Agro-industrial residues are difficult to dispose of or reuse; however, it can be used to generate goods such as biodegradable packaging. The aim was to isolate and characterize fibers from corn ...stalks, husks, and cobs, and apply them in starch composite films (control, 5 g 100 g
−1
, 10 g 100 g
−1
, 15 g 100 g
−1
and 20 g 100 g
−1
). The cellulose fibers were isolated by alkaline treatment and characterized by its morphology, crystallinity, and chemical structure, showing materials with different lengths and diameters, and intermediate crystallinity. The composite films were evaluated by morphological characteristics, water-solubility, water vapor permeability, chemical structure, mechanical properties, and sorption isotherms. Generally, fibers reinforcement decreased moisture adsorption. The tensile strength and Young's modulus increased adding straw fiber (5 g 100 g
−1
and 10 g 100 g
−1
) and stalk and cob fibers (5 g 100 g
−1
). The use of cellulose fibers in films is important to expand and improve the current lack of biodegradable packaging.
Pinhão starch was modified by annealing (ANN), heat-moisture (HMT) or sonication (SNT) treatments. The starch was also modified by a combination of these treatments (ANN-HMT, ANN-SNT, HMT-ANN, ...HMT-SNT, SNT-ANN, SNT-HMT). Whole starch and debranched starch fractions were analyzed by gel-permeation chromatography. Moreover, crystallinity, morphology, swelling power, solubility, pasting and gelatinization characteristics were evaluated. Native and single ANN and SNT-treated starches exhibited a CA-type crystalline structure while other modified starches showed an A-type structure. The relative crystallinity increased in ANN-treated starches and decreased in single HMT- and SNT-treated starches. The ANN, HMT and SNT did not provide visible cracks, notches or grooves to pinhão starch granule. SNT applied as second treatment was able to increase the peak viscosity of single ANN- and HMT-treated starches. HMT used alone or in dual modifications promoted the strongest effect on gelatinization temperatures and enthalpy.
•Films produced with oxidized starch are more homogeneous than native starch.•Films of starch oxidized with 1.5% active chlorine had the highest tensile strength.•The presence of cellulose fibers in ...the films increased their tensile strength.•Celullose fibers in films increases its thermal stability.•The addition of cellulose fiber in the films of oxidized starches reduced their solubility.
Starch and cellulose fibers were isolated from grains and the husk from barley, respectively. Biodegradable films of native starch or oxidized starches and glycerol with different concentrations of cellulose fibers (0%, 10% and 20%) were prepared. The films were characterized by morphological, mechanical, barrier, and thermal properties. Cellulose fibers isolated from the barley husk were obtained with 75% purity and high crystallinity. The morphology of the films of the oxidized starches, regardless of the fiber addition, was more homogeneous as compared to the film of the native starch. The addition of cellulose fibers in the films increased the tensile strength and decreased elongation. The water vapor permeability of the film of oxidized starch with 20% of cellulose fibers was lower than the without fibers. However the films with cellulose fibers had the highest decomposition with the initial temperature and thermal stability. The oxidized starch and cellulose fibers from barley have a good potential for use in packaging. The addition of cellulose fibers in starch films can contribute to the development of films more resistant that can be applied in food systems to maintain its integrity.
Carioca bean starch is isolated and modified by annealing (ANN), heat‐moisture‐treatment (HMT), and sonication (SNT), as well as combined dual modifications (ANN‐HMT, ANN‐SNT, HMT‐ANN, HMT‐SNT, ...SNT‐ANN, SNT‐HMT). Single and dual modifications did not cause molecular damage in starch fractions. Starch B‐type fraction in native Carioca bean increases after the ANN treatment. Dual ANN‐SNT modification (ANN‐SNT or SNT‐ANN) promotes a synergic behavior on crystallite collapse, causing a decrease in relative crystallinity. The ANN as the second treatment results in irregular surface morphologies and granule disintegration. The ANN‐SNT and SNT‐ANN modifications increase the pasting viscosity synergistically in contrast to individual SNT or ANN treatments. The HMT process promotes the disruption of crystallites upon the subsequent ANN treatment, confirmed by an increase in enthalpy (ΔH). The starch modification techniques reported here can provide new opportunities to utilize damaged and hard‐to‐cook Carioca beans in the food industry.
Heat‐moisture‐treatment (HMT), annealing (ANN), and sonication (SNT) are used as single and dual physical modification methods for Carioca bean starch. Some changes of its characteristics are noticed. These combinations can improve Carioca beans starch application to food and nonfood products. HMT shows the most effective result in the combined starch physical modification.
Starch nanocrystals (SNCs) are insoluble platelet particles with multifunctional properties. SNCs production is mainly based on acid hydrolysis of cornstarch with low yield. This study focuses on ...investigating the effect of pretreatments (heat‐moisture‐treatment HMT, annealing ANN, and sonication SNT) on unconventional pinhão starch to produce SNCs by acid hydrolysis to improve the yield and SNCs properties. All starches hydrolysis is described by a first‐order model reaction and shown two phases related at k values. The faster hydrolysis is from SNT (k = 0.61 day−1) and the slower one is at ANN (k = 0.40 day−1). Furthermore, the acid hydrolysis is described by a rapid (0–2 days) phase, followed by a slow phase lasing 3–7 days. The HMT increases the yield of the SNCs (14.7%) but promotes losses in the RC (47.34%) as compared with the native starch (yield 10.23%; RC 52.23%). The ANN improves crystallites perfection, protecting them from acid attack. The pretreatments allow pinhão starch to be used as promising feedstock to produce SNCs with good yield and RC. In addition, ANN can be useful to improve the thermal stability and SNT to speeding up the hydrolysis for SNCs production, while HMT can increase the hydrolysis yield.
