Traditional and Non-Conventional Pasta-Making Processes: Effect on In Vitro Starch Digestibility

Effect of shape, gluten, and mastication effort on in vitro starch digestion and the predicted glycemic index of pasta

Gluten-containing (GC) and gluten-free (GF) pasta consumption has been growing in recent years. The market offers a wide variety of pasta types, with differences in shape and formulation that influence the mastication process and, consequently, their nutritional behaviors (i.e. starch digestibility and glycemic response). This study investigated the effect of shape, gluten, and structural breakdown on in vitro starch digestibility and predicted the glycemic index (pGI) of GC and GF penne, spaghetti, and risoni. Pasta was cooked and minced to mimic short, intermediate, and long mastication efforts. Short mastication led to a higher number of big particles than intermediate and long mastications for all pasta samples, which was reflected in the different starch digestibility and pGI patterns. Multivariate analysis of variance showed that the three studied factors differently affected the in vitro starch digestion of pasta. Mastication effort, shape, and their interaction mainly affected the starch digestion rate and pGI. Gluten was the major factor in affecting the amount of digested starch. The results suggested that small shapes (i.e. risoni), the presence of gluten, and short mastication effort led to a lower pGI. The findings will be useful for the development of pasta products tailored to fulfill the needs of specific consumers following a rational food design approach.

Enhancing Nutritional Profile of Pasta: The Impact of Sprouted Pseudocereals and Cushuro on Digestibility and Health Potential

We hypothesized that optimizing the formulation of pasta by incorporating sprouted pseudocereal flours, specifically quinoa (Chenopodium quinoa Willd) or kiwicha (Amaranthus caudatus L.) and cushuro (Nostoc sphaericum Vaucher ex Bornet & Flahault) flours, could offer the potential to simultaneously enhance nutritional quality and health-promoting properties in pasta. In this study, our objective was to optimize the formulation of composite flour (a ternary blend of wheat, sprouted pseudocereal, and cushuro flours) using a mixture composite design to maximize total soluble phenolic compounds (TSPC), γ-aminobutyric acid (GABA), antioxidant activity, and mineral bioaccesilability by reducing phytic acid (PA) content. Two optimal formulations were identified: one consisting of 79% wheat flour (WF), 13% SQF, and 8% CuF (oPQC), and the other composed of 70% WF, 15% SKF, and 15% CuF (oPKC). These optimized pastas exhibited reduced starch content and notably higher levels of total dietary fiber (1.5-3.61-fold), protein (1.16-fold), fat (1.3-1.5-fold), ash (2.2-2.7-fold), minerals (K, Na, Fe, Zn, Mg, Mn, and Ca), PA (3-4.5-fold), TSPC (1.3-1.9-fold), GABA (1.2-2.6-fold), and ORAC (6.5-8.7-fold) compared to control pasta (100% WF). Notably, the glycemic index of oPQC (59.8) was lower than that of oPKC (54.7) and control pasta (63.1). The nutritional profile of the optimized pasta was largely retained after cooking, although some significant losses were observed for soluble dietary fiber (18.2-44.0%), K (47.5-50.7%), Na (42.5-63.6), GABA (41.68-51.4%), TSPC (8-18%), and antioxidant activity (45.4-46.4%). In vitro digestion of cooked oPQC and oPKC demonstrated higher bioaccessible content of GABA (6.7-16.26 mg/100 g), TSPC (257.7-261.8 mg GAE/100 g), Ca (58.40-93.5 mg/100 g), and Fe (7.35-7.52 mg/100 g), as well as antioxidant activity (164.9-171.1 µmol TE/g) in intestinal digestates compared to control pasta. These findings suggest that the incorporation of sprouted pseudocereals and cushuro flour offers a promising approach to enhance the nutritional quality and bioactive content of wheat-based pasta, potentially providing health benefits beyond traditional formulations.

