Angelita Duarte Corrêa

Antinutrients in the cassava (Manihot esculenta Crantz) leaf powder at three ages of the plant

In Brazil, the cassava leaf meal (CLM) has been used to strive against undernourishment because it is a high source of vitamins and minerals. However, the wide variation in the chemical composition of the different cultivars, as well as their antinutritional substances may be a restriction to their uses. The levels of some antinutrients in CLM from five cultivars at three ages of the plant (TAP) were investigated, in order to select the cultivars and plant ages that would be more appropriate for human consumption. The lowest contents of antinutrients were observed in the 12-month old plants, except for nitrate and hemagglutinin from which the lowest contents were found for the 17 month old ones. The cultivar IAC 289-70 had the lowest antinutrient levels, except for saponin and oxalate. Thus, the cultivar IAC 289-70 at 12 months is the most appropriate for human consumption.

Efeito da estocagem e das condições de colheita sobre algumas propriedades físicas, químicas e nutricionais de três cultivares de feijão (Phaseolus vulgaris, L.)

In Brazil, bean stands out as one of the most important food and it is found nationwide. Providing essential nutrients, it is utilized an as alternative, in substituting of meats or other proteic products, but it presents some problems like low digestibility if compared to animal proteins, which can be reduced under special storage conditions. This research aimed to evaluate the effect of storage and harvest conditions on some nutritious, physical and chemical properties of three bean cultivars. The results show that the average moisture contents were higher before storage and, after storage, the grains came into hygroscopic equilibrium with the environment in the studied cultivars. Early harvested cultivars presented higher water-absorbing capacity, which reduced during the storage period at the harvested samples. The level of phenolic compounds was higher in early harvested samples, which makes us conclude that these compounds would not be affecting the grain hydration capacity. The early harvested samples presented higher values of protein. After storage period, beans presented protein content slightly higher. The digestibility reduced during the months of storage. Reaction between proteins and phenols in processing may be associated to the low digestibility due to the negative correlation between the in vitro digestibility and tannin content present in the product.

Anthocyanins, pigment stability and antioxidant activity in jabuticaba [Myrciaria cauliflora (Mart.) O. Berg]

Diferentes solventes foram avaliados para a extracao de pigmentos antociânicos da jabuticaba, identificacao, quantificacao e verificacao da estabilidade das antocianinas, assim como a conducao de tres testes de atividade antioxidante e determinacao dos niveis de vitamina C. A maceracao com etanol acidificado com HCl 1.5 mol L-1 (85:15) promoveu melhor extracao e estabilidade dos pigmentos. As cascas sao ricas em pigmentos antociânicos, apresentando 1,59 e 2,06 g 100 g-1 de materia seca (MS) nas variedades Paulista e Sabara, respectivamente. Cyanidina 3-glucosideo e o pigmento majoritario nas cascas, seguido pela delphinidina 3-glucosideo. Os niveis de vitamina C foram mais altos nas cascas e sementes de ambas as variedades. Foi verificado que as cascas apresentaram maior atividade antioxidante, tanto na captura de radical livre, quanto no retardo do processo de oxidacao lipidica.

Remoção de polifenóis da farinha de folhas de mandioca

Even featuring a relatively high level in proteins, the flour of cassavaleaves presents low digestibility, mainly, due to the presence of such substances as polyphenols. Seeking to improve the protein availability of such flour, three solvents (water, ethanol 50mL/100mL and ammonium hydroxide 1mol/L) were used for the removal of the polyphenols. Mature leaves of cassava were picked in phase of vegetative development, in three repetitions, they were placed in paper trays and dried under shadow, on a wood bench, in a shut and airy place, at room temperature. After drying, the petioles were removed and the leaves were ground and sieved using 40-mesh sieve. The flour was submitted, before e after removal of polyphenols, to the analyses of moisture, neutral detergent fiber (NDF), acid detergent fiber (ADF), total sugars, crude protein, vitamin total C, b-carotene, cyanide, trypsin inhibitor, polyphenols and in vitro protein digestibility. After the removal of the polyphenols, there was a decrease in the levels of total sugars, vitamin total C, trypsin inhibitor and polyphenols and an increase in the levels of NDF, ADF, crude protein, b-carotene and in vitro protein digestibility. Of the solvents employed in the removal the polyphenols, the ammonium hydroxide was the most effective, with index of removal of 94%, followed by the ethanol (83%) and water (65%). The in vitro protein digestibility increased of 74%, when the solvent employed in the removal of the polyphenols was the ammonium hydroxide.

Nutrients in the cassava (Manihot esculenta Crantz) leaf meal at three ages of the plant

The high number of cassava cultivars adapted to many different regions provides a wide variation in the chemical composition of cassava leaves meal (CLM). Therefore, the contents of some nutrients in CLM from five cultivars at three ages of the plant were investigated in order to select the cultivars and ages with superior levels of these nutrients. When the plants were 12 months old, the highest levels of crude protein (CP), b-carotene, iron, magnesium, phosphorus and sulfur were observed. The IAC 289-70 cv. showed the highest levels of magnesium, as well as considerable contents of CP, b-carotene, iron, zinc and sulfur, which did not differ statistically from the cultivars showing the highest levels of these nutrients.

