Physical-chemical characteristics and antioxidant potential of seed and pulp of Ximenia americana L. from the semiarid region of Brazil

Ximenia americana popularly known as wild plum grow wildly in Brazilian semiarid region and its fruit were harvested in two maturity stages and evaluated for quality. The experimental design was completely randomized with three treatments (immature, mature pulp and seeds), and treatment effect was evaluated for pulp fraction (composed of both mesocarp and exocarp or peel) in maturation stages: immature (largest size with green colored peel), mature (largest size with yellow colored peel) and seeds of mature fruits, from eight repetitions of 25 fruits each, totaling 200 fruits per treatment. Fruit were separated and evaluated for physical and physicochemical variables, mineral composition, bioactive compounds content and total antioxidant activity (TAA). The X. americana grown in Brazilian semiarid region presents a great potential to further commercial exploitation. The pulp, aside its maturation stage contains high levels of lipids, proteins, sugars, starch, titratable acidity, vitamin C, yellow flavonoids, polyphenols and antioxidant activity. The seed also presents high levels of lipid, protein, starch, total extractable polyphenols and antioxidant activity. Imature pulp stands out for acidity, polyphenol, flavonoid and anthcyanin levels, while mature fruit pulp has higher yield, sugar and vitamin C levels. Seeds have higher starch, protein and lipi levels. The antioxidant activity found for wild plum pulp could be attributed to polyphenol and vitamin C contents; meanwhile, the antioxidant activity of seeds was dependent only on polyphenolic content. Pulp had higher Na, K, Mg, Ca and Fe levels, however, both seed and pulp fractions have substantial contents of P, K, Cu and Mn.Key words: Development, bioactive compounds, antioxidant activity, minerals, quality

Evaluation of alternative preservation treatments (water heat treatment, ultrasounds, thermosonication and UV-C radiation) to improve safety and quality of whole tomato

Previously optimised postharvest treatments were compared to conventional chlorinated water treatment in terms of their effects on the overall quality of tomato (‘Zinac’) during storage at 10 °C. The treatments in question were water heat treatment (WHT = 40 °C, 30 min), ultrasounds (US = 45 kHz, 80 %, 30 min), thermosonication (TS =40 °C, 30 min, 45 kHz, 80 %) and ultraviolet irradiation (UV-C: 0.97 kJ m−2). The quality factors evaluated were colour, texture, sensorial analysis, mass loss, antioxidant capacity, total phenolic content, peroxidase and pectin methylesterase enzymatic activities, and microbial load reduction. The results demonstrate that all treatments tested preserve tomato quality to some extent during storage at 10 °C. WHT, TS and UV-C proved to be more efficient on minimising colour and texture changes with the additional advantage of microbial load reduction, leading to a shelf life extension when compared to control trials. However, at the end of storage, with exception of WHT samples, the antioxidant activity and phenolic content of treated samples was lower than for control samples. Moreover, sensorial results were well correlated with instrumental colour experimental data. This study presents alternative postharvest technologies that improve tomato (Zinac) quality during shelf life period and minimise the negative impact of conventional chlorinated water on human safety, health and environment.info:eu-repo/semantics/publishedVersio

H-2 control of discrete-time Markov jump linear systems with uncertain transition probability matrix: improved linear matrix inequality relaxations and multi-simplex modelling

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)This study is concerned with the problem of H-2 state-feedback control design for discrete-time Markov jump linear systems (MJLS), assuming that the transition probability matrix is not precisely known, but belongs to a polytopic domain, or contains unknown or bounded elements. As a first contribution, the uncertainties of the transition probability matrix are modelled in terms of the Cartesian product of simplexes, called multi-simplex. Thanks to this representation, the problem of robust mean square stability analysis with an H-2 norm bound can be solved through convergent linear matrix inequality (LMI) relaxations constructed in terms of polynomial solutions. The proposed conditions yield a better trade-off between precision and computational effort when compared with other methods. As a second contribution, new conditions in terms of LMIs with a scalar parameter lying in the interval (-1, 1) are proposed for H-2 state-feedback control with complete, partial or no observation of the Markov chain. Owing to the presence of the scalar parameter, less conservative results when compared with other conditions available in the literature can be obtained, at the price of increasing the associated computational effort. Numerical examples illustrate the advantages of the proposed methodology.71216651674Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2011/08312-6