Recent progress in pectin extraction and their applications in developing films and coatings for sustainable food packaging: A review

Structural characterization and immunomodulatory activity analysis of a novel pectic polysaccharide extracted from Tetrastigma hemsleyanum Diels et Gilg and its hydrolysis products

Tetrastigma hemsleyanum Diels et Gilg (T. hemsleyanum) is a rare traditional Chinese medicine with high medicinal value and T. hemsleyanum polysaccharides (THPs) have attracted increasing attention in recent years. However, detailed structural and functional insights into THPs remain limited. Here, a novel pectic polysaccharide (STHP4) with an average molecular weight (Mw) of 119 kDa was extracted and purified from the aboveground part of T. hemsleyanum. Structurally, STHP4 was mainly composed of galacturonic acid, glucuronic acid, and galactose, with minor glucose, rhamnose, arabinose, and mannose, and its primary backbone was 1,4-GalA. Pectinase treatment of STHP4 yields two distinct fractions: STHP4-1 and STHP4-2. STHP4-1 shared the same types of monosaccharides with STHP4, except for the absence of glucose, but had a broad Mw distribution (9.9 to 251 kDa). Another product, STHP4-2, a mixture of oligosaccharides and free monosaccharides, has a Mw of 1.387 kDa. Their structures were further elucidated via methylation analysis and NMR spectra. Furthermore, STHP4-1 exhibited superior immune regulatory effects on macrophages, including increased nitric oxide release and elevated interleukin-6, interleukin-1β, and tumor necrosis factor α expression. These findings suggest that STHP4-1 might be the core active domain of STHP4, and both STHP4 and STHP4-1 are potential immune enhancers.

High-adhesion antimicrobial composite coating incorporating quaternary chitosan and tea tree oil for enhanced preservation of fruits and vegetables

This study developed high-adhesion quaternary chitosan coatings using amphiphilic HACC-oleic acid conjugates (HACC-OA) to enhance fruit and vegetable preservation. HACC-OA demonstrated improved viscosity and adhesion, providing a stable carrier for tea tree oil (TTO). The resulting TTO@HACC-OA coatings exhibited significantly reduced contact angle (43.7°) and increased retention amount on strawberry surfaces. Furthermore, TTO@HACC-OA demonstrated a lower volatilization rate of TTO (27.8 %) compared to pure TTO (49.5 %) and an enhanced synergistic antimicrobial activity (EC50 = 1.51 mg/mL) against Botrytis cinerea Pers compared to HACC alone (EC50 = 1.58 mg/mL). Preservation experiments revealed that TTO@HACC-OA effectively maintained color and firmness, reduced decay index and weight loss, delayed decline in vitamin C content of strawberries, postponed increase in total phenolic content, and mitigated malondialdehyde accumulation. Therefore, the prepared TTO@HACC-OA composite coating with excellent adhesion ability and preservation effect holds great potential for applications in fruit and vegetable preservation.

A sustainable extraction approach for recovery of Rhamnogalacturonan I enriched pectin from Amazonian cocoa pod husk

Approximately 16,000 thousand tonnes of cocoa husk are produced annually worldwide during the chocolate production chain, representing considerable potential for pectin extraction. The aim of this study was to investigate a new extraction technique using a binary system composed of carbon dioxide and water (CO2 + H2O) at high pressure and temperature, on cocoa sample from floodplain ecosystem. Temperatures of 393.15 K and 413.15 K and pressures of 20 and 30 MPa were used. Under these combined conditions overall yields ranging from 5.10 % to 10.70 % were obtained. The monosaccharide composition confirmed the extraction of pectic fractions. Uronic acid was identified as the primary monosaccharide (47.2-52.8 %), followed by galactose (19.3-23.6 %) and rhamnose (10.3-13.0 %), which resulted in high percentages of the RG-I region (51.2-44.3 %), which was significantly more prevalent in the extracts obtained with the CO2 + H2O binary system compared to traditional methods. The protein and phenolic contents were lower than found for pectins previously extracted with boiling water from the same raw material. The condition of 413.15 K/20 MPa yielded a pectic fraction with the highest degree of purity (91.05 % ± 0.95 %). The extracted pectins had a low degree of methyl esterification (18.8-22.6 %) and a high degree of acetylation (45.7-52.1 %). The molecular weight of the polysaccharides was in the range of 3.0 × 105 to 5.4 × 105 g/mol. The results demonstrated that the CO2 + H2O binary system is an efficient approach for the sustainable utilization of cocoa pod husk as a source of rhamnogalacturonan I enriched pectins with features that favour the applications as emulsifier agent in the food and pharmaceutical industries.

