Recent advances in modified starch based biodegradable food packaging: A review.

This study reviews the importance of resistant starch (RS) as the polymer of choice for biodegradable food packaging and highlights the RS types and modification methods for developing RS from native starch (NS). NS is used in packaging because of its vast availability, low cost and film forming capacity. However, application of starch is restricted due to its high moisture sensitivity and hydrophilic nature. The modification of NS into RS improves the film forming characteristics and extends the applications of starch into the formulation of packaging. The starch is blended with other bio-based polymers such as guar, konjac glucomannan, carrageenan, chitosan, xanthan gum and gelatin as well as active ingredients such as nanoparticles (NPs), plant extracts and essential oils to develop hybrid biodegradable packaging with reduced water vapor permeability (WVP), low gas transmission, enhanced antimicrobial activity and mechanical properties. Hybrid RS based active packaging is well known for its better film forming properties, crystalline structures, enhanced tensile strength, water resistance and thermal properties. This review concludes that RS, due to its better film forming ability and stability, can be utilized as polymer of choice in the formulation of biodegradable packaging.

Modifications of native lotus (Nelumbo nucifera G.) rhizome starch and its overall characterization: A review.

Lotus (Nelumbo nucifera G.) rhizomes are an under-utilized and sustainable starch source that constitutes up to 20 % starch. The review mainly focused on the extraction methods of starch, the chemical composition of LRS, and techno-functional characteristics such as swelling power, solubility, in vitro digestibility, pasting property, and gelatinization is highlighted in LRS review. Lotus rhizome starch (LRS) is also used as a water retention agent, thickening, gelling, stabilizing, and filling in food and non-food applications. Native starch has limited functional characteristics in food applications so by modifying the starch, functional characteristics are enhanced. Single and dual treatment processes are available to enhance microstructural properties, resistant starch, techno-functional, morphological, and, film-forming properties. Compared with other starch sources, there is a lack of systematic information on the LRS. Many industries are interested in developing food products based on starch such as nanoparticles, hydrogels, edible films, and many others. Additionally, there are several recommendations to improve the applications in the food industry. Finally, we provide an outlook on the future possibility of LRS.

Curcumin encapsulation in capsules and fibers of potato starch by electrospraying and electrospinning: Thermal resistance and antioxidant activity.

The aim of this work was to encapsulate curcumin at different concentrations in capsules and fibers of native potato starch by electrospraying and electrospinning. The best conditions for the production of capsules and fibers were obtained by varying the polymer concentration and resting time of the polymer solution. The best conditions were used for the encapsulation of curcumin. The curcumin-loaded capsules and fibers had an average diameter of 1373 nm to 1787 nm and 108 nm to 142 nm, respectively, and had a high curcumin loading capacity with values ranging from 79.01 % to 97.09 %. Curcumin encapsulated in starch capsules and fibers showed higher thermal stability at 180 °C for 2 h compared to unencapsulated curcumin. The antioxidant activity of starch fibers containing 1 % of curcumin had the greatest ability to inhibit the ABTS radical (45 % inhibition). These materials are promising for use in food or active packaging.

Relation between adhesiveness and surface leachate rheological properties of cooked noodles: From the view of starch fine molecular structure.

Adhesiveness is one of the important sensory properties of noodles. A better understanding of the molecular basis of the sensory property would allow for a more reasonable selection of wheat ingredients. In this study, the adhesiveness of cooked noodles made from reconstituted wheat flour was evaluated using a texture profile analyzer. The rheological properties of dissolved solids from the noodle surface were measured. The composition and structure of leachate, as well as multi-structure of native starch were analyzed. The correlation analysis showed that adhesiveness positively correlates with the loss modulus parameters [log K' (consistency coefficient) and Ea (activation energy)]. Increased content of leached starch can ascend the rheological parameters (log K' and Ea). In addition, more short amylose chains with 100-500 degree of polymerization (DP) in leached starch also induced the increase of log K' (p < 0.01) and Ea (p < 0.01). The fraction of short amylose chains in leached starch was negatively correlated with the content of long amylopectin chains ranged from 37 to 100 DP in native starch (p < 0.05), as well as the median diameter of particles (p < 0.01). Multi-level structures of native starch granules largely determine the composition and molecular structure of noodle leachate, consequently contributing to surface rheological properties. It is thus proposed that wheat starch with more long amylopectin chains and large granules could be used to reduce noodle adhesiveness. Moreover, the rheological approach using noodle surface materials proposed here is useful to predict the noodle adhesiveness as an important sensory characteristic.

