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

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.

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.

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.