The Beneficial Role of Polysaccharide Hydrocolloids in Meat Products: A Review

Polysaccharide hydrocolloids have garnered increasing attention from consumers, experts, and food processing industries due to their advantages of abundant resources, favorable thickening properties, emulsification stability, biocompatibility, biodegradability, and high acceptance as food additives. This review focuses on the application of polysaccharide hydrocolloids and their beneficial roles in meat products by focusing on several commonly used polysaccharides (i.e., cellulose, chitosan, starch, sodium alginate, pectin, and carrageenan). Firstly, the recent advancements of polysaccharide hydrocolloids used in meat products are briefly introduced, along with their structure and potential application prospects. Then, the beneficial roles of polysaccharide hydrocolloids in meat products are comprehensively summarized and highlighted, including retarding lipid and protein oxidation, enhancing nutritional properties, improving texture and color quality, providing antibacterial activity, monitoring freshness, acting as a cryoprotectant, improving printability, and ensuring security. Finally, the challenges and opportunities of polysaccharide hydrocolloids in meat products are also introduced.

Efficient pectin recovery from sugar beet pulp as effective bio-based coating for Pacific white shrimp preservation

This study demonstrates the valorization of sugar beet pulp (SBP)-derived pectin to produce bio-based coatings for shrimp preservation. Pectin extraction was assessed at varying temperatures and extraction times to achieve tailored properties (high methoxyl-pectins, degree of esterification-DE >79.0 %) leading to 11.5 % extraction yield, 78.1 % galactouronic acid content and 80 % DE at optimal conditions (pH 1.5, 80 °C, 2 h). Pectin-based coatings supplemented with ascorbic acid (AA) (0.5-2.0 %) led to organoleptically acceptable shrimps with significantly lower total color differences during 28-days of storage, compared to uncoated and pectin-coated counterparts. AA-based coatings delayed shrimp melanosis, expressed as reduced polyphenoloxidase activity (48-86 %). Rich-in-holocellulose solids derived after pectin extraction were used for bacterial cellulose (BC) production, pinpointing the SBP potential as a multi-purpose feedstock. Fed-batch fermentation enhanced BC concentration (by 110 %) and productivity (1.6-fold higher) compared to batch-cultures. Pectin produced within a SBP-based biorefinery could be applied as bio-based coating with food packaging potential.

An in-depth review: Unraveling the extraction, structure, bio-functionalities, target molecules, and applications of pectic polysaccharides

Pectic polysaccharides have long been a challenging subject of research in the field of macromolecular science, given their complex structures and wide range of biological effects. However, the extensive exploration of pectic polysaccharides has been limited due to the intricacy of their structures. In this comprehensive review, we aim to provide a thorough summary of the existing knowledge on pectic polysaccharides, with a particular focus on aspects such as classification, extraction methodologies, structural analysis, elucidation of biological activities, and exploration of target molecules and signaling pathways. By conducting a comprehensive analysis of existing literature and research achievements, we strive to establish a comprehensive and systematic framework that can serve as a reference and guide for further investigations into pectic polysaccharides. Furthermore, this review delves into the applications of pectic polysaccharides beyond their fundamental attributes and characteristics, exploring their potential in fields such as materials, food, and pharmaceuticals. We pay special attention to the promising opportunities for pectic polysaccharides in the pharmaceutical domain and provide an overview of related drug development research. The aim of this review is to facilitate a holistic understanding of pectic polysaccharides by incorporating multifaceted research, providing valuable insights for further in-depth investigations into this significant polymer.