Combination of Sorbitol and Glycerol, as Plasticizers, and Oxidized Starch Improves the Physicochemical Characteristics of Films for Food Preservation.

The aim of this work was to use glycerol (Gly) and sorbitol (Sor) as plasticizers with oxidized starch potato (OS) to produce biodegradable and environmentally friendly films, and to demonstrate the resulting physicochemical and functional viability without subtracting the organoleptic characteristics of the food. Analyses by water vapor permeability (WVP), attenuated total reflection Fourier transform infrared spectra (ATR-FTIR), scanning electron microscopy (SEM), tensile strength (TS), and transparency (UV) showed that the best film result was with 1.5 g of Gly and 2.0 g of Sor, conferred shine, elasticity 19.42 ± 6.20%, and mechanical support. The starch oxidized to 2.5%, contributing a greater transparency of 0.33 ± 0.12 and solubility of 78.90 ± 0.94%, as well as less permeability to water vapor 6.22 ± 0.38 gmm-2 d-1 kPa-1. The films obtained provide an alternative for use in food due to their organic compounds, excellent visual presentation, and barrier characteristics that maintain their integrity and, therefore, their functionality.

Physicochemical properties, oxidative stability and antioxidant capacity of clean label meat-based sauces: effects of phenolic extracts addition and cold storage.

Physicochemical properties, oxidative stability and antioxidant capacity (AC) of clean label meat-based sauces (MBSs) were investigated with reference to cold storage time (ST) and addition of phenolic extracts (PEs): green coffee bean (GCE), green tea (GTE), knotweed rhizome (KRE). All parameters determined were compared to a control sample (CS), prepared without extracts. MBSs enriched with GCE or KRE were stable during the whole ST (90 days), while the CS and samples containing GTE, showed descending trend regarding physical stability after 10 days of storage. MBSs prepared with PEs (90 days storage) demonstrated: peroxide value (PV) < 8.5 mEq O2/kg lipids, TBARS < 5.6 mg MDA/kg lipids, carbonyl content < 4.7 nmol/mg protein, and the values were significantly (p < 0.05) smaller than those found in CS. Irrespectively of the applied measurements (ABTS, DPPH, FRAP) the values of AC (trolox equivalent, TE) decreased with ST, and regarding ABTS assay were in ranges: 0.73-0.42 mM TE (CS), 3.54-2.75 mM TE (GCE), 4.89-3.29 mM TE (GTE) and 3.86-2.25 mM TE (KRE). ANOVA revealed that rheological parameters obtained from Herschel-Bulkley's and Bohlin's models were predominantly (p < 0.001) affected by ST. After 90 days of storage, values of the desirability index were significantly (p < 0.05) higher for GCE-fortified MBS than for samples prepared with GTE and KRE. The results of this study can be useful to optimize composition of meat-based sauces containing bioactive ingredients and exhibiting desired by the consumer sensory features.

Structural and physicochemical property changes during pyroconversion of native maize starch.

Pyrodextrins are widely applied in industry as adhesives, coatings, binders, and in food as dietary fiber. In this study, the dynamic changes of structure and physicochemical property during pyroconversion of native maize starch are investigated. By quantifying the variations of chain-length distribution (CLD) between native starch and pyrodextrins, it is found that 1) the long starch chains with degree of polymerization (DP) about 500-20000 are degraded while its content is not significantly varied between pyrodextrins; 2) the content of intermediate-long chains with DP 20-500 increases with temperature, indicating more pyrodextrin molecules with the equivalent Rh∼1.5-9.4 nm are newly formed; 3) the content of A and B1 chains are not largely varied between pyrodextrins with temperature ≤190 °C, suggesting that the repolymerization might be more likely occur in the amorphous lamellae. This study improves the understanding of structural and physicochemical property changes during the pyroconversion process of native maize starch.

First-line anti-tubercutilosis drugs-loaded starch nanocrystals for combating the threat of M. tuberculosis H37Rv strain.

Nanoparticles-based drug delivery is at the forefront in the field of pharmaceutical and medicinal research to eradicate or alleviate the associated impediments, such as prolonged treatment time, high doses, toxicity and resistance problem of anti-tuberculosis drugs for the treatment of age-old tuberculosis disease. Herein, the first-line anti-tuberculosis drugs were loaded into the biodegradable starch nanocrystals and native starch to improve the therapeutic profile addressing the existing issues related to conventional drugs. The loading performance of anti-tuberculosis drugs with starch nanocrystals and native starch was found in the range of 65-95%. According to the release study, the native starch was not appropriate, however, the starch nanocrystals demonstrated sustained release drug delivery for isoniazid and pyrazinamide ranging from 50 to 93% for 24 h; the burst release for streptomycin was reported at pH 2 in 6.5 h while only 14% rifampicin was released at pH 8 buffer. An anti-mycobacterium analysis of strain H37Rv showed that minimum inhibition concentration of starch nanocrystals loaded with isoniazid and pyrazinamide (0.033 µg/mL and 1.25 µg/mL, respectively) were more effective than the parent isoniazid (0.2 µg/mL) and pyrazinamide (25.0 µg/mL) at pH 5.5.

