Effects of ultrasound treatment on the starch properties and oil absorption of potato chips

As a non-thermal processing method, the ultrasound treatment prior to the frying process has been demonstrated with great potential in reducing the oil absorption of fried food. This research aimed to evaluate the effect of ultrasound pretreatment on starch properties, water status, pore characteristics, and the oil absorption of potato slices. Ultrasound probe set with two power (360 W and 600 W) at the frequency of 20 kHz for 60 min was applied to perform the pretreatments. The results showed that ultrasound pretreatment led to the surface erosion of starch granules and higher power made the structure of starch disorganized. Moreover, the fraction of bound water and immobilized water were changed after ultrasonic pretreatment. Pores with the minor diameters (0.4–3 μm and 7–12 μm) were formed after ultrasound pretreatment. The penetrated surface oil (PSO) content, and structure oil (STO) content were reduced by 27.31% and 22.25% respectively with lower power ultrasound pretreatment. As the ultrasound power increased, the surface oil (SO) content and PSO content increased by 25.34% and 12.89% respectively, while STO content decreased by 38.05%. By using ultrasonic prior to frying, the quality of potato chips has been greatly improved.     

Optimization of starch-based candy supplemented with date palm (Phoenix dactylifera) and tamarind (Tamarindus indica L.)

The various health challenges posed by conventional candies necessitate the development of health-promoting and phytochemicals supplemented varieties. The current study explored medicinal properties of date palm and tamarind in the formulation of a starch-based candy, using response surface method for the production optimization. Experimental design variables include the starch (90–100%), date palm (0–10%), and tamarind (0–10%), while the functional, phytochemical, and antioxidant properties were the responses. The candy modification response results are as follows: pH (2.80–3.00), crude fibre (4.41–6.43%), soluble sugar (91.69–126.96%), total titrable acidity (90.00–120.00%), total phenolics (0.039–0.063 mg GA/mL), total flavonoids (0.0006–0.001 mg RU/mL), vitamin C (0.362–0.516 mg/mL), hydroxyl radical scavenging activities (14.28–26.67%), 1, 1- diphenyl-2-picryhydrazyl (1.12–3.88%) and ferric reducing property (0.09–0.31 mg/mL). The experiments revealed that most of the nutritional properties of the candies increased favorably with the incorporation of date palm and tamarind pulps and decreasing starch content. Significant (p ≤ 0.05) interactive effects were revealed between the diverse variables. The experiments also revealed the positive influence of the date palm and tamarind fruit pulps on the functional, phytochemical, and antioxidant properties of starch-based candies; hence demonstrating the possibility of developing nutraceutical based-candies with a more beneficial health effect.     

Preparation and characterization of edible films composed of Dioscorea opposita Thunb. mucilage and starch

With the goals of reducing negative environmental impacts and improving the novel food packaging industry, edible films composed of Chinese yam mucilage (DOM) and starch were prepared via a casting method. The films were characterized by analysing the physical, morphological, mechanical and barrier properties, performing a thermal analysis, and finally performing an acute toxicity analysis in rats that ingested the film-forming solutions. Four film samples (F1, F2, F3 and F4) were prepared to evaluate the effects of ultrasound and the addition of sodium carboxymethyl cellulose (CMC) on DOM. DOM films presented a compact and uniform structure without toxicological responses, and the optimal DOM film-forming solution contained 20.0% mucilage, 10.0% starch, 1.0% glycerol, and 2.0% CMC after a 1 h ultrasound treatment. The solubility, swelling degree and water vapour permeability (WVP) of DOM film were 41.11%, 95.03% and 55.30 g mm/m²·d·kPa, respectively. The functional groups analysed by FT-IR and thermal degradation were not affected by the different formulations. Therefore, the non-toxic and bio-degradable films prepared using DOM have the great potential to be used in applications in food packaging.     

Physical and mechanical properties of plant-derived soft-shell capsules formulated with hydroxypropyl starches from different botanical sources

Soft-shell capsules are prepared herein using hydroxypropyl starches from different botanical sources (maize, waxy maize, potato, and cassava) as a replacement for animal-based materials such as gelatin. The physical, mechanical, and morphological properties of the starch films are characterized to investigate the possibility of manufacturing soft-shell capsules. Starch films originating from tubers, including potato and cassava, exhibit higher tensile strength, resulting in higher hardness of the soft-shell capsules compared to those originating from maize and waxy maize starches. None of the starch-based soft-shell capsules broke in a brittleness test, and there are no distortion defects in the seams that seal the capsules. Disintegration and stability tests over six months show that although the soft-shell capsules manufactured from maize and potato starch disintegrate faster than those from waxy maize and cassava starch, all of the capsules disintegrate within 1200 s, which is acceptable for commercial application.     

Effects of boron nitride nanopowder on thermal,chemical and gas barrier properties of starch

Starch/boron nitride （starch/BN） bionanocomposites were prepared with the reinforcement of boron nitride nano powder by solution technique. The dispersion of BN in the starch was achieved by a continuous sonication process. The interaction between starch and boron nitride nanopowder was investigated by Fourier transform infrared （FTIR） spectroscopy. The structural properties of starch/BN bionanocomposites was studied by X-ray diffraction （XRD）. The high resolution transmission electron microscopy （HRTEM） was used for the study of dispersion of boron nitride in starch matrix and diffraction patterns were studied by selected area electron diffraction （SAED）. Thermal stability of the starch was increased with rising concentrations of boron nitride due to incorporation of rigid nano BN with starch matrix. The substantial reduction in oxygen permeability was obtained by increasing the concentration of BN. The biodegradability of synthesized bionanocomposites was measured by using activated sludge water. Further, it was noticed that, starch/BN bionanocomposites are resistant towards inorganic acids and bases. The tensile strength of starch/BN bionanocomposites was increased whereas; the water resistance property of the materials was decreased with increasing BN loading.     