Source, Extraction, Properties, and Multifunctional Applications of Pectin: A Short Review

Pectin, a heteropolysaccharide derived from plant cell walls, is essential in the food, pharmaceutical, and environmental industries. Currently, citrus and apple peels are the primary sources for commercial pectin production. The yield and quality of pectin extracted from various plant sources significantly differ based on the extraction methods employed, which include physical, chemical, and biological processes. The complex structures of pectin, composed of polygalacturonic acid and rhamnogalacturonan, influence its physicochemical properties and, consequently, its functionality. As a common polysaccharide, pectin finds applications across multiple sectors. In the food industry, it acts as a gelling agent and a packaging material; in pharmaceuticals, it is utilized for drug delivery and wound healing. Environmentally, pectin contributes to wastewater treatment by adsorbing pollutants. Current research focuses on alternative sources, sustainable extraction methods, and multifunctional applications of pectin. Ongoing studies aim to enhance extraction technologies and broaden the applications of pectin, thereby supporting sustainable development goals.

Efficacy of an Edible Coating with Carvacrol and Citral in Frozen Strawberries and Blueberries to Control Foodborne Pathogens

Adding essential oils in an edible coating could be an alternative for the food industry to control foodborne pathogens. In 2014, EFSA published a report highlighting the risk associated with Salmonella spp. and Norovirus in fresh and frozen berries. This study aimed to evaluate the efficacy of an edible coating (RP-7) with carvacrol and citral on reducing the population of Salmonella enterica, Escherichia coli O157:H7, Listeria monocytogenes, and murine Norovirus (MNV-1) in frozen strawberries and blueberries. Before evaluating the efficacy, the best method for applying the coating on fruit was studied. The immersion method was selected, with an optimal drying time of 45 min. After this, the berries were frozen and stored for one, two, three, four, and eight weeks at -18 °C. In strawberries, all bacteria were reduced to below 0.7 log cfu/strawberry in the eighth week, and the MNV-1 infectivity showed a reduction of nearly 2 logarithmic units. In blueberries, S. enterica and E. coli O157:H7 were reduced to 0.8 log cfu/blueberries within a week, and MNV-1 achieved a reduction of 0.8 logarithmic units at the end of the assay. The application of RP-7 affected the studied microorganisms in frozen strawberries and blueberries.

Review of Bio-Based Biodegradable Polymers: Smart Solutions for Sustainable Food Packaging

Conventional passive packaging plays a crucial role in food manufacturing by protecting foods from various external influences. Most packaging materials are polymer-based plastics derived from fossil carbon sources, which are favored for their versatility, aesthetic appeal, and cost-effectiveness. However, the extensive use of these materials poses significant environmental challenges due to their fossil-based origins and persistence in the environment. Global plastic consumption for packaging is expected to nearly triple by 2060, exacerbating the ecological crisis. Moreover, globalization has increased access to a diverse range of foods from around the world, heightening the importance of packaging in providing healthier and safer foods with extended shelf life. In response to these challenges, there is a growing shift to eco-friendly active packaging that not only protects but also preserves the authentic qualities of food, surpassing the roles of conventional passive packaging. This article provides a comprehensive review on the viability, benefits, and challenges of implementing bio-based biodegradable polymers in active food packaging, with the dual goals of environmental sustainability and extending food shelf life.

Optimization of ultrasound-assisted pectin recovery from cocoa by-products using response surface methodology

BACKGROUND

This study aimed to address the significant challenges associated with agricultural and cocoa waste disposal within the context of global food waste concerns. The magnitude of global food waste is staggering, estimated at 1.6 Gt of primary product equivalents, with 1.3 Gt attributed specifically to the edible parts of food. Focusing on cocoa waste, which constitutes around 80% of total cocoa production, management poses a considerable environmental challenge, with over 60% of this waste either burnt or left to rot in plantations.

METHOD

Ultrasound-assisted extraction of pectin from cocoa pulp mucilage (CPM), cocoa pod husk (CPH), and cocoa bean shell (CBS) was achieved with a central composite design (CCD) using response surface methodology (RSM).

