Mechanism of firmness loss in guava cv. Pedro Sato during ripening at room temperature

Abstract Guava (Psidium guajava L.) is fruit with very short shelf life due to associated with the loss of firmness in the pulp and information on the activity of enzymes that degrade pectic substances, as well as the amount of pectin, is very contradictory and not clearly defined. This work showed that the firmness of the fruit decreased sharply on the first four day­s of ripening. The identified phenolic compounds had their content increased with fruit maturation. The addition of the enzymes cellulase and hemicellulase in the pectin extraction in fruits of Psidium guajava revealed higher contents of this polyssacaride that the ones reported in literature, highlighting pectin as the responsible for the firmness of these fruits at more adequate contents. β-D-glucosidase was identified as one of the responsible enzymes for the maturation of P. guajava fruits. Thus, studies about possible inhibitory effects of this enzyme in P. guajava fruits may reveal an important tool to reduce pectin release and early maturation of these fruits.

Anti-obesity Effects of the Administration of Tournefortia paniculata Cham Extract on Wistar Rats Subjected to a Hypercaloric Diet

The aim of this study was to evaluate the therapeutic and toxicologic effects of the administration of the powered vegetable extract and aqueous extract of Tournefortia paniculata leaves on Wistar rats, subjected to a hypercaloric diet for 42 days. The rats were divided into five groups and were given the following treatments by gavage: T0 (control) - 1.0 mL water day-1; T1 - aqueous extract containing 14 mg phenolic compounds kg-1 rat day-1; T2 - 14 mg quercetin kg-1 rat day-1; T3 - 50 mg powered vegetable extract from T. paniculata leaves (PVE) kg-1 rat day-1 and T4 - 100 mg PVE kg-1 rat day-1. The treatments did not significantly alter the weight, but were effective in reducing liver fat, glucose and serum triglycerides. The treatment T1 reduced food consumption and lipid peroxidation. None of the treatments showed genotoxic potential. Results showed that T. paniculata leaves possessed an anti-obesity potential. However, a more detailed study of the medicinal potential and characterization of phytochemicals in this plant would be still necessary for a better understanding of its mechanisms of action, enabling future applications in the treatment of this pathology or for various therapeutic purposes.

Composição química e fitoquímica das farinhas da casca e da semente de lichias (Litchi chinensis Sonn) cultivar 'Bengal' / Chemical and phytochemical composition of flours from skin and seeds of 'Bengal' lychee (Litchi chinensis Sonn)

Este estudo teve como objetivo determinar a composição química e fitoquímica das farinhas da casca e da semente de lichias (Litchi chinensis Sonn), família Sapindaceae, da cultivar 'Bengal'. A composição centesimal, o valor energético total, sólidos solúveis, pH, acidez e os teores de compostos fenólicos, antocianinas, flavonoides, minerais, açúcares, vitamina C e a triagem fitoquímica foram determinados. A farinha da casca de lichia apresentou os maiores teores de flavonoides, vitamina C, compostos fenólicos, antocianinas, lipídios, proteínas, cinzas e fibras, enquanto a farinha da semente se destacou pelos teores de potássio, enxofre, cobre e zinco. Ambas as farinhas apresentaram resultado positivo para açúcares redutores, proteína e aminoácidos, taninos, catequinas, flavonoides, depsídeo e depsidonas. Somente a farinha da casca apresentou resultado positivo para alcaloides. As farinhas dos subprodutos da lichia apresentaram-se como fontes promissoras de nutriente e substâncias bioativas, no entanto suas propriedades biológicas devem ser estudadas.

This study had the objective to determine the chemical and phytochemical composition of flours from skin and seeds of 'Bengal' lychees (Litchi chinensis Sonn), Sapindaceae family. Proximate composition, total energy value, soluble solids, pH, acidity and levels of phenolic compounds, anthocyanins, flavonoids, minerals, sugars, vitamin C and the phytochemical screening were determined. Lychee skin flour presented the highest levels of flavonoids, vitamin C, phenolic compounds, anthocyanins, lipids, proteins, ash and fiber, while the seed flour stood out for the contents of potassium, sulfur, copper, and zinc. Both flours were positive for reducing sugars, protein and amino acids, tannins, catechins, flavonoids, depsides and depsidones. Only the skin flour showed a positive result for alkaloids. The flours made from lychee by-products were promising sources of nutrients and bioactive substances; however, their biological properties need to be further studied.

