Effects of 1-MCP on the post-harvestABSTRACT -The aim of this work was to analyse the effects of 1-MCP upon the post-harvest quality of the orange cv. Pera stored for 45 days at a temperature of 7 ºC. The fruit was divided into four treatments, and then submitted to the application of three concentrations of 1-methylciclopropene (0.1, 0.5 and 1.0µL.L -1 ) for a period of 12 hours.The fruitwas again then stored at a temperature of 7 ºC. The rate of respiration was determined, together withcoloration of the epidermis, SS, TA, ratio, vitamin C, total carotenoids, phenolic compounds, total and reducing sugars, weight loss and juice yield. The data were submitted to analysis of variance (F-Test), and the averages were analysed by regression (P 0.05). According to the results, it could be seen that higher doses of 1-MCP may have caused chemical stress to the orangesunder evaluation, being responsible for the increasein the rate of respiration.Achange in coloration of the epidermis from green to yellow/orange was delayed by the application of 1-MCP; the application of 1-MCP did not cause any alteration to such chemical characteristics as SS, TA, ratio, carotenoids, phenolic compounds or sugars. RESUMO -o objetivo deste trabalho foi analisar os efeitos do 1-MCP sobre a qualidade pós-colheita de laranjas cv. Pera, armazenadas ao longo de 45 dias à temperatura de 7 °C. Os frutos foram separados em quatro tratamentos e em seguida submetidos à aplicação de 1-metilciclopropeno em três concentrações (0,1; 0,5 e 1,0 L L -1 ) por um período de 12 horas e posteriormente armazenados à temperatura de 7 °C. Determinou-se: taxa respiratória, coloração da epiderme, SS, AT, ratio, vitamina C, carotenóides totais, compostos fenólicos, açúcares redutores e totais, perda de massa e rendimento de suco. Os dados foram submetidos à análise de variância (teste F) e as médias estudadas por meio de regressão (P 0,05). De acordo com os resultados obtidos, observou-se que: as doses mais elevadas de 1-MCP podem ter causado estresse químico nas laranjas analisadas, sendo responsável pela elevação na taxa respiratória; a mudança de coloração da epiderme dos frutos, de verde para amarela/laranja, foi retardada pela aplicação de 1-MCP; a aplicação de 1-MCP não causou alterações nas características químicas como SS, AT, ratio, carotenóides, compostos fenólicos e açúcares.

Abstract:The present study aimed to evaluate the volatiles profile of red mombin (Spondias purpurea) pulp and its powder produced by spray-drying (SD) as an example to show utility of headspace solid-phase microextraction (HS-SPME) in the analysis of parameters such as the quality and stability of fruit products. Volatiles profiles of the pulp were identified by gas chromatography-mass spectrometry (GC-MS), quantified by gas chromatography-flame ionization detector (GC-FID) and compared to the profile of the powder stored at 0, 60 and 120 days in plastic (PP) or laminated packages (LP). The results showed that the technique was able to identify 36 compounds in the red mombin pulp, 17 out of which have been described for the first time in this fruit, showing that red mombin fresh pulp appears to be unique in terms of volatiles composition. However, only OPEN ACCESSMolecules 2014, 19 16852 24 compounds were detected in the powder. This decrease is highly correlated (r 2 = 0.99), at least for the majority of compounds, to the degree of volatility of compounds. Furthermore, the powder stored in PP or LP showed no statistical differences in the amounts of its components for a period of 120 days of storage. Finally, this work shows how HS-SPME analysis can be a valuable tool to assess the quality and stability of fruit products.

With the objective of utilizing agro-industrial by-products and enhancing the quality attributes of dehydrated fruits, this study evaluated the effects of edible pectin-based coatings containing disintegrated guava byproducts (up to 50% concentration) and drying temperatures (46-74°C) on the drying kinetics and nutritional properties of dried red guava. Coatings were applied to guava slices prior to hot-air drying. A central composite rotatable design was used to optimize carotenoid and phenolic compound retention. The effects of the edible coating compositions combined with the drying temperatures affected the effectiveness of the film as a barrier to carotenoid oxidation. Total phenolic compound retention, however, was affected only by temperature. Responses were simultaneously optimized, and high carotenoid and total phenolic retentions were obtained at approximately 60°C with 25% by-product concentration. The effective water diffusivities were mainly affected by temperature. Consequently, the coatings improved nutritional quality without having a major impact on drying times.

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This work aimed to investigate the effects of temperature and relative humidity on the moisture transfer kinetics and browning during black garlic processing. The final product quality was also evaluated based on the total phenolic compounds (TPC) content and antioxidant activity (AA). Garlic bulbs were stored in a temperature and humidity controlled room in NaCl and KCl saturated solutions at 65, 72.5, and 80°C for several days. The diffusion equation that considered external resistance was able to represent the mass transfer kinetics well. The browning kinetics was modeled according to a zero‐order reaction. Black garlic of a suitable color (L*≅10) was obtained in short time periods of 5 days at 80°C, 8 days at 72.5°C and 15 days at 65°C with the water content nearly 42% (NaCl) and 45.5% (KCl), also permitted some formation of TCP compounds and an increasing in AA. Practical applications Despite a number of works concerning the production of black garlic, literature remains somewhat empirical and, because of this, there is a lack of mathematical models describing this process. Black garlic processing is in general carried out under a controlled high‐temperature and relative humidity for a long time period. This is, therefore, an energy intensive process. However, as demonstrated in this study, if the operation variables are properly chosen, it is possible to reduce the processing time and, thus, the energy expenditure. Therefore, the present results are useful for the process design and manufacturing of black garlic.

Edible coatings based on polysaccharides have been applied on pieces of fruits and vegetables before drying because of their potential to improve physical and nutritional characteristics of dehydrated plant foods. In the present study, physical and thermal properties of pectin-based films, with and without the incorporation of by-products obtained from the processing of red guava, were determined. These properties allow one to predict the likely behaviour of these films when used as edible coatings on guava pieces, during and after their dehydration. Thus the structural and morphological characteristics and the physical, thermal and sorption properties of the films and of the fruit pulp were determined, using scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and the static gravimetric method to determine the water-sorption curves. The addition of by-products provided crystallinity to the pectin film, attributed to their cellulose content, and hardly altered the water retention capacity of the pectin films. However, the pectin contributed to presenting a slightly higher sorption moisture at equilibrium, as compared to the guava pulp. The glass transition temperatures reported at extremely low moisture contents, both in the pulp and in the films with added by-products, indicated that at intermediate moisture contents, the fruit/film ensemble was in the rubbery state at room temperatures, providing softness to the dehydrated product. The images showed good integration of the edible films with the surface of the guava pieces.