Enzymatic and anaerobic degradation of amylose based acrylic copolymers, for use as matrices for drug release

The aim of this investigation is the use of starch for effective colon-targeted drug delivery. To this end, high-amylose starch-based copolymers were tested as matrices for drug delivery. Ethyl methacrylate (EMA) was grafted onto a high-amylose starch (A). Copolymer synthesis and characterization as well as other experiments to test the enzymatic resistance and the capacity for fermentation of these products by colonic bacteria were carried out. Finally, tablets developed with our copolymers were tested to observe the dissolution behaviour of a model drug and a model protein. Our findings indicate that large quantities of grafted PEMA are not necessary to obtain high enzymatic resistance. Fermentation experiments indicate that the carbohydrate of A-EMA copolymers is susceptible to fermentation in spite of the EMA coating around the amylose backbone and that these materials could favour colon-targeted delivery.     

Replacement of plasma by high molecular weight substances

In the course of the development work, natural and synthetic polymers were examined to see whether they were suitable for use as plasma substitutes. The criteria of a plasma substitute are discussed in this connection. The most important of the base substances used at present (dextran, modified gelatin, polyvinylpyrrolidone, and hydroxyethyl starch) are described, and a typical example of proven therapeutic value is discussed for each type.     

Foamed articles based on potato starch, corn fibers and poly(vinyl alcohol)

Single-use packaging materials made of expanded polystyrene (EPS) have been identified as suitable items to be replaced by biodegradable materials. Plates made with EPS represent a source of non-degradable waste that is difficult to collect and to recycle. Potato starch based foamed plates have been prepared by a baking process. Presently, foam plates have been prepared by baking aqueous mixtures of potato starch, corn fibers, and poly(vinyl alcohol) (PVA) inside a hot mold. The effects of the addition of corn fibers, a co-product of bio-ethanol production, on mechanical properties and moisture resistance of potato starch based foamed plates were investigated. The addition of corn fiber to potato starch batter increased baking time and an increased batter volume is needed to form a complete tray. The mechanical properties of the trays decreased with added corn fiber. In previous studies PVA has been added as aqueous solution to improve strength, flexibility, and water resistance of baked starch trays. In this study, 88% hydrolyzed PVA was added as a powder in the mixture, avoiding the time consuming and costly step of pre-dissolving the PVA. The addition of PVA to potato starch batters containing corn fiber mitigated the reduction in tensile properties seen in trays with added corn fiber. Starch-based trays produced with a high fiber ratio and PVA, showed improved water resistance.     

Transitional properties of starch colloid with particle size reduction from micro- to nanometer

High-pressure homogenization was used to disperse starch particles in water and reduce the size from micro- to nanometer. The resultant starch colloids were characterized by particle morphology, mean size, size distribution, and zeta potential. Starch slurries were transformed from a mixture containing sediment, dispersion, and sol, to gel as a result of reduction of the particle size from 3–6 μm to 10–20 nm under a pressure of 207 MPa. Furthermore, this process led to the transition of fluid properties without affecting the crystal structure and thermal stability of starch granules. Viscosity of the colloids increased with an increased number of homogenization passes, accompanied by a decreased particle size, narrower particle size distribution (PSD), and an increased absolute zeta potential, indicating the formation of a suspension or stable gel composed of nanoparticles. Lognormal and two other mathematical functions were established to describe the PSDs and their relationship to the homogenization passes. Hence, an environmentally friendly means of producing starch-based nanoparticles or nanogels with high yields, and predictable size and viscosity properties was presented.     

Primary and secondary dielectric relaxations in semi-crystalline and amorphous starch

The thermally stimulated depolarization current technique, TSDC, has been used to study the dielectric relaxations in cassava starch on semi-crystalline and amorphous samples. The A-type structure was observed by WAXS experiments and the variation of the crystallinity as a function of the moisture content, h, was followed on native starch. Retrogradation of the amorphous sample occurred at room temperature after 4 weeks in a closed vessel with a water activity 97.3%. In these conditions the humidity content reached a value of 28.5 wt% dry base and the crystallinity degree was comparable to that of the native starch. Three secondary relaxation modes were detected and attributed to short range orientations of polar groups and to main chain restricted motion. The influence of the moisture plasticization effect on the relaxation parameters of the local modes, was determined by decomposing the global TSDC curve in elementary Debye peaks with Arrhenius relaxation times. The main relaxation, α, which is proposed to be the dielectric manifestation of the dynamic glass transition, sweeps a wide temperature interval around room temperature as the sample dries, shifting to higher temperatures as a result of the plasticization of the polysaccharide by water molecules. The α peak deconvolution lead to the 2D relaxation time distribution and Vogel-Tammann-Fulcher parameters were obtained confirming the cooperative character of this mode. The transformed sample showed a bimodal distribution of segmental relaxation times that is interpreted as the existence of a heterogeneous amorphous phase: the mobile one which is similar to the original disordered phase present in semi-crystalline native starch and a more restricted one originated by the disruption of the crystalline lamellae during the pre-gelatinization process.