Downstream processing and structural confirmation of pullulan - A comprehensive review

Pullulan is a microbial polymer, commercially produced from Aureobasidium pullulans. Downstream processing of pullulan involves a multi-stage process which should be efficient, safe and reproducible. In liquid-liquid separations, firstly cell free extract is separated. Cell biomass can be separated after fermentation either by centrifugation or filtration. Due to practically insolubility of pullulan in organic solvents, ethanol and isopropanol are the most commonly used organic solvents for its recovery. Pullulan can also be purified by chromatographic techniques, but these are not cost effective for the purification of pullulan. Efficient aqueous two-phase system can be used for the purification of pullulan. The current review describes the methods and perspectives used for solid-liquid separation, liquid-liquid separations and finishing steps for the recovery of pullulan. Techniques used to determine the structural attributes of pullulan have also been highlighted.

Emerging trends in environmental and industrial applications of marine carbonic anhydrase: a review

Biocatalytic conversion of greenhouse gases such as carbon dioxide into commercial products is one of the promising key approaches to solve the problem of climate change. Microbial enzymes, including carbonic anhydrase, NAD-dependent formate dehydrogenase, ribulose bisphosphate carboxylase, and methane monooxygenase, have been exploited to convert atmospheric gases into industrial products. Carbonic anhydrases are Zn²⁺-dependent metalloenzymes that catalyze the reversible conversion of CO₂ into bicarbonate. They are widespread in bacteria, algae, plants, and higher organisms. In higher organisms, they regulate the physiological pH and contribute to CO₂ transport in the blood. In plants, algae, and photosynthetic bacteria carbonic anhydrases are involved in photosynthesis. Converting CO₂ into bicarbonate by carbonic anhydrases can solidify gaseous CO2, thereby reducing global warming due to the burning of fossil fuels. This review discusses the three-dimensional structures of carbonic anhydrases, their physiological role in marine life, their catalytic mechanism, the types of inhibitors, and their medicine and industry applications.

Black soybean (Glycine max (L.) Merr.): paving the way toward new nutraceutical

Black soybean (BS) is a nutritious legume that is high in proteins, essential amino acids, dietary fiber, vitamins, minerals, anthocyanins, phenolic acids, isoflavones, and flavones. Traditional approaches for extracting BS bioactive compounds are commonly employed because they are simple and inexpensive, but they use toxic solvents and have lower yields. As a result, new extraction techniques have been developed, such as microwave, ultrasound, and enzyme-assisted extraction. Modern approaches are less harmful to the environment, are faster, and produce higher yields. The major anthocyanin in the BS seed coat was discovered as cyanidin-3-O-glucoside, accounting for nearly 75% of the total anthocyanins. BS and its seed coat also contains phenolic acids (p-hydroxybenzoic, gallic, vanillin, syringic acid), isoflavones (daidzein, glycitein and genistein), flavones, flavonols, flavanones, and flavanols. Bioactive compounds present in BS exhibit antioxidant, anti-cancerous, anti-diabetic, anti-obesity, anti-inflammatory, cardio and neuroprotective activities. The characterization and biological activity investigation of these bioactive compounds has provided researchers and food manufacturers with valuable information for developing functional food products and nutraceutical ingredients. In this review, the nutritional makeup of BS is reviewed, and the paper seeks to provide an insight of bioactive compound extraction methods as well as bioactive compounds identified by various researchers. The biological activities of BS extracts and their potential applications in food products (noodles), biodegradable films (pH sensitive film), and therapeutic applications (wound healing and anti-inflammation) are also discussed in the study. Therefore, BS have enormous potential for use in developing functional foods and nutraceutical components. This is the first review of its sort to describe and explain various extraction methodologies and characterization of bioactives, as well as their biological activity recorded in diverse works of literature, making it possible for food manufacturers and scientists to get a quick overview.

Skincare application of medicinal plant polysaccharides - A review

Polysaccharides are macromolecules with important inherent properties and potential biotechnological applications. These complex carbohydrates exist throughout nature, especially in plants, from which they can be obtained with high yields. Different extraction and purification methods may affect the structure of polysaccharides and, due to the close relationship between structure and function, modify their biological activities. One of the possible applications of these polysaccharides is acting on the skin, which is the largest organ in the human body and can be aged by intrinsic and extrinsic processes. Skincare has been gaining worldwide attention not only to prevent diseases but also to promote rejuvenation in aesthetic treatments. In this review, we discussed the polysaccharides obtained from plants and their innovative potential for skin applications, for example as wound-healing, antimicrobial, antioxidant and anti-inflammatory, antitumoral, and anti-aging compounds.

