Pasting properties of A- and B-type wheat starch granules and annealed starches in relation to swelling and solubility

Wheat starch contains two distinct groups of granules, A-type and B-type, which have different compositions and properties. The aim of this study was to investigate the differences in pasting properties of A- and B-type wheat starch granules and their annealed starches, and to relate them to swelling properties and solubility. A- and B-type wheat starch granules were fractionated. The differences in pasting properties between A- and B-type wheat starch granules depended on starch solids content. The A-type starch had a higher pasting viscosity at ≥8 % solids content, but the trend was reversed at a lower solids content (5 %). This cross-over phenomenon in the pasting viscosity can be explained because A-type wheat starch granules have more starch molecules leached out, while swelled less at high temperatures and are probably more rigid than B-type wheat starch granules. This is the first study to show the cross-over in the pasting viscosity-starch concentration between A-type and B-type wheat starches and that B-type wheat starch has higher pasting viscosity than A-type at a low solids content. When annealed in warm water, both annealed A- and B-type wheat starch granules had higher pasting viscosities than untreated counterparts by altering the swelling of starch.

Influence of Non-Thermal Plasma Treatment on Structural Network Attributes of Wheat Flour and Respective Dough

Due to its "generally recognized as safe status" (GRAS) and moderate treatment temperatures, non-thermal plasma (NTP) has lately been considered a suitable replacement for chemicals in the modification of food properties and for preserving food quality. One of the promising areas for the application of NTP is the treatment of wheat flour, leading to improved flour properties and product quality and consequently to higher customer satisfaction. In the present research, the German wheat flour type 550, equivalent to all-purpose flour, was treated using NTP in a rotational reactor to determine the influence of short treatment times (≤5 min) on the properties of flour (moisture and fat content, protein, starch, color, microbial activity, and enzymes), dough (visco-elastic properties, starch, wet and dry gluten, and water absorption), and baking products (color, freshness, baked volume, crumb structure, softness, and elasticity). Based on the properties of NTP, it was expected that even very short treatment times would have a significant effect on the flour particles, which could positively affect the quality of the final baking product. Overall, the experimental analysis showed a positive effect of NTP treatment of wheat flour, e.g., decreased water activity value (<0.7), which is known to positively affect flour stability and product shelf life; dough stability increased (>8% after 5 min. treatment); dough extensibility increased (ca. 30% after 3 min treatment); etc. Regarding the baking product, further positive effects were detected, e.g., enhanced product volume (>9%), improved crumb whiteness/decreased crumb yellowness, softening of breadcrumb without a change in elasticity, and limited microorganism and enzymatic activity. Furthermore, no negative effects on the product quality were observed, even though further food quality tests are required. The presented experimental research confirms the overall positive influence of NTP treatment, even for very low treatment times, on wheat flour and its products. The presented findings are significant for the potential implementation of this technique on an industrial level.

Mechanical, chemical, and bio-recycling of biodegradable plastics: A review

The extensive use of petroleum-based non-biodegradable plastics for various applications has led to global concerns regarding the severe environmental issues associated with them. However, biodegradable plastics are emerging as green alternatives to petroleum-based non-biodegradable plastics. Biodegradable plastics, which include bio-based and petroleum-based biodegradable polymers, exhibit advantageous properties such as renewability, biocompatibility, and non-toxicity. Furthermore, certain biodegradable plastics are compatible with existing recycling streams intended for conventional plastics and are biodegradable in controlled and/or predicted environments. Recycling biodegradable plastics before their end-of-life (EOL) degradation further enhances their sustainability and reduces their carbon footprint. Since the production of biodegradable plastic is increasing and these materials will coexist with conventional plastics for many years to come, it is essential to identify the optimal recycling options for each of the most prevalent biodegradable plastics. The substitution of virgin biodegradable plastics by their recyclates leads to higher savings in the primary energy demand and reduces global warming impact. This review covers the current state of the mechanical, chemical, and bio-recycling of post-industrial and post-consumer waste of biodegradable plastics and their related composites. The effects of recycling on the chemical structure and thermomechanical properties of biodegradable plastics are also reported. Additionally, the improvement of biodegradable plastics by blending them with other polymers and nanoparticles is comprehensively discussed. Finally, the status of bioplastic usage, life cycle assessment, EOL management, bioplastic market, and the challenges associated with the recyclability of biodegradable plastics are addressed. This review gives comprehensive insights into the recycling processes that may be employed for the recycling of biodegradable plastics.

