Pectin Films Research Articles

Preparation of bioactive gelatin film using semi-refined pectin reclaimed from blueberry juice pomace: Creating an oxidation and light barrier for food packaging

Semi-refined blueberry pectin (SBP) was extracted from the waste following blueberry juice processing. SBP and gelatin (Gel) were used as the base formulation for the preparation of a composite packaging film (SBP/Gel film), while Gel film, SBP film, apple pectin (AP) film, and an AP and Gel composite film (AP/Gel film) were prepared for comparison. The physicochemical properties, microscopic morphology and antioxidant activity of the prepared films were analyzed. The tensile strength and thermal stability of the SBP/Gel film were improved in comparison with the control films, and the moisture content, hygroscopicity and water vapor permeability were reduced when SBP was incorporated into the gelatin film formulation. Scanning electron microscopy verified the compatibility between SBP and Gel in the SBP/Gel film. Fourier-transform infrared spectroscopy showed that SBP changed the secondary structure of the Gel through non-covalent bonds in the SBP/Gel film. Compared with the AP/Gel and Gel films, the light barrier properties and antioxidant activities of the SBP/Gel film were enhanced significantly. When the SBP/Gel composite film was used to package olive oil or lutein, the SBP/Gel film could retard the oxidation of olive oil and delay the photodegradation of lutein, respectively.

Fabrication and characterization of pectin films incorporated with clove essential oil emulsions stabilized by modified sodium caseinate

The objective of this work was to develop pectin films with antioxidant activity through the incorporation of clove essential oil (CEO) emulsions stabilized by cold plasma- (CP) and moderate electric field- (MEF) treated sodium caseinate. The CEO emulsions fabricated by CP- and MEF-treated caseinate revealed smaller droplet size and higher physical stability than the untreated caseinate. The pectin films embedded by CEO emulsions were evaluated in terms of structure, morphology, and thermal stability, as well as DPPH scavenging activity, mechanical, physical, and UV-Vis light barrier properties. The FTIR, MDSC and SEM results demonstrated the compatibility between pectin and impregnated CEO emulsions. The stabilization of CEO with CP- and MEF-treated caseinates provided substantially higher mechanical strength and stretchability, and more CEO retention during the storage time in the pectin films compared to untreated caseinate. These outcomes highlight the great potential of pectin films incorporated by CP- and MEF-treated caseinate CEO emulsions to be applied as active green packaging for extending the shelf-life of foodstuffs susceptible to oxidation, and as a promising alternative to minimize the adverse environmental effects.

Molecular Simulations to Understand the Moisture, Carbon Dioxide, and Oxygen Barrier Properties of Pectin Films.

Density functional theory and molecular dynamic simulations were used to understand the microscopic-level interactions of pectin-based thin films with moisture (H2O), carbon dioxide (CO2), and oxygen (O2). Galacturonic acid (GA), which forms ~65% of the smooth region of pectin polymer, was chosen for the current study. The electrostatic potential and Fukui function maps indicate that oxygen atoms of -OH groups of GA are the most reactive sites for electrophilic attack and hydrogen atoms on the carboxylic group (-COOH) are the reactive sites for nucleophilic attack. The GA molecule has shown strong interaction via hydrogen bonding with H2O (E= ~ 40 kJ/mol) followed by CO2 (E = ~ -13 kJ/mol). Nucleophilic O2 showed insignificant interaction with GA. Surface interaction, adsorption, and diffusion of sorbate molecules on the GA film followed the order of H2O >CO2 > O2. Molecular interaction studies provided atomistic insights into the weak moisture and high gas barrier properties of pectin films.

