Marta de Toledo Benassi

Interaction of Curcumin and Bixin with β-Cyclodextrin: Complexation Methods, Stability, and Applications in Food

This work aimed to compare methods for the formation of complexes of bixin and curcumin with β-cyclodextrin (β-CD) and to evaluate the stability of the complexes formed by these methods and their food applications. The stoichiometric relationship between curcumin and β-CD was 1:2 and that between bixin and β-CD was 1:1. Curcumin-β-CD and bixin-β-CD complexes formed by kneading, coprecipitation, and simple mixing were evaluated by differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), or nuclear magnetic resonance (NMR-H). For both curcumin and bixin, the best method of complexation was coprecipitation. Complexation of colorants with β-CD promoted an intensification of color and increased water solubility; however, stabilization in the presence of light occurred only for bixin. Application of curcumin-β-CD in cheese and yogurt and bixin-β-CD in the curd did not alter the initial characteristics of the products, which were sensorialy well accepted. Therefore, the complexation of these natural colorants with β-CD favors their use in low-fat foods, broadening the field of industrial application.

Caracterização físico-química de polpas de frutos da Amazônia e sua correlação com a atividade anti-radical livre

Physical and chemical characteristics (color, pH, titratable acidity, total soluble solids, lipid content, moisture) and levels of bioactive compounds (ascorbic acid, total phenolics) were determined in fifteen samples of fruit pulps from Amazonia (abiu, acerola, acai, araca-boi, bacaba, bacuri, buriti, caja, cajarana, caju, cupuacu, graviola, murici, noni e tamarindo). The free radical scavenger activity was evaluated by the ABTS assay. Some pulps presented high antioxidant potential, associated with the free radical scavenger activity measured and the content of bioactive components, such as phenolic compounds and ascorbic acid, especialy in acerola and acai. The total phenolic content was correlated to antioxidant capacity of pulps.

Bioactive compounds from several tropical fruits and correlation by multivariate analysis to free radical scavenger activity

O alto consumo de frutas tem sido associado a baixa incidencia de doencas cronicodegenerativas, provavelmente devido a presenca de compostos bioativos, como os antioxidantes, nestes alimentos. Os teores de compostos bioativos -acido ascorbico, fenolicos totais, flavonoides e carotenoides totais - foram determinados em polpas obtidas a partir de 18 frutas tropicais adquiridas no Brasil. A atividade anti-radical livre foi avaliada pelo metodo ABTS. As frutas que apresentaram maior teor de compostos bioativos foram buriti, caja-manga, canistel, murici, physalis, piquia e tucuma. Considerando a composicao dos compostos bioativos analisados e as atividades anti-radical livre, as frutas foram divididas em 5 grupos, segundo Analise Hierarquica de Agrupamentos. Aplicando a Analise de Componentes Principais, a atividade anti-radical livre mostrou alta correlacao com compostos fenolicos totais (r = 0,99) e flavonoides (r = 0,86); porem, a correlacao encontrada foi muito pequena para acido ascorbico (r = 0,02) e carotenoides totais (r = 0,08). High ingestion of fruits has been associated with low incidence of chronic-degenerative diseases, probably due to the presence of bioactive compounds in these foods, such as antioxidants. The levels of bioactive compounds - ascorbic acid, total phenolics, flavonoids and carotenoids - were determined in 18 pulps obtained from tropical fruits acquired in Brazil. The free radical scavenger activity was evaluated by the ABTS assay. The fruits that showed higher levels of bioactive compounds were buriti, otaheite apple, egg-fruit, golden spoon, physalis, piquia and star nut palm. Considering the composition of bioactive compounds and free radical scavenger capacities the fruits were divided into five groups, according to Hierarchical Cluster Analysis. Applying Principal Component Analysis, free radical scavenger showed high correlation with total phenolic compounds (r = 0.99) and flavonoids (r = 0.86); however, the correlation was found to be very poor with ascorbic acid (r = 0.02) and with total carotenoids levels (r = 0.08).

Produtos de acerola: estudo da estabilidade de vitamina C

o C apresentaram teores de 1.314±6 e 1.322±2 mg vit.C/ 100g, respectivamente, representando uma perda de, aproximadamente, 3% e o suco apresentou uma perda de 32%, correspondendo a um teor final de 673±17mg vit.C/100g. Palavras-chave: armazenagem; congelamento; suco; polpa; frutas; rotulagem; cinetica. SUMMARY WEST INDIAN CHERRY PRODUCTS: STUDY OF VITAMIN C STABILITY. West indian cherry is a very perishable fruit and its vitamin C content is its principal nutritional appeal. Brazilian legislation admits a 20% variation in the nutrient content from the one specified on the label. Due to this requirement the initial vitamin C content and losses during storage should be known in products. Vitamin C stability in pasteurized pulp and west indian cherry in natura, both frozen and stored at -12 o C e -18 o C and of the pasteurized juice stored at room temperature, were determined during four months. Frozen pulps had no significant vitamin C degradation during this period and fruits in natura showed first order kinetics degradation and zero order for the juice. After four months, west indian cherry fruits stored at -12 o C and -18 o C showed 869±12 and 1.223±148 mg vit.C/100g, representing losses of 43% and 19%, respectively. Pulps at -12 o C and -18 o C showed a 1.314±6 and 1.322±2 mg vit.C/100g, respectively, representing approx. 3% losses and the juice

Evaluation of kahweol and cafestol in coffee tissues and roasted coffee by a new high-performance liquid chromatography methodology.

