Influence of the incorporation of fibers in biscuit dough on proton mobility characterized by time domain NMR

Synergistic quantification of mixed insulin preparations using time domain NMR techniques

Diabetes patients often rely on tailored insulin therapies, necessitating precise blends of various insulin types to achieve optimal pharmacokinetic profiles, including the quantity and action duration of insulin absorption into the bloodstream. This study aimed to develop an accurate quantification method for mixed insulin preparations, consisting of Insulin-NPH and Insulin Regular in ratios varying between 0:100-100:0. Time Domain NMR (TD-NMR) techniques, T2 relaxation times, and T1T2 maps were used to analyze the mixtures. Individually, neither technique provided a reliable determination of insulin ratios. However, the integration of both methods through chemometrics has been proven to be a synergistic approach, yielding a robust quantification technique suitable for quality control in the assessment of mixed insulin drugs. This innovative combined TD-NMR method is non-invasive, cost-effective, and user-friendly, offering at the same time a significant potential for preventing health complications associated with improper insulin dosing. Furthermore, our work elucidates the broader applicability of converging multiple TD-NMR techniques for analyzing intricate mixtures.

Effects of food processing on in vitro glucose release of high methylester pectin-enriched doughs

The incidence of type 2 diabetes is linked to consuming processed, high-glycemic foods low in dietary fiber. Soluble dietary fibers are known to improve blood glucose tolerance. This study examined the impact of processing on the in vitro glucose release of fiber-rich, high-glycemic foods. The impact of composition and microstructure on in vitro glucose release and starch digestibility was evaluated in doughs - untreated, baked at 180 °C, and extruded at 150 °C and 180 °C - with partial enrichment of high-methylester pectin. Pectin enrichment decreased starch digestibility, altered the food matrix, and doubled in vitro chyme-viscosity resulting in reduced glucose release in baked (180 °C), and extruded (150 °C) products. Baking or extrusion cooking increased starch digestibility - converting slowly into rapidly available starch and free glucose. Additionally, resistant starch levels were enhanced by up to fivefold. The variations in glucose release originated from a complex interplay between starch digestibility, viscosity, and the food matrix.

Promising effects of β-glucans on gelation in protein-based products: A review

Gel property is one of the most important abilities to endow protein-based food products with a unique texture and higher overall acceptability. Cereal β-glucan (BG) is widely applied in protein-based products to improve the stability of the protein gel by increasing water holding capacity, storage modulus (G'), loss modulus (G") and linking with protein through more exposed sites, making it easier to form a stronger three-dimensional gel network. In addition, BG may be cross-linked with proteins, or physically embedded and covered in protein network structures, interacting with proteins mainly through non-covalent bonds including hydrogen bonding and electrostatic interaction. Furthermore, the transition of the α-helix to the β-form in the protein secondary structure also contributes to the stability of the protein gel. The practical applications of BG from different cereals in protein-based products are summarized, and the rheological properties, microstructure of protein as well as the underlying interaction mechanisms between BG and protein are discussed. In conclusion, cereal BG is a promising polysaccharide in developing nutritional protein-based products with better sensory properties.

Konjac glucomannan-dihydromyricetin complex improves viscosity and hydration capacity of konjac glucomannan as well as the thermal stability of dihydromyricetin

The nutritional benefits of soluble dietary fiber were mainly attributed to its viscosity and hydration capacity. This study was aimed to investigate the effects of the interaction between konjac glucomannan (KGM) and dihydromyricetin (DMY) on the viscosity and hydration capacity of KGM and the thermal stability of DMY. In contrary to most reports, the addition of DMY to KGM resulted in an increase of viscosity and hydration capacity determined via rheology and nuclear magnetic resonance spectroscopy characterization. Meanwhile the prototype retention of DMY in the presence of heating condition at 60 °C and 100 °C were improved. The radical scavenging capacity of DMY under heating condition was improved at 100 °C via the quantification of ABTS⁺ and DPPH. KGM-DMY complex was a non-covalent compound connected by hydrogen bonds which was characterized with particle size analyses, zeta potential analyses, transmission electron microscopy, infrared spectroscopy, X-ray diffraction, and isothermal titration calorimetry. This study was beneficial to the development of polyphenol-enriched nutrition based on KGM, especially in the aspects of satiety, appetite regulation and glucose regulation.