Controlled Drug Release from Loratadine-Loaded Pectin Film Dosage Forms

Controlled Drug Release from Loratadine-Loaded Pectin Film Dosage Forms

Characterization of edible film fabricated with HG-type hawthorn pectin gained using different extraction methods

In this study, four HG-type pectins were obtained using hydrochloric acid extraction (HA-HP), citric acid extraction (CA-HP), ultrasonic-assisted extraction (UA-HP), and microwave-assisted extraction (MA-HP). Four pectin films (HA-HPF, CA-HPF, UA-HPF, and MA-HPF) were prepared by a solution casting method, respectively. Compared to four pectins, the asymmetric COO − vibrational peak of UA-HPF, HA-HPF, and CA-HPF were blue-shifted (1604–1606 cm−1), while was red-shifted (1611 cm−1) in MA-HPF. The crystallinity was greater for HA-HPF and CA-HPF than UA-HPF and MA-HPF. Four pectin films all had relatively homogeneous surface morphology. CA-HPF had the best mechanical properties and oxygen barrier performance, HA-HPF had the best transparency. UA-HPF had the lowest hydrophilicity and water vapor permeability. MA-HPF had the best thermal stability. Our study shows that different physicochemical properties of HG-type pectins can influence the physicochemical properties of films. The difference of these properties gives the resulting film different possibilities for application.

Effect of different cation in situ cross-linking on the properties of pectin-thymol active film

In this work, the effect of in situ cross-linking of different cations on the properties of pectin-thymol active films was investigated. Specifically, pectin-thymol composite films (P-T) were developed by solution casting method, and then P-T/Ca, P-T/Fe, and P-T/Cu films with enhanced properties were developed by in situ cation cross-linking in 50% (v/v) ethanol-water solution containing Ca2+, Fe3+, and Cu2+, respectively. The thickness, color, optical properties, water sensitivity, water vapor permeability, mechanical properties, antimicrobial properties and thymol release properties of films were investigated. The interactions and specific micromorphology of films were also analyzed using FTIR and scanning electron microscope. The results showed that Fe3+ and Cu2+ could be uniformly distributed on the film surface and diffused into the interior by external in situ cross-linking. And the water resistance of the composite pectin films was significantly enhanced by the in situ cross-linking with different cations. The P-T/Fe films exhibited excellent UV-barrier properties. The mechanical properties and water vapor barrier properties of cation cross-linked P-T films were also improved. In addition, this work indicated that “egg-box” model formed between the cation and pectin molecule has a slow release effect on thymol in pectin films, which provides a new idea for the controlled release of active substances in pectin films.

Strategies to Improve the Barrier and Mechanical Properties of Pectin Films for Food Packaging: Comparing Nanocomposites with Bilayers

Traditional food packaging systems help reduce food wastage, but they also produce environmental impacts when not properly disposed of. Bio-based polymers are a promising solution to overcome these impacts, but they have poor barrier and mechanical properties. This work evaluates two strategies to improve these properties in pectin films: the incorporation of cellulose nanocrystals (CNC) or sodium montmorillonite (MMT) nanoparticles, and an additional layer of chitosan (i.e., a bilayer film). The bionanocomposites and bilayer films were characterized in terms of optical, morphological, hygroscopic, mechanical and barrier properties. The inclusion of the nanofillers in the polymer reduced the water vapor permeability and the hydrophilicity of the films without compromising their visual properties (i.e., their transparency). However, the nanoparticles did not substantially improve the mechanical properties of the bionanocomposites. Regarding the bilayer films, FTIR and contact angle studies revealed no surface and/or chemical modifications, confirming only physical coating/lamination between the two polymers. These bilayer films exhibited a dense homogenous structure, with intermediate optical and hygroscopic properties. An additional layer of chitosan did not improve the mechanical, water vapor and oxygen barrier properties of the pectin films. However, this additional layer made the material more hydrophobic, which may play an important role in the application of pectin as a food packaging material.

Physical and morphological characteristics of edible coatings based on pectin and guava by-products applied to guava pieces

ABSTRACT: Edible coatings based on polysaccharides have been applied on pieces of fruits and vegetables before drying because of their potential to improve physical and nutritional characteristics of dehydrated plant foods. In the present study, physical and thermal properties of pectin-based films, with and without the incorporation of by-products obtained from the processing of red guava, were determined. These properties allow one to predict the likely behaviour of these films when used as edible coatings on guava pieces, during and after their dehydration. Thus the structural and morphological characteristics and the physical, thermal and sorption properties of the films and of the fruit pulp were determined, using scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and the static gravimetric method to determine the water-sorption curves. The addition of by-products provided crystallinity to the pectin film, attributed to their cellulose content, and hardly altered the water retention capacity of the pectin films. However, the pectin contributed to presenting a slightly higher sorption moisture at equilibrium, as compared to the guava pulp. The glass transition temperatures reported at extremely low moisture contents, both in the pulp and in the films with added by-products, indicated that at intermediate moisture contents, the fruit/film ensemble was in the rubbery state at room temperatures, providing softness to the dehydrated product. The images showed good integration of the edible films with the surface of the guava pieces.

