of acai pulp on cross-flow microfiltration (CFMF) performance and on phytochemical and functional characteristics of their compounds. Analyses of fouling mechanisms were carried out through resistance in series and blocking in law models. The enzymatic treatment was conducted using Ultrazym(R) AFPL (Novozymes A/S) at 500 mg kg(-1) of acai pulp for 30 min at 35 degrees C. Before microfiltrations, untreated and enzyme-treated acai pulps were previously diluted in distilled water (1:3; w/v). CFMFs were conducted using commercial alpha-alumina (alpha-Al2O3) ceramic membranes (Andritz AG, Austria) of 0.2 mu m and 0.8 mu m pore sizes, and 0.0047 m(2) of filtration area. The microfiltration unit was operated in batch mode for 120 min at 25 degrees C and the fluid-dynamic conditions were transmembrane pressure of Delta P = 100 kPa and cross-flow velocity of 3 m s(-1) in turbulent flow. The highest values of permeate flux and accumulated permeate volume were obtained using enzyme-treated pulp and 0.2 mu m pore size membranes with steady flux values exceeding 100 L h(-1) m(-2). For the 0.8 mu m pore size membrane, the estimated total resistance after the microfiltration of enzyme-treated acai pulp was 21% lower than the untreated pulp, and for the 0.2 mu m pore size membrane, it was 18%. Cake filtration was the dominant mechanism in the early stages of most of the CFMF processes. After approximately 20 min, however, intermediate pore blocking and complete pore blocking contributed to the overall fouling mechanisms. The reduction of the antioxidant capacity of the permeates obtained after microfiltration of the enzyme-treated pulp was higher (p < 0.01) than that obtained using untreated pulp. For total polyphenols, on the contrary, the permeates obtained after microfiltration of the enzyme-treated pulp showed a lower mean reduction (p < 0.01) than those from the untreated pulp. The results show that the enzymatic treatment had a positive effect on the CFMF process of acai pulp. (C) 2012 Elsevier Ltd. All rights reserved.

Potential dietary sources of ellagic acid and other antioxidants among fruits consumed in Brazil: Jabuticaba (Myrciaria jaboticaba (Vell.) Berg)

BACKGROUND: The objectives of this study were (1) to evaluate the content of ellagic acid in fruits consumed by the Brazilian population, including native ones; (2) to further characterize rich sources in relation to ascorbic acid, phenolics contents and in vitro antioxidant capacity; and (3) to study the distribution and effect of ripening stage on ellagitannins content of jabuticaba (Myrciaria jaboticaba). The content of free ellagic acid and ellagic acid derivatives such as ellagitannins was analyzed using high-performance liquid chromatography (HPLC). RESULTS: Ellagic acid was detected in 10 out of a total of 35 fruits analyzed. The content of free ellagic acid in fruits varied from 0.0028 to 0.085 g kg(-1) (FW) and total ellagic acid varied from 0.215 to 3.11 g kg(-1) (FW). All the seven fruits belonging to the Myrtaceae family evaluated in this study presented high contents of ellagitannins in their composition, with jabuticaba, grumixama and cambuci (all native from Brazil) showing the highest total ellagic acid contents. Jabuticaba, the most consumed in Brazilamongthose and already adapted to commercial plantations, contained concentrated phenolics compounds, including ellagitannins, in the peel. Anthocyanins (cyanidin derivatives) increased significantly through ripening of jabuticaba and were not present in the pulp or seeds. Samples collected from three different locations during summer, winter and spring had total ellagic contents varying from 1.88 to 3.31 g kg(-1) (FW). The decrease in ellagic acid content with ripening was more accentuated for pulp (eight times) compared to seeds (2.3 times) and peel (2.0 times). CONCLUSION: These results showed the potential of jabuticaba as dietary source of ellagic acid and reinforced consumption of the whole fruit by the population. (C) 2011 Society of Chemical Industry

Antioxidant capacity and mineral content of pulp and peel from commercial cultivars of citrus from Brazil