The use of time domain 1 H NMR to study proton dynamics in starch-rich foods: A review

Starch is a major contributor to the carbohydrate portion of our diet. When it is present with water, it undergoes several transformations during heating and/or cooling making it an essential structure-forming component in starch-rich food systems (e.g., bread and cake). Time domain proton nuclear magnetic resonance (TD ¹ H NMR) is a useful technique to study starch-water interactions by evaluation of molecular mobility and water distribution. The data obtained correspond to changes in starch structure and the state of water during or resulting from processing. When this technique was first applied to starch(-rich) foods, significant challenges were encountered during data interpretation of complex food systems (e.g., cake or biscuit) due to the presence of multiple constituents (proteins, carbohydrates, lipids, etc.). This article discusses the principles of TD ¹ H NMR and the tools applied that improved characterization and interpretation of TD NMR data. More in particular, the major differences in proton distribution of various dough and cooked/baked food systems are examined. The application of variable-temperature TD ¹ H NMR is also discussed as it demonstrates exceptional ability to elucidate the molecular dynamics of starch transitions (e.g., gelatinization, gelation) in dough/batter systems during heating/cooling. In conclusion, TD NMR is considered a valuable tool to understand the behavior of starch and water that relate to the characteristics and/or quality of starchy food products. Such insights are crucial for food product optimization and development in response to the needs of the food industry.

Biscuits: a systematic review and meta-analysis of improving the nutritional quality and health benefits

Biscuits are ready-to-eat foods that are traditionally prepared mainly with wheat flour, fat, and sugar. Recently, biscuits’ technologies have been rapidly developed to improve their nutritional properties. This study aimed to determine the strategies of improving the nutritional quality of biscuits and the potential health benefits associated with them. A systematic review and meta-analysis were conducted, including articles on biscuits improved by technological processes and raw materials variation. Studies were searched from Google Scholar, PubMed, Scopus, and Web of Science published between 1997 and 2020, in English and French. The meta-analysis was performed using RStudio software, version 4.0.4 to classify the biscuits. One hundred and seven eligible articles were identified. Rice, pea, potato, sorghum, buckwheat, and flaxseed flours were respectively the most found substitutes to wheat flour. But the meta-analysis shown that the copra and foxtail millet biscuit fortified with amaranth, the wheat biscuits fortified with okra, and rice biscuits fortified with soybeans had a high protein content. These biscuits therefore have a potential to be used as complementary foods. The substitution of sugar and fat by several substitutes lead to a decrease in carbohydrates, fat, and energy value. It has also brought about an increase in other nutrients such as dietary fiber, proteins/amino acids, fatty acids, and phenolic compounds. Among the sugar and fat substitutes, stevia and inulin were respectively the most used. Regarding the use of biscuits in clinical trials, they were mainly used for addressing micronutrient deficiency and for weight loss.

Development of a separated-dough method and flour/starch replacement in gluten free crackers by cellulose and fibrillated cellulose

Two strategies were combined and applied in this study to achieve a desired structure and texture of gluten free crackers and to reduce the calorie content. The first strategy is increasing structural heterogeneity of crackers and doughs and a separated-dough method was developed. A butter dough and a water dough were prepared separately and mixed together and the influence of mixing time was investigated. In the second strategy, which is the incorporation of a structuring material, powdered cellulose and fibrillated cellulose were incorporated in formulation to replace flour and pregelatinised starch with enhanced health benefits of low calorie and high fibre. Powdered cellulose played the role of the skeleton of the gluten free crackers. A laminar structure was observed in crackers when powdered cellulose was initially added to the butter dough. The crackers exhibit high thickness, hardness and fracturability and sharp sound emission which are typically observed in wheat crackers. Pregelatinised starch can be replaced by fibrillated cellulose at a lower addition level.