Optimization of process conditions for the development of pectin and glycerol based edible films: Statistical design of experiments

Biopolymer based edible films have emerged as potential alternatives for conventional plastics in food packaging industry. The properties such as thickness, water vapour transmission rate (WVTR) and transparency of these films would be significantly influenced by the solution components and concentration and process conditions (pH, temperature and relative humidity of drying). Control and glycerol blended pectin films were developed as per 2 3 (two-level three-factor) factorial design of experiments by varying glycerol fraction (25% and 40% w/w) and solution concentration (3% and 5% w/v). The films made from 5% solution showed good moisture barrier properties. Glycerol addition reduced the moisture barrier capability of the films compared to control pectin films. Statistical analysis suggests that, the solution pH and drying temperature considerably affect film properties while the effect of relative humidity of drying is not evident enough. However, the interaction effect of relative humidity (H) with the pH and temperature appeared significant. Regression models were fitted to the data by considering the main and interaction effects, which were significantly affecting a particular property. Detailed analysis reveals that for obtaining pectin based films with less thickness, low WVTR and high transparency, the optimal conditions preferred are low pH = 3, high T = 48°C and low to medium humidity of drying (H = 40–50%). The fitted regression models were statistically significant at 90% confidence level, pass Lack-of-fit analysis and are adequate to describe the effects of different factors on the targeted film properties. How to cite: Mehraj S, Sistla YS. Optimization of process conditions for the development of pectin and glycerol based edible films: statistical design of experiments. Electron J Biotechnol 2022;55. https://doi.org/10.1016/j.ejbt.2021.11.004

Thermal and functional properties of a biofilms composed of fruits and vegetables waste

This study includes the development of biofilms from orange peel (OP), apple pomace (AP), tomato pomace (TP), and potato peel (PP). Thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FTIR), transparency, and water solubility were performed on the synthesized films. The biofilms were prepared using the casting method. The OP, AP, and TP, along with pectin and glycerol, form a flexible film at a concentration of 6%, whereas the PP forms a film at 4%. The TGA results showed that the OP film has the highest decomposition temperature, ranging from 194.5℃ to 246.92℃. The FTIR spectra of the biofilms revealed the interaction between the plasticizer and polysaccharide compounds. The pectin film (PF) had a transparency of 2.19%, while the TP film had a transparency of 7.45%, the highest among the fruit & vegetable waste (FVW) films. The lower the transparency score, the more transparent the film. The water solubility of PF film was 89%, while that of FVW-based films was lower. The usage of FVW-based biofilms and their use in food packaging would minimize plastic products, resulting in reduced pollution.

Pequi mesocarp: a new source of pectin to produce biodegradable film for application as food packaging

This study aimed to develop biodegradable films from pectin extracted from pequi mesocarp and commercial pectin. The films were produced using the casting technique and characterized in terms of their physical, water-related, mechanical, thermal, optical, and microstructural properties. The highest yield of pectin extracted from pequi (26.6%) was obtained using 4% citric acid, a temperature of 80 °C, and an extraction time of 160 min. Commercial-pectin films had a smoother and more regular surface than pequi-pectin films. Pequi-pectin films had higher moisture content (36.25%) and water solubility (76.99%) than commercial pectin films. Pequi-pectin films also showed lower luminosity (55.67*) and higher values of a* (11.56), b*(27.35), opacity (10.67), and Young modulus (82.16 Mpa) than commercial-pectin films. The films exhibited similar thermal behavior, highlighting the presence of exothermic and endothermic peaks for both samples. In the biodegradability tests, both films proved to be 100% biodegradable in four days. The pectin extracted from the pequi mesocarp showed potential for the production of biodegradable films, and this discovery opens up new possibilities for using this byproduct as a raw material for the production of sustainable food packaging.

