Luciana Neves Ellendersen

Development and sensory profile of a probiotic beverage from apple fermented with Lactobacillus casei

The objective of this study was the development and optimization of a probiotic apple beverage as well as the establishment of a sensory profile by using chemical, microbiological, and quantitative descriptive analysis (sensory profiling). For this purpose, both Lactobacillus casei and L. acidophilus were tested in two different media ‐ Fuji and Gala apple juices ‐ at different pH values. The optimal conditions to develop the apple probiotic beverage were obtained by response surface methodology. They were found to be 10 h of fermentation at 37oC in Gala apple juice. Sensorially, the clarified Gala apple juice was characterized by a caramel color, apple aroma, and an acidic apple taste. The fresh fermented probiotic apple beverage was characterized by a thick texture and sweet taste. The probiotic apple beverage stored for 28 days at 7oC presented a thick texture and acidic taste. Finally, when the fermented probiotic beverage was tested by potential consumers, it presented an acceptance index of 96%.

Almond and peanut flours suppelmented with iron as potential ingredients to develop gluten-free cookies

Brazil is the second biggest worldwide producer of cookies and there are many varieties in the market; however, only a few are gluten-free. The objectives of this work were to formulate two gluten-free cookies added with iron, peanut or almond, and analyze their physicochemical, chromatic and sensory properties. Moisture, instrumental color (L*, a*, b* and C*), ash, proteins, lipids, iron, carbohydrates (estimated by difference), and water activity were determined. The acceptance of the products was assessed by 115 untrained taste panelists using a five-point hedonic scale. The data collected from the physicochemical analyses were submitted to Levenes, ANOVA, and Tukeys tests, which showed statistical difference (p < 0.05) in all the attributes for centesimal composition, water activity, and color of the cookies. Peanut and almond cookies could be considered sources of iron once they presented at least 15% of the daily recommended value of intake. They also garnered acceptance indexes of 80 and 85%, respectively, concluding that both formulations developed in this study were source of iron and contained high concentration of lipids and proteins with great sensory acceptance, suggesting their potential consumption by gluten-intolerants.

Influence of the Addition of Ovalbumin and Emulsifier on the Physical Properties and Stability of Yacon (Smallanthus sonchifolius) Juice Foams Prepared for Foam Mat Drying Process

Yacon juice and concentrated yacon juice were added with an ovalbumin or emulsifier in order to form foams which were subjected to different whipping times according to a 22 factorial design. After formation of the foams, their density, overrun, physical stability, yield stress, and structural microscopy were assessed. The data analysis obtained by response surface methodology was able to identify that the concentration of the foaming agent together with the time of air incorporation led to reduced density, increased expansion and air volume fraction, and physical stability of the product. Foams formed with the addition of an ovalbumin showed higher yield stress values than those added with an emulsifier. During the resting period, the yield stress was reduced for both foaming agents. By analyzing the images of the foams, it was found that the greater the number of air bubbles present, the smaller their diameter, a behavior affected by the resting time. Foams formed with higher concentrations of foaming agent and longer whipping times showed the most desirable characteristics for the purpose of foam mat drying.

Development of Chitosan Membranes as a Potential PEMFC Electrolyte

Commercial chitosan and chitosan extracted from shrimp shells are being used to design membranes to be tested as low cost electrolyte in PEM fuel cells. This study investigated the influence of the deacetylation degree (DD) and molar mass (MV) of the chitosans used in the composition of membranes on its performance regarding to proton conductivity and other properties. Preliminary results indicate that the chitosan extracted from shrimp shells generated membranes with promising properties such as proton conductivity, which demonstrated to be even a 100 times higher than those shown by commercial chitosan membranes. The significant increase in proton conductivity can be associated with the higher number and availability of amino groups (–NH2) in the chitosan produced in the laboratory, which presents higher DD and lower MV. It is believed that the properties of chitosan can be manipulated in such a way that it would be possible to obtain proton conductivity values closer to that presented by Nafion®.