Effect of arabinoxylan and β-glucan stearic acid ester coatings on post-harvest quality of apple (Royal Delicious)

Arabinoxylan-based films and coatings for fresh produce: A review of emerging trends in food packaging

Arabinoxylans (AX) are the major non-cellulosic polysaccharides found in cereals and grasses. It comprises a linear chain of β-(1,4)-xylopyranosyl units, which can be substituted at the O-3 and O-2 positions. The high molar mass of cereal AXs provides a robust foundation for developing packaging materials with excellent mechanical properties. Combined with their solubility, biocompatibility, and ability to form films, AXs emerge as a promising candidates for advanced packaging applications. The hydrogen bonding (H-bonding) between adjacent AX chains forms a dense macromolecular network, resulting in reduced mobility and, consequently, improved barrier properties against oxygen in packaging films. Furthermore, the natural variability due to their reactive -OH enables multi-faceted strategies to enhance their material properties. AX-based films have proven to be an economical and effective solution for extending the shelf life of fresh produce during transportation and storage. Considering AXs potential to reduce plastic waste significantly, this review compiles the latest research findings to elucidate the structure and composition of arabinoxylans, their significance in packaging, and their impact on the characteristics of AX-based films. Additionally, the review highlights the application of AX-based films, showcasing their beneficial role in advancing packaging technology.

Shellac-based films/coatings: Progress, applications and future trends in the field of food packaging

As a natural biopolymer from the secretion of insect Laccifer Lacca, shellac shows excellent film-forming ability and safety, making it an attractive material to replace synthetic materials for food packaging. On the basis of an introduction to the structure and properties of shellac, the information on single shellac films/coatings and composite films/coatings of shellac and other bio-based materials such as proteins, polysaccharides, and lipids, including the effects of adding antimicrobial agents (i.e., natural antimicrobials, synthetic antimicrobials, and metal oxide nanoparticles) on films/coatings, was comprehensively summarized. Besides, the current application status of shellac-based films/coatings as preservation packaging for poultry products, fruits, vegetables and other food products was systematically documented. Finally, the future research directions of shellac-based films/coatings such as optimizing shellac concentrations, conducting toxicological evaluation and reducing production costs were discussed. This paper will provide guidance for a systematic understanding of the research advances on shellac-based films/coatings and possible future directions.

Shellac-based materials: Structures, properties, and applications

Shellac stands out among natural polymers as the sole animal-derived resin, boasting a complex polyester composition comprising polyhydroxy long-chain fatty acids and sesquiterpene acids. Its unique attributes include biocompatibility, non-toxicity, distinctive amphiphilicity, superb film-forming and adhesive properties, excellent dielectric properties, rapid drying, and solubility in alkaline solutions while resisting acidic ones. These exceptional qualities have propelled shellac beyond its traditional role as a varnish and decorative material, positioning it as a viable option for diverse applications such as food packaging, pharmaceutical formulations, electronic devices, fiber dyeing, and wood restoration. Furthermore, shellac serves as a crucial carbon source for graphene materials. This review comprehensively explores shellac's contributions to prolonging food shelf life, enhancing the carbon sourcing of graphene materials, facilitating the delivery of active substances, boosting the performance of organic field-effect transistors, enabling environmentally friendly textile dyeing, and providing protective coatings for wood. Additionally, it delves into the current limitations and future directions of shellac's applications. By disseminating this knowledge, we aim to deepen researchers' comprehension of shellac and inspire further exploration, thereby fostering sustainable advancements across various industries.

Shellac-based delivery systems for food bioactive compounds

Shellac is a natural resin featuring some attractive properties such as amphiphilicity, pH responsiveness, biocompatibility, and biodegradability. There has been increasing interest in employing shellac for controlled delivery of food bioactive compounds. This review outlines the recent advances in different types of shellac-based delivery systems, including nanoparticles, zein-shellac particles, hydrogels, nanofibers, and nanomicelles. The preparation method, formation mechanism, structure, and delivery performance are investigated. These systems could improve the stability and shelf-life of bioactive compounds, allow for targeted release at the small intestine or colon site, and increase bioavailability. The deficiencies and challenges of each of the systems are also discussed. The promising results in this review could guide future trends in more efficient shellac-based delivery platforms for functional food applications.