Caracterização química das hortaliças não-convencionais conhecidas como ora-pro-nobis / Chemical characterization of the non-conventional vegetable known as ora-pro-nobis

Esse estudo teve como objetivo realizar a caracterização química das hortaliças não-convencionais conhecidas como ora-pro-nobis (Pereskia aculeata e Pereskia grandifolia). Foi determinada a composição centesimal e mineral, bem como os teores de vitamina C, carotenoides totais, -caroteno, licopeno, ácido oxálico, nitrato, saponinas, compostos fenólicos e o inibidor da tripsina da farinha das folhas destas plantas. P. grandifolia apresentou os maiores teores de proteínas e de lipídios e os menores de cinzas e fibra alimentar total, que P. aculeata. Já P. grandifolia apresentou maior teor de cálcio, e para os demais minerais a P. aculeata se destacou. A P. aculeata também apresentou os maiores teores de vitamina C e -caroteno. Quanto aos carotenoides totais e o ácido oxálico P. grandifolia apresentou maiores níveis, sendo que na P. aculeata não foi detectado o licopeno, mas os teores de nitratos foram 15 vezes superiores ao de P. grandifolia, apresentando também maior inibição da tripsina. Os teores de saponinas foram semelhantes nas duas amostras de farinhas analisadas. Conclui-se que as folhas destas cactáceas são importantes fontes de proteínas, fibras, minerais (principalmente o cálcio e o ferro) e de compostos bioativos. Mesmo sendo detectados antinutrientes nas farinhas, seu consumo diário não será suficiente para causar malefícios à saúde humana.

The aim of this study was to chemistry characterize the non-conventional vegetable known as ora-pro-nobis (Pereskia grandifolia and Pereskia aculeata). The proximate and mineral compositions were determined as well as vitamin C, total carotenoids, -carotene, lycopene, oxalic acid, nitrate, saponins, phenolic compounds and the trypsin inhibitor from flour produced from the leaves of these plants. P. grandifolia showed higher levels of proteins and lipids and lower ash and total dietary fiber than P. aculeata. The P. grandifolia showed greater calcium concentrations while P. aculeata presented higher concentrations of the other minerals. The P. aculeata also showed the highest levels of vitamin C and -carotene. Regarding total carotenoids and oxalic acid the P. grandifolia showed higher levels, while in P. aculeata lycopene was not detected, but nitrate levels were 15 times higher than in P grandifolia, also showing greater trypsin inhibition. The saponin contents were similar in the two flour samples analyzed. It was concluded that these plants are important sources of proteins, fibers, minerals (especially calcium and iron) and bioactive compounds. Although antinutrients were found in flour, it is suggested that these cacti can enrich the diet with nutrients, since daily intake does not present harm to human health.

Antioxidants from Medicinal Plants Used in the Treatment of Obesity.

Aims: The objective of this work was to quantify phenolic compounds, flavonoids, vitamin C, total carotenoids, β-carotene and lycopene and to measure the antioxidant activity in the medicinal plants Aloe vera (L.) Burm. (aloe), Simaba ferruginea St. Hil. (calunga), Baccharis trimera (Less.) DC (carqueja), Garcinia cambogia Desr., and Tournefortia paniculata Cham. (marmelinho) and of the phytotherapic made with the combination of these plants. Place and Duration of Study: Chemistry Department of Federal University of Lavras – UFLA, Brazil between June 2011 and September 2012. Methodology: Phenolic compounds, flavonoid, vitamin C, total carotenoids and β-carotene and lycopene contents were quantified by UV-Vis spectrophotometer and antioxidant activity by ABTS and β-carotene/linoleic acid methods. Results: High contents of phenolic compounds were found in marmelinho (36.19g 100g-1 dry matter – DM), followed by carqueja (4.03g 100g-1DM) and calunga (1.62g 100g-1DM); of flavonoids in marmelinho (480.30mg 100g-1DM) and carqueja (173.68mg 100g-1DM); of vitamin C in marmelinho (652.80mg 100g-1DM) and G. cambogia (127.63mg 100g-1DM); and of carotenoids in marmelinho (23.16 mg 100 g-1). The antioxidant activity, in µmol trolox g-1, by the ABTS method, was considered moderate in the aqueous (728.80) and ethanolic (731.06) marmelinho extracts, and weak for the other plants. However, by the β-carotene/linoleic acid method, the aqueous and ethanolic marmelinho extracts show great antioxidant potential at all tested concentrations (above 80% inhibition), and those of carqueja, calunga and the ethanolic of the phytotherapic, at the concentrations of 40,000 and 20,000mg L-1, also showed good antioxidant potencies (over 60% inhibition). Conclusion: Those five species of plants showed antioxidant activity with potential for use in pharmaceutical and food preparations, with possible health benefits.