RESULTS

Ultrasound-assisted extraction takes into consideration independent factors such as temperature, sonication time, pH, solid-liquid ratio, and ultrasonic power intensity. This study achieved the highest yield, anhydrouronic acid content, and degree of esterification under optimum conditions - sonication time of 20 min, pH of 2.5, solid-solvent ratio of 1:40 g mL-1, and ultrasonic power intensity of 64 W cm-2. The composition and characterization of pectin showed that its anhydrouronic acid content was 68.59 ± 0.2% when extracted from CPH, 50.7 ± 0.5% when extracted from CBS, and 43.97 ± 0.17% when extracted from CPM with citric acid.

CONCLUSION

This study underscored the potential to reduce the environmental impact of cocoa waste, offering improved pectin extraction and sustainable methods for handling agricultural by-products. It is relevant for individuals interested in waste reduction and resource efficiency within the broader agricultural industry, showcasing the potential for practical and sustainable solutions in cocoa waste management. © 2024 Society of Chemical Industry.

Clay Minerals and Biopolymers in Film Design: Overview of Properties and Applications

Research to replace petroleum-based plastics has been quite challenging. Currently, there is a lot of interest in biopolymers as an alternative. However, biopolymers do not have suitable mechanical properties when in film form, which limits their applications. To resolve this issue, clay minerals are being incorporated as a strategy. Clay minerals offer the films good barrier, thermal, rheological, optical, and mechanical properties. They can also work with other additives to promote antioxidant and antimicrobial activity. This brief review focuses on incorporating clay minerals with other nanofillers and bioactives to improve their physical, chemical, and functional characteristics. The synergy of these materials gives the films exceptional properties and makes them suitable for applications such as food coatings, packaging materials, dressings, and bandages for treating skin wounds.

Developing active and intelligent biodegradable packaging from food waste and byproducts: A review of sources, properties, film production methods, and their application in food preservation

Food waste and byproducts (FWBP) are a global issue impacting economies, resources, and health. Recycling and utilizing these wastes, due to processing and economic constraints, face various challenges. However, valuable components in food waste inspire efficient solutions like active intelligent packaging. Though research on this is booming, its material selectivity, effectiveness, and commercial viability require further analysis. This paper categorizes FWBP and explores their potential for producing packaging from both animal and plant perspectives. In addition, the preparation/fabrication methods of these films/coatings have also been summarized comprehensively, focusing on the advantages and disadvantages of these methods and their commercial adaptability. Finally, the functions of these films/coatings and their ultimate performance in protecting food (meat, dairy products, fruits, and vegetables) are also reviewed systematically. FWBP provide a variety of methods for the application of edible films, including being made into coatings, films, and fibers for food preservation, or extracting active substances directly or indirectly from them (in the form of encapsulation) and adding them to packaging to endow them with functions such as barrier, antibacterial, antioxidant, and pH response. In addition, the casting method is the most commonly used method for producing edible films, but more film production methods (extrusion, electrospinning, 3D printing) need to be tried to make up for the shortcomings of the current methods. Finally, researchers need to conduct more in-depth research on various active compounds from FWBP to achieve better application effects and commercial adaptability.

Recent Highlights in Sustainable Bio-Based Edible Films and Coatings for Fruit and Vegetable Applications

The present review paper focuses on recent developments in edible films and coatings made of base compounds from biological sources, namely plants, animals, algae, and microorganisms. These sources include by-products, residues, and wastes from agro-food industries and sea products that contribute to sustainability concerns. Chitosan, derived from animal biological sources, such as crustacean exoskeletons, has been the most studied base compound over the past three years. Polysaccharides typically constitute no more than 3-5% of the film/coating base solution, with some exceptions, like Arabic gum. Proteins and lipids may be present in higher concentrations, such as zein and beeswax. This review also discusses the enrichment of these bio-based films and coatings with various functional and/or bioactive compounds to confer or enhance their functionalities, such as antimicrobial, antioxidant, and anti-enzymatic properties, as well as physical properties. Whenever possible, a comparative analysis among different formulations was performed. The results of the applications of these edible films and coatings to fruit and vegetable products are also described, including shelf life extension, inhibition of microbial growth, and prevention of oxidation. This review also explores novel types of packaging, such as active and intelligent packaging. The potential health benefits of edible films and coatings, as well as the biodegradability of films, are also discussed. Finally, this review addresses recent innovations in the edible films and coatings industry, including the use of nanotechnologies, aerogels, and probiotics, and provides future perspectives and the challenges that the sector is facing.