Four Citrus species (C. sinensis, cvs. Pera and Lima; C. latifolia Tanaka cv. Tahiti; C limettioides Tanaka cv. Sweet lime and C. reticulate, cv. Ponkan) grown in Brazil were characterised in relation to contents of minerals, ascorbic acid, total polyphenols and antioxidant capacity of pulps and peels. In general, the peels demonstrated significantly higher contents of all compounds than the pulps (p < 0.05), with the exception of the Pera orange pulp that presented the highest acid ascorbic content (68 mg/100 ml), while the Tahiti lime peel presented the lowest (8 mg/100 g). Citrus showed high levels of potassium, calcium and magnesium, and the peels were considered sources of these minerals. The Ponkan mandarin peel presented the highest antioxidant capacity. The antioxidant capacity of citrus was correlated both to vitamin C and phenolics. Aside from citrus pulps, the peels are also good sources of bioactive compounds and minerals, and can be explored for their health promoting values in food products. (C) 2012 Elsevier Ltd. All rights reserved.

Fresh Pasta Production Enriched with Spirulina platensis Biomass

The aim of this work was to study the enrichment of Spirulina platensis in wheat flour to prepare fresh pasta to evaluate the green color and nutritional enrichment in addition to functional properties due to the presence of the bioactive compounds in the cyanobacterium. The pastas were evaluated for the centesimal composition, microbiological contamination, sensorial acceptance and technological characteristics such as cooking time, water absorption, volume displacement and loss of solids. The superior protein contents and the satisfactory technological and sensorial attributes compared with the control with no cyanobacterium showed the usefulness of incorporating S. platensis biomass in the fresh pastas. The microbiological quality was in compliance with the legislation in force. The sensorial quality was considered satisfactory ("liked very much") and purchase intention high ("probably would buy").

Clustering of variables around latent components: an application in consumer science

The present work proposes a method based on CLV (Clustering around Latent Variables) for identifying groups of consumers in L-shape data. This kind of datastructure is very common in consumer studies where a panel of consumers is asked to assess the global liking of a certain number of products and then, preference scores are arranged in a two-way table Y. External information on both products (physicalchemical description or sensory attributes) and consumers (socio-demographic background, purchase behaviours or consumption habits) may be available in a row descriptor matrix X and in a column descriptor matrix Z respectively. The aim of this method is to automatically provide a consumer segmentation where all the three matrices play an active role in the classification, getting homogeneous groups from all points of view: preference, products and consumer characteristics. The proposed clustering method is illustrated on data from preference studies on food products: juices based on berry fruits and traditional cheeses from Trentino. The hedonic ratings given by the consumer panel on the products under study were explained with respect to the product chemical compounds, sensory evaluation and consumer socio-demographic information, purchase behaviour and consumption habits.

Biological effects of bioactive components and extracts derived from edible plants commonly used in human nutrition

The main aim of this PhD research project was the evaluation of the biological effects of bioactive compounds derived from edible plants, with particular attention on their possibility to counteract oxidative damage and inflammation. After a preliminary study of in vitro antioxidant activity, regarding the modification eventually occurring after home freezing and cooking of edible vegetables, cultured mammalian cells were used as experimental model systems. Soluble extract and essential oils derived from different cultivars of Brassicaceae and Lamiaceae were tested as possible tools for the counteraction of the oxidative damage due to reactive oxygen species (ROS), underlining differences related to cultivar and agronomic techniques. Since accumulating evidence indicates that phytochemicals exhibit several additional properties in complex biological systems, a nutrigenomic approach was used to further explain the biological activity of a green tea extract, and to evidence the anti-inflammatory role of bioactive compounds derived from different foods. Overall, results obtained could contribute to a better understanding of the potential health benefit of plant foods.

Alkylidene malonates and acetoacetates as intermediates for the preparation of bioactive molecules

In this thesis we investigated the versatility and the potential applications of different kinds of alkylidene malonates, acetoacetates, malonamides and acetoacetoamides. Our research group devoted great attention to this kind of compounds since alkylidenes can be considered important intermediates in the synthesis of several scaffolds, to be inserted into molecules of potential biological and pharmaceutical interest. The increasing use of alkylidenes is due to their ability to react as unsaturated electrophiles and to the possibility to exploit them as intermediates for the introduction of different kind of functionalities.The preparation of alkylidene malonates, acetoacetates, malonamides and acetoacetoamides is presented in chapter 1. This section deals with different preparation methods of alkylidenes that we developed during the last few years and to the technologies involved for each synthetic protocol. The reactivity that allowed to use the alkylidenes as intermediates in the synthesis of scaffolds for biologically active compounds is shown in chapter 2. In particular, we will discuss the most important reactions used to obtain the desired molecules, and we will focus on the most interesting aspects of these latter ones. Finally, chapter 3 will illustrate the potential applications and the related syntheses of potential bioactive compounds. The synthesized molecules find application in several fields and for this reason we considered each class of compounds in its related branch of interest.