Physical treatments(heat‐moisture‐treatment HMT, annealing ANN, and sonication SNT) can be useful for pinhão SNCs production; SNT can speed up the hydrolysis for SNCs production; HMT can increase the hydrolysis yield; ANN promotes the formation of SNCs with high thermal stability.
The
Ilex paraguariensis
, known as yerba-mate, is widely consumed as a hot or cold infusion in South America. Every year during the leaves harvesting, a rate of 5 tons/ha of branches is generated due ...to the tree trimming. The epidermis of these branches (IPC) is characterized by a high concentration of chlorogenic acids. Due to its promising high compound concentration, IPC extract is well-suited for various applications, and its preservation is particularly crucial, especially in bakery goods. This study aimed to optimize the spray-drying encapsulation of IPC extract to enhance the stability of chlorogenic acids for baked product applications. Through multivariate design, the optimal encapsulation conditions were determined, resulting in 75% encapsulation efficiency (%EE), 66.5% loading capacity (%LC), a 41 ºC increase in thermal stability, and particles with an average diameter of up to 5 µm. In sponge cakes formulated with encapsulated IPC extract (IPCE), an average of 94.4% of chlorogenic acids was preserved, compared to only 69.3% when free-IPC extract was used. Furthermore, the chlorogenic acids in IPCE exhibited excellent stability over 12 months when stored at 4ºC. Spray-drying encapsulation proved to be a rapid and effective process for the food industry, preserving chlorogenic acids for at least one year during storage under conditions that would naturally lead to degradation. These findings encourage the application of encapsulates to enhance the functionality of foods and add value to a naturally neglected commercial product.
The growing concern on environment preservation and the impact of the packaging from the non‐renewable materials improve the interest at biodegradable and active packages development for food ...applications. The aim was to develop starch films with yerba mate extract (YME) made with water: ethanol (50:50% vol/vol) at 50°C followed by characterization. The YME was applied to the cassava starch films (control, 5, 10, 15, and 20%). The thickness, water vapor permeability (WVP), tensile strength, elongation as well as the Young’s Modulus, water solubility, phenolic compounds, antioxidant activity (DPPH•), color and opacity and sorption isotherms of the films were characterized. The starch films decrease tensile strength, Young’s module and elongation increased as the YME concentration increased. In addition, the sorption isotherms were adjusted to the GAB model (R2 > 0.96). The moisture absorption by the samples of starch films with 5, 10, and 15%, had similar moisture absorption, higher than the control samples.
Practical applications
In this research, we developed a biodegradable active film with Yerba mate extract (YME), which is in good agreement with the growing concern in the preservation of the environment through minimization of the environmental impact of packaging from the non‐renewable raw material. YME increased the phenolic compounds and antioxidant activity of the starch films. This behavior is good for fatty food applications, since fat acids may undergo oxidative processes and change sensorial and nutritional characteristics; and antioxidants will slow down these reactions. The YME also promoted a plasticizing effect in the cassava starch films, decreasing tensile strength and increasing the elongation. This behavior allows the application of systems that do not need high mechanical efforts.
Biodegradable starch foam trays offer an eco-friendly substitute for petroleum-based single-use packaging, notably polystyrene foams. However, they lack flexibility, tensile strength, and ...water-sensitivity, addressable through lignocellulosic reinforcement. This study aimed to develop biodegradable starch foam trays filled with different food-chain side streams for sustainable alternative packaging. Corncob, soybean straw, cassava peel, araucaria seed hull, yerba mate stalks and yerba mate leaves petiole were collected, dried and ground to <250 μm. The trays were filled with 13 % (w/w) of each food-chain side streams and produced by hot molding. The trays morphology, moisture, water activity (aw), thickness, bulk density, tensile strength, elongation at break, Young's modulus, bending strength, maximum deflection, and sorption isotherms were investigated. Reinforcements slightly increased the foams bulk density, reduced the tensile strength and maximum deflection and while bending strength increased from 0.20 MPa to 1.17–1.80 MPa. The elasticity modulus decreased by adding any filling, that resulted in ductility improvement; however, these packaging have moisture-sensitive material especially for aw higher than 0.52, which drives the use recommendation for dry products storage or shipping/transport. The biodegradable starch foam trays filled with side streams were successfully produced and offer excellent alternative to petroleum-based packaging low-density material with bending strength improved.
•Cassava starch was used to develop biodegradable foam trays.•Six lignocellulosic food-chain side streams were used as filler in starch foam trays.•The bending strength was enhanced up to 800 % upon trays filling.•Relative humidity higher than 0.5 was responsible for trays softening.
The aim of this work was to prepare a flexible nanocomposite from ultra-fine titanium oxide (
TiO
2
) growth on carbon fibre via microwave-assisted hydrothermal synthesis (MHS) and to evaluate its ...photocatalytic properties. The
TiO
2
nanoparticles were directly grown on the carbon fibre (CF). Thus, a study comparing the conventional titania coating
vs.
the MHS were performed. The significant layer interaction as a function of the coating method on the visible and dark dye photodegradation performance was observed. Techniques such as X-ray diffraction, electron microscopy (field-emission scanning electron microscope (FESEM)), Raman spectroscopy, among others were used aiming to characterize the different route samples. This study reports a reproducible and single method to manufacture of nanocomposites through the growth of
TiO
2
nanoparticle on CF by MHS that allow controlling the thickness layer. Similar procedure of synthesized nanocomposite could be applied in different chemical compositions to advanced applications, based on the electrochemical nanostructure.
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