Viscosity is an important rheological property, which may have impact on the glycemic response of starchy foods. However, the relationship between starch gels viscosity on its hydrolysis has not been elucidated. The aim of this work was to assess the effect of gels viscosity on the microstructure, and the kinetics of enzymatic hydrolysis of starch. Corn starch gels were prepared from starch:water ratios varying from 1:4 to 1:16. A structural model was proposed that correlated (R-square = 0.98) the porous structure (cavity sizes, thickness walls) of gels and its viscosity. Kinetics constants of hydrolysis decreased with increasing starch content and consequently with gel viscosity. Relationships of viscosity with the microstructural features of gels suggested that enzyme diffusion into the gel was hindered, with the subsequent impact on the hydrolysis kinetics. Therefore, starch digestibility could be governed by starch gels viscosity, which also affected their microstructure.

Health-driven innovation is transforming bakery products, particularly with non-conventional ingredients. This study aimed to produce healthy and technologically acceptable flatbreads, exploring the inclusion (2%) of vegetable powders (black and green olives, orange peel, lemon, tomato, beetroot, carrot, onion, artichoke, spinach, chard, kale and pak choi). Spinach and chard increased the mineral content (1.42 and 1.30 g/ 100 g) respect to control (1.01 g/100 g). Fibre content ranged from 9.33 to 11.18 g/100 g when added onion, chard, pak choi, tomato or artichoke. Beetroot was the most effective changing the colour (ΔE* 43.09), while tomato reduced the hardness (4.06 vs 5.29 N in the control). Lemon and tomato were effective reducing the extent of starch enzymatic hydrolysis by 65% and 34%, respectively. Vegetable powders can be innovative, natural, sustainable and healthy ingredients in the breadmaking of flatbreads. The incorporation of these non-conventional ingredients opens new opportunities for the bakery industry.

The main objective of this work is to study the effect of polyphenols, from the brown seaweed Ascophyllum nodosum, on the structure and digestion behaviour of gels at two corn starch concentrations (1.95 and 5.00% w/w) as well as the structure, color and texture features of crumbs from gluten-free breads. Adsorption isotherms of polyphenols on native and gelled starches were carried out and modelled by means of Langmuir and Henry models, respectively. The formation and characteristics of tested gels were rheologically monitored by means of heating ramp, time sweep at high temperature, cooling ramp and frequency sweep at 25 °C. Elastic modulus values decreased with the presence of polyphenols. Additionally, the polyphenols significantly decreased the digestion rate, measured by both chemical and rheological procedures, and the final concentration of digested starch. Finally, the presence of polyphenols in breads increased the hardness and chewiness values and decreased the cohesiveness and resilience values as well as the crumb hardening during storage.

Polyphenols have been often related with reducing starch digestibility. Gluten free breads are rich in starch, their enrichment in phenolic acids can modulate starch digestibility. Aim is to evaluate the effect of three powdered ingredients (artichoke, tomato, lemon) at varying concentrations (2, 5, and 10 g/100 g) on the technological and in vitro digestibility of gluten free flatbreads (FB). The polyphenols profile content of the FB was quantified, and they were correlated with in vitro starch digestion parameters. The incorporation of artichoke, tomato, lemon powders in FB reduced luminosity and hardness. Specific phenolic compounds were identified in artichoke FB (apigenin-7-O-glucoside, syringic acid, catechin gallate, luteolin-7-O-glucoside, and luteolin-7-O-rutinoside), and in lemon FB (eriocitrin and hesperidin). The principal component analysis indicated that lemon-enriched FB exhibited the lowest starch hydrolysis, potentially due to its acidic pH and polyphenols content. These functional ingredients provide a promising alternative to obtain innovative gluten free bakery products.