A reverse phase high-performance liquid chromatography (HPLC) method was developed for the simultaneous quantification of kahweol and cafestol in tissues of fresh fruits, leaves, and roasted coffee beans. The best resolution was obtained with isocratic elution of acetonitrile/water (55/45% v/v) and UV detection. A single sample preparation method carried out by direct saponification and extraction with organic solvent was standardized for all matrices. Good recovery (average of 99% for kahweol and 94% for cafestol), repeatability, and linearity were obtained. Detection limits of 2.3 and 3.0 mg/100 g were observed for kahweol and cafestol. The HPLC method was effective in quantifying these diterpenes in the different coffee matrices. The endosperm and perisperm of Coffea arabica cv. IAPAR 59 showed elevated amounts of kahweol as compared to the pericarp and leaves. On the other hand, cafestol was detected in all samples except in leaves from Coffea canephora cv. Apoatā.

Metodologia para análise simultânea de ácido nicotínico, trigonelina, ácido clorogênico e cafeína em café torrado por cromatografia líquida de alta eficiência

A reverse phase liquid chromatography method was developed for simultaneous determination of trigonelline, caffeine, nicotinic and chlorogenic (5-CQA) acids in roasted coffee. A gradient of acetic acid/acetonitrile was used as mobile phase and detection was carried out in the UV. The samples were extracted with acetonitrile/water (5:95 v/v) at 80 oC/10 min. Good recovery (89 to 104%), repeatability and linearity were obtained. Detection limits of 0.01, 0.15, 0.04 and 0.04 mg mL-1 were observed for nicotinic acid, trigonelline, 5-CQA and caffeine. The method, applied to arabica and robusta coffees with different degrees of roasting, was efficient and fast (~35 min) and also allowed identification of cinnamic acids.

Stability of unpasteurized and refrigerated orange juice

The stability of orange juice obtained from a small extractor and stored in a polyethylene bottle was assessed under isothermal and non-isothermal storage conditions at 4, 8 and 12oC for 72 hours. pH, titratable acidity and Brix did not alter significantly during the 72 hours storage. Microbiological analysis showed high initial count for moulds and yeasts that increased in the juice stored for 72h under the non-isothermal conditions with temperature abuse (12oC/4h). Date of the sensory evaluation showed a small reduction in product acceptance in this condition. The juice, in the recommended validity period (48h), presented losses of less than 20% of the initial ascorbic acid content regardless of the treatment. However, after this time, the degradation became accentuated reaching, at 72h storage, retentions of 72 to 85%.

Quinoa and flaxseed: potential ingredients in the production of bread with functional quality.

The objective of this work was to compare the physicochemical characteristics of quinoa and flaxseed bread. Sensory acceptance, color and texture were also appraised. They showed appropriate balances between their content of polyunsaturated and saturated fatty acids and low levels of trans fatty acids. Flaxseed bread had larger amounts of mono and polyunsaturated fatty acids, omega-6 and omega-3, as well as a more balanced omega-6/omega-3 ratio. Quinoa bread, on the other hand, had the advantage of presenting smaller contents of saturated fatty acids. With regard to color and texture, quinoa bread had similar characteristics to the flaxseed bread. The quinoa bread was well accepted by the consumers, who expressed high interest in buying it.

Discrimination of commercial roasted and ground coffees according to chemical composition

Roasted and ground 38 commercial coffees and coffees of known species (arabica, robusta) were characterized by principal component analysis using as variables nicotinic acid, trigonelline, 5-o-caffeoylquinic acid (5-CQA), caffeine, kahweol and cafestol, which are potentially indicative of species. The objective of the study was to assess the relevance of such parameters in coffee discrimination. Nicotinic acid allowed the characterization of roasting degree. Trigonelline and 5-CQA presented variability among arabica and robusta coffees as well as among commercial ones. Thermostable parameters (caffeine, kahweol and cafestol) had high discriminative potential between the species. In general, high levels of caffeine and low levels of diterpenes (kahweol and cafestol) were related with higher proportions of robusta in the products, which were observed by the decreasing kahweol/cafestol ratio and increasing caffeine/kahweol ratio. The use of these new parameters (kahweol/cafestol and caffeine/kahweol ratios) was suggested as tools for assessing the addition of robusta in commercial coffees.

EMBALAGEM INDIVIDUAL DE MANGAS CV. TOMMY ATKINS EM FILME PLÁSTICO: EFEITO SOBRE A VIDA DE PRATELEIRA

Effects of packaging in polyvinyl chloride (PVC) film on postharvest shelf-life of mango cv. Tommy Atkins stored under refrigeration were studied. Mangos at mature green color stage were individually sealed in 10mm thick film and stored for 28 days at 12oC (80-90% RH). Non-sealed fruits served as control. During the storage period, sensory evaluation was carried out using an unstructured hedonic scale for overall acceptance of appearance and flavor, with 30 untrained assessors per session. Mangos were also analyzed for weight loss, titratable acidity, total soluble solids and vitamin C during storage time. The packed mangos had a shelf life of 21 days against 6 days of the control ones, and weight loss rates 3.5 times smaller than the control ones. There was no difference in vitamin C degradation rate between treatments. The combination of packaging with storage at 12oC was efficient to extend shelf life by reducing metabolic activity and decay in mangos.