Changes in the physicochemical properties of barley and oat starches upon the use of environmentally friendly oxidation methods

Debranching by enzymatic extrusion of oat flour for enhanced amylose-lipid complex formation: Effects on in vitro digestibility and functional properties

The amylose-lipid complex, also known as resistant starch type 5, is classified as dietary fibre with well-recognized health benefits. This study investigated its formation in pre-gelatinized whole oat flour using enzymatic extrusion-debranching and evaluated its effects on in vitro digestibility and functional properties. Whole oat grains were cooked in a steam oven, dried, ground, blended with pullulanase (60 U/g), and extruded enzymatically. Enzymatic extrusion increased oat flour's amylose content from 16.71 % to 26.93 % and resistant starch from 6.87 % to 31.99 %. Enzyme-extruded oat flour exhibited a V-type crystallinity pattern, confirmed amylose-lipid complex formation, and showed good thermal stability with two endothermic peaks at 90-110 °C and 110-130 °C. Additionally, enzymatic extrusion reduced the flour's viscosity and increased the water solubility index. These findings confirm that pullulanase extrusion effectively enhances resistant starch in lipid-rich cereal flour.

Oxygen promotes radical-mediated heterogeneous hygrothermal degradation of konjac glucomannan: Molecular structure and influence mechanism

Heterogeneous hygrothermal degradation (HHTD) efficiently produces partially depolymerized konjac glucomannan (KGM). However, KGM degrades considerably faster in oxygen-containing air packaging than in oxygen-free vacuum packaging. This study investigated the effects of different atmosphere conditions on the molecular structure of KGM and the radicals involved in its degradation system. Results indicated that the presence of oxygen increased the CO generation in depolymerized KGM molecules and the chain conformation parameters α and β values but lowered the df value. The radical type responsible for the HHTD of KGM in different atmosphere conditions was primarily carbon-centered radicals with a g-factor of 2.0033. The relative radical intensity increased with increasing treatment temperature and time. The presence of oxygen dramatically enhanced the HHTD efficiency of KGM by increasing the radical generation rate in the degradation system. Therefore, the HHTD of KGM was a radical-mediated thermo-oxidative degradation reaction, and convenient air-containing heat-sealed packaging could achieve efficient HHTD similar to pure oxygen packaging. This study provides insight into the mechanism by which oxygen influences the HHTD of KGM, highlighting the great potential of HHTD as an efficient and convenient method for KGM degradation.

Relationship Between Physical Characteristics of Cereal Polysaccharides and Soft Tribology-The Importance of Grain Source and Malting Modification

Starch and non-starch polysaccharides ((N)SPs) are relevant in cereal-based beverages. Although their molar mass and conformation are important to the sensory characteristics of beer and non-alcoholic beer, their triggering mechanism in the mouth is not fully understood. Soft tribology has emerged as a tool to mimic oral processing (drinking). The contribution of each (N)SPs to the friction coefficient can be determined when they are enzymatically isolated and characterized by chromatography techniques. Thus, this work aimed to study the relationship between the physical characteristics of isolated (N)SPs and their possible contribution to oral processing through soft tribology (friction). To accomplish this, this research analyzes the effect of grain source (barley, wheat, and oats) and its modification (by steeping degree at two levels) to the (N)SPs´ physical characteristics in wort produced on a laboratory scale. Different characteristics were present in the (N)SPs due to the grain source and the degree of modification. When comparing the impact of the grain source, the malted oats showed the highest molar masses. A higher modification degree produced smaller and more compact structures except for wheat's arabinoxylans and dextrins. The conformation ratio (r rms / r hyd ) values indicate the existence of sphere and micro-gel structures within each (N)SPs, with branches in arabinoxylans and dextrins. Subsequently, soft tribology was measured on all the worts and their correlation to the (N)SPs' data was performed by multivariate analysis. The wort produced with high modification grains generated higher friction responses. However, this was only statistically significant in barley samples. The multivariate analysis showed that within the mouth (tongue) velocity, the apparent density of the (N)SPs, and the molar mass of arabinoxylans and β-glucans may influence the friction response and, hence, the oral processing in the mouth during oral processing (drinking).

Functionalization Methods of Starch and Its Derivatives: From Old Limitations to New Possibilities

It has long been known that starch as a raw material is of strategic importance for meeting primarily the nutritional needs of people around the world. Year by year, the demand not only for traditional but also for functional food based on starch and its derivatives is growing. Problems with the availability of petrochemical raw materials, as well as environmental problems with the recycling of post-production waste, make non-food industries also increasingly interested in this biopolymer. Its supporters will point out countless advantages such as wide availability, renewability, and biodegradability. Opponents, in turn, will argue that they will not balance the problems with its processing and storage and poor functional properties. Hence, the race to find new methods to improve starch properties towards multifunctionality is still ongoing. For these reasons, in the presented review, referring to the structure and physicochemical properties of starch, attempts were made to highlight not only the current limitations in its processing but also new possibilities. Attention was paid to progress in the non-selective and selective functionalization of starch to obtain materials with the greatest application potential in the food (resistant starch, dextrins, and maltodextrins) and/or in the non-food industries (hydrophobic and oxidized starch).

