Analytical characteristics and discrimination of Brazilian commercial grape juice, nectar, and beverage

The production and commercialization of Brazilian grape juice is increasing annually, mainly due to its typicality, quality, and nutritional value. The present research was carried out in view of the great significance of Brazilian grape juice for the grape and wine industry. The purpose of this study, therefore, was to assess its composition as well as the discrimination between grape juice and other beverages. Twenty four samples of whole, sweetened, and reprocessed grape juices, grape nectar, and grape beverage were evaluated. Classical variables were analyzed by means of physicochemical methods; tartaric and malic acids, by HPLC; methanol, by gas chromatography; minerals, by atomic absorption spectrophotometry. These products were discriminated by the Principal Component Analysis (PCA). Results show that whole and sweetened grape juices were discriminated from other grape products because they featured higher values of total soluble solids, tartaric and malic acids, most minerals, phenolic compounds, and K/Na ratio, whereas grape nectar and grape beverage presented higher values of ºBrix/titratable acidity ratio. Reprocessed juice was discriminated due to its higher concentrations of Li and Na and lower hue.

Particle size and cholesterol content of a mayonnaise formulated by OSA-modified potato starch

Egg yolk was partially replaced (0, 25, 50, 75, and 100%) with octenyl succinic anhydride (OSA)-modified potato starch in a reduced-fat mayonnaise formulation to curtail the problems associated with high cholesterol and induced allergic reactions. The physicochemical properties included parameters such as: pH, fat content, and emulsion stability of the formulations analyzed. The samples with 75% and 100% egg yolk substitute showed the maximum emulsion stability (>95% after two of months storage), and they were selected according to cholesterol content, particle size distributions, dynamic rheological properties, microstructure, and sensory characteristic. A significant reduction (84-97%) in the cholesterol content was observed in the selected samples. Particle size analysis showed that by increasing the amount of OSA starch, the oil droplets with the peak size of 70 µm engulfed by this compound became larger. The rheological tests elucidated that in the absence of egg yolk, OSA starch may not result in a final product with consistent texture and that the best ratio of the two emulsifiers (OSA starch/egg yolk) to produce stable reduced-fat, low cholesterol mayonnaise is 75/25. The microscopic images confirmed the formation of a stable cohesive layer of starch surrounding the oil droplets emulsified in the samples selected.

Sequence-characterized amplified region (SCAR) technique used for variety discrimination in vinca (Catharanthus roseus (L.) G.Don)

Sequence-Characterized Amplified Region (SCAR) appears as a useful technique for genetic purity testing and variety discrimination, applicable to species in which some other techniques have failed. In particular, this technique is very attractive with species in which RAPD results were not consistent. The RAPD polymorphic bands were cloned, sequenced and from the sequence information, primers pairs for normal PCR were developed. Since the probability of obtaining successful SCAR primers from RAPD polymorphic bands was about 50%, a larger number of RAPD polymorphic bands are needed to develop sufficient SCAR primers for varietal discrimination in vinca. In addition, the efficiency of the SCAR technique is strongly affected by the quality of DNA extracted from seeds. The SCAR banding patterns obtained from vinca seed were consistent and repeatable making the results reliable for genetic purity testing and variety discrimination. The SCAR technique is simple, fast, relatively inexpensive and allows the use of DNA extracted from dry seeds, which is very important in a seed-quality evaluating program

Tariff discrimination on Brazil's soluble coffee: an economic analysis

This article evaluates the impacts of the imposition of tariffs on the Brazilian soluble coffee mainly by European countries as of the 1990s. More particularly, it verifies whether the imposition of discriminatory trade tariffs by the European Union and of non-discriminatory ones by some Eastern European countries reflects on the international demand for this commodity. For this purpose, dynamic models of global demand for Brazilian soluble coffee were estimated for the 1995-2003 period using data from the International Coffee Organization. Findings suggest that existing tariffs significantly account for the reduction of Brazilian share of soluble in the world market.