Maria Eletta Moriano’s research while affiliated with University of Milan and other places

This work aims at assessing the performances of eight commercial emulsifier substitutes (not identified as additives) in an artisanal ice cream formulation, in comparison with the common mono- and di-glycerides of fatty acids (MDG). Besides the quality features of mixes (density, soluble solids, rheological properties, freezing point depression) and ice creams (extrusion parameters, overrun, firmness, melting behavior, shape retention), also the emulsifying activity index (EAI) and creaming stability (CS) of the considered ingredients were tested. No significant correlations were found between EAI or CS and quality characteristics of ice creams, confirming the singular role of MDG in ice cream structuring. Citrus fibers excessively increased the mix apparent viscosity compared to the reference sample containing MDG (435 ± 3 vs 89 ± 1 mPa s). Lupine, pea, and rice proteins, as well as citrus fibers significantly improved ice cream melting behavior (1.60 ± 0.12 – 2.33 ± 0.01 g/min melting rate vs. 2.62 ± 0.05 g/min of the reference sample). However, at the tested doses there was not a single ingredient as effective as MDG on ice cream properties. A combination of different substitutes in different amounts can be a valuable strategy in order to effectively replace MDG and attain the goal of an ice cream with good quality and clean label.

This work aims at studying the effects of whey protein concentrate (WP) and egg white powder (EW) as structuring agents in double emulsions (W1/O/W2). A D-optimal design was developed considering the following factors: type (WP, EW) and concentration (0, 5, 10 g/100 mL) of protein used to gel the inner water phase (W1), W1 volume percentage (20%, 30%, and 40%) in primary emulsion (W1/O), and W1/O volume percentage (40, 50, 60%) in W1/O/W2. The 21 samples were investigated by FT-IR spectroscopy, which revealed different protein conformations depending on W1 and W1/O fractions, and a better interaction with oil of WP rather than EW. Highly significant (p < 0.001) multivariate models were computed for yield, rheological properties, and creaming stability of W1/O/W2, being W1 and W1/O the most influent factors. Protein type significantly affected W1/O/W2 rheology, revealing a better structuring ability of EW with respect to WP, resulting in higher apparent viscosity and consistency coefficient values. A W1/O/W2 optimized for maximum values of apparent viscosity, yield, and creaming stability was developed, composed of 10 g/100 mL EW in W1, 29% W1, and 60% W1/O, with an oil content of 42.6 mL/100 mL. The optimized emulsion gave results in good agreement with the predicted values, thus confirming the validity of the developed multivariate models for the design of double emulsions with desired features. Graphical abstract

This work aimed at investigating relationships among structure, nutritional properties, and sensory acceptability of reduced-fat biscuits in comparison with a full-fat biscuit (STD). Four reduced-fat formulations were tested: OPT (46.3% fat reduction), an optimized formulation containing polydextrose and resistant starch; RAW and EXTR, obtained by substituting resistant starch with raw and extruded bean powders, respectively; WOW, in which a double emulsion was used instead of shortening. Fracture strength resulted comparable in STD and OPT, but increased for the other samples due to the structuring role of bean protein or the very low amount of fat. Scanning Electron Microscopy images revealed a well-developed protein structure in all samples, except for WOW that presented a more continuous and closed network. EXTR showed the lowest level of rapidly digestible starch and lipid digestibility. RAW showed the highest protein digestibility, significantly different from STD (12.1 ± 2.7 vs 3.7 ± 1.6 g/100 g proteins). Thanks to the holistic approach used, the influence of fat content on dough and biscuit structure as well as on colour was assessed, demonstrating also an effect on nutritional properties and consumers’ acceptance.

