Papers by Pablo Rodriguez
Journal of The Science of Food and Agriculture, 2009
BACKGROUND: The alkalization process is extensively used in the cocoa industry, but information i... more BACKGROUND: The alkalization process is extensively used in the cocoa industry, but information is scarce and not easy to acquire. The goal of the study was to evaluate the effect of different types and concentrations of alkali on the color of cocoa liquor. Dried beans from Chuao (state Aragua, Venezuela) were used to produce cocoa liquors. Samples of liquors were alkalized with solutions of NaHCO 3 , Na 2 CO 3 and NaOH at concentrations of 10, 20 and 30 g kg −1. RESULTS: The data showed that values of the coordinates L * , a * and b * decrease when liquors were treated with the three different types and concentrations of alkalis. Almost all samples had E * values above 1. The ratios b * /a * and a * /b * and the proximate composition were also modified. Crude protein, crude fat and polyphenol concentrations were decreased and the ash content augmented as concentrations of the alkalis were increased. The fatty acid and sugar profiles were also affected. These ratios were most pronounced when NaOH was used. CONCLUSION: The selection of the type or concentration of alkali is a function of the type of product to be elaborated.
This study was carried out to evaluate the effect of pectin-based edible emulsion coating on acti... more This study was carried out to evaluate the effect of pectin-based edible emulsion coating on activity and disease severity of Lasiodiplodia theobromae in avocados, and their subsequent influence on the fruit quality. In order to assess the influence of coating and disease, avocados were sorted and devided into four equal lots and all were incubated at 20°C for up to 4 days. The first and second lots constituted samples which were stored as coated and uncoated, respectively, without fungal inoculation. The third and fourth lots were coated and un-coated fruits inoculated with the fungal disease. For coating, a previously standardized pectin-based emulsion was used. The incubated fruits were examined for the spread of disease, respiration rate and quality parameters, color and texture. As the incubation time increased, the volume of disease (VDS) increased, which in turn influenced the respiration rate (RR) in both coated and uncoated fruits. However, the coated fruits sustained a significantly slower rate of disease spread and RR. Similarly, the associated quality changes (texture and color) were much lower in coated fruits as compared with the control. Thus, the pectin based coating was effective in controlling the spread and severity of stem end rot in avocados. Changes in physical and physiological parameters of coated and uncoated fruits were well described by some form of semi-logarithmic models and were related to the VDS as well as case dependent incubation time.
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Papers by Pablo Rodriguez