Effects of mixing, sheeting, and cooking on the starch, protein, and water structures of durum wheat semolina and chickpea flour pasta.

The influence of the pasta preparation stages on starch, proteins, and water structures of semolina and chickpea pasta was studied. The hydrated starch structures (995/1022 FTIR ratio) increased in semolina and reduced in chickpea pasta. The processing stages in semolina pasta led to a significant increase of ß-sheet structures (~50% to ~68%). The ß-sheet structures content in chickpea pasta was lower (~52%), and was most affected by sheeting and cooking. The water structure was assessed by the analysis of the OH fingerprint FTIR region (3700-2800 cm-1) and showing that water molecules (~90%) are strongly and moderately bound. The chickpea pasta displayed the highest content of strongly bonded water (about 55%) in contrast to the semolina pasta (~48%). A principal component analysis showed that the molecular organization of semolina pasta was mostly affected by dough formation and cooking; the molecular organization of chickpea pasta was determined by the cooking stage.

Addition of chickpea markedly increases the indigestible carbohydrate content in semolina pasta as eaten.

BACKGROUND: There is a growing interest in increasing dietary fiber (DF) consumption because of the health benefits associated with this nutrient. Pulses are considered a good source of non-digestible carbohydrates. The aim of this study was to investigate the possibility of substituting semolina with chickpea flour to increase indigestible carbohydrate content without altering the texture of the pasta. RESULTS: Pasta was prepared by extruding semolina-chickpea blends. The protein and DF content in the cooked pasta increased with the chickpea level, with an important contribution of resistant starch (RS) to the DF values. The optimum cooking time decreased as the chickpea content increased, which was related to the degree of starch gelatinization of the raw pasta. The in vitro digestible starch content decreased with the chickpea substitution level, concomitant with the increase in RS content. In general, the texture of the chickpea-containing pasta was similar to that of semolina pasta. CONCLUSIONS: Pending acceptability studies on these pastas may grant their promotion as good fiber sources, probably helpful in the fight against obesity and diet-related non-communicable diseases. © 2020 Society of Chemical Industry.

Extruded Unripe Plantain Flour as an Indigestible Carbohydrate-Rich Ingredient.

There is a growing interest in the development of functional ingredients, including those with high indigestible carbohydrate content. Unripe plantain flour (UPF) is a source of indigestible carbohydrates, type II resistant starch (RS) in particular. A major drawback of UPF, however, is that its RS content decreases sharply after wet heat treatment. Here, we explore the possibility of preparing an extruded UPF-based functional ingredient that retains limited starch digestibility features and high dietary fiber content. Both an unripe plantain pulp flour (UPFP) and a whole (pulp and peel) unripe plantain flour (UPFW) were prepared, extruded under identical conditions and evaluated for their gelatinization degree, total starch (TS), resistant starch (RS), and total dietary fiber (TDF) content; functional properties, such as pasting profile, water retention capacity, and solubility, and oil absorption index were also analyzed. The extruded functional ingredient was added to a yogurt and the rheological characteristics and in vitro starch digestibility of the product were evaluated. The extruded UPFW showed a lower gelatinization degree than the extruded UPFP, which may be due to the higher non-starch polysaccharide content of the former. A high TDF content was recorded in both extrudates (12.4% in UPFP and 18.5% in UPFW), including a significant RS fraction. The water retention capacity and solubility indices were higher in the extruded flours, particularly in UPFW, while only marginal differences in oil retention capacity were observed among the products. The addition of UPFP or UPFW (1.5 g TDF, w/v) to a yogurt did not alter the viscosity of the product, an important characteristic for the consumer's approval. Moreover, the composite yogurt showed a relatively low starch digestion rate. Extrusion of UPFs may be an alternative for the production of functional ingredients with important DF contents.