Effect of mung bean protein isolate/pullulan films containing marjoram (Origanum majorana L.) essential oil on chemical and microbial properties of minced beef meat

In this study, the effect of marjoram essential oil (MEO) on the mechanical, barrier, antioxidant and antimicrobial properties of mung bean protein isolate (MPI)/pullulan (PU) composite films and its influence on the quality of minced beef meat during 14 days storage at 4 °C was studied. The Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) results confirmed the compatibility between components. Also, depend on the different ratios of combination of MEO and MPI/PU, tensile strength (TS) and elongation at break (EAB) were varied. The results showed that an increase in the level of the MPI led to a significant increment in TS and water-proof properties of the composite films. Also, with addition of MEO, the EAB of the antimicrobial blend-films was decreased, while TS and water-proof properties were increased. In addition, enrichment of the films with MEO led to a considerable positive effect on DPPH radical scavenging and antibacterial activity against pathogenic bacteria (Staphylococcus aureus and Escherichia coli). Based on the bacterial and chemical analyses of the minced meat samples, MEO-incorporation in MPI/PU films enhanced oxidative stability of minced beef samples, and also showed effective antimicrobial activity against all of the tested bacteria.

Native Amine-Directed ortho-C–H Halogenation and Acetoxylation /Condensation of Benzylamines

Free or unfunctionalized benzylamines are well known to participate in C–H activation in the presence of palladium salts. Despite the ease with which these complexes can be activated, subsequent functionalization of the dimeric cyclometalates can be challenging. We demonstrate herein a free primary amine based C–H activation/functionalization protocol that allows for the ortho-C–H chlorination and bromination of unprotected benzylamines. We also demonstrate how use of fluorine-based oxidants gives rise to a unique acetoxylation/­cyclization owing to the nucleophilicity of the free primary amine directing group.

Recent insights into carrageenan-based bio-nanocomposite polymers in food applications: A review

Nanotechnology has proven as progressive technology that enables to contribute, develop several effective and sustainable changes in food products. Incorporating nanomaterials like TiO₂, SiO₂, Halloysite nano clay, Copper sulfide, Bentonite nano clay, in carrageenan to develop innovative packaging materials with augmented mechanical and antimicrobial properties along with moisture and gas barrier properties that can produce safe and healthy foods. Intervention of carrageenan-based bio-nanocomposites as food packaging constituents has shown promising results in increasing the shelf stability and food quality by arresting the microbial growth. Nanomaterials can be incorporated within the carrageenan for developing active packaging systems for continuous protection of food products under different storage environments from farm to the fork to ensure quality and safety of foods. Carrageenan based bio nanocomposite packaging materials can be helpful to reduce the environmental concerns due to their high biodegradability index. This review gives insight about the current trends in the applications of carrageenan-based bio nanocomposites for different food packaging applications.

Electro-hydrodynamic assisted synthesis of lecithin-stabilized peppermint oil-loaded alginate microbeads for intestinal drug delivery

Peppermint oil (PO) is the most prominent oil using in pharmaceutical formulations with its significant therapeutic value. In this sense, this oil is attracting considerable attention from the scientific community due to its traditional therapeutic claim, biological and pharmacological potential in recent research. An organic solvent-free and environment-friendly electrohydrodynamic assisted (EHDA) technique was employed to prepared PO-loaded alginate microbeads. The current study deals with the development, optimization, in vitro characterization, in vivo gastrointestinal tract drug distribution and ex-vivo mucoadhesive properties, antioxidant, and anti-inflammatory effects of PO-loaded alginate microbeads. The optimization results indicated the voltage and flow rate have a significant influence on microbeads size and sphericity factor and encapsulation efficiency. All these optimized microbeads showed a better drug release profile in simulated intestinal fluid (pH 6.8) at 2 h. However, a minor release was found in acidic media (pH 1.2) at 2 h. The optimized formulation showed excellent mucoadhesive properties in ex-vivo and good swelling characterization in intestine media. The microbeads were found to be well distributed in various parts of the intestine in in vivo study. PO-loaded alginate microbeads similarly showed potential antioxidant effects with drug release. The formulation exhibited possible improvement of irritable bowel syndrome (IBS) in MO-induced rats. It significantly suppressed proinflammatory cytokines, i.e., interleukin- IL-1β, and upregulated anti-inflammatory cytokine expression, i.e., IL-10. It would be a promising approach for targeted drug release after oral administration and could be considered an anti-inflammatory therapeutic strategy for treating IBS.