Optimization of Microwave Pre-Cooked Conditions for Gelatinization of Adzuki Bean

Pre-cooked adzuki beans (Vigna angularis), which looks like dried adzuki bean, is easily cooked and preserved. This study aimed to optimize the microwave pre-cooked conditions on adzuki beans by applying the response surface methodology. The results showed that soaking time has a significant effect on the gelatinization degree of adzuki beans according to microwave time. The most suitable gelatinization and the sensory scores were obtained with a soaking time of 7.8 h, a microwave power of 830 W, and microwave time of 92 s. The pre-cooked treatment had no significant effect (p > 0.05) on the protein, free amino acid, fat and starch content of adzuki bean products. The results of SEM and polarized light microscopy showed that the surface and center of starch were damaged after microwave treatment. XRD showed that microwave pre-cooking did not change the crystal structure of starch and maintained the original order of type A structure while reducing the relative starch crystallinity. FT-IR showed that the pre-cooked treatment did not produce new structure in adzuki bean starch, but the ratio of 1047/1022 cm^-1 was slightly decreased, indicating that the starch crystallization area decreased relative to the amorphous area and the relative crystallinity decreased. The results of FTIR were consistent with X-ray diffraction results. Therefore, microwaves improved the gelatinization of adzuki beans and made the pre-cooked adzuki beans more suitable.

The influence of Konjac glucomannan on the functional and structural properties of wheat starch

The aim of this study was to characterize the influence of Konjac glucomannan (KGM) on the functional and structural properties of wheat starch. Results showed that KGM significantly decreased the starch hydrolysis rate, with a lower level of rapidly digestible starch (RDS), and a higher content of slowly digestible starch (SDS). Besides, KGM decreased the content of leached amylose, while enhanced the swelling power, water-holding capacity, freeze-thaw stability, and paste clarity of wheat starch, which indicated a good improvement on the functional properties. Differential scanning calorimetry (DSC) and X-ray diffraction patterns (XRD) manifested that the addition of KGM disrupted the original crystalline structures of wheat starch, which may result in the increased hydrolysis rate of starch. Interestingly, this did not consist with the decreased starch hydrolysis rate showed in the study. Moreover, FTIR results showed the existence of the interaction between KGM and starch. The morphological characterization demonstrated that the addition of KGM contributed to a more compact structure of freeze-dried wheat starch. And KGM inhibited the expansion of starch granules and formed a barrier around the gelatinized starch. Therefore, the barrier around the starch granules and the interaction between KGM and starch were considered to be the important reasons that affected the starch digestibility.

Amylose-Free ("waxy") Wheat Colonization by Fusarium spp. and Response to Fusarium Head Blight

Hexaploid waxy wheat (Triticum aestivum L.) has null mutations in Wx genes and grain lacking amylose with increased digestibility and usability for specialty foods. The waxy cultivar Mattern is susceptible to Fusarium head blight (FHB) caused by Fusarium graminearum species complex, which produces the mycotoxin deoxynivalenol (DON). In experiment 1, conducted during low natural FHB, grain from waxy breeding lines, Mattern, and wild-type breeding lines and cultivars were assessed for Fusarium infection and DON concentration. Nine Fusarium species and species complexes were detected from internally infected (disinfested) grain; F. graminearum infections were not different between waxy and wild-type. Surface- and internally infected grain (nondisinfested) had greater numbers of Fusarium isolates across waxy versus wild-type, but F. graminearum-like infections were similar; however, DON levels were higher in waxy. In experiment 2, conducted during a timely epidemic, disease severity, Fusarium-damaged kernels (FDK), and DON were assessed for waxy breeding lines, Mattern, and wild-type cultivars. Disease severity and FDK were not significantly different from wild-type, but DON was higher in waxy than wild-type lines. Across both experiments, waxy breeding lines, Plant Introductions 677876 and 677877, responded similarly to FHB as moderately resistant wild-type cultivar Overland, showing promise for breeding advanced waxy cultivars with reduced FHB susceptibility.

Structural, morphological, functional and digestibility properties of starches from cereals, tubers and legumes: a comparative study

A comparison between structural, morphological, functional and digestibility studies of starches from cereals i.e. wheat (WS), corn (CS), low amylose corn (LACS) and rice (RS), tubers i.e. potato (PS) and sweet potato (SP), and legumes i.e. kidney bean (KB) were investigated. The shape of granules varied from oval to elliptical or spherical according to the source. Distribution of iso- amylase debranched materials revealed that long and short side chains fractions of amylopectin ranged from 12.6 to 33.1% and 40.5 to 52.5% respectively. KB starch showed the highest amylose content (49.50%) while RS showed the lowest (8.51%). Starches with greater granule size (PS, SP and KB) showed higher proportion of long side chains of amylopectin (AP) (Fr.II) than short side chains of AP (Fr.III). Peak viscosity (PV), breakdown viscosity (BV) and final viscosity (FV) showed significant positive relationship with Fr. II and negative with apparent amylose content (AAC) and Fr.III. Tuber starches showed greater paste viscosities followed by legume starches. Tuber and legume starches with higher apparent amylose content and Fr. II showed greater crystallinity. Gel hardness and gelatinization temperatures showed inverse relationship with RS starch having higher proportion of smaller granules (0-10 µm). KB with higher amylose content showed maximum rapidly digestible starch (RDS) content while SP showed the highest resistant starch. Above observations would be utilized in modifying properties of native starches and help in improving texture, moisture retention capacity and gel firmness of starch and its products.

