Preparation and characterization of corn flours with variable starch digestion

Effects of zein extractions on the structural properties of SPI-zein composite gels: Implications for gluten-free plant-based products

The growing global interest in physical and environmental health has led to the development of plant-based products. Although soy protein and wheat gluten are commonly utilized, concerns regarding gluten-related health issues have driven exploration into alternative proteins. Zein has emerged as a promising option. This research investigated the impact of extraction methods on zein characteristics and the structures of SPI-zein composite gels. Different extraction methods yielded zein with protein contents ranging from 48.12 % to 64.34 %. Ethanol-extracted Z1 and Z3, obtained at different pH conditions, exhibited zeta potential of -3.25 and 5.43 mV, respectively. They displayed similar characteristics to commercial zein and interacted comparably in composite gels. Conversely, alkaline-extracted Z2 had a zeta potential of -2.37 mV and formed distinct gels when combined with SPI. These results indicated that extraction methods influence zein behaviour in composite gels, offering possibilities for tailored formulations and expanding zein's applications, particularly in gluten-free plant-based products.

In vitro gastrointestinal digestion methods of carbohydrate-rich foods

The trend toward healthier food products has led to an increase in the research of in vitro gastrointestinal digestion methods. Among the most used models, static models are the simplest. Most static models have three stages: oral, gastric, and intestinal, simulating the enzymatic, electrolyte, pH, temperature, and bile salt conditions. The studies that have taken the most notice are those related to antioxidant activity, followed by those dealing with proteins and carbohydrates using most of them static in vitro digestion models. The number of these studies has increased over the years, passing from 45 to 415 in a 10-year period (2012-2023) and showing an interest in knowing the impact of food on human health. Nevertheless, published papers report different methodologies and analytical approaches. This review discusses the similarities and differences between the published static in vitro gastrointestinal digestion methods, with a focus on carbohydrates, finding that the most used protocol is Infogest, but with differences, mainly in the type of enzymes and their activity. Regarding in vitro gastrointestinal digestion of carbohydrates, many of the published studies are related to food and biomacromolecules, being the oral phase the most omitted, while the intestinal phase in the most diverse. Other methodologies to study the intestinal phase have been recommended, but the number of in vitro digestion studies using these methodologies (RSIE and BBMV) is still scarce but could represent a good alternative to analyze carbohydrates foods when combining with Infogest. More studies are required in this area.

Purple red rice bran anthocyanins reduce the digestibility of rice starch by forming V-type inclusion complexes

Purple red rice bran, a by-product of the rice polishing process, contained abundant anthocyanins. However, most of them were discarded resulting in a waste of resources. This study investigated the effects of purple red rice bran anthocyanin extracts (PRRBAE) on the physicochemical properties and digestive properties of rice starch and its mechanism of action. Infrared spectroscopy and X-ray diffraction indicated that PRRBAE could interact with rice starch through non-covalent bonds to form intrahelical V-type complexes. The DPPH and ABTS⁺ assays showed that PRRBAE could confer better antioxidant activity on rice starch. In addition, the PRRBAE could increase the resistant starch content and decrease the enzyme activities by changing the tertiary and secondary structure of starch-digesting enzymes. Further, molecular docking suggested that aromatic amino acids play a key role in the interaction of starch-digesting enzymes with PRRBAE. These findings will contribute to a better understanding of the mechanism of PRRBAE reducing starch digestibility, and to the development of high value-added products and low glycemic index (GI) foods.

Sulfur functionality-modified starches: Review of synthesis strategies, properties, and applications

Starch is the second most abundant naturally-occurring polymer after cellulose that possess superior physicochemical and biological features with numerous practical applications ranging from industrial to biomedical. Despite, native starch suffer from some drawbacks, including difficult processability, low shear and thermal stability, weak mechanical properties, and tendency to easily retrograde and undergo syneresis. Therefore, modification of native starch is necessary for circumvent the above-mentioned problems and expanding application ranges. This natural polymer can be modified using chemical, physical, enzymatic, and genetic engineering strategies. Amongst, chemical approaches have received more attention owing to enhancing physicochemical and biological features that lead to higher performance than those of the other strategies. In this context, incorporation of sulfur functionality-containing groups (sulfonation and sulfation) can be considered as an efficient approach due to significant enhancement in physiochemical properties, including zeta potential (move to negative values), molecular weight, processiability (e.g., solubility and meltability), and rheology. Furthermore, this strategy can modified some biological features, such as hemocompatibility, protein sorption, biostability, adhesion and proliferation of numerous cells, antithrombogenicity, antiinflammatory, antiviral, antimicrobial, antioxidant, antifungal, anticoagulant and antifouling properties. Accordingly, this review highlight's the synthesis strategies, physiochemical and biological properties, as well as applications of sulfur functionality-modified starches in numerous practical fields.