Starch hydrogels: The influence of the amylose content and gelatinization method

Obtaining and characterization of natural extracts from mango (Mangifera Indica) peel and its effect on the rheological behavior in new mango kernel starch hydrogels

Hydrogels based on natural polymers have aroused interest from the scientific community. The aim of this investigation was to obtain natural extracts from mango peels and to evaluate their addition (1, 3, and 5%) on the rheological behavior of mango starch hydrogels. The total phenolic content, antioxidant activities, and phenolic acid profile of the natural extracts were evaluated. The viscoelastic and thixotropic behavior of hydrogels with the addition of natural extracts was evaluated. The total phenol content and antioxidant activity of the extracts increased significantly (p<0.05) with the variation of the ethanol-water ratio; the phenolic acid profile showed the contain of p-coumaric, ellagic, ferulic, chlorogenic acids, epicatechein, catechin, querecetin, and mangiferin. The viscoelastic behavior of the hydrogels showed that the storage modulus G' is larger than the loss modulus G'' indicating a viscoelastic solid behavior. The addition of extract improved the thermal stability of the hydrogels. 1% of the extracts increase viscoelastic and thixotropic properties, while concentrations of 3 to 5% decreased. The recovery percentage (%Re) decreases at concentrations from 0% to 1% of natural extracts, however, at concentrations from 3% to 5% increased.

Improvement of 3D printing age-friendly brown rice food on rough texture, swallowability, and in vitro digestibility using fermentation properties of different probiotics

Probiotics can promote the balance of the intestinal microbial community and enhance the biological activity of food. They are beneficial to the health of elderly people. Therefore, five different probiotics (4% of the total weight) were added to pasted brown rice to study the printability, swallowability, and digestibility of fermented inks (at 40 °C for 10 h). The results showed that probiotics reduced the apparent viscosity and resistance to deformation of brown rice inks. The inks with Lactobacillus bulgaricus (LB), Bifidobacterium longum (BL), and Lactiplantibacillus plantarum (LP) had better printing properties and finer appearances. Probiotics significantly reduced the adhesiveness, gumminess, and hardness of inks but had little effect on cohesiveness. LB, Streptococcus thermophilus (ST), and LP were categorized as having class 4 consistency with easy-to-swallow characteristics. The growth and multiplication of probiotics detached the internal structure of brown rice inks and reduced the relative crystallinity. They also modulated the nutrient content and flavor components by producing short-chain fatty acids, and improved the digestion of starch.

Plant-based fascia tissues: Exploring materials and techniques for realistic simulation

The growing demand for sustainable and ethical food options has led to significant advancements in plant-based meat substitutes (PBMS). PBMS have made considerable progress in simulating the taste, texture, and sensory properties of animal meat. Connective tissue is a fundamental component of animal meat that significantly influences tenderness, texture, and sensory properties. However, the imitation of realistic connective tissues has received relatively less attention in the PBMS industry. The current work focuses on exploring materials and techniques for the replication of plant-based connective tissues (PBCT). By understanding the structural and functional characteristics of animal connective tissues (ACT), it is possible to replicate these characteristics in PBCT. Hydrogels, with their ability to simulate certain properties of ACT, present a viable material for the creation of PBCT. To achieve the desired simulation, their mechanical and structural properties need to be enhanced by using several materials and several physical techniques.

Incorporation of amylose improves rheological and textural properties of Moringa oleifera seed salt-soluble protein

The interactions between corn amylose (CA) and Moringa oleifera seed salt-soluble protein (MOSP) were explored to improve the gel properties of MOSP. With increasing CA content, the MOSP-CA gel network structure was improved but the size of the gel porosity decreased firstly and then increased; the water holding retention (WHR) of MOSP-CA was decreased from approximately 94 % to 85.43 ± 2.54 %. The MOSP-CA-2.5 gel exhibited the best water holding stability (WHS), with a value of 37.1 ± 0.33 %. The MOSP-CA gel hardness increased with CA concentration, and MOSP-CA-2.5 showed relatively optimal cohesiveness, elasticity, adhesiveness, and chewiness. Meanwhile, MOSP-CA-2.5 exhibited gel strength. Incorporation of CA significantly increased the exposure of hydrophobic residues and the concentration-dependent increase in disulfide bonds in MOSP-CA gel. Thus, hydrophobic interactions, hydrogen bonds, and disulfide bonds collectively stabilized the structure of MOSP-CA gel. The findings would broaden the application of MOSP and improve the utilization value of MOSP in various industries.

Antimicrobial starch-based cryogels and hydrogels for dual-active food packaging applications

The present study reports on the valorisation of starch waste biomass to produce dual-active cryogels and hydrogels able to adsorb water and deliver antimicrobial substances for fresh food packaging applications. Starch hydrogels were prepared by oxidation with sodium metaperiodate in water and mild conditions, while cryogels were obtained by freeze-drying process. To explore the role of starch composition on the final properties of materials, two starches differing in amylose/amylopectin ratio, were evaluated. The prepared materials were microstructurally and morphologically characterized by FTIR and NMR spectroscopy (1D, 2D, and DOSY experiments), and SEM microscopy. To provide the materials with active properties, they were loaded with antimicrobial molecules by absorption, or by crosslinking via Schiff-base reaction. All materials demonstrated high water absorption capacity and ability to deliver volatile molecules, including diacetyl and complex mixtures like mint essential oil. The release profiles of the adsorbed molecules were determined through quantitative NMR spectroscopy over time. The antibacterial activity was successfully demonstrated against Gram-positive bacterial strains for unloaded cryogels and hydrogels, and after loading with diacetyl and essential oil. The developed materials can be regarded as part of active pads for food packaging applications capable to control moisture inside the package and inhibit microbial contamination.

Mechanistic understanding of changes in physicochemical properties of different rice starches under high hydrostatic pressure treatment based on molecular and supramolecular structures

The molecular and supramolecular structures of japonica and waxy rice starches under high hydrostatic pressure treatment (450 MPa) were studied and the changes in physicochemical properties were analyzed based on these structures. The molecular structures of japonica and waxy rice starch cause differences in the lamellar structure and physicochemical properties. The thickness of amorphous lamella of japonica rice starch increased at 5 min (2.95 nm) followed by a gradual collapse of lamellar structure. Whereas the thickness of crystalline lamellae of waxy rice starch increased at 15 min (5.92 nm) and the lamellae collapsed suddenly at 20 min. The pasting, rheological and textural characteristics of both starches increased significantly within 10 to 15 min. The decreasing onset temperature and enthalpy of high hydrostatic pressure-treated starches indicated easier gelatinization. High hydrostatic pressure-treatment offers potential for developing starch-based products with low swelling capacity, easy gelatinization, high viscosity and hardness.

