Nicoletta A. Miele

Temporal dominance of sensations and dynamic liking evaluation of polenta sticks

Purpose – Temporal dominance of sensation (TDS) is a sensory method developed by Pineau et al. (2003) which studies the sequence of dominant sensations of a product during its consumption. TDS is believed to be more appropriate to explain consumer responses than static descriptive analysis due to its temporal element. The purpose of this paper is to define the temporal sensory profile of a new product: polenta stick. In particular, TDS method was used to measure the dominance of sensory attributes in polenta stick samples and dynamic consumer tests were performed in order to verify if the acceptability changed over time during sample consumption. Design/methodology/approach – Eight polenta sticks, different in terms of storage conditions, cooking procedures and serving temperatures, were analysed by means of TDS with 13 assessors. During two preliminary sessions, the attributes list, constituted by the nine most cited sensations, was generated. Five replications were carried out. In dynamic consumer tests...

A preliminary study on the application of natural sweet proteins in agar-based gels

Natural sweet proteins may be used as sugar replacer in simple liquid food systems but their applicability in more complex matrices has not been investigated yet. Gelling agent nature and texture characteristics as well as type and distribution of a stimulus in a gel could affect taste perception through inhibition or enhancement of tastants migration to the receptors. The mechanical, nonoral texture and time-intensity sweetness characteristics of sweet proteins MNEI and super sweet Y65R mutant, aspartame and saccharin added at a concentration iso-sweet to 40 g/L of sucrose in three agar gel concentrations (1%, 1.5%, and 2%) were evaluated. The results have shown that agar concentration and agar sweetener interaction particularly affect mechanical fracture stress and non oral hardness of the sweetened gels. Time intensity results illustrated that unlike in solution, the intensity of sweet taste in a gelled system over time decreases. Indeed, the behavior of the sweet proteins differed greatly in the gelled system compared to when they are in solution. PRACTICAL APPLICATIONS MNEI has been proved to be a high-potency sweetener for beverages, but the possibility to use it in semisolid foodstuff was not investigated yet. This study represented a preliminary characterization of two variants of natural sweetener monellin, MNEI and Y65R in semisolid model foodstuff. The data were an important scientific contribution to the knowledge of sweet proteins in agar-based gels and could be useful in order to extend the possible application of these sweet proteins as low calorie sweeteners in semisolid foodstuffs. Some problems concerning their delivered sweetness in agar gels were underlined and their application should be optimized in order to improve sweetness conveyed.

Polenta-based snack development: from maize flour to final product by assessing structural, mechanical and sensory properties

The aim of this paper was to study, step by step, the effect of ingredients and storage conditions on several properties of both the maize-based dough and the final product, during the new polenta-based snack food developing. Two different maize flours were characterized through water activity determination, particle size analysis, scanning electronic microscopy; then, dough made with different ratio of these were evaluated for mechanical properties and microstructure. According to the preliminary physicochemical characterization of both flour and dough, the final formulation was chosen for the polenta-based snacks. Thus, mechanical and sensory analyses, as well as microstructure determination, were performed on the final product. Results showed that the two maize flours presented different particle size distribution and gelatinization enthalpy, and affected the mechanical properties of intermediate products. The storage conditions dramatically affected the characteristics of the final products. Sensory results demonstrated that breading improves the crispness of external part but keeping creamy the product inside. The chosen approach was useful for understanding that flour particle size and storage are the critical factors that should be considered for this type of snack. The best formulation was made by mixing coarse and fine maize flours and by adding a batter.