Textura de goiabas "Pedro Sato" submetidas à aplicação de cloreto de cálcio

Among the techniques used to maintain the post-harvest quality of fruits, stands out the application of calcium, usually associated to the refrigeration. However, not all the producers have access to cold cameras, therefore it was aimed at in this work, to evaluate the isolated treatment with calcium chloride in the maintenance of the appearance of guavas (Psidium guajava L.) destined to the consumption “in nature”, stored in environmental conditions. The hydrothermical treatment at the temperature of 30oC, with calcium chloride 1g/100 mL, was tested comparing with fruits without treatment. Soon after the fruits were stored under environmental conditions (22,6oC (±1), UR 75% (±5) for four days. After the storage, the contents of total and soluble pectin and the pectinametilesterase and poligalacturonase activities were evaluated. The employment of calcium affected the analyzed characteristics providing smaller content of soluble pectin and lower activities of pectinametilesterase and poligalacturonase, promoting a less intense softening, maintaining the firmness of the fruits during the storage period.

Immobilized soybean hull peroxidase for the oxidation of phenolic compounds in coffee processing wastewater.

Chitosan beads were prepared, using glutaraldehyde as a crosslinking agent for the immobilization of soybean hull peroxidase (SBP). The activity of free and immobilized SBP was studied. The optimum pH was 6.0 for both the free and immobilized enzyme; however, enzyme activity became more dependent on the temperature after immobilization. This study evaluated the potential use of immobilized and free enzyme in the oxidation of caffeic acid, of synthetic phenolic solution (SPS) and of total phenolic compounds in coffee processing wastewater (CPW). Some factors, such as reaction time, amount of H2O2 and caffeic acid were evaluated, in order to determine the optimum conditions for enzyme performance. Both enzymes showed a potential in the removal of caffeic acid, SPS and CPW, and immobilized SBP had the highest oxidation performance. The immobilized enzyme showed a potential of 50% in the oxidation of caffeic acid after 4 consecutive cycles.

Alterações pós-colheita da "fruta-de-lobo" (Solanum lycocarpum St. Hil.) durante o amadurecimento: análises físico-químicas, químicas e enzimáticas

Estudaram-se, neste trabalho, algumas modificacoes fisico-quimicas, quimicas e enzimaticas, em pos-colheita, durante o amadurecimento da fruta-de-lobo, comparando-as com as de outros frutos. Os frutos colhidos de plantas nativas no inicio do estadio de amadurecimento foram selecionados e armazenados durante 18 dias a temperatura ambiente (17,1 a 26,9oC). Os frutos foram lavados com agua destilada, descascados, picados, congelados em nitrogenio liquido e liofilizados ate massa constante. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repeticoes de 3 frutos. Os valores de pH e acidez titulavel nao variaram estatisticamente durante o amadurecimento. A atividade de amilase e os teores de amido diminuiram gradativamente com o aumento dos acucares soluveis totais e nao redutores, enquanto os teores dos redutores se mantiveram constantes. Os teores de pectinas totais e soluveis diminuiram, enquanto a atividade de pectinametilesterase manteve-se constante. As atividades das enzimas poligalacturonase e polimetilgalacturonase nao foram detectadas no fruto. Observou-se diminuicao dos teores de polifenois e das atividades das enzimas peroxidase e polifenoloxidase e consequente diminuicao do escurecimento da polpa do fruto.

Utilização de cactáceas do gênero Pereskia na alimentação humana em um município de Minas Gerais

The objective of this study was to evaluate the use of cacti of the genus Pereskia, for human consumption food. The study was conducted in 1.525 households in the city of Sao Goncalo do Abaete (MG). In this city where the socioeconomic questionnaire was applied regarding the dietary use of this plant, commonly referred to as ora-pro-nobis, only 25 of the households possessed plants of the genus Pereskia. In 22 households there was the presence of Pereskia grandifolia, in three households there was Pereskia aculeata, and one had both types. The presence of nutrients in the ora-pro-nobis was cited by 83.33% of respondents, where 33.37% cited monthly consumption. The plant was cited by 66.67% of the respondents as important in the treatment of iron deficiency anemia, by 16.67% as a therapeutic agent for cancer, by 12.50% for prevention or treatment of osteoporosis and 8.33% for the treatment of constipation. ora-pro-nobis was classified as a vegetable by 54.17% of respondents. It was concluded that the cultural revival of consumption of this type of plant may improve nutritional status and income of lower-class families in both urban and rural regions, from different regions of Brazil.

Sugars, organic acids, minerals and lipids in jabuticaba

O objetivo deste trabalho foi determinar a composicao dos acucares, acidos orgânicos e minerais do fruto inteiro e fracoes (casca, polpa e semente) dos genotipos de jabuticabeira Paulista (Plinia cauliflora) e Sabara (P. jaboticaba), assim como a composicao do oleo das cascas e sementes. As frutas apresentaram elevados teores de acucares totais, destacando-se a frutose, seguida de glicose e sacarose. No genotipo Paulista, foram encontrados teores mais elevados de acucares totais e redutores na polpa e na casca, o que nao foi observado ao comparar os frutos inteiros dos dois genotipos. Foram encontrados cinco acidos orgânicos na seguinte ordem quantitativa: acido citrico > acido succinico > acido malico > acido oxalico > acido acetico. Potassio foi o mineral mais abundante encontrado. A fruta mostrou tambem ser rica em magnesio, fosforo, calcio e cobre. O oleo das sementes mostrou ter praticamente a mesma constituicao do oleo extraido das cascas, e os compostos majoritarios foram um fitosterol nao identificado, os acidos palmitico, linoleico e oleico e o esqualeno.