Effect of typical starch on the rheological properties and NMR characterization of myofibrillar protein gel.

BACKGROUND: Composite gels were individually prepared from 20 g kg-1 myofibrillar protein (MP) imbedded with typical native starch (potato, tapioca, rice or corn starch) in 0.6 mol L-1 NaCl at pH 6.2. The gel strength, water holding capacity, rheological properties and microstructure of the obtained myofibrillar protein-starch composite gels were evaluated. RESULTS: Tapioca starch improved (P < 0.05) gel strength and water holding capacity of MP composite gel at 80 °C. Rheological properties of MP-starch composites differed significantly with the addition of different types of native starch. Additionally, the promoting effect of starch on the storage modulus of the composite gels positively correlated with the gelatinization properties of different typical starch. Environmental scanning electron microscopy showed that the filling effect of starch on the composite gel was related to the pasting temperature and particle size of typical starch, with almost no particles forming at 80 °C. Moreover, the addition of starch changed the relaxation peak area and increased the relaxation time in nuclear magnetic resonance tests, which suggested that starch could improve the water holding capacity of MP-starch composite gels. CONCLUSION: Different typical native starch has varied impacts on the gel strength, water holding capacity, rheological properties and microstructure of MP gels, indicating the potential and feasibility of these typical native starches as an addition agent to modify the textural properties in comminuted meat products. © 2019 Society of Chemical Industry.

Native starch as in situ binder for continuous twin screw wet granulation.

The use of native starch as in situ binder in a continuous twin screw wet granulation process was studied. Gelatinization of pea starch occurred in the barrel of the granulator using a poorly soluble excipient (anhydrous dicalcium phosphate), but the degree of gelatinization depended on the liquid-to-solid ratio, the granule heating and the screw configuration. Furthermore, the degree of starch gelatinization was correlated with the granule quality: higher binder efficiency was observed in runs where starch was more gelatinized. SEM and PLOM images showed experimental runs which resulted in completely gelatinized starch. Other starch types (maize, potato and wheat starch) could also be gelatinized when processed above a critical barrel temperature for gelatinization. This barrel temperature was different for all starches. In situ starch gelatinization was also investigated in combination with a highly soluble excipient (mannitol). The lower granule friability observed using pure mannitol compared to a mannitol/starch mixture indicated that starch did not contribute to the binding, hence starch did not gelatinize during processing. The study showed that native starch can be considered as a promising in situ binder for continuous twin screw wet granulation of a poorly soluble formulation.

The structure and properties of granular cold-water-soluble starch by a NaOH/urea aqueous solution.

The NaOH/urea treatment of starch results in granular cold-water-soluble starch (GCWSS). The research indicated that the optimized condition for this treatment was aqueous solution of 14% w/v NaOH and 12% w/v urea (all dosages based on starch weight) at ambient temperature (25 °C) for 10 min with stirring. The aqueous solution was then treated a water-extraction and alcohol-precipitation method. The solid sample was dried in an oven at 60 °C. The GCWSS displayed a cold-water solubility of ~90%. The GCWSS had lower amylose content. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction also indicated that it was an amorphous solid with a V-type pattern (single-helix). The NaOH/urea solution could destroy the inter and intra hydrogen bonding of starch thereby decreasing glass transition temperature, and improve the cold water solubility of native starch.

Simultaneous saccharification and fermentation of native rye, wheat and triticale starch.

BACKGROUND: The increasing global demand for starchy raw material requires new methods for obtaining ethanol from a range of plants using environmentally friendly methods. Granular starch-hydrolyzing enzymes (GSHE) can effectively support the development of the distillery industry. RESULTS: The aim of this study was to evaluate the effectiveness of simultaneous saccharification and fermentation of native rye, wheat or triticale starch. Mashes were prepared using methods that limit water and energy consumption (pre-hydrolysis at 35 °C for 30 min). The results show that the degree of starch saccharification depended on the raw material. However, the highest yields of ethanol were obtained with 100 kg of triticale mashes (38.9 ± 1.4 L absolute alcohol) as compared to rye and wheat mashes. The concentration of dry matter (between 250 and 280 g L-1 ) in the mashes was not associated with a decrease in ethanol yield and improved efficiency in the case of wheat and triticale. CONCLUSION: Simultaneous saccharification and fermentation offers a low-cost and environmentally friendly alternative to existing procedures for industrial ethanol production, which may be of particular interest to raw-spirit producers, as well as to the food and fermentation industry at large. © 2019 Society of Chemical Industry.