Hydrogel delivery systems of functional substances for precision nutrition

Hydrogel delivery systems based on polysaccharides and proteins have the ability to protect functional substances from chemical degradation, control/target release, and increase bioavailability. This chapter summarizes the recent progress in the utilization of hydrogel delivery systems for nutritional interventions. Various hydrogel delivery systems as well as their preparation, structure, and properties are given. The applications for the encapsulation, protection, and controlled delivery of functional substances are described. We also discuss their potential and challenges in managing chronic diseases such as inflammatory bowel disease, obesity, liver disease, and cancer, aiming at providing theoretical references for exploring novel hydrogel delivery systems and their practical prospects in precise nutritional interventions.

Effects of the Amylose/Amylopectin Ratio of Starch on Borax-Crosslinked Hydrogels

Herein, we simultaneously prepared borax-crosslinked starch-based hydrogels with enhanced mechanical properties and self-healing ability via a simple one-pot method. The focus of this work is to study the effects of the amylose/amylopectin ratio of starch on the grafting reactions and the performance of the resulting borax-crosslinked hydrogels. An increase in the amylose/ amylopectin ratio increased the gel fraction and grafting ratio but decreased the swelling ratio and pore diameter. Compared with hydrogels prepared from low-amylose starches, hydrogels prepared from high-amylose starches showed pronouncedly increased network strength, and the maximum storage modulus increased by 8.54 times because unbranched amylose offered more hydroxyl groups to form dynamic borate ester bonds with borate ions and intermolecular hydrogen bonds, leading to an enhanced crosslink density. In addition, all the hydrogels exhibited a uniformly interconnected network structure. Furthermore, owing to the dynamic borate ester bonds and hydrogen bonds, the hydrogel exhibited excellent recovery behavior under continuous step strain, and it also showed thermal responsiveness.

Early Detection and Monitoring of Anastomotic Leaks via Naked Eye-Readable, Non-Electronic Macromolecular Network Sensors

Anastomotic leakage (AL) is the leaking of non-sterile gastrointestinal contents into a patient's abdominal cavity. AL is one of the most dreaded complications following gastrointestinal surgery, with mortality rates reaching up to 27%. The current diagnostic methods for anastomotic leaks are limited in sensitivity and specificity. Since the timing of detection directly impacts patient outcomes, developing new, fast, and simple methods for early leak detection is crucial. Here, a naked eye-readable, electronic-free macromolecular network drain fluid sensor is introduced for continuous monitoring and early detection of AL at the patient's bedside. The sensor array comprises three different macromolecular network sensing elements, each tailored for selectivity toward the three major digestive enzymes found in the drainage fluid during a developing AL. Upon digestion of the macromolecular network structure by the respective digestive enzymes, the sensor produces an optical shift discernible to the naked eye. The diagnostic efficacy and clinical applicability of these sensors are demonstrated using clinical samples from 32 patients, yielding a Receiver Operating Characteristic Area Under the Curve (ROC AUC) of 1.0. This work has the potential to significantly contribute to improved patient outcomes through continuous monitoring and early, low-cost, and reliable AL detection.

A Comprehensive Review on Starch-Based Hydrogels: From Tradition to Innovation, Opportunities, and Drawbacks

Natural hydrogels based on renewable and inexpensive sources, such as starch, represent an interesting group of biopolymeric materials with a growing range of applications in the biomedical, cosmeceutical, and food sectors. Starch-based hydrogels have traditionally been produced using different processes based on chemical or physical methods. However, the long processing times, high energy consumption, and safety issues related to the synthesis of these materials, mostly causing severe environmental damage, have been identified as the main limitations for their further exploitation. Therefore, the main scientific challenge for research groups is the development of reliable and sustainable processing methods to reduce the environmental footprint, as well as investigating new low-cost sources of starches and individuating appropriate formulations to produce stable hydrogel-based products. In the last decade, the possibility of physically modifying natural polysaccharides, such as starches, using green or sustainable processing methods has mostly been based on nonthermal technologies including high-pressure processing (HPP). It has been demonstrated that the latter exerts an important role in improving the physicochemical and techno-functional properties of starches. However, as for surveys in the literature, research activities have been devoted to understanding the effects of physical pre-treatments via high-pressure processing (HPP) on starch structural modifications, more so than elucidating its role and capacity for the rapid formation of stable and highly structured starch-based hydrogels with promising functionality and stability, utilizing more sustainable and eco-friendly processing conditions. Therefore, the present review addresses the recent advancements in knowledge on the production of sustainable starch-based hydrogels utilizing HPP as an innovative and clean-label preparation method. Additionally, this manuscript has the ambition to give an updated overview of starch-based hydrogels considering the different types of structures available, and the recent applications are proposed as well to critically analyze the main perspectives and technological challenges for the future exploitation of these novel structures.

Starch-guest complexes interactions: Molecular mechanisms, effects on starch and functionality

Starch is a natural, abundant, renewable and biodegradable plant-based polymer that exhibits a variety of functional properties, including the ability to thicken or gel solutions, form films and coatings, and act as encapsulation and delivery vehicles. In this review, we first describe the structure of starch molecules and discuss the mechanisms of their interactions with guest molecules. Then, the effects of starch-guest complexes on gelatinization, retrogradation, rheology and digestion of starch are discussed. Finally, the potential applications of starch-guest complexes in the food industry are highlighted. Starch-guest complexes are formed due to physical forces, especially hydrophobic interactions between non-polar guest molecules and the hydrophobic interiors of amylose helices, as well as hydrogen bonds between some guest molecules and starch. Gelatinization, retrogradation, rheology and digestion of starch-based materials are influenced by complex formation, which has important implications for the utilization of starch as a functional and nutritional ingredient in food products. Controlling these interactions can be used to create novel starch-based food materials with specific functions, such as texture modifiers, delivery systems, edible coatings and films, fat substitutes and blood glucose modulators.

Utilizing Synchrotron-Based X-ray Micro-Computed Tomography to Visualize the Microscopic Structure of Starch Hydrogels In Situ

This study aimed to visualize the microstructures of starch hydrogels using synchrotron-based X-ray micro-computed tomography (μCT). Waxy maize starch (WMS, 3.3% amylose, db), pea starch (PS, 40.3% amylose), and high-amylose maize starch (HMS, 63.6% amylose) were cooked at 95 and 140 °C to prepare starch hydrogels. WMS and HMS failed to form a gel after 95 °C cooking and storage, while PS developed a firm gel. At 140 °C cooking, HMS of a high amylose nature was fully gelatinized and generated a rigid gel with the highest strength. Both scanning electron microscopy (SEM) and μCT revealed the unique structural features of various starch hydrogels/pastes prepared at different temperatures, which were greatly affected by the degree of swelling and dispersity of the starches. As a nondestructive method, μCT showed certain advantages over SEM, including minimal shrinkage of the hydrogels, relatively simple sample preparation, and allowing for three-dimensional reconstruction of the hydrogel microstructure. This study indicated that synchrotron-based μCT could be a useful technique in visualizing biopolymer-based hydrogels.

Starch-based hydrogels for environmental applications: A review

Water sources have become extremely scarce and contaminated by organic and inorganic industrial and agricultural pollutants as well as household wastes. Poisoning water resources by dyes and metals is a problem because contaminated water can leak into subsurface and surface sources, causing serious contamination and health problems. Therefore, developing wastewater treatment technologies is valuable. Today, hydrogels have attracted considerable attention owing to their broad applications. Hydrogels are polymeric network compositions with significant water-imbibing capacity. Hydrogels have potential applications in diverse fields such as biomedical, personal care products, pharmaceuticals, cosmetics, and biosensors. They can be prepared by using natural (biopolymers) and synthetic polymers. Synthetic polymer-based hydrogels obtained from petrochemicals are not environmentally benign; thus, abundant plant-based polysaccharides are found as more suitable compounds for making biodegradable hydrogels. Polysaccharides with many advantages such as non-toxicity, biodegradability, availability, inexpensiveness, etc. are widely employed for the preparation of environmentally friendly hydrogels. Polysaccharides-based hydrogels containing chitin, chitosan, gum, starch (St), etc. are employed to remove pollutants, metals, and dyes. Among these, St has attracted a lot of attention. St can be mixed with other compounds to make hydrogels, which remove dyes and metal ions to variable degrees of efficiency. Although St has numerous advantages, it suffers from drawbacks such as low stability, low water solubility, and fast degradability in water which limit its application as an environmental adsorbent. As an effective way to overcome these weaknesses, various modification approaches to form starch-based hydrogels (SBHs) employing different compounds have been reported. The preparation methods and applications of SBH adsorbents in organic dyes, hazardous materials, and toxic ions elimination from water resources have been comprehensively discussed in this review.

Characterization of Polyphenol Composition and Starch and Protein Structure in Brown Rice Flour, Black Rice Flour and Their Mixtures

The study investigates the structural and chemical properties of brown rice flour (WRF), black rice flour (BRF) and their mixtures in ratios of 25%, 50% and 75% to provide reference information for the gluten-free bakery industry. BRF contains higher concentrations of proteins, lipids, total minerals, crude fiber, total polyphenols, proanthocyanidins and flavonoids than WRF. A higher amylose content in BRF than in WRF resulted in flour mixtures with slower starch digestion and a lower glycemic response depending on the BRF ratio added. Differences in the chemical composition of WRF and BRF led to improved composition of the flour mixtures depending on the BRF ratio. The presence of anthocyanidins and phenolic acids in higher concentrations in the BRF resulted in a red-blue color shift within the flour mixtures. The deconvoluted FTIR spectra showed a higher proportion of α-helixes in the amide I band of BRF proteins, indicating their tighter folding. An analysis of the FTIR spectra revealed a more compact starch structure in BRF than in WRF. By processing reflection spectra, nine optically active compound groups were distinguished in rice flour, the proportion in BRF being 83.02% higher than in WRF. Due to co-pigmentation, the bathochromic shift to higher wavelengths was expressed by the proanthocyanins and phenolic acids associated with the wavelengths 380 nm to 590 nm and at 695 nm. Anthocyanins, protein-tannin complexes, methylated anthocyanins and acylated anthocyanins, associated with wavelengths 619, 644 and 668 nm, exhibited a hypsochromic effect by shifting the wavelengths to lower values. This research represents a first step in the development of rice-based products with increased nutritional value and a lower glycemic index.

Rice starch modification by thermal treatments with avocado oil: Autoclave versus microwave methods

This study aimed to evaluate the physical and chemical alterations in rice starch modified by heat-moisture treatment (HMT) using an autoclave and a microwave, in association with avocado oil (AO), and evaluate the effects on thermal and structural properties, in vitro digestibility, and estimated glycemic index (eGI). Samples were adjusted to 30 % (w/w) moisture and 2, 4 and 8 % AO. HMT was conducted at 110 °C for 1 h in the autoclave (A0%, A2%, A4%, and A8%) and at 50 °C for 3 min in the microwave (M0%, M2%, M4%, and M8%). Both procedures did not alter the starch crystallinity pattern (type-A). Pasting viscosity, setback, relative crystallinity, and gelatinisation enthalpy decreased as the AO content increased in both HMT processes. The M8% showed reduced digestibility, decreased eGI (72.99, p < 0.05), and lower starch hydrolysis concentration (62.75 %, p < 0.05). The application of HMT with the addition of AO may be an interesting process for obtaining resistant starch since its content increased after both treatments (A8%, M4%, and M8%). The microwave process proved efficient, making it possible to use a lower temperature, less time, and less energy for modification and obtain starches with improved characteristics.

Changes in the pasting and rheological properties of wheat, corn, water caltrop and lotus rhizome starches by the addition of Annona montana mucilage

Annona montana mucilage (AMM) is a novel mucilage with unique but limited information. This study investigated the effects of AMM addition on the pasting and rheological properties of wheat starch (WS), corn starch (CS), water caltrop starch (WCS), and lotus rhizome starch (LRS). The addition of AMM generally increased the pasting temperature and peak viscosity, but reduced the setback value of all starches to varying degrees, and the initiation of viscosity-increase for cereal starch/AMM systems during pasting occurred at lower temperatures, accompanied with a distinctive two-stage swelling process as well as lower peak and final hot paste viscosity at 50 °C. AMM significantly increased the pseudoplasticity and entanglement of the systems to varying degrees (LRS > WS > WCS > CS). Under a constant shear rate of 50 s-1, the consistency level was found to fall in honey-like for cereal starch/AMM groups, and honey-like to extremely thick levels for WCS and LRS/AMM groups. Except for the WCS/AMM systems, the storage and loss modulus as well as tan increased with increasing AMM concentration. Short-term retrogradation of starch at 4 °C was pronouncedly retarded by the addition of AMM for WS, CS and WCS groups, but was less affected for LRS group.

Fabrication of all-starch-based hydrogels as eco-friendly water-absorbent resin: Structure and swelling behaviors

Water-absorbent resin has gained wide applications due to the capability in absorbing and retaining substantial amounts of water, while it's a challenge to fabricate a full biobased water-absorbent resin with excellent biodegradability and eco-friendliness. In this study, starch was sulfonated (SS) and crosslinked with epichlorohydrin to fabricate all-starch-based hydrogels (SSH) as water-absorbent resin with advantages of intrinsic biodegradability and low cost. The results confirmed that the hydrogen atoms of -OH groups in starch chains were partially replaced by -SO3- and the substitution degree (DS) of SS reached 0.008-0.344. By controlling DS and gelation process of SS, the swelling ratio (Qe) of SSH was improved in distilled water, reaching 244.47 g/g for samples prepared using SS with medium DS (SSMDSH). SSMDSH showed relatively loose network structure with low cross-linking density and large pore size. Meanwhile, -SO3- groups on SSMDSH chains facilitated strong ion-dipole interactions with water molecules, resulting in an increase in content of non-freezing bound water within hydrogels and thus improvement in water absorption capacity. Besides, SSH showed desired fertilizer absorption performance and complete biodegradability in α-amylase solution, which made it to be a promising candidate in agricultural fields as eco-friendly water-absorbent resin.

Investigation of 3D printing of toddler foods with special shape and function based on fenugreek gum and flaxseed protein

The practicability of using corn and flaxseed protein as printing inks for manufacture of printed products specifically designed for toddlers as a dysphagia diet with high precision and special shapes with addition of fenugreek gum (FGG) was investigated. 3D printing was used to process grains and dysphagia-compatible food (corn) into a dietary product with attractive appearance which was also easy to swallow. Rheological measurements shown that appropriate amount of flaxseed protein (FP, 0-10 %) can reduce the stickiness and yield strength of printing material. Based on FTIR measurements, FP weakened the hydrogen bond strength of inks, but it was still an important gradient for the formation of the ink suitable for precision 3D printing. The TPA results shown that the addition of FP (0-10 %) remarkably reduced both the stickiness and hardness of the ink. These results shown that compared with the control group, materials with FGG additions possessed higher printing accuracy and self-supporting ability. Ink with 5 % FP content exhibited the best printability and swallowability, while ink with 10 % FP content had the lowest viscosity and hardness, but it was not suitable for 3D printing. 3D printing of objects printed using Ink-C (5%FP and 0.8 %FGG) showed high support characteristic and attractive appearance. According to the international IDDSI testing standards, Ink-C (5%FP and 0.8 %FGG), Ink-E (15%FP and 0.8 %FGG), and Ink-F (20%FP and 0.8 %FGG) were defined as level 5-minced and moist foods.

Physicochemical, thermal, pasting, morphological, functional and bioactive binding characteristics of starches of different oat varieties of North-Western Himalayas

Starches were isolated from five oat varieties (SFO-1, SFO-3, Sabzar, SKO-20 and SKO-96) grown in North-Western Himalayas of India. Moisture content of the varieties ranged from 9.25 ± 0.09 to 13.21 ± 0.11 %, indicating their shelf-stability. Results suggested >90 % purity of starches as was evident from values of ash, proteins, and lipids. Amylose content results showed that all starches fall within category of intermediate-amylose starches. Lambdamax, blue value and OD620/550 were found significantly (p ≤ 0.05) higher in SKO-20. Sabzar exhibited higher starch hydrolysis percentage of 85.16 % whereas, lowest was observed in SKO-20 (78.12 %). Degree of syneresis was higher in SKO-20 however, its freeze-thaw stability was lesser. Wide peak in FTIR spectra at 3320 cm-1 confirms nature of starches. SKO-20 exhibited significantly higher onset gelatinization temperature (65.19 ± 1.06 °C) and enthalpy (15.78 ± 0.15 J/g) whereas, Sabzar exhibited lowest enthalpy. Pasting characteristics indicated lowest and highest final viscosity in SKO-20 (341.30 ± 2.11 mPas) and SKO-96 (1470 ± 4.56 mPas), respectively. SEM results indicated irregular and polygonal shape of starches with size <10 μm. SKO-20 exhibited lowest disintegration time of 2.08 ± 0.01 min and Sabzar showed highest (3.31 ± 0.07 min). SKO-20 released more curcumin (71.28 %) whereas, Sabzar released less. This suggests that SKO-20 could be used as better excipient for delivery of curcumin at target site.

The influence of cooperative fermentation on the structure, crystallinity, and rheological properties of buckwheat starch

The effects of co-fermentation of yeast and Lactiplantibacillus plantarum 104 on buckwheat starch physical properties were investigated by various analytical techniques. To investigate the regulations of starch modification during fermentation and to provide a foundation for improving the performance of modified properties of buckwheat starch food. The pasting properties were decreased by co-fermentation also resulted in a reduction in the relative crystallinity. Scanning electron microscopy (SEM) demonstrated that more holes and a relatively rough granule surface were seen in the co-fermentation group. Fourier transform-infrared spectroscopy (FT-IR) results suggested that co-fermentation fermentation decreased the degree of short-range order (DO) and degree of t1he double helix (DD). The results demonstrated that co-fermentation altered these properties more rapidly than spontaneous fermentation. In conclusion, Lactiplantibacillus plantarum 104 could be used for buckwheat fermentation to improve food quality.

Proteomics and Metabolomics Reveal that an Abundant α-Glucosidase Drives Sorghum Fermentability for Beer Brewing

Sorghum (Sorghum bicolor), a grass native to Africa, is a popular alternative to barley for brewing beer. The importance of sorghum to beer brewing is increasing because it is a naturally gluten-free cereal, and climate change is expected to cause a reduction in the production of barley over the coming decades. However, there are challenges associated with the use of sorghum instead of barley in beer brewing. Here, we used proteomics and metabolomics to gain insights into the sorghum brewing process to advise processes for efficient beer production from sorghum. We found that during malting, sorghum synthesizes the amylases and proteases necessary for brewing. Proteomics revealed that mashing with sorghum malt required higher temperatures than barley malt for efficient protein solubilization. Both α- and β-amylase were considerably less abundant in sorghum wort than in barley wort, correlating with lower maltose concentrations in sorghum wort. However, metabolomics revealed higher glucose concentrations in sorghum wort than in barley wort, consistent with the presence of an abundant α-glucosidase detected by proteomics in sorghum malt. Our results indicate that sorghum can be a viable grain for industrial fermented beverage production, but that its use requires careful process optimization for efficient production of fermentable wort and high-quality beer.

Hydrogel properties of non-conventional starches from guabiju, pinhão, and uvaia seeds

The physicochemical properties of starch vary depending on the botanical sources, thereby influencing the gelatinisation/retrogradation properties and subsequently affecting the hydrogels characteristics. This study aimed to assess the influence of botanical sources influence on starch and hydrogel properties using non-conventional starch derived from guabiju, pinhão, and uvaia seeds. Hydrogels were prepared by starch gelatinisation followed by 6 h ageing period at room temperature (20 ± 2 °C) and subjected to five freeze-thaw cycles. Pinhão starch exhibited a higher viscosity peak and breakdown, along with a lower final viscosity and setback, compared to guabiju and uvaia starches. The significantly different pasting properties influenced the porous microstructure, water absorption (p-value: 0.01), and resistance of the hydrogels (p-value: 0.01). The guabiju starch hydrogels showed a uniform pore structure without cavities, whereas pinhão and uvaia starch hydrogels exhibited agglomerated and spongy pore structures. Furthermore, the guabiju starch hydrogel demonstrated the lowest water absorption (4.56 g/g) and the highest compression resistance (1448.50 g) among all the studied starch hydrogels. In contrast, the pinhão starch hydrogel showed the highest water absorption (7.43 g/; p-value: 0.01) among all studied starch hydrogels. The hardness of uvaia starch hydrogel did not differ significantly from the guabiju and pinhão starch hydrogel. The different non-conventional starches reveal important variations in the hydrogels characteristics. This provides insights into how amylose and amylopectin interact and present alternatives for using these unique starch-based hydrogels in diverse applications.

Development of Novel Multifunctional Electroactive, Self-Healing, and Tissue Adhesive Scaffold To Accelerate Cutaneous Wound Healing and Hemostatic Materials

Designing a multifunctional conducting hydrogel wound dressing of suitable mechanical properties, adhesiveness, self-healing, autolytic debridement, antibacterial properties, and radical scavenging ability, as well as retaining an appropriate level of moisture around the wound is highly desirable in clinical application for treating cutaneous wounds healing. Here, we designed a novel class of electroactive hydrogel based on thiol-functionalized silver-graphene oxide nanoparticles (GO/Ag/TGA) core polyaniline (PANI) shell GO/Ag/TGA/PANI nanocomposites. Thus, a series of physically cross-linked hydrogel based on GO/Ag/TGA/PANI and poly(vinyl alcohol) (PVA) was prepared by freeze-thawing method. The hydrogel was characterized by XRD, UV, FTIR, TGA, TEM, SEM, Raman spectroscopy, cyclic voltammetry (CV), and four probes test. The hydrogel showed favorable properties such as excellent tensile strength, suitable gelation time (30-56 s), tunable rheological properties (G' ∼ 1 kPa), adhesiveness, and interconnected porous structure (freeze-dried). Besides this, the hydrogel also exhibits excellent exudate uptake capacity (10.4-0.2 g/g), high swelling ratio (72.4 to 93.5%), long-term antibacterial activity against multidrug-resistant (MDR) bacterial isolates, promising antioxidant (radical scavenging) efficiency, keeping the wound moisturized, prominent hemostatic efficiency, and fast self-healing ability to bear deformation. Interestingly, in vivo experiments indicated that electroactive hydrogels can significantly promote the healing rate of artificial wounds in rats, and histological analysis by H&E reveals higher granulation tissue thickness, collagen deposition, hair follicles, dermal papillary, keratinocytes, and marked increase (P < 0.05) in hydroxyproline at the wound site during 15 days of healing of impaired wounds. On the basis of vivo and vitro assay results, it is concluded that electroactive-hydrogel-attributed multifunctional properties may serve as suitable scaffold for treating chronic wound healing and skin regeneration.

Natural Polymer-Based Hydrogels: From Polymer to Biomedical Applications

Hydrogels prepared from natural polymer have attracted extensive attention in biomedical fields such as drug delivery, wound healing, and regenerative medicine due to their good biocompatibility, degradability, and flexibility. This review outlines the commonly used natural polymer in hydrogel preparation, including cellulose, chitosan, collagen/gelatin, alginate, hyaluronic acid, starch, guar gum, agarose, and dextran. The polymeric structure and process/synthesis of natural polymers are illustrated, and natural polymer-based hydrogels including the hydrogel formation and properties are elaborated. Subsequently, the biomedical applications of hydrogels based on natural polymer in drug delivery, tissue regeneration, wound healing, and other biomedical fields are summarized. Finally, the future perspectives of natural polymers and hydrogels based on them are discussed. For natural polymers, novel technologies such as enzymatic and biological methods have been developed to improve their structural properties, and the development of new natural-based polymers or natural polymer derivatives with high performance is still very important and challenging. For natural polymer-based hydrogels, novel hydrogel materials, like double-network hydrogel, multifunctional composite hydrogels, and hydrogel microrobots have been designed to meet the advanced requirements in biomedical applications, and new strategies such as dual-cross-linking, microfluidic chip, micropatterning, and 3D/4D bioprinting have been explored to fabricate advanced hydrogel materials with designed properties for biomedical applications. Overall, natural polymeric hydrogels have attracted increasing interest in biomedical applications, and the development of novel natural polymer-based materials and new strategies/methods for hydrogel fabrication are highly desirable and still challenging.

Enhancing Starch-Based Packaging Materials: Optimization of Plasticizers and Process Parameters

In order to actively promote green production and address these concerns, there is an urgent need for new packaging materials to replace traditional plastic products. Starch-based packaging materials, composed of starch, fiber, and plasticizers, offer a degradable and environmentally friendly alternative. However, there are challenges related to the high crystallinity and poor compatibility between thermoplastic starch and fibers, resulting in decreased mechanical properties. To address these challenges, a novel approach combining plasticizer optimization and response surface method (RSM) optimization has been proposed to enhance the mechanical properties of starch-based packaging materials. This method leverages the advantages of composite plasticizers and process parameters. Scanning electron microscopy and X-ray crystallography results demonstrate that the composite plasticizer effectively disrupts the hydrogen bonding and granule morphology of starch, leading to a significant reduction in crystallinity. Fourier transform infrared spectroscopy results show that an addition of glycerol and D-fructose to the starch can form new hydrogen bonds between them, resulting in an enhanced plasticizing effect. The optimal process parameters are determined using the RSM, resulting in a forming temperature of 198 °C, a forming time of 5.4 min, and an AC content of 0.84 g. Compared with the non-optimized values, the tensile strength increases by 12.2% and the rebound rate increases by 8.1%.

Edible Film Casting Techniques and Materials and Their Utilization for Meat-Based Product Packaging

According to a profusion of academic studies on the use of organic materials or biopolymers as key components, the current trajectory of food packaging techniques is showing a positive inclination. Notably, one such biopolymer that has attracted much attention is edible film. The biopolymers that have been stated as constitutive components are composed of polysaccharides, lipids, proteins, or a combination of these, which work together to reinforce one another's properties and create homogenous mixtures. An edible film provides a clear, thin layer that encases foodstuffs, including their packaging. The production and use of edible film have recently been the focus of much research in the field of food polymers. Extending the shelf life of food goods is the goal of this research. Given their great susceptibility to change brought on by outside forces or pollutants, which may result in oxidative rancidity, the proper storage of nutrient-dense food items, particularly meat products, deserves careful study. Many edible films have been found to contain active ingredients, such antimicrobials or antioxidants, that can successfully prevent the spoiling of meat products, a process that can happen in a short amount of time. Surprisingly, a number of scholarly examinations reveal that edible film may be cooked alongside meat because of its organic makeup. We hope that the use of edible film will lead to a more environmentally responsible method of food packaging than has previously been possible.