β-glucan-induced disease resistance in plants: A review

Systemic acquired resistance (SAR) and induced systemic resistance (ISR) are caused by various factors, including both pathogenic and non-pathogenic ones. β-glucan primarily originates from bacteria and fungi, some species of these organisms work as biological agents in causing diseases. When β-glucan enters plants, it triggers the defense system, leading to various reactions such as the production of proteins related to pathogenicity and defense enzymes. By extracting β-glucan from disturbed microorganisms and using it as an inducing agent, plant diseases can be effectively controlled by activating the plant's defense system. β-glucan plays a crucial role during the interaction between plants and pathogens. Therefore, modeling the plant-pathogen relationship and using the molecules involved in this interaction can help in controlling plant diseases, as pathogens have genes related to resistance against pathogenicity. Thus, it is reasonable to identify and use biological induction agents at a large scale by extracting these compounds.

Immobilization of α-transglucosidase on silica-coated magnetic nanoparticles and its application for production of isomaltooligosaccharide from the potato peel

In this study, the production of isomaltooligosaccharide from potato peel starch was carried out in three steps: liquefaction, saccharification, and transglucosylation. Further, cloning α-transglucosidase gene from Aspergillus niger (GH31 family), transforming into E. coli BL21 (DE3), overexpressing and purifying the resulting protein for the production of α-transglucosidase. The generated α-transglucosidase was then bound with magnetic nanoparticles, which improved reusability up to 5 cycles with more than 60% activity. All the modifications were characterized using the following methods: Fourier transform infra-red analysis, Transmission Electron Microscopy, Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray spectroscopy, X-Ray Diffraction Spectroscopy, Thermogravimetric Analysis, and Dynamic Light Scattering (DLS) analysis. Further, the optimum conditions for transglucosylation were determined by RSM as follows: enzyme-to-substrate ratio 6.9 U g-1, reaction time 9 h, temperature 45 °C, and pH 5.5 with a yield of 70 g l-1 (± 2.1). MALDI-TOF-MS analysis showed DP of the IMOs in ranges of 2-10. The detailed structural characterization of isomaltooligosaccharide by GC-MS and NMR suggested the α-(1 → 4) and α-(1 → 6)-D-Glcp residues as major constituents along with minor α-(1 → 2) and α-(1 → 3) -D-Glcp residues.

Recent Developments in Molecular Characterization, Bioactivity, and Application of Arabinoxylans from Different Sources

Arabinoxylan (AX) is a polysaccharide composed of arabinose, xylose, and a small number of other carbohydrates. AX comes from a wide range of sources, and its physicochemical properties and physiological functions are closely related to its molecular characterization, such as branched chains, relative molecular masses, and substituents. In addition, AX also has antioxidant, hypoglycemic, antitumor, and proliferative abilities for intestinal probiotic flora, among other biological activities. AXs of various origins have different molecular characterizations in terms of molecular weight, degree of branching, and structure, with varying structures leading to diverse effects of the biological activity of AX. Therefore, this report describes the physical properties, biological activities, and applications of AX in diverse plants, aiming to provide a theoretical basis for future research on AX as well as provide more options for crop breeding.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2019-2020

This review is the tenth update of the original article published in 1999 on the application of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2020. Also included are papers that describe methods appropriate to analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. The review is basically divided into three sections: (1) general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, quantification and the use of arrays. (2) Applications to various structural types such as oligo- and polysaccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals, and (3) other areas such as medicine, industrial processes and glycan synthesis where MALDI is extensively used. Much of the material relating to applications is presented in tabular form. The reported work shows increasing use of incorporation of new techniques such as ion mobility and the enormous impact that MALDI imaging is having. MALDI, although invented nearly 40 years ago is still an ideal technique for carbohydrate analysis and advancements in the technique and range of applications show little sign of diminishing.

Structural insight into a glucomannan-type extracellular polysaccharide produced by a marine Bacillus altitudinis SORB11 from Southern Ocean

Extracellular polysaccharide (EPS) produced by a deep-sea, psychrotolