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

Pasta is a carbohydrate-rich food with a low glycemic index (GI) and is one of the main sources of slowly digestible starch (SDS). The presence of bran fractions (BFs) in pasta may enhance its health potential, owing to the content of fiber, micronutrients, and bioactive compounds; however, at the same time, BF may affect starch digestibility. In this study, the bioaccessibility of starch in pasta made with BF-enriched semolina (BF pasta), or only with micronized debranned kernel (DK pasta), and a control pasta made with traditional semolina was evaluated by applying two different in vitro models. The control pasta showed a percentage of SDS about four-fold higher than that of the BF pasta and 1.5-fold higher than that of the DK pasta (p < 0.05). The amount of starch released during simulated gastrointestinal digestion was slightly lower, but not significantly different, for the control pasta than for both the BF and DK pasta. These results suggest that the presence of a higher amount of dietary fiber in BF pasta can affect the structure of the food matrix, interfering with the formation of the gluten network, water absorption, and starch granule accessibility, while micronization could enhance starch digestibility due to starch gelatinization. These findings emphasize the need to optimize the process for producing fiber-rich pasta without affecting its low starch digestibility and, consequently, its GI.

In vitro digestibility and the characteristics of puffed products from different degrees of milling and moisture content of adlay grain (Coix lacryma – jobi L.)

Adlay (Coix lacryma–jobi L.) is one of the cereals that can be developed into slowdigesting instant food. The degree of milling and moisture content of cereals can affect the digestibility of the food products. The purpose of this study was to determine the proper degree of milling and moisture content of adlay seeds so that a puffing product with high slowly digestible starch (SDS) content and organoleptic characteristics acceptable to the panelists was produced. This study used an experimental method consisting of two main treatments: the degree of milling (whole grain and polished) and the moisture content of adlay seeds (10%, 13%, 16%, and 19%). In vitro digestibility was measured by used pancreatic porcine α-amylase. The results showed that puffed adlay with the highest SDS and organoleptic characteristics that were still acceptable to the panelists was puffed polished adlay with an initial moisture content of 13%. The adlay puffed had SDS of about 35.98%, hardness 2795.83 gf, degree of gelatinization 67.90%, the moisture content of 5.94%, and rehydration power of 59.40%. The preferences for color, taste, aroma, and after-taste of adlay puffed were in the normal category while the texture was in the preferred category.

A systematic review of sweet potato-derived nutritional products for athletes

The sweet potato (Ipomoea batatas L. Lamarck syn. Convolvulus batatas L.) is a perennial, herbaceous climber with tuberous edible roots, and is a major leguminous crop of global importance with widespread applicability and economic value of its products in the global market. The aim of the presented investigations was to review the experimental articles and patents referring to the application of sweet potato-based nutritional products for athletes published in the period 2000–2020. Altogether, 69 patents and 12 experimental articles were included in the analysis. The statistical analysis showed that similar number of inventions was patented in periods 2000–2005, 2006–2010, 2011–2015 and 2016–2020. Generally, the inventors patented food supplements in different forms (e.g. bars, beverages, powders, snacks, tablets). Other authors invented methods of extraction and application of sweet potato constituents such as carbohydrates (i.a. slowly digestible starch) and polyphenols (i.a. anthocyanins). The empirical articles evidenced wide acceptability of sweet potato products due to their beneficial effects on health and performance such as improvement of cardiopulmonatory functions, prolongation of physical performance and recovery from fatigue. Despite growing interest in the application of sweet potato constituents in nutritional products for athletes, further investigations are highly desirable.

Impact of physical modifications on starch nutritional fractions: Rapidly Digestible Starch, Slowly Digestible Starch and Resistant Starch

The industrial utilization of native starches is limited because of their poor qualities and different starch modifications are used to improve functionality of starch. Physical modification of starch is preferred since it is simple, inexpensive, and specially it does not involve any chemical reagents. Physical modifications can be divided into thermal and non-thermal treatments. These techniques alter physicochemical properties of starch including in vitro digestibility, which indicates the nutritional value of starch. Starch nutritional fractions are of three types; RDS (rapidly digestible starch), SDS (slowly digestible starch) and RS (resistant starch). It is important to understand how physical modifications affect starch nutritional fractions as both SDS and RS have beneficial health effects and specially RS has the potential to be used as a natural bioactive compound. This review aims to summarize the recent knowledge regarding the physical modifications and their impact on in vitro digestibility and nutritional fractions of starch.

The Influence of Starch Modification with Amylosucrase Treatment on Morphological Features

Amylosucrase (AS) is a starch-modifying enzyme from Neisseria polysaccharea used to produce low-glycemic starches such as slowly digestible starch (SDS) and resistant starch (RS). The morphology of native, control, and AS-modified waxy corn starches (230 and 460 U) was examined using a particle size analyzer and field-emission scanning electron microscopy (FE-SEM). AS modification of the starch elongated the glucose and resulted in higher SDS and RS contents. The mean particle sizes of the control, 230 U-AS-, and 460 U-AS-treated starches were 56.6 µm, 128.0 µm, and 176.5 μm, respectively. The surface of the 460 U-AS-treated starch was entirely porous and coral-like, while the 230 U-AS-treated starch had a partial dense and flat surface which did not react with AS. FE-SEM of the granule cross section confirmed that the center contained a dense and flat region without any evidence of AS reaction to either of the AS-treated starches. It was assumed that the particle size and porous and sponge-like particle features might be related to the SDS and RS fractions.

Design and Validation of a Diet Rich in Slowly Digestible Starch for Type 2 Diabetic Patients for Significant Improvement in Glycemic Profile

This study aimed at designing a—diet high in slowly digestible starch (SDS) by carefully selecting high-SDS starchy products and to validate its implementation, acceptance, and impact on the postprandial glycemic response in patients with type 2 diabetes (T2D). Starchy products were screened and classified as being either high (high-SDS) or low (low-SDS) in SDS (in vitro SDS method). A randomized controlled cross-over pilot study was performed: Eight patients with T2D consumed randomly a high-SDS or a low-SDS diet for one week each, while their glycemic profile was monitored for 6 days. Based on 250 food product SDS analyses and dietary recommendations for patients with T2D, the high-SDS and low-SDS diets were designed. The high-SDS diet significantly increased SDS intake and the SDS/carbohydrates proportion compared to the low-SDS diet (61.6 vs. 11.6 g/day and 30% vs. 6%; p < 0.0001, respectively). Increasing the SDS/carbohydrate proportion to 50% of the meal was significantly correlated with a 12% decrease in tAUC0–120 min and a 14% decrease in the glycemic peak value (p < 0.001 for both). A high-SDS diet can be easily designed by carefully selecting commercial starchy products and providing relevant recommendations for T2D to improve their glycemic profile.