The Role of Amylose in Gel Forming of Rice Flour

In this study, Glutinous rice (GR), Japonica rice (JR), and Indica rice (IR), with amylose contents at 1.57 ± 0.18%, 15.88 ± 1.16%, and 26.14 ± 0.25%, respectively, were selected to reveal the role of amylose in the gel forming of rice flours. The strength and elasticity of the associated gels were found in an ascendant order with the increase in amylose content. For the retrograded gels (at 4 °C for 7 days), the peak temperature (Trp) was positively related to the amylose content. In general, Trp of IR increased to 63.21 ± 0.13 °C, and the relative crystallinities of IR were in the top ranking at 10.67 ± 0.16%, followed by those of JR and GR. The relative amounts of short-range ordered structures to amorphous regions in JR and IR were also higher than that of GR, and the number of compact network structure were positively related to the amylose content. These results indicated that amylose can enhance the strength and elasticity of gels by facilitating the formation of crystalline, short-range ordered, and compact network structures. These results can provide a reference for the development of rice products.

Encapsulating biocontrol bacteria with starch as a safe and edible biopolymer to alleviate plant diseases: A review

Healthy foods with few artificial additives are in high demand among consumers. Preserving conventional pesticides, frequently used as chemicals to control phytopathogens, is challenging. Therefore, we proposed an innovative approach to protect agricultural products in this review. Biocontrol bacteria are safe alternatives with low stability and low efficiency in the free-form formulation. The encapsulation technique for covering active compounds (e.g., antimicrobials) represents a more efficient protection technology because encapsulation causes the controlled release of bioactive materials and reduces the application doses. Of the biopolymers able to form a capsule, starch exhibits several advantages, such as its ready availability, cost-effectively, edible, colorless, and tasteless. Nevertheless, the poor mechanical properties of starch can be improved with other edible biopolymers. In addition, applying formulations incorporated with more than one antimicrobial material offers synergistic effects. This review presented the starch-based capsules used to enclose antimicrobial agents as effective tools against phytopathogens.

Relationship among gelatinization, retrogradation behavior, and impedance characteristics of potato starch

In this study, the physicochemical properties of potato starch from different varieties were investigated. Furthermore, the relationships among gelatinization, retrogradation behavior, and impedance characteristics of potato starch gels were evaluated by texture analysis, low-field nuclear magnetic resonance spectroscopy, and electrical impedance spectroscopy. The results indicated amylose content was positively correlated with setback viscosity, and negatively correlated with T_o and ΔH. In addition, impedance values of potato starch gels differed in a frequency-dependent manner. Notably, higher frequencies resulted in low diffusion of ions in prepared gels, which combined with the concentration of mobile ions in free water, led to a gradual decrease in impedance module. Compared with phase values, impedance module showed high correlation with gelatinization parameters (T_o, T_p, and T_c) and viscosity parameters (peak temperature and setback viscosity), more notably at frequencies below 100 Hz. In this context, the electric current flowed through mobile ions that interacted with bound water attached to the starch molecules at lower voltage frequencies, and were repressed by the formation of an ordered and compact gel network during retrogradation. Collectively, these results indicate that impedance spectroscopy can be potentially used as an efficient and reliable method to predict gelatinization and retrogradation behavior of potato starch.

Effects of the Amylose/Amylopectin Content and Storage Conditions on Corn Starch Hydrogels Produced by High-Pressure Processing (HPP)

In this study, the effects of the amylose/amylopectin content on starch gelation and the physical characteristics of hydrogels produced by HPP were studied by optical and rheological measurements in steady-state conditions. Additionally, the effects of the storage temperature (4 °C and 20 °C) and type of packaging (plastic bags or sealed Petri dishes) on the physical stability of the hydrogels were evaluated for 30 days of storage by evaluating the shrinkage of the granules, as well as the weight loss, water activity, organoleptic, and rheological properties. The experimental findings suggested that amylose plays an antagonistic role in determining the capacity of the starch granules to absorb water under pressure and to create stable and structured gels and on the physical stability of hydrogels due to its influence over the starch retrogradation extent during storage. Twenty per cent amylose was the minimum concentration to form stable corn starch HPP hydrogels with good physical and rheological properties. Moreover, a storage temperature of 20 °C and the use of polymeric bags were evaluated as the most suitable storage conditions and packaging materials enabling the long storage of corn starch hydrogels.

Study on structural characteristics, physicochemical properties, and in vitro digestibility of Kudzu-resistant starch prepared by different methods

Three different methods, including autoclaving, autoclaving-debranching, and purification, were used to prepare Kudzu-resistant starch (KRS) from Kudzu starch (KS). The physicochemical properties, such as thermodynamic properties, pasting properties, solubility, swelling, and coagulability, as well as the in vitro digestive characteristics of the three kinds of KRS were studied. The results showed that the morphology of starch granules of KRS prepared by autoclave, autoclave enzymatic hydrolysis, and purification methods was changed and the relative crystallinity was significantly decreased compared with the original starch. X-ray diffraction (XRD) showed that KRS exists in the form of C and C+V crystalline form. There was a significant increase in the pasting temperature and a remarkable decrease in the peak viscosity and the expansion degree of the KRS prepared by all three methods. The solubility of the resistant starch (RS) obtained by autoclaving-debranching and that by purification were both increased compared to that of native KS, while the solubility of the RS obtained by autoclaving was decreased. Meanwhile, the retrogradation of the three RS was also improved to varying degrees. The contents of RS in the samples were: P-KRS (71%) > DA-KRS (43%) > A-KRS (42%) > KS (9%). Simulated human in vitro digestion experiments showed that RS has stronger antidigestibility properties than native starch. Among them, the RS prepared by the purification method has stronger antidigestive properties, and it is predicted that it may have a better potential value in regulating blood glucose. These results indicated that the processing properties of KRS, especially the digestibility, are significantly improved and can be used as a new functional food ingredient, which deserves thorough study.

A Novel Starch from Talisia floresii Standl Seeds: Characterization of Its Physicochemical, Structural and Thermal Properties

Colok seed (Talisia floresii Standl) represents 80% of the total fruit weight and is obtained from trees that grow mainly in Yucatan Peninsula. The aim of this work was the physicochemical characterization from colok starch seeds as an alternative to conventional sources and to identify its characteristics for potential applications in different industrial sectors. Starch yield was 42.1% with low levels of lipids, ashes and fibers. The amylose content was 33.6 ± 1.15%. The gelatinization temperature was 85 ± 0.25 °C. Color analysis resulted in a starch with an intermediate luminosity, reflecting a dark color. Finally, in morphology, starch granule exhibited an average size of 18.7 μm, spherical, uniform and without fractures. Overall results demonstrated that isolated colok starch can be used in food products that require high processing temperatures, such as sauces, cookies, noodles, bread and food packages.

