Consumers and the food industry are demanding healthier products. Expanded snacks with a high nutritional value were developed from different rice, pea and carob flour blends. The proximate composition, starch (total and resistant), amylose and amylopectin, dietary fiber (soluble and insoluble) contents, and the in vitro protein digestibility of different rice-legume formulations, were evaluated before and after the extrusion process. Compared with the corresponding non-extruded blends (control), the extrusion treatment did not change the total protein content, however, it reduced the soluble protein (61–86%), the fat (69–92%) and the resistant starch contents (100%). The total starch content of all studied blends increased (2–19%) after extrusion. The processing increased the in vitro protein digestibility, reaching values around 88–95% after extrusion. Total dietary fiber was reduced around 30%, and the insoluble fraction was affected to a larger extent than the soluble fraction by the extrusion process. Because of its balanced nutritional composition, high dietary fiber content, as well as low energy density, these novel gluten-free snack-like foods could be considered as functional foods and a healthier alternative to commercially available gluten-containing or gluten-free and low nutritional value snacks.
Legumes have been consumed since ancient times all over the world due to their easy cultivation and availability as a low-cost food. Nowadays, it is well known that pulses are also a good source of bioactive phytochemicals that play an important role in the health and well-being of humans. Pulses are mainly consumed after processing to soften cotyledons and to improve their nutritive and sensorial characteristics. However, processing affects not only their nutritive constituents, but also their bioactive compounds. The final content of phytochemicals depends on the pulse type and variety, the processing method and their parameters (mainly temperature and time), the food matrix structure and the chemical nature of each phytochemical. This review focuses on the changes produced in the bioactive-compound content of pulses processed by a traditional processing method like cooking (with or without pressure) or by an industrial processing technique like extrusion, which is widely used in the food industry to develop new food products with pulse flours as ingredients. In particular, the effect of processing methods on inositol phosphates, galactosides, protease inhibitors and phenolic-compound content is highlighted in order to ascertain their content in processed pulses or pulse-based products as a source of healthy phytochemicals.
1 March 2019 in Innovative Food Science & Emerging Technologies