Bioactive Pectin-Murta (Ugni molinae T.) Seed Extract Films Reinforced with Chitin Fibers.

This study investigated the biocomposite pectin films enriched with murta (Ugni molinae T.) seed polyphenolic extract and reinforced by chitin nanofiber. The structural, morphological, mechanical, barrier, colorimetric, and antioxidant activity of films were evaluated. The obtained data clearly demonstrated that the addition of murta seed extract and the high load of chitin nanofibers (50%) provided more cohesive and dense morphology of films and improved the mechanical resistance and water vapor barrier in comparison to the control pectin film. The antioxidant activity ranged between 71% and 86%, depending on the film formulation and concentration of chitin nanofibers. The presented results highlight the potential use of chitin nanofibers and murta seed extract in the pectin matrix to be applied in functional food coatings and packaging, as a sustainable solution.

Apple-based coatings incorporated with wild apple isolated yeast to reduce Penicillium expansum postharvest decay of apples

The aim of this work has been to prevent the growth of Penicillium expansum on the surface of apples by means of the use of biocontrol agents in combination with edible coatings. For that, Metschnikowia pulcherrima yeast isolated from wild apples was incorporated in edible film matrices based on pectins, cellulose ethers with and without the addition of liquid culture medium (yeast extract and glucose) and apple pomace residues.The viability and biocontrol activity of the yeast incorporated in the films were evaluated after film drying process and after being stored for 21 days at 10 °C. Furthermore, the matrix that exhibited the best results was applied as a coating on apples artificially inoculated with P. expansum in order to evaluate its antifungal activity against P. expansum during storage and to prevent the production of its mycotoxin, the patulin. M. pulcherrima remained viable in films after drying step and after 21 days storage, but viability depended on the matrix composition, being lower in pectin films and higher in apple pomace films. The highest antimicrobial activity in vitro was observed in methylcellulose films supplemented with yeast extract and glucose (YEG), and in apple pomace residues films, matrix which was therefore selected to be applied as coatings on apples inoculated with P. expansum. The results proved that bioactive coatings significantly reduce P. expansum growth and patulin production during storage. The results obtained in this work give added value to the apple industry residues which, in combination with apple isolated M. pulcherrima can be applied as coatings on apples to provide protection against blue mold and its mycotoxin as an alternative of postharvest disease management.

INCREASING THE EFFICIENCY OF POULTRY AND FISH FREEZING USING PROTECTIVE PECTIN COATINGS

Maintaining the quality of poultry and pond fish as much as possible is important. Freezing poultry immediately after slaughter and fish after catching allows you to solve this problem. Freezing in liquid media leads to an increase in the speed of the process and, accordingly, a better preservation of the quality indicators of products. At the same time, in the process of freezing in brines containing calcium chloride, it leads to the diffusion of calcium ions into the muscle tissue of poultry or fish and the appearance of a bitter taste. To prevent salting out of raw materials, we have proposed the use of biologically inert coatings based on pectin.
 The purpose of this study is to study the possibility of using low methoxylated pectin substances to improve product quality. The influence of a number of technological factors on the protective properties of the coating is studied. These factors include the concentration of pectin substances, the pH of the medium, the presence or absence of pretreatment of the surface of a poultry or fish carcass with citric acid. The strength of the coating and its barrier properties with respect to the diffusion of calcium ions have been studied. It is recommended to use a concentration of pectin substances of 3% with preliminary treatment of the carcass surface with 1% citric acid solution, followed by fixing the formed pectin film with 1% calcium chloride solution. Such processing allows to achieve a maximum concentration of calcium chloride in the muscle tissue of poultry or fish of no more than 0.5% – the value allowed by the standard.
 It is shown that the use of freezing in brine leads to a significant decrease in the weight loss of the product during storage compared to freezing in air – three times. The use of a coating based on pectin can reduce weight loss by a factor of eight. The quality indicators of products are also much better preserved – water retention capacity, acid number of fat and peroxide value of fat. The organoleptic properties of poultry and fish processed according to the proposed technology are noticeably superior to those of raw materials frozen both in air and in brine without applying a protective coating.