Biopolymer from Water Kefir as a Potential Clean-Label Ingredient for Health Applications: Evaluation of New Properties

The present work aimed to characterize the exopolysaccharide obtained from water kefir grains (EPSwk), a symbiotic association of probiotic microorganisms. New findings of the technological, mechanical, and biological properties of the sample were studied. The EPSwk polymer presented an Mw of 6.35 × 105 Da. The biopolymer also showed microcrystalline structure and characteristic thermal stability with maximum thermal degradation at 250 °C. The analysis of the monosaccharides of the EPSwk by gas chromatography demonstrated that the material is composed of glucose units (98 mol%). Additionally, EPSwk exhibited excellent emulsifying properties, film-forming ability, a low photodegradation rate (3.8%), and good mucoadhesive properties (adhesion Fmax of 1.065 N). EPSwk presented cytocompatibility and antibacterial activity against Escherichia coli and Staphylococcus aureus. The results of this study expand the potential application of the exopolysaccharide from water kefir as a potential clean-label raw material for pharmaceutical, biomedical, and cosmetic applications.

Progress in Starch-Based Materials for Food Packaging Applications

The food packaging sector generates large volumes of plastic waste due to the high demand for packaged products with a short shelf-life. Biopolymers such as starch-based materials are a promising alternative to non-renewable resins, offering a sustainable and environmentally friendly food packaging alternative for single-use products. This article provides a chronology of the development of starch-based materials for food packaging. Particular emphasis is placed on the challenges faced in processing these materials using conventional processing techniques for thermoplastics and other emerging techniques such as electrospinning and 3D printing. The improvement of the performance of starch-based materials by blending with other biopolymers, use of micro- and nano-sized reinforcements, and chemical modification of starch is discussed. Finally, an overview of recent developments of these materials in smart food packaging is given.

Effect of cassava starch structure on scalding of dough and baking expansion ability

Fermented cassava products are important starchy food staples in South America. The quality of the products is affected by the baking expansion ability of the dough, which is in turn influenced by the starch fermentation process and drying method employed. We investigated the structural properties of cassava starch after different fermentation and drying treatments, and the effect of starch structure on scalding of dough and baking expansion ability. Fermentation combined with either exposure to sunlight or UV light treatment resulted in high cassava starch baking expansion. Moreover, we observed decreased crystallinity and increased disordered crystalline regions with lower molecular weight in the two types of starch-fermented combined with sunlight or UV light treatment-and both appeared to have a continuous network structure and polarized cross in scalded dough, which are conducive to holding gas and losing water, thus promoting high baking expansibility.

Modifying Effects of Physical Processes on Starch and Dietary Fiber Content of Foodstuffs

Carbohydrates are one of the most important nutrients in human consumption. The digestible part of carbohydrates has a significant role in maintaining the energy status of the body and the non-digestible parts like dietary fibers have specific nutritional functions. One of the key issues of food processing is how to influence the technological and nutritional properties of carbohydrates to meet modern dietary requirements more effectively, considering particularly the trends in the behavior of people and food-related health issues. Physical processing methods have several advantages compared to the chemical methods, where chemical reagents, such as acids or enzymes, are used for the modification of components. Furthermore, in most cases, these is no need to apply them supplementarily in the technology, only a moderate modification of current technology can result in significant changes in dietary properties. This review summarizes the novel results about the nutritional and technological effects of physical food processing influencing the starch and dietary fiber content of plant-derived foodstuffs.

Dual-process of starch modification: Combining ozone and dry heating treatments to modify cassava starch structure and functionality

This work evaluated for the first time the effect of dual modification of cassava starch by using ozone (O₃) and dry heating treatment (DHT). The dual modification was capable to promote fissures on the surface of the starch granule (DHT + O₃), affected the starch amorphous domains, presented greater degree of starch oxidation (DHT + O₃) and different profiles of starch molecular size distribution. These modifications resulted in starches with different properties. Moreover, the sequence of treatments was decisive for the hydrogel properties: while DHT + O₃ resulted in formation of stronger gels, O₃ + DHT resulted in weaker gels. In conclusion, this proposed dual modification was capable to produce specific modified starch when compared with the isolated treatments, also expanding the potential of cassava starch applications.