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This study investigated the formation mechanism of enzyme-resistant structures in extruded starch, specifically, fatty acid-starch complexes (FASCs). The effects of fatty acids (FAs) with different carbon-chain lengths (C12-C18) and degrees of unsaturation (C18:0-C18:2) on complex formation were evaluated, with fluorescence microscopy verifying complex formation. The complexed-lipid content and degree of relative crystallinity increased with the carbon-chain length and degree of FA unsaturation. FAs with fewer carbons were more likely to generate stable complexes (e.g., form II, melted at 100-120 °C), while FAs with more carbons tended to produce relatively unstable complexes (e.g., form I, melted at 80-100 °C). After reheating and cooling, a new amylose-lipid complex and an amylose-amylopectin network was formed in the unsaturated FASC samples, which restricted the penetration of enzymes into starch granules. A starch-linoleic acid complex exhibited the highest resistant starch content (15.7%) and lowest predicted glycaemic index (88.4)., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The development of gluten-free pasta with functional characteristics is an important strategic area for the food industry. The objective of this study was to evaluate the influence of the polyphenols present in blue maize flour (BMF) on the antioxidant properties and starch digestibility of composite gluten-free pasta. Composite pasta was prepared with 25, 50, or 75% BMF in a laboratory-scale process using white maize as the control. The addition of blue maize flour at 50% and 75% imparted high levels of protein, dietary fibre, and bioactive compounds with antioxidant capacity, which resulted in an increase in slowly digestible and resistant starch fractions in the gluten-free pasta. The anthocyanin content in BMF was positively correlated (p<0.05) with a decrease in the predicted glycaemic index. BMF is a readily available ingredient for the production of gluten-free pasta with high dietary fibre and slowly digestible starch contents that can contribute to reduce the risk for diet-related metabolic diseases. [ABSTRACT FROM AUTHOR]

The rate of carbohydrate digestion and the pattern of glucose release are very important in hyperglycaemic individuals. Grain structure, composition and the extent of processing are known to influence the rate of starch hydrolysis. By applying the kinetics of starch hydrolysis, predicted glycaemic index (pGI) was computed. Wheat products-cracked wheat (1058 ± 24 coarse semolina (724 ±15μ), fine semolina (460 ± 18μ), whole wheat flour (125 ±2μ), refined flour (75 ± 1μ) and rice productsbroken rice (1269 ±58μ), rice semolina (460 ±18μ) and rice flour (138 ± 4μ) were prepared for the study. Protein, dietary fiber and starch content of the wheat products varied depending on degree of grinding. The rate of starch hydrolysis was inversely proportional to particle size. The differences were significant in whole wheat products, refined flours and rice products. Predicted glycaemic index ranged from 60-73 for wheat products and 63-77 for rice products. Differential Scanning Calorimetry (DSC) analysis showed that enthalpy change of gelatinization of wheat and rice products with smaller particle size was higher than the products with larger particle size. The starch present in the products of larger particle size underwent hydrolysis more slowly than that of the products of smaller particle size. [ABSTRACT FROM AUTHOR]

BACKGROUND: Previous experiences revealed that increasing the amylose content through the substitution of normal amylose (NA) with high amylose (HA) flours can improve slowly digestible starch properties of cereal-based foods. However, data for wheat-based breads are not clear, since HA sources are frequently used in combination with organic acids and/or specific baking conditions know to reduce rate and extent of starch digestion. OBJECTIVE: The aim was to conduct an in vitro evaluation of starch digestibility of wheat-based breads characterised by increasing amylose levels. METHODS: Wheat-based breads were formulated with increasing amylose levels derived from the substitution of NA white wheat (NAWW) flour with HA maize starch (HAMS) represented by substitution ratio of 0%, 15% and 30% on a total flour basis. RESULTS: Dietary fibre increased (p < 0.05) whereas crude protein decreased (p < 0.05) when the level of HAMS increased in the recipe. The resistant starch and slowly digestible starch fractions increased (p < 0.05), whereas the predicted glycaemic index and the in vitro rate of starch hydrolysis decreased (p < 0.05) when HAMS increased in the formulation. CONCLUSIONS: Present findings suggested that the use of HA ingredients could contribute to formulate wheat-based breads with overall slowly digestible starch properties. [ABSTRACT FROM AUTHOR]

Different starchy foods are frequently consumed in the Mexican diet. Some of them were developed by Pre-Columbian Mesoamerican civilizations. Until today, common beans ( Phaseolus vulgaris), tortillas made with maize ( Zea mays) and related maize-based products are some of the main staple foods. Additionally, wheat-based foods are also important starch sources, incorporated in different dishes. This review deals with the in vitro digestibility of the starch fraction in foods commonly consumed in Mexico, paying attention to the addition of unconventional, natural raw materials, such as flour and starch from unripe banana, mango dietary fibre and common legumes. These ingredients enhance potential health-beneficial properties of the diet in cases of non-communicable diseases, particularly those related to obesity and glycaemic homeostasis. Since Mexico is among the countries with greatest indices of overweight and obesity, this paper reviews the in vitro starch availability features, including predicted GI, of various Mexican foods. Attention is also paid to the effect of cold storage conditions on starch digestibility. As an example, starch digestibility in blue maize tortillas (58%) is lower than in white tortillas (70-89%) and a maize tortilla/boiled bean composite dish ranks as a food with low predicted GI (pGI = 51). [ABSTRACT FROM AUTHOR]