Delineating the inherent functional descriptors and biofunctionalities of pectic polysaccharides

Pectin is a plant-based heteropolysaccharide macromolecule predominantly found in the cell wall of plants. Pectin is commercially extracted from apple pomace, citrus peels and sugar beet pulp and is widely used in the food industry as a stabilizer, emulsifier, encapsulant, and gelling agent. This review highlights various parameters considered important for describing the inherent properties and biofunctionalities of pectins in food systems. These inherent descriptors include monosaccharide composition, galacturonic acid content, degree of esterification, molecular weight, structural morphology, functional group analysis, and functional properties, such as water and oil holding capacity, emulsification, foaming capacity, foam stability, and viscosity. In this study, we also delineate their potential as a nutraceutical, prebiotic, and carrier for bioactive compounds. The biofunctionalities of pectin as an anticancer, antioxidant, lipid-lowering, and antidiabetic agent are also conceptually elaborated in the current review. The multidimensional characteristics of pectin make it a potential candidate for use in food and biomedical science.

HPTLC-densitometry quantification of fructooligosaccharides from inulin hydrolysate

The objective of present research was to develop an easy, precise and accurate HPTLC densitometry method for quantification of fructooligosaccharides (FOSs) from inulin hydrolysate. The chromatographic separation of FOSs was performed on pre-coated silica gel (60, F₂₅₄) TLC plates using a mobile phase (butanol:ethanol:water, 60:24:16), and densitometry evaluation of FOSs was performed at A₅₀₀. Both kestose and nystose were successfully resolved with R_f value of 0.43 and 0.34, respectively. The accuracy, reliability and reproducibility of developed method was assessed by percent relative standard deviation of kestose and nystose for instrument precision (1.43% and 1.50%), repeatability (1.48% and 1.56%), intra-day precision (1.60% and 1.63%), inter-day precision (1.62% and 1.66%), limit of detection (4.58 ng/spot and 4.58 ng/spot), limit of quantification (13.87 ng/spot and 13.89 ng/spot) and recovery (98.81% and 98.69%). Moreover, overlapping spectra of test sample with standard confirms the specificity of developed method, which was validated as per ICH guidelines.

Studies to predict the effect of pregelatinization on excipient property of maize and potato starch blends

This study focuses on the effect of co-processing on physicochemical and drug release properties of starch mixtures. Different mixtures of native maize and potato starch were pregelatinized for different time intervals. The pregelatinized starch mixture was observed to have higher amylose content than that of native starches. The flow properties of starch mixtures were found to improve after pregelatinization. FTIR and XRD showed changes in structure and crystallinity of native starch due to pregelatinization. The FESEM images showed complete disruption of granular structure of native starch. Native starch was found to be more viscous than pregelatinized starch and all starch samples exhibited Non-Newtonian shear thinning behaviour. The tablets prepared from native starch showed rapid release of drug compared to the modified starches, and increase in the amount of potato starch resulted in sustained drug release. This indicates the utility of pregelatinized starch mixtures with high proportion of potato starch in sustained drug delivery systems.

Pullulan in biomedical research and development - A review

Pullulan is an imperative microbial exo-polymer commercially produced by yeast like fungus Aureobasidium pullulans. Its structure contains maltosyl repeating units which comprises two α-(1 → 4) linked glucopyranose rings attached to one glucopyranose ring through α-(1 → 6) glycosidic bond. The co-existence of α-(1 → 6) and α-(1 → 4) glycosidic linkages endows distinctive physico-chemical properties to pullulan. It is highly biocompatible, non-toxic and non-carcinogenic in nature. It is extremely resistant to any mutagenicity or immunogenicity. The unique properties of pullulan make it a potent candidate for biomedical applications viz. drug delivery, gene delivery, tissue engineering, molecular chaperon, plasma expander, vaccination, etc. This review highlights the potential of pullulan in biomedical research and development.