A multi-criteria optimization and decision-making approach for improvement of food engineering processes.

The objective of this study was to propose a multi-criteria optimization and decision-making technique to solve food engineering problems. This technique was demostrated using experimental data obtained on osmotic dehydratation of carrot cubes in a sodium chloride solution. The Aggregating Functions Approach, the Adaptive Random Search Algorithm, and the Penalty Functions Approach were used in this study to compute the initial set of non-dominated or Pareto-optimal solutions. Multiple non-linear regression analysis was performed on a set of experimental data in order to obtain particular multi-objective functions (responses), namely water loss, solute gain, rehydration ratio, three different colour criteria of rehydrated product, and sensory evaluation (organoleptic quality). Two multi-criteria decision-making approaches, the Analytic Hierarchy Process (AHP) and the Tabular Method (TM), were used simultaneously to choose the best alternative among the set of non-dominated solutions. The multi-criteria optimization and decision-making technique proposed in this study can facilitate the assessment of criteria weights, giving rise to a fairer, more consistent, and adequate final compromised solution or food process. This technique can be useful to food scientists in research and education, as well as to engineers involved in the improvement of a variety of food engineering processes.

Atividade da própolis verde contra o fitopatógeno Pythium aphanidermatum e análise da interação do composto majoritário Artepillin C com sistemas biomiméticos de membranas

O aumento da resistência microbiana devido a fatores como uso excessivo e ineficiente de antibióticos convencionais acarreta a necessidade da busca por novos compostos bioativos que atuem por mecanismos de ação diferentes aos fármacos já conhecidos. Na agricultura, o uso intensivo de pesticidas para o combate de microrganismos que comprometem principalmente a parte alimentícia também traz diversos problemas relacionados à resistência antimicrobiana e a riscos ambientais, oriundos do acúmulo dessas substâncias no solo. Dentro deste aspecto, o pseudofungo Pythium aphanidermatum, da classe dos oomicetos, destaca-se por ser uma espécie agressiva e altamente resistente a fungicidas comuns, apodrecendo raízes e frutos de cultivos de tomate, beterraba, pepino, pimentão, etc. A própolis verde, constituída em sua grande parte por material resinoso coletado e processado pela abelha da espécie Apis mellifera tem sido utilizada na medicina tradicional devido ao seu amplo espectro de ações preventivas e tratamentos de doenças, possuindo propriedades anti-inflamatórias, antimicrobianas, anticancerígenas e antioxidantes, tornando-se um produto de grande interesse na busca de novos compostos bioativos. Dentro destes aspectos apresentados, neste trabalho investigamos a ação da própolis verde contra o fitopatógeno P. aphanidermatum e identificamos através da técnica de cromatografia e bioensaios que a Artepillin C (3,5-diprenil-4-ácido-hidroxicinâmico), majoritária na própolis verde, foi o principal composto nesta ação. Os efeitos terapêuticos desta molécula tem sido foco de muitos estudos, porém ainda não há evidência em sua interação com agregados anfifílicos que mimetizam membranas celulares. O caráter anfifílico do composto, elevado pela presença dos grupos prenilados ligados ao ácido cinâmico, favoreceram a sua inserção nas membranas modelo, principalmente em seu estado agregado. Estas conclusões puderam ser inferidas devido às alterações nas propriedades das bicamadas lipídicas na presença da Artepillin C, podendo causar, especificamente para o caso de fitopatógenos como o P. aphanidermatum, perdas funcionais das proteínas de membranas, liberação de eletrólitos intracelulares e desintegração citoplasmática dos micélios e esporos. Ainda, as diferentes composições lipídicas nas vesículas influenciam no modo de interação do composto e consequentes alterações em suas estruturas, principalmente na presença do colesterol, que auxilia na manutenção da permeabilidade da bicamada lipídica, que pode contribuir para a integridade do conteúdo citoplasmático da célula.