Antioxidant capacity of durum wheat large flour particles may be evaluated by QUENCHER_ABTS assay by adopting a proper calculation mode

Assessment of Antioxidant Capacity (AC) of foods is useful to consider cumulative/ synergistic action of all dietary antioxidants, thus providing a more integrated information than the simple sum of measurable antioxidants. Among the different AC assays, the QUENCHERABTS (QUick, Easy, New, CHEap and Reproducible) procedure is based on the direct reaction of ABTS•+ reagent with fine solid food particles without extraction of antioxidants. This assay is able to measure both soluble and insoluble antioxidants, that simultaneously come into contact with ABTS•+ molecules by either liquid–liquid or solid–liquid interactions, respectively. These interactions may change depending on the particle diameter. Usually, particles having 0.1–0.3 mm size are used. Here, AC was evaluated on whole flour (WF), derived from a mix of grains of ten durum wheat varieties, characterized by three different particle sizes: a smaller one, ≤0.2 mm (control, WF0.2), and two larger ones, ≤0.5 mm and ≤1 mm (WF0.5 and WF1, respectively). Moreover, a novel AC calculation procedure based on the slope value of the regression line of ABTS•+ response vs flour amount is presented in detail. The classical QUENCHERABTS procedure provided for WF0.2 an AC value of 42.0±2.7 μmol eq. Trolox/g d.w. A similar result was obtained for WF0.5 (38.3±0.9 μmol eq. Trolox/g d.w.), thus indicating that these large particles may be analyzed by the QUENCHERABTS assay provided that the “slope” calculation procedure is used. On the contrary, WF1 showed about half AC (20.3±0.2 μmol eq. Trolox/g d.w.), thus showing that very large particles cannot be used even adopting the “slope” calculation

Study of different technological strategies for sugar reduction in muffin addressed for children

To exceed in sugar consumption is one of the main causes of overweight and obesity, especially for children and adolescent. However, sugar reduction, especially in baked goods, is challenging due to its effect not only on sensorial properties but also for other quality parameters. Multiple technological strategies to obtain muffins at low sugar content addressed for children were studied. Specifically, the inhomogeneous spatial distribution of sucrose (1, 3 and 5 layers of food formula at different sugar content), the taste enhancement by vanillin addition (0, 1 and 2%) and the use of different particle size of sugar (200, 400 and 600 μm) were investigated through a Box-Behnken design. Physical attributes were negatively affected by spatial distribution due to the substantial role of sucrose in the expansion of muffins. Indeed, maximum height of homogeneous muffins was of 37.8 ± 3.9 mm, while in inhomogeneous samples reached values of ≈ 30 mm. The low expansion of inhomogeneous muffins was also attested by porosity fraction which notably decreased from 68.2% in 1-layer muffin to 58.4% and 65.6% in 3-layers and 5-layers muffins, respectively. The perception of sweetness was improved for the inhomogeneous muffins and with a mass fraction of added vanillin at 1% confirming its great potential as taste enhancer, especially when using particle size of sugar less than 400 μm. Based on sensorial and physical data, stratified muffins with 3 layers, a mass fraction of added vanillin at 1% and sugar particle size in the range between 200 and 600 μm, showed excellent results. The proposed strategy could be used to design and develop innovative muffins designed for children contributing in the reduction of sugar intake in the daily diet

Extending the 3D food printing tests at high speed. Material deposition and effect of non-printing movements on the final quality of printed structures

3D Food Printing has unprecedented ambitions but for its practical use the increase of the speed of material deposition is a challenge to tackle. We have extended the information on this aspect by using a workflow that analyzes the screw-based deposition, at medium-high speed and the effect of some undervalued variables on the quality of 3D printed cereal-based structure. The most familiar approach utilized to compute the right extrusion rate for a good replica of the 3D virtual model completely fails at high print speed. Improvements would be possible only by using a flow of 300% or by changing, as input data, the diameter of filament at 1.0 mm. However, additional irregularities are caused by undervalued variables such as retraction distance being the most important for the printing quality while the travel speed and retraction speed are crucial to reduce printing time. Finally, desirability approach was able to define the conditions capable to get a maximum desirability of 0.85 at speed of 200 mm/s

Programmable texture properties of cereal-based snack mediated by 3D printing technology