Microencapsulation of Citral and its Antifungal Activity into Pectin Films

Citral is an essential oil with great antimicrobial activity, but its use in the food industry is limited due to its easy decomposition in room conditions. Therefore, this study aimed to microencapsulate citral by the spray drying process and incorporate the powder into pectin films to assess their antifungal activity. For this, solutions of maltodextrin (MD), Arabic gum (AG) sodium alginate (SA) at different concentrations were used to emulsify citral. The emulsion with 10:10:0.1 MD:AG:SA was selected to spray the drying process due to its small droplet size, monomodal size distribution, and low D[3,2], D[4,3], and span index. The dried powder had high solubility (83.4%), and low wettability time (27 s), moisture content (4.05%), and bulk density (0.72 g/cm3), allowing to infer powder stability and showing appropriate handling qualities on a large scale. Thermal analyses reveal that microparticles and pectin films provide thermal protection to citral from 37 to 175 °C. Concerning the antagonistic activity, pectin films added with citral microencapsulated had antifungal activity ranging from 42-68% against Penicillium italicum, Colletotrichum gloeosporioides, and Aspergillus niger under in vitro conditions. Therefore, these films serve as a basis for developing new edible coatings with practical applications in the postharvest management of phytopathogenic fungi.

Edible pectin film added with peptides from jackfruit leaves obtained by high-hydrostatic pressure and pepsin hydrolysis

Jackfruit (Artocarpus heterophyllus Lam.) is an evergreen tree that produces a high waste of leaves. This study evaluated the obtention of peptides from jackfruit leaves using pancreatin and pepsin, their antifungal activity, and their effect on pectin films. The protein content was 7.64 ± 0.12 g/100 g of jackfruit fresh leaves. Pancreatin produced a higher yield than pepsin in the obtention of peptides (p ≤ 0.05). However, peptides obtained after 2 h by pepsin hydrolysis (Pep-P) had six essential amino acids and inhibited > 99% of mycelial growth and spore germination of Colletotrichum gloeosporioides. Pectin films with Pep-P showed a slight brown color, lower thickness, water vapor permeability, and moisture content, as well as higher thermal stability and better inhibition properties against C. gloeosporioides than pectin films without Pep-P (p ≤ 0.05). Pectin films added with Pep-P from jackfruit leaf could be a green alternative to anthracnose control in tropical fruits.

Functionality of different probiotic strains embedded in citrus pectin based edible films

SummaryThe inclusion of probiotics into the packaging films has emerged as a novel approach to provide edible packaging with new functionalities. In this study, probiotic films were developed by embedding four different probiotics (Lactobacillus casei, Bifidobacterium bifidum, Lactobacillus acidophilus, and Lactobacillus rhamnosus) into citrus pectin films and their viability was checked at 25 and 4 °C for 30 days. A reduction of 0.44, 1.04, 0.32, and 1.0 log CFU g−1 was observed in probiotic films containing L. casei, B. bifidum, L. acidzophilus, and L. rhamnosus respectively during drying process of film’s formation. The viability of all probiotics (except B. bifidum) was decreased from 109 to 106 CFU g−1 in 30 days storage at 25 °C. Whereas, only 2 log reduction was observed for films stored at 4 °C during 30 days. The physical and optical properties of the films were affected slightly by inclusion of bacterial cells. The presence of live cells in films made them less resistant to elongation and less stretchable. All bacterial films inhibited the growth of L. monocytogenes by 1.5 logs compared to control. The results suggest the entrapment of probiotics in pectin can be used as an effective packaging technology for ensuring food safety.