Effect of phosphate salts on the gluten network structure and quality of wheat noodles

The effects of three phosphate salts (PS) on the secondary structure, microstructure of gluten, rheological properties of dough and water status of noodles were investigated to determine the mechanisms underlying the changes in the quality of noodles. Changes in the secondary structure detected were the increased number of β-sheet and decreased number of random coil structures. PS reduced the content of free sulfhydryl (SH) and increased the content of disulfide (SS) bonds. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis indicated that the band density of the high molecular regions of the gluten was reduced. The results showed that adding PS induced a more compact microstructure and improved the G' and G'' values of the dough. After adding PS, the water-solids interaction in noodles was enhanced by the decreased water mobility. It was concluded that PS promoted the water holding capacity of the noodles and strengthened the gluten network.

Insight into molecular and rheological properties of sprouted sorghum flour

This work investigated the effect of sprouting and drying post-sprouting on technological functionalities of sorghum flour as probed by Low-resolution Proton Nuclear Magnetic Resonance (¹H NMR) and Dynamic Mechanical Analysis (DMA). Multivariate statistics were used to assess the effect of flour (from sprouted and unsprouted sorghum, and wholewheat) and hydration level on flour-water systems molecular and viscoelastic properties. Overall, sorghum-based systems showed greater molecular mobility explaining poorer viscoelastic properties than those obtained from wheat. Sprouting affected the molecular properties of sorghum flour-water systems, while no differences were observed in the two sprouted samples dried in different conditions. However, sprouting did not affect the viscoelastic properties of sorghum-water systems. These results bolster the use of sprouted sorghum in composite flours for the development of sustainable finished products with high nutritional value and satisfactory technological and organoleptic properties.

The quality of gluten-free bread made of brown rice flour prepared by low temperature impact mill

Our previous work reported that the brown rice flour prepared by low temperature impact mill possessed excellent physicochemical properties. The performance of brown rice flour in making gluten-free bread was further investigated. It was found that the starch crystal structure was destroyed and the damaged starch content increased as the particle size of brown rice flour decreased. The interaction between the starch and water in the model dough and the matrix structures among the endosperm masses were enhanced as the particle size decreased, making the gluten-free dough more viscoelastic. However, dough made with finer flour was too sticky, which limited the expansion of dough. Gluten-free bread prepared with medium-sized brown rice flour had favorable quality characterized by large specific volume, low hardness, numerous and homogeneous gas cells.

Use of the 1H NMR technique to describe the kneading step of wholewheat dough: The effect of kneading time and total water content

The kneading step of wholewheat flour (WWF) dough was monitored using low-resolution ¹H nuclear magnetic resonance (NMR). The tested variables were kneading time and total water content. Two ¹H Free induction decay (FID) (A and B) and four ¹H T₂ Car-Purcell-Meiboom-Gill (CPMG) (C, D, E and F) proton populations were observed and the attribution to the different proton domains was made based on the literature and data acquisition. Kneading time significantly increased the mobility and the relative abundance of popA, the relative abundance and strength of protons of popC, D and E, while significantly reducing the relative amount of popF and increasing its mobility. This evolution of the proton populations during kneading was interpreted as chemical/physical transformations of the flour constituents. The use of WWF may reveal the changes in molecular dynamics underlying the higher water requirements of unrefined doughs, often associated with improved bread quality.