Effect of the Pasta Making Process on Slowly Digestible Starch Content

The rate at which starch is digested in the human intestine elicits different glycemic responses and reflects the glycemic index (GI) of foods. In vitro measurement of starch digestibility can reflect the GI of food. Differences in starch digestibility among four durum wheat pasta samples, couscous, and bread were evaluated to better describe the role of the pasta making process in affecting starch digestibility. Statistical differences in RDS (rapidly digestible starch), SDS (slowly digestible starch), and RS (resistant starch) of products were found (p < 0.05). As expected, pasta samples showed the highest value of SDS/av starch compared to couscous and bread. Fusilli and cavatelli samples presented the highest SDS/av starch ratio (55.80 ± 3.06% and 53.91 ± 3.50%, respectively), then came spaghetti 49.39 ± 2.83% and penne 45.93 ± 1.19%, while couscous presented the lowest value of SDS/av starch (2.64 ± 0.50%), followed by bread (11.78 ± 2.63%). Our study confirmed that the pasta making process efficiently mediates an increase in SDS/Av starch content, which has been specifically quantified above 40%, therefore strongly related to a lowered glycemic response in vivo. Our results strengthened the concept that pasta is a good source of SDS, which makes it useful for glycemic control.

In vitro macronutrient digestibility and mineral bioaccessibility of lentil-based pasta: The influence of cellular intactness

Recently, pulse ingredients with (partial) cellular intactness are put forward as promising innovative food ingredients with slowed macronutrient digestibility. This study compared cooking quality and nutrient (starch, protein, and mineral) digestibility/bioaccessibility of lentil-based pasta prepared from 100% raw-milled flour, and by substituting 30% of the formulation by isolated cotyledon cell powder or whole precooked powder. Formulation had little effect on cooking properties. Both amylolysis and proteolysis were significantly slowed by incorporating cellular ingredients: towards the end of simulated digestion, amylolysis was lowered by 16-25%, while differences in proteolysis became small. Cellular ingredient incorporation slightly decreased Zn and Mg but did not affect Ca and Fe bioaccessibility, overall yielding a low mineral bioaccessibility comparable to cooked whole pulses. To conclude, lentil-based pasta substituted with cellular ingredients showed improved nutritional properties (i.e., high in digestible protein and slowed amylolysis), with perspectives for the development of different innovative foods with targeted nutritional properties.

Evaluation of Glycemic Index of Six Different Samples of Commercial and Experimental Pasta Differing in Wheat Varieties and Production Processes

Pasta is a staple food of the Mediterranean Diet, and it is traditionally made of durum wheat semolina. In Sicily, durum wheat production and its transformation into semolina, bread, and pasta are well-developed economic sectors. For pasta, there is a wide supply of commercial brands, whether coming from conventional industrial manufacturing or from medium to small and local handcrafted production. Both conventional durum wheat and local durum wheat landraces, such as Timilia and Russello, are used for pasta production, but local landraces are, for the most, transformed into handcrafted pasta. The market of local landraces durum wheat pasta has risen in recent decades, in Sicily and in Italy as well, boosted by a perceived high nutritional and healthy value of these wheat derivatives. In particular, a popular and scientifically unproven idea suggests that a reduced glycemic response might be elicited by these pasta landraces. Therefore, to test this hypothesis, the main objective of the present study was the evaluation of the glycemic index (GI) of four samples of Timilia and Russello handcrafted pasta and two samples of conventional durum wheat pasta. The study enrolled fourteen healthy weight male and female volunteers aged from 18 to 46; eight test sessions were performed twice a week, every session testing a pasta sample (six sessions) or the glucose solution chosen as reference food (two sessions). The standard methodology for GI measurement was followed during each step of the study. The six tested pasta samples were characterized regarding their composition (protein, fiber, and starch content) and their whole production processes (milling method and milling diagram of flour or semolina, drying temperature, and diagram of pasta shape). The six tested pasta samples showed GI values ranging from low (34.1) to intermediate (63.1). Timilia and Russello pasta are the first GI calculations available. The two samples made of conventional grains showed lower values of GI (34.1 and 37.8). The results do not support the popular idea of a reduced glycemic response elicited by Timilia and Russello wheat landrace pasta; the tested samples showed GI values in the range of 56.2 to 63.1. However, some consideration should be made of factors other than wheat varieties and related to production processes that may have affected the final GIs of the pastas. Even if the study is not designed to discriminate among factors related to wheat varieties or processes used to produce different pasta, it is a preliminary step in the characterization of the healthy potential of the local wheat landraces, popularly called ancient grain. A future implementation of the local wheat landraces supply chain should pay attention to all the factors above, from a better seed identity certification to the production process in order to further improve the healthy value of these staples of the Mediterranean Diet.