Preparation of Pectin Films from Coffee Cherry and Its Antibacterial Activity

This study aimed to utilize the waste from the coffee bean production process as high value-added material. Pectin extracted from the coffee pulp was classified as low methoxyl pectin (LMP) with the Degree of Esterification (DE) at 33.33 % For further application or upscaling production, the coffee pulp was boiled to retrieve the highest yield at 15.68 g/100 g DW. The antimicrobial assays of crude pectin via minimum inhibition concentration (MIC) showed that coffee pectin could inhibit the growth of Staphylococcus aureus TISTR 1466 in the range of 2.5 - 0.62 mg, while the commercial apple pectin exhibited the inhibition only slightly. The pectin film from the coffee pectin blended with the commercial apple pectin also exhibited antimicrobial activity against S. aureus TISTR 1466. This study shows that coffee pectin could be an alternative material for antibacterial film and other applications. HIGHLIGHTS Pectin extracted from the coffee pulp by this extraction method is classified as low methoxyl pectin with the degree of esterification (DE) at 33.33 % which retrieve the highest yield at 15.68 g/100 g DW of coffee pulp The minimum inhibition concentration (MIC) of the coffee pectin against Staphylococcus aureus TISTR 1466 in the range of 2.5 - 0.62 mg, while the commercial apple pectin did not exhibit antimicrobial activity The pectin film from the coffee pectin 5 % blended with the commercial apple pectin also exhibited antimicrobial activity against aureus TISTR 1466 Given its antibacterial activities, as well as the ability to form film, coffee pectin could be potentially used for application in biomedical or pharmaceutical fields. Importantly, pectin from the coffee pulp could add more value to coffee by-products GRAPHICAL ABSTRACT

Effect of emulsifier and droplet size on the antibacterial properties of emulsions and emulsion‐based films containing essential oil compounds

In this study, the physical properties and antibacterial activity of emulsions prepared through four different combinations of essential oils (EOs) (trans-cinnamaldehyde [TC] and citral) and emulsifiers (sodium caseinate and lecithin) were investigated. The results showed that the four different nanoemulsions had nanometric sizes ranging from 142.3 to 273.1 nm, exhibiting high negative zeta potential (−25.3 to −42.7 mV) at pH 7. Nanoemulsions containing TC exhibited higher antimicrobial activities against Escherichia coli and Listeria innocua than nanoemulsions containing citral irrespective of the emulsifier used. These nanoemulsions were then incorporated into low methoxyl pectin films and the obtained results showed that films containing TC stabilized by sodium caseinate had a larger inhibition zone than the one stabilized by lecithin irrespective of the EO used. Finally, the obtained results showed that nanosized emulsions were more stable than microsized ones, but no significant differences were observed concerning their antibacterial activity. Practical applications This work should be an interesting basis for developing innovative antimicrobial packaging containing nanoemulsions. The interfacial membrane that surrounds the droplets of the emulsified antimicrobial provides an additional barrier that the active agent should cross before leaving the polymer matrix of the packaging film. Thus, the release kinetics will be modified and the efficiency could be improved.

Effect of whey protein isolate addition on thermoplasticized pectin packaging properties

AbstractPectin is a natural polysaccharide from plants and the peel of some fruits and is available as a byproduct from the fruit juice industry. Whey protein isolate (WPI) is available as a byproduct of cheese production. Both the pectin and WPI are biodegradable polymers, atoxic, biocompatible, and not expensive. The aim of this article was the study the effect of the WPI addition (0, 5, 10, 15, and 20 wt%) on thermoplasticized extruded/thermo‐compressed pectin film (TPP). The films were compact and homogenous and did not present statistical differences in mechanical properties, independent of WPI concentration. Furthermore, infrared spectra of the samples with WPI presented an indication of Maillard reaction by the characteristic presence of melanoidin, which was also observed in colorimetric results. Thermogravimetric results indicated the samples were thermal stable with the increase of WPI amount. Moreover, the barrier properties and contact angles suggested the films presented major barrier properties and hydrophilic surfaces for samples with WPI. Finally, the addition of WPI in TPP resulted in a potential material for applications in several industries.Practical applicationsPectin and whey protein isolate (WPI) are biodegradable polymers and byproducts of the food industry. The aim of this article was the study the effect of the WPI addition on thermoplasticized extruded/thermo‐compressed pectin film (TPP), in other words, packagings produced by the industrial method. The samples with WPI presented an indicative of Maillard reaction by the presence of melanoidin, which was also observed in color. The addition of WPI in TPP resulted in a potential material for applications in several industries.