Natural Starch in Biomedical and Food Industry: Perception and Overview.

Utilization of native starch is increasing globally because of its wide distribution and natural occurrence. Starch is mainly abundant in tubers and food grains. Scientific research on starch is increasing in recent years due to its unique physiochemical and biomedical properties. Native starch is an emerging biopolymer and copolymer in the biomedical and pharmaceutical areas due to its renewability, biocompatibility, biodegradability, and relative inexpensiveness. Today, there is an increasing interest in natural starches to design and produce diverse products due to their pertinent structural properties and non-toxicity. Due to these attributes, these natural polymers are becoming functional core materials in the biomedical industry, construction materials, medicine industry, food industry, food packaging, and carrier for active drugs. In this paper, we mainly attempt to analyze the physicochemical attributions and the biomedical applications on native or non-conventional starches obtained from the natural botanical sources.

Physicochemical, Thermal, Structural and Pasting Properties of Unconventional Starches from Ginger (Zingiber officinale) and White Yam (Dioscorea sp)

Abstract Ginger and white yam starches were investigated and compared with maize starch. Proximal composition, thermogravimetry, differential scanning calorimetry, microscopy, colourimetry, X-ray powder diffractometry and pasting profile were analysed. The unconventional starches presented higher protein and ash contents than the maize starch, that had the highest thermal stability. Higher gelatinisation temperatures were reported for ginger starch, and the enthalpy of the unconventional starches were similar. The maize starch presented the lowest gelatinisation values. For the corn starch the granules were polygonal and smaller than the unconventional starches, and oval shapes and larger diameters were found for the ginger and yam starches. The unconventional starches presented less brightness and a greater tendency to red and yellow. The maize and ginger starches had A-type diffraction patterns, while the white yam starch had a C-type pattern. The highest relative crystallinity was observed for the ginger starch and there were small differences between the yam and maize starches. Higher peak viscosity and final viscosity and lower pasting temperature were observed for the yam starch. Ginger starch showed the highest shear and stability of heating glue, so may be used in products processed under high temperatures; and yam starch can be used in acidic foods that require high viscosities.

Novel starch based emulsion gels and emulsion microgel particles: Design, structure and rheology.

Novel starch-based emulsion microgel particles were designed using a facile top-down shear-induced approach. The emulsion droplets were stabilized using octenyl succinic anhydride (OSA) modified starch and incorporated into heat-treated and sheared native starch gels, forming emulsion gels. Using gelation kinetics and small deformation rheological measurements of sheared native starch gels and emulsion gels, OSA starch-stabilized emulsion droplets were demonstrated to act as "active fillers". By varying native starch concentrations (15-20wt%) and oil fractions (5-20wt%), optimal concentrations for the formation of emulsion microgel particles were identified. Microscopy at various length scales (transmission confocal laser scanning and cryo-scanning electron microscopy) and static light scattering measurements revealed emulsion microgel particles of 5-50µm diameter. These novel emulsion microgel particles created via careful combination of gelatinized native starch and OSA stabilised-emulsion droplets acting as active fillers may find applications in food and personal care industries for delivery of lipophillic molecules.

Characteristics of granular cold-water-soluble potato starch treated with alcohol and alkali.

The characteristics of cold-water-soluble potato starch (CWSS) produced using alcoholic-alkaline treatment were determined using scanning electron microscopy, rapid visco analysis (RVA), X-ray diffraction, differential scanning calorimetry, storage modulus (G'), loss modulus (G″), and gel images. Scanning electron microscopy revealed a damaged crystalline structure when CWSS was suspended in ethanol. The RVA analysis of native starch showed a peak value of viscosity at high temperatures, whereas the viscosity of CWSS did not show such a peak. The DSC diagram of native starch showed a gelatinization peak temperature; however, no such peak was observed for CWSS. Cold-water solubility tremendously increased in CWSS owing to the loss of crystallinity. The values of G' and G″ in CWSS decreased with increasing temperature; the opposite was observed for normal potato starch. These results indicate that alcoholic-alkaline treatment affects the starch structure and produces totally different physicochemical properties from native starch; this makes CWSS feasible for use in a variety of food materials.