The aim of this work was a multivariate study of polydextrose and resistant starch (high amylose maize starch; Hi-Maize™ 260) effects on reduced-fat soft-dough biscuits. Design of Experiments and Response Surface Methodologies were applied to model the effects on dough rheology and biscuit quality of a partial substitution of fat with polydextrose (0–50%) and of flour with resistant starch (0–80%). The calculated models evidenced highly significant effects (p < 0.001) of the experimental factors on dough density and rheological behaviour and on most biscuit characteristics (colour, milk absorption, and fracture strength). With the increase of shortening reduction, higher density and lower complex modulus of dough were observed. The biscuit quality characteristics most influenced by shortening and flour substitution were fracture strength and strain, redness (a*), heterogeneity, and milk absorption. The obtained models were used in a desirability function for the optimization of the reduced-fat formulation based on the following constraints: 25–50% shortening reduction; 41–44 g/100 g milk absorption; 100–160 kPa fracture strength. The optimized product (17.54 ± 0.05 g/100 g fat), obtained with 46.3% shortening reduction and 12.5% flour replacement, had quality characteristics similar to those of full-fat biscuits (31.1 ± 0.4 g/100 g fat).

The aim of this work was to evaluate the use of sunflower oil organogels made with phytosterols and γ-oryzanol as milk cream substitutes in artisanal ice creams. Fat amount (4 and 8 g/100 g) and type (milk cream, sunflower oil, and organogels containing two levels of gelators) were considered as factors. The higher fat amount significantly decreased density (1.08 ± 0.01 g/mL vs 1.10 ± 0.01 g/mL) and soluble solid content (27.2 ± 0.3 °Bx vs 30.1 ± 0.3 °Bx) of mixes, as well as ice cream overrun (31.1 ± 0.6% vs 37.3 ± 0.6%) and melting rate (2.5 ± 0.1 g/min vs 2.9 ± 0.1 g/min). The use of organogels with the highest gelator concentration yielded ice creams with quality characteristics comparable to those of the samples containing milk cream, and even better overrun (42.4 ± 0.8% vs 37.1 ± 0.8%) and melting starting time (20 ± 1 min vs 16 ± 1 min). Thus, the application of organogels in artisanal ice creams is a successful approach in order to obtain “low saturated fat” products (saturated fat < 0.9 g/100 g) “with added plant sterols and stanols” intended for people who want to lower their blood cholesterol level.

The objective of this study was to examine the influence of flour quality on the properties of bread made from pre-fermented frozen dough. The physicochemical parameters of 8 different wheat flours were determined in detail. A standardized baking experiment was performed with frozen storage periods from 1 to 168 days. Baked bread was characterised for specific loaf volume, crumb firmness and elasticity. Duration of frozen storage significantly affected loaf volume and crumb firmness. The reduction of loaf volume was different among the used flours and its behaviour and intensity was highly influenced by flour properties. For control (none frozen) breads wet gluten, flourgraph E7 maximum resistance and RVA peak viscosity were positively correlated with loaf volume. However, after 1–28 days of frozen storage, wet gluten content did not significantly influence loaf volume, while other parameters were still significantly correlated with bread properties. After 168 days of frozen storage all breads showed low quality, thus no significant correlations between flour properties und bread quality were found. Findings suggest that flours with strong gluten networks, which show high resistance to extension, are most suitable for frozen dough production, but starch pasting characteristics also affected bread quality in pre-fermented frozen dough.

The use of sucrose-alternative sweeteners in ice cream production could satisfy requirements of modern consumers focused on natural and nutritionally balanced foods. The aim of this work was to fill the gap in basic knowledge about the effects of honey, trehalose, and erythritol on the properties of artisanal ice cream. A milk-based sucrose-sweetened ice cream was produced as reference sample (REF), using then the alternative sweeteners to partially (50%) or totally (100%) substitute sucrose. With respect to REF, honey-containing ice cream mix revealed a significantly lower value of soluble solids (30.4 °Bx vs. 34.5 °Bx) and apparent viscosity (36.5 mPa s vs. 47.6 mPa s) and a significantly higher extrusion time (8.18 min vs. 7.04 min). The total substitution of sucrose with trehalose and erythritol led to a melting rate (2.07 and 1.56 g/min, respectively) significantly lower than REF (2.75 g/min), a very high firmness (508 and 725 N vs. 4 N), and a higher extrusion temperature (-7.1 and -5.3 °C vs. 9.3 °C). The results of this study represent a guideline for the successfully utilization of honey, trehalose, and erythritol in peculiar ice cream formulations (e.g. non-sweet or low-calorie products).