Impact of enrichment with egg constituents on water status in gluten-free rice pasta - nuclear magnetic resonance and thermogravimetric approach

Effects of freeze-dried egg white, yolk and whole egg enrichment on water behaviour in fresh pasta dough, dried and cooked rice pasta with respect to control samples were studied by ¹H nuclear magnetic resonance (NMR) relaxometry and thermogravimetric analysis. Enrichments caused lower mobility of water (T₂) localised within the starch-protein matrix in fresh dough as well as dried pasta. Water compartmentalization was also downgraded in cooked products. Water fractions with different T₂ values were linked to temperature peaks at the first derivative of the thermogravimetric (DTG) curve. From the DTG curve strong interaction of water molecules with proteins of egg white was revealed. Egg proteins also influenced viscoelastic properties of dough, and enhanced the firmness and chewiness of cooked pasta. Structural changes induced by various types of enrichment were reflected in the different molecular mobility at the water-matrix interface (T₁). The enrichments also altered the colour and cooking properties.

Effect of formulation and baking conditions on the structure and development of non-enzymatic browning in biscuit models using images

The aim of this research was to determine the effect of composition (dietary fiber = DF, fat = F, and gluten = G) and baking time on the target microstructural parameters that were observed using images of potato and wheat starch biscuits. Microstructures were studied Scanning Electron Microscope (SEM). Non-enzymatic browning (NEB) was assessed using color image analysis. Texture and moisture analysis was performed to have a better understanding of the baking process. Analysis of images revealed that the starch granules retained their native form at the end of baking, suggesting their in complete gelatinization. Granules size was similar at several different baking times, with an average equivalent diameter of 9 and 27 µm for wheat and potato starch, respectively. However, samples with different levels of DF and G increased circularity during baking to more than 30%, and also increasing hardness. NEB developed during baking, with the maximum increase observed between 13 and 19 min. This was reflected in decreased luminosity (L*) values due to a decrease in moisture levels. After 19 min, luminosity did not vary significantly. The ingredients that are used, as well as their quantities, can affect sample L* values. Therefore, choosing the correct ingredients and quantities can lead to different microstructures in the biscuits, with varying amounts of NEB products.

Multi-scale NMR and MRI approaches to characterize starchy products

This review deals with the use of Nuclear Magnetic Resonance techniques to monitor the behavior of starch as well as the migration and distribution of water during the processing or storage of starchy matrices. The aim is to emphasize the potentials of NMR techniques for the quantitative characterization of water transfers in starch-water systems on different length scales. Relaxation and self-diffusion experiments using low-field NMR spectrometry provided important information on the relationship between water dynamics and the microscopic organization of starch granules at various temperatures and water contents. Some works dealt with the botanical origin of starch but also the impact of possible additives. Indeed, the investigation on model starch-based systems was recently expanded to more complex real systems, including dough, bread, cakes, spaghetti and lasagna. Two-dimensional (2D) cross correlation methods have also been developed to elucidate chemical and diffusional proton exchange phenomena, and to improve the interpretation of results obtained in 1D. Finally, magnetic resonance micro-imaging methods were developed to study or to quantify water intake into starch-based matrices.

Effect of different fibers on dough properties and biscuit quality

BACKGROUND

This study forms part of a broader project aimed at understanding the role of fibers from different sources in high-fat, high-sugar biscuits and at selecting the best fibers for biscuit quality. The main purpose of this work was to understand the rheological and structural properties involved in fiber-enriched biscuit dough. High-amylose corn starch (RSII), chemically modified starch (RSIV), oat fiber (OF) and inulin (IN) were used at two different levels of incorporation (6 and 12 g) in dough formulation. The influence of fiber on the properties of biscuit dough was studied via dynamic rheological tests, confocal microscopy and spreading behavior. Biscuit quality was assessed by width/thickness factor, texture and surface characteristics, total dietary fiber and sensory evaluation.

RESULTS

Main results indicated that IN incorporation increased the capacity of dough spreading during baking and thus improved biscuit quality. OF reduced dough spreading during baking and strongly increased its resistance to deformation. RSII and RSIV slightly affected the quality of the biscuits. Sensory evaluation revealed that the panel liked IN-incorporated biscuits as much as control biscuits.

CONCLUSION

The increase in total dietary fiber modified dough behavior and biscuit properties, and the extent of these effects depended on the type of fiber incorporated. © 2016 Society of Chemical Industry.