The reduce of water vapor permeability of polysaccharide-based films in food packaging: A comprehensive review

Polysaccharide-based films are favored in the food packaging industry because of their advantages of green and safe characters, as well as natural degradability, but due to the structural defects of polysaccharides, they also have the disadvantages of high water vapor permeability (WVP), which greatly limits their application in the food packaging industry. To break the limitation, numerous methods, e.g., physical and/or chemical methods, have been employed. This review mainly elaborates the up-to-date research status of the application of polysaccharide-based films (PBFs) in food packaging area, including various films from cellulose and its derivatives, starch, chitosan, pectin, alginate, pullulan and so on, while the methods of reducing the WVP of PBFs, mainly divided into physical and chemical methods, are summarized, as well as the discussions about the existing problems and development trends of PBFs. In the end, suggestions about the future development of WVP of PBFs are presented.

Effects of gum-based coatings combined with ultrasonic pretreatment before drying on quality of sour cherries

Application of pretreatment methods such as ultrasound and edible coatings is used to reduce processing time and/or preserve food product quality in drying technology. The aim of this research was to measure the impacts of gum-based coatings (guar, sodium alginate, and basil seed gums) in combination with sonication before drying on total phenolic content (TPC), antioxidant capacity (AC), effective water diffusivity (Deff), total color difference (ΔE), surface shrinkage (SS), and rehydration ratio (RR) of sour cherries. Ultrasonic pretreatment (40 kHz, 150 W, at 25 °C, for 12 min) increased the TPC, AC, Deff, and RR, and decreased the drying time, ΔE, and SS values of sour cherries. Edible coating increased the TPC, AC, drying time, and RR, and decreased the Deff, ΔE, and SS values of sonicated sour cherries. The TPC for untreated, uncoated-sonicated, guar gum-coated, sodium alginate-coated, and basil seed gum-coated sour cherries were 2965.9, 3398.1, 3480.8, 3511.0, and 3898.3 Âµg gallic acid equivalent/g dry, respectively. The highest value of AC (71.2±3.7 %) was observed on coated sour cherries by basil seed gum. The experimental data for drying curves were fitted to several widely used models, and the Midilli model using the experimental constants that best represent the drying rate of sour cherries. The edible coatings significantly reduced the color changes and shrinkage of dried sour cherries, with the lowest ΔE and SS values in the basil seed gum-coated samples (p < 0.05).

Study of the Physical, Chemical, and Structural Properties of Low- and High-Methoxyl Pectin-Based Film Matrices Including Sunflower Waxes

The development of bio-based materials remains one of the most important alternatives to plastic materials. Although research in this field is growing, reporting various materials and methodologies, it is still necessary to increase exploration. The aim of this work was to expand and complement previous research on the preparation and characterization of high- and low-methoxyl pectin films obtained by casting, with the addition of commercial and recovered sunflower waxes. The results showed that the addition of sunflower waxes to the pectin matrix generated some discontinuity in the aggregate, increasing the thickness and roughness of the film. However, due to their hydrophobic nature, the waxes contributed to lower vapor transmission rate values of the films. On the other hand, the low-methoxyl pectin films had a more crystalline structure, which could help to diminish water vapor permeability values, mechanical resistance and rigidity, and improve their elongation. Regarding chemical characteristics, most of the raw materials' chemical groups were found in the resulting films, and the presence of C-H bending due to pectin gelation was observed. Finally, the compatibility and contribution of pectin and sunflower waxes to the production of the films were demonstrated, as well as the possibility of using materials from industrial waste in food packaging applications.