3D food printing (3DFP) creates edible structures by a layer-by-layer deposition with the main aim of creating personalized food structures. We studied the capability to create 3D printed cereal snacks with different texture by a controlled generation of pores. The snacks well captured the overall features of the virtual model with size reduction less than 8%. Contrarily, the 3D printed snacks exhibited a great increase in porosity fraction, from 5 to 25%, while the pore's length reduced due to the crushing of dough's filament. The hardness of the snacks reduced from 289 N to 84 N following the reduction of the relative density, from 0.569 to 0.401. The model of Gibson and Ashby satisfactory fitted the experimental data showing that printed snacks with controlled voids follow the rule of cellular material. The results open interesting perspectives of creating novel foods with desired texture addressing specific requirements, or novel sensory/satiety perception

From biorefinery of microalgal biomass to vacuum impregnation of fruit. A multidisciplinary strategy to develop innovative food with increased nutritional properties

A multi-disciplinary approach based on the biorefinery of microalgae biomass (Chlorella sorokiniana) to remove the lipid fraction responsible of the green color and the ‘fishy’ aroma and vacuum impregnation technique to create innovative apple snacks with improved nutritional properties has been investigated. The pressure (150 mbar – 650 mbar), vacuum time (1–7 min) and relaxation time (3–13 min) were modulated by using a Box-Behnken experimental design. The filling of apple pores occurred with a maximum gaining weight of 19.5% and a reduction of porosity fraction from 15.32% to less than 5% but only the pressure and relaxation time significantly affect the level of impregnation. While the texture did not show any difference compared to fresh apples, the color of impregnated apple was affected with minor change in comparison. Industrial relevance: Results positively fuel the food chain sustainability by proposing multidisciplinary tools that combine microalgae cultivation, biorefinery and vacuum impregnation processing capable to improve the nutritional quality of fruit products. Biorefinery is proved to be an essential technology for fractionating chemical compounds from raw microalgae and improving their potential use in food industry as source of nutrient by eliminating some undesired components such as lipid fractions related to the fishy aroma. Finally, the obtained results may be used as basic protocols for the optimization of VI treatments aiming to enrich fruit product of proteins and micronutrients

Analyzing the effects of 3D printing process per se on the microstructure and mechanical properties of cereal food products

3D Food Printing has gaining interest to create food with personalized properties. In order to customize the texture it is necessary to explore whether and how 3D printing process per se has consequences on the mechanical features. As test case, a cubical cereal-based structure was manufactured by traditional processing and 3D printing. Microstructure properties and mechanical attributes were analyzed. Here we show that 3D printing clearly affects the microstructure generating bigger pores, less in number and like-round in shape. Also, we have observed that the positions of the pores are greatly driven by the printing movements. These features significantly affect the mechanical properties of 3D samples showing high hardness, chewiness and cohesiveness. The obtained data have been linked and interpreted on the basis of three main key-points: 1. the printing path; 2. the imbalance between speed printing and extrusion rate; 3. the compression of the food formula in the extrusion system. These findings should be considered for creating food with innovative texture perceptions. Industrial relevance: The creation of 3D printed food with programmed texture has the ambitions of getting personalized properties improving industry competitiveness by novel texture perceptions and also helping to mitigate swallowing or mastication problems of vulnerable peoples. Here we show that 3D Printing process per se – intrinsically – modifies the morphology and the distribution of pores in 3D structure thereby affecting the texture of cereal-based snacks. All these because pores generation is not ‘randomly’ distributed as for traditional manufacturing methods but driven by printing movements previously planned during the slicing of digital model. With the aim to get personalized food texture the intimate relationship between the movements of printing and the food texture shall taken into account by interested industries and producers

Analyzing the most promising innovations in food printing. Programmable food texture and 4D foods

With the increase of the published scientific results, 3D food printing is suddenly growing with many opportunities and possibilities to contribute to the current challenges of the food system. We present a brief review focused on two promising applications that are drawing where and how food printing is currently evolving: 4D food printing and the creation of programmable food texture. We found an interesting number of scientific documents regarding 4D foods generating changes of colour, shape, dimension, aroma and nutritional content. Among others, these changes are activated by many external stimuli such as acid/alkaline conditions, the anisotropic behaviour of printed materials during drying, but further experiments and discussions are still needed considering the effect of such stimuli on other important points such as safety and quality parameters. Contrarily, very few results have been published on the programmable food texture, but these few allow us to glimpse breakthrough innovations capable to completely renew the texture perception and mechanical properties of food products with extreme benefits for market innovation and consumer's desires and needs such as the creation of a fragile structure for people suffering dysphagia