RESUMO: O objetivo deste trabalho foi determinar a composição nutricional, atividade antioxidante e teor de compostos fenólicos totais de farinhas de batata-doce de diferentes cultivares: batata-doce Beauregard (FB) e batata-doce comum, cv. Brazlândia Rosada (FC). Foram realizadas as análises de lipídeos, proteínas, umidade, carboidratos, pH, acidez titulável, fibras, cinzas, ferro, zinco, betacaroteno, vitamina A e determinação do valor calórico. Também foram determinadas a atividade antioxidante, pelos métodos DPPH (2,2-difenil-1-picril-hidrazil), ABTS (2,2-azinobis (3-etilbenzotiazolina-6-ácido sulfônico) e FRAP (Ferric Reducing Antioxidant Power), e compostos fenólicos totais. A FC apresentou maiores teores de carboidratos, cinzas, fibras, pH e atividade antioxidante pelo método ABTS. Os teores de proteínas e zinco foram semelhantes entre as duas farinhas. A FB apresentou maiores teores de umidade, valor calórico, lipídeos, ferro, capacidade sequestradora de radicais DPPH e atividade antioxidante pelo método FRAP, compostos fenólicos totais, conteúdo de betacaroteno e vitamina A. Os dados revelaram uma boa composição nutricional para ambas as farinhas analisadas. O destaque para a farinha da batata-doce Beauregard é maior em relação ao seu teor de betacaroteno e ferro. Sendo a farinha obtida pela batata-doce Beauregard uma boa fonte de pró-vitamina A, além de ser fonte de fibras.

ABSTRACT: This research determined the nutritional composition, antioxidant activity and total phenolic compound content of sweet potato flour from different cultivars: Beauregard cv. sweet potato (BF) and the common sweet potato Brazlândia Rosada cv. (CF). Total lipids, proteins, moisture, carbohydrates, pH, titratable acidity, fiber, ash, iron, zinc, beta-carotene, vitamin A and determination of caloric value were analyzed. Antioxidant activity and total phenolic compounds were also determined by the DPPH (2,2-diphenyl-1-picryl-hydrazyl), ABTS (2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) and FRAP (Ferric Reducing Antioxidant Power) methods. CF showed higher levels of carbohydrates, ash, fiber, pH and antioxidant activity by the ABTS method. Protein and zinc contents were similar between the two flours. BF had higher moisture content, caloric value, lipids, iron, DPPH radical scavenging capacity and antioxidant activity by the FRAP method, as well as total phenolic compounds, beta-carotene and vitamin A content. The data revealed good nutritional composition for both analyzed flours. The Beauregard flour can be highlightedregarding its higher beta-carotene and iron content. Moreover, the Beauregard sweet potato flour is a good source of provitamin A, in addition to being a source of fiber.

Abstract Synthetic colourants are widely used for colouring foods. However, their safety has been questioned. Due to this limitation and the global trend of consuming healthy foods, the industry is faced with the need to replace artificial colourings, which has given rise to a growing interest in colourants from natural sources. Thus, this work obtained the moisture adsorption isotherms of the natural food dyes of anthocyanins, betalains and curcumin and evaluated the humidity, water activity (aw), hygroscopicity, colour and antioxidant capacity in vitro. Isotherms were determined by the static gravimetric method with saturated salt solutions (LiCl. H2O, MgCl2.6H 2O, Mg(NO3)2.6H2O, NaCl, KCl and K2 SO4) at 25 °C. Experimental data were adjusted by GAB, BET, Halsey, Oswin and Henderson models. All models, except Henderson's for Curcumin, fitted the data and BET was used to represent the moisture adsorption isotherm. All the isotherms were type sigmoidal, characteristic of most foods. The observed water content (<0.3%) and a w (<0.03) can be considered favourable to stability. Colour analysis indicated a high colouring strength and the antioxidant capacity suggested that, in addition to representing a source of colour in food products, natural dyes may have an additional function, with possible health benefits.

Abstract The objective of this study was to develop, characterize and evaluate the stability of whey protein beverages containing anthocyanins from jabuticaba skins. Beverage formulations containing 0.5% (F1), 2.0% (F2), 4.0% (F3) and 6.0% (F4) of whey proteins and 2.0 mL of the concentrated phenolic extract from jabuticaba skins were developed. Physicochemical parameters (pH, acidity, total soluble solids, protein content, viscosity, color), antioxidant capacity, total anthocyanins and total phenols of the beverages were determined. In addition, a sensory acceptance test and a stability study were performed. The physicochemical analyses indicated that the protein concentration significantly (p < 0.05) affected the values of acidity, total soluble solids, total phenols and antioxidant capacity. The protein content also influenced the total color difference (ΔE) between formulations. The greater differences were observed in the formulation pairs containing low and high protein contents. The formulations F1, F2 and F3 were equally accepted on overall impression and color attributes. The stability study demonstrated that there was no significant change (p > 0.05) in the total anthocyanins and in the physicochemical properties of F3 over storage time, which indicated a good stability and a great market potential of the whey protein beverages containing anthocyanins from jabuticaba skins.

RESUMO: Este estudo teve como objetivo desenvolver e caracterizar bebidas formuladas com proteínas de soro de leite adicionadas de luteína. Bebidas formuladas com 0,5 (F1), 2,0 (F2), 4,0 (F3) e 6,0% m/v (F4) de proteínas de soro caracterizadas fisico-quimicamente e microbiologicamente e, avaliadas sensorialmente. As análises físico-químicas indicaram que o teor de proteína alterou significativamente (P<0,05) os valores de acidez, sólidos solúveis e as coordenadas colorimétricas, foi possível ajustar modelos matemáticos para todas essas variáveis. As análises microbiológicas mostraram contaminação não significativa (P<0,05) durante o processamento que poderia comprometer a qualidade das bebidas. Os teores de carotenoides e a atividade antioxidante não variaram significativamente (P>0,05) com o aumento do teor de proteína. A formulação F2 apresentou a maior aceitação sensorial. As bebidas são uma alternativa promissora para o uso do soro de leite e aumentam o valor agregado do produto pela adição de luteína.

ABSTRACT: This study aimed to develop and characterize beverages formulated with whey protein and added lutein. Beverages formulated with 0.5 (F1), 2.0 (F2), 4.0 (F3) and 6.0% w/v (F4) whey protein were physicochemically and microbiologically characterized, and sensory evaluated. The physicochemical analyses indicated that the protein content significantly changed (P<0.05) the acidity values, soluble solids and the colorimetric coordinates, making possible to adjust mathematical models for all these variables. Microbiological analyses showed no significant contamination (P<0.05) during processing that would compromise drinks quality of the drinks. Carotenoid content and the antioxidant activity did not change significantly (p>0.05) with increased protein content. The F2 formulation showed the highest sensory acceptance. Beverages offer a promising alternative to whey use and enhance the value of the product by the addition of lutein.