Ready-To-Eat Rice in Retort Pouch Packaging as an Alternative Emergency Food Product

Recently, the rising incidence of natural catastrophe has increased the disaster preparedness, aiming to mitigate its devastating effect. Developing an emergency food is one of meaningful attempts to rise the preparedness. This research aimed to determine the best formula of ready-to-eat rice in retort pouch packaging accepted by consumers, and to determine the operating time to reach a lethality value (F0) to meet the commercial shelf-stable food requirements as an emergency food. The thermal process adequacy (F0) was used to determine the commercial shelf-stable products according to Indonesian regulation. The results showed that the determination of ready-to-eat rice was dependent on the ratio of rice and water. The most accepted product was determined according to quality attributes and organoleptic tests applied to meet the criteria for emergency food, namely color, flavor, and texture and best perceived by consumers. A formula with 140 g of half-cooked rice and 60 g of water was attributed to the best sample, having hardness of 7305.45 gf, elasticity of 36.40%, gumminess of 2185.720 gf, and adhesiveness of -167.975 g.s. In terms of microbiological quality, the TPC for the half-cooked rice sample reached 7.2×107 CFU/mL, while cooked rice in retort pouch packaging was <25 CFU/mL. Using heat distribution curve, heating at 110°C produced a come up time (CUT) after 40 min. Furthermore, the F0 value was 4.12 which was in accordance with the Indonesian regulation.

Reactive Extrusion-Assisted Process to Obtain Starch Hydrogels through Reaction with Organic Acids

A totally green process based on reactive extrusion was used for the production of cassava starch hydrogels through reaction with two organic crosslinking agents, citric (CA) and tartaric (TA) acids. CA and TA were used at different concentrations (0, 2.5, 5.0, 10.0, 15.0, and 20.0%). Degree of substitution (DS) of hydrogels ranged from 0.023 to 0.365. Fourier transform infrared spectroscopy results showed a new band appearing at 1730 cm−1 associated with ester carbonyl groups. X-ray diffraction indicated that reactive extrusion resulted in the disappearance of diffraction peaks of native starch and samples with lower crystallinity indices ranging from 37% (native starch) to 8–11% in starch hydrogels. Morphology analysis showed that the original granular structure of starch was lost and replaced by a rougher and irregular structure. Water holding capacity values of starch hydrogels obtained by reactive extrusion were superior to those of native starch and the control sample (extruded without the crosslinking agents). Hydrogels obtained with the highest CA or TA concentration (20.0%) resulted in the higher DS and swelling capacities, resulting in samples with 870 and 810% of water retention, respectively. Reactive extrusion was effective in obtaining starch hydrogels by reaction with organic acids.

Non-conventional starch from cubio tuber (Tropaeolum tuberosum): Physicochemical, structural, morphological, thermal characterization and the evaluation of its potential as a packaging material

This work aimed to characterize the physicochemical, structural, morphological, and thermal properties of a non-conventional starch obtained from cubio (Tropaeolum tuberosum), as well as to evaluate the potential use of this native Andean tuber in the preparation of biodegradable packaging. The cubio starch (CUS) showed an intermediated apparent amylose content (31.2 %) accompanied by a high CIE whiteness index (90.8). About the morphology and particle size, the CUS exhibited irregular oval and round shapes and a smooth surface with a mean particle diameter of 14.04 ± 0.1 μm. Although it showed good stability regarding pasting properties, the final viscosity was low. Native CUS exhibits a typical B-type diffraction structure, with a relative crystallinity of 16 %. The resistant starch (RS) fraction of the CUS was 94 %, indicating a low susceptibility to enzymatic hydrolysis. The thermal analysis demonstrated that the CUS showed good thermal stability. Additionally, the films prepared using CUS as raw material showed continuous surfaces without porosities, good thermal stability, and high transparency. The results of this work demonstrate the industrial potential of the CUS as it presents characteristics comparable to commercial potato starch.

Environmental Properties and Applications of Biodegradable Starch-Based Nanocomposites

In recent years, the demand for environmental sustainability has caused a great interest in finding novel polymer materials from natural resources that are both biodegradable and eco-friendly. Natural biodegradable polymers can displace the usage of petroleum-based synthetic polymers due to their renewability, low toxicity, low costs, biocompatibility, and biodegradability. The development of novel starch-based bionanocomposites with improved properties has drawn specific attention recently in many applications, including food, agriculture, packaging, environmental remediation, textile, cosmetic, pharmaceutical, and biomedical fields. This paper discusses starch-based nanocomposites, mainly with nanocellulose, chitin nanoparticles, nanoclay, and carbon-based materials, and their applications in the agriculture, packaging, biomedical, and environment fields. This paper also focused on the lifecycle analysis and degradation of various starch-based nanocomposites.

Thermoplastic Starch Composites Reinforced with Functionalized POSS: Fabrication, Characterization, and Evolution of Mechanical, Thermal and Biological Activities

Rapid advancements in materials that offer the appropriate mechanical strength, barrier, and antimicrobial activity for food packaging are still confronted with significant challenges. In this study, a modest, environmentally friendly method was used to synthesize functionalized octakis(3-chloropropyl)octasilsesquioxane [fn-POSS] nanofiller. Composite films compared to the neat thermoplastic starch (TS) film, show improved thermal and mechanical properties. Tensile strength results improved from 7.8 MPa to 28.1 MPa (TS + 5.0 wt.% fn-POSS) with fn-POSS loading (neat TS). The barrier characteristics of TS/fn-POSS composites were increased by fn-POSS by offering penetrant molecules with a twisting pathway. Also, the rates of O₂ and H₂O transmission were decreased by 50.0 cc/m²/day and 48.1 g/m²/day in TS/fn-POSS composites. Based on an examination of its antimicrobial activity, the fn-POSS blended TS (TSP-5.0) film exhibits a favorable zone of inhibition against the bacterial pathogenic Staphylococcus aureus and Escherichia coli. The TS/fn-POSS (TSP-5.0) film lost 78.4% of its weight after 28 days in natural soil. New plastic materials used for packaging, especially food packaging, are typically not biodegradable, so the TS composite with 5.0 wt.% fn-POSS is therefore of definite interest. The incorporation of fn-POSS with TS composites can improve their characteristics, boost the use of nanoparticles in food packaging, and promote studies on biodegradable composites.

Assessment of physicochemical, rheological, and thermal properties of Indian rice cultivars: Implications on the extrusion characteristics

The implications of physicochemical, rheological, and thermal properties of seven eminent Indian rice cultivars (PR 114, 121, 122, 123, 124, 126, and 127) on the extrusion behavior and physico-functionalities of the extrudates were investigated. The amylose and amylopectin content of the cultivars ranged between 12.72 to 28.86% and 71.14 to 87.28% in addition with protein and crude fat content that varied from 7.05 to 9.15% and 0.49 to 1.17%, respectively. The onset (r = 0.98), peak (r = 0.95), and conclusion (r = 0.98) temperatures of the cultivars were in positive correlation with amylose. Likewise, pasting temperature (r = 0.979), final viscosity (r = 0.91), set back viscosity (r = 0.89), and stability ratio (r = 0.90) of the cultivars demonstrated a significant positive correlation with the amylose content. However, peak (r = - 0.879) and hold viscosity (r = - 0.89) were negatively correlated. The cultivars were extruded at feed moisture of 15%, screw speed of 500 rpm and barrel temperature of 150°C. The extrudates characteristics viz., expansion ratio-1.82 (PR 123); bulk density-184 g/cc (PR 123); specific mechanical energy-262.35 Wh/kg; water absorption index (WAI)-6.26 (PR 122); water solubility index-48.52% (PR 123); hardness-148.63 N (PR 122); and hydration power-284% (PR 122) were viably hyphenated with the physicochemical and rheological behavior of cultivars. The physico-functional characterization of the extrudates in terms of their starch and protein structural indexes, α-amylase susceptibility; water soluble carbohydrates and proteins revealed the possibility of exploring these cultivars as a functionally viable and diverse ingredient for the production of ready-to-eat extrudates.

Development of Injectable and Biodegradable Needle-Type Starch Implant for Effective Intratumoral Drug Delivery and Distribution

Introduction

Compared to intravenous administration, intratumoral drug administration enables the direct delivery of drugs to tumors and mitigates the systemic absorption of drugs and associated drug-induced side effects. However, intratumoral drug administration presents several challenges. The high interstitial fluid pressure (IFP) of the tumor prevents the retention of drugs within the tumor; thus, significant amounts of the drugs are absorbed systemically through the bloodstream or delivered to non-target sites. To solve this problem, in this study, a drug-enclosed needle-type starch implant was developed that can overcome IFP and remain in the tumor.

Methods

Injectable needle-type starch implants (NS implants) were prepared by starch gelatinization and drying. The structure, cytotoxicity, and anticancer effects of the NS implants were evaluated. Biodistribution of NS implants was evaluated in pork (in vitro), dissected liver (ex vivo), and 4T1 tumors in mice (in vivo) using a fluorescence imaging device.

Results

The prepared NS implants exhibited a hydrogel structure after water absorption. NS implants showed effective cytotoxicity and anticancer effects by photothermal therapy (PTT). The NS implant itself has sufficient strength and can be easily injected into a desired area. In vivo, the NS implant continuously delivered drugs to the tumor more effectively and uniformly than conventional hydrogels and solutions.

Conclusion

This study demonstrated the advantages of needle-type implants. An injectable NS implant can be a new formulation that can effectively deliver drugs and exhibit anticancer effects.

Synthesis and Characterization of Novel Patchouli Essential Oil Loaded Starch-Based Hydrogel

Starch hydrogels are highly available, biocompatible and biodegradable materials that have promising applications in medical and pharmaceutical industries. However, their applications are very limited due to their poor mechanical properties and fragility. Here, we investigated, for the first time, conventional corn and waxy corn starch-based hydrogels for loading patchouli essential oil. The essential oil extracted by supercritical carbon dioxide with a yield reached 8.37 ± 1.2 wt.% (wet sample) at 80 °C temperature and 10 MPa pressure. Patchouli essential oil exhibited a 23 to 28 mm zone of inhibition against gram-positive and gram-negative bacteria. Waxy starch hydrogels had better properties in term of viscosity, water evaporation stability and the delivery of essential oil than conventional starch hydrogels. The viscosity and spreadability of a 6% waxy starch sample were 15,016 ± 59 cP and 4.02 ± 0.34 g·cm/s, respectively, compared with those of conventional starch hydrogel (13,008 ± 29 cP and 4.59 ± 0.88 g·cm/s). Waxy starch-based hydrogels also provided slower in vitro biodegradation behavior and sustained release of essential oil compared with conventional starch hydrogels. All the samples were biocompatible and non-cytotoxic to fibroblast cells; the addition of patchouli essential oil enhances the proliferation of the cells. The enhanced viscosity, good antibacterial and improved biocompatibility results of prepared hydrogels confirm their suitability for wound healing applications.

Effects of composition and storage time of biopolymers-based emulsion-filled gels on the retention and release of aroma compounds: Thermodynamic and kinetic studies

Studies were performed to determine retention (R) and release kinetics (k_r) of aroma compounds (ACs): ethyl butyrate, linalool, 1-octen-3-ol, 2-heptanone and octanal from emulsion-filled gels (EFGs), stabilized by myofibrillar proteins and waxy rice starch (WRS) or tapioca starch (TS). The R and k_r parameters were affected by non-covalent interactions of ACs with biopolymers and the development of a compact structure induced by starch addition. Higher k_r magnitudes were found in WRS-based samples (88.2-12.8 × 10^-3 day^-1) than in counterparts prepared with TS (87.6-8.96 × 10^-3 day^-1). Thermodynamic tests revealed that vaporization enthalpies of ACs were in ranges: 22.6-41.2 kJ mol^-1 or 21.4-39.8 kJ mol^-1 in samples containing WRS or TS, respectively. This study provides new insight into the factors affecting ACs stability in the EFGs, and the results reported can be used by industry to design relevant systems with extended volatiles retention.

Potential interactions between starch and fruit pomace may impact the expansion ratio of direct expanded extrudates

Due to their dense characteristics, direct-expanded products fortified with insoluble fiber are generally not well accepted. Understanding the interactions between starch and fiber could help to effectively choose and modify ingredients to produce products containing high amounts of fiber. Therefore, this study aims to explain the interplay between two starches (native and waxy corn) and two pomace types (blueberry and cranberry). Blends up to 100% of pomace were extruded using a co-rotating twin-screw extruder. Raw material and milled extrudates were analyzed for their pasting and hydration properties. Fourier-transform infrared (FTIR) and solid-state nuclear magnetic resonance (NMR) spectroscopy were conducted to observe molecular changes. The expansion ratio (ER) significantly decreased as pomace was added and ranged from 3.85 for pure waxy corn starch to approximately 1 for blends that contained 80% pomace. Distinctions between the blends were observed. Particularly, at 20% of pomace inclusion, native corn starch with cranberry pomace showed a significantly higher ER. Different behaviors were also detected during the physicochemical analyses. A nonlinear trend between pomace level and water solubility as well as absorption was observed for native corn starch blends, suggesting that molecular interactions between the biopolymers occur. FTIR and NMR results give no evidence for new covalent bonds; hence, the most likely interactions occurring are hydrogen bonds. In addition to the dilution effect of pomace addition, the enhancement or weakening of such interactions between starch molecules by pomace compounds may reduce the ER.