Effect of high-amylose corn starch addition on canning of yellow alkaline noodle composed of wheat flour and microbial transglutaminase: Optimization by RSM

Mixture experiment was applied to optimize the canned cross-linked high-amylose starch yellow alkaline noodle formula. Processing factors of canned yellow alkaline noodle (YAN) cross-linked by MTGase at different levels of Hylon VII were surveyed. The factors were wheat flour, Hylon VII starch (HAS) as a high-amylose starch, and water in the mixture to achieve reduction in cooking loss, water uptake, swelling index, and thickness. Due to the effect of retort processing on YAN, pH, color, and texture were also examined. Analysis of variance showed that the linear mixture had a significant effect on the noodle properties. Optimum conditions were as follows: wheat flour of 75 g, HAS of 15 g, and water 67 ml. Results showed the suitable effect of Hylon in improving texture of canned YAN as well as high gel strength, neutral pH, lowest cooking loss, water uptake, swelling index, and color after retort processing. Therefore, high-amylose decreased swelling of starch, cooking yield, and improved hardness which obtain a strong gel and better stability in canned noodle. The pH fall and the attainment of yellow color in the YAN containing Hylon can be explained by the availability of two important amino acids, lysine and glutamine which were involved in both cross-linking reactions. The synergistic effect of low amount of flour and Hylon produced more tensile and hardness properties in canned noodle. Overall, the canned YAN prepared by adding Hylon developed the stronger gel which can withstand at high thermal retort processing and finally improve the shelf life of the final product.

Proteomic analysis of the impacts of powdery mildew on wheat grain

Powdery mildew of wheat is one of the major foliar diseases, causing significant yield loss and flour quality change. In this study, grain protein and starch response to powdery mildew infection were investigated. Total protein, glutenin and gliadin exhibited a greater increase in grains from infected wheat, while the content of total starch and amylopectin was decreased. Comparative proteomic analysis demonstrated that the overabundant protein synthesis-related proteins might facilitate the accumulation of storage proteins in grains from infected plants. The significant increase in triticin, serpin and HMW-GS in grains from infected wheat might relate to the superior gluten quality. In addition, overabundant carbohydrate metabolism-related proteins in grains from infected wheat were conducive to the depletion of starch, whereas the decreased abundance of ADP glucose pyrophosphorylase might be related to the deficiency of starch synthesis. These results provide a deeper understanding on the change of wheat quality under powdery mildew infection.

Wheat dough microstructure: the relation between visual structure and mechanical behavior

The microstructure of food matrixes, and specifically that of wheat-flour dough, determines mechanical behavior. Consequently, the analysis of such microstructure is both necessary and useful for understanding the physico-chemical and mechanical alterations during the production of cereal-based products such as breads. Confocal laser scanning microscopy (CLSM) is an established tool for the investigation of these matrix properties due to its methodical advantages such as easy preparation and handling, and the high depth resolution due to the optical sectioning of probes. This review focuses on the microstructure of wheat-flour dough from a mechanical and visual point of view. It provides an overview of the dependencies between the visibly detectable microstructural elements achieved by CLSM and the physical determined rheological properties. Current findings in this field, especially on numerical microstructure features, are described and discussed, and possibilities for enhancing the analytical methodology are presented.

Effect of the Amount and Particle Size of Wheat Fiber on the Physicochemical Properties and Gel Morphology of Starches

Effects of added wheat fiber, with different levels and particle sizes, on the physicochemical properties and gel morphology of wheat starch and mung bean starch were investigated, using rapid visco analyzer (RVA), texture analyzer (TPA) and scanning electron microscopy (SEM). Each starch was added with wheat fiber at 10, 20, 30 and 40% (weight basis, g/100g), and different sizes of 60, 100 and 180 mesh, respectively. The peak viscosity (PV) of starches with wheat fiber were higher than the control. Starches had the highest PV with 40%, 60 mesh wheat fiber. The starches with wheat fiber showed higher hardness when compared to the control. Wheat starch and mung bean starch, with 40%, 60 mesh wheat fiber, had the highest hardnesses of 147.78 and 1032.11g, respectively. SEM showed that the dense honeycomb structure of starch gel was diminished with increasing wheat fiber. Additionally, the number of internal pores was reduced, and a large lamellar structure was formed.

Comparison of Physicochemical and Gel Characteristics of Hydroxypropylated Oat and Wheat Starches

The main objective of this study was to compare the characteristics of hydroxypropylated (HP) wheat and oat starches. Higher degree of modification was obtained for HP wheat starch. Hydroxypropylation did not change the morphological features of HP oat starch granules, while it had some effects on the granular structure of HP wheat starch. The relative crystallinity of HP oat starch was higher than that of HP wheat starch. The water swelling and solubility of the HP wheat starch were higher than the HP oat starch. In contrast to HP wheat starch, the HP oat starch gel showed improved textural properties. After hydroxypropylation, peak and breakdown viscosity increased while set back viscosity and peak time decreased. Higher onset, peak and conclusion temperatures, and higher enthalpy of gelatinization were obtained for the HP oat starch. HP wheat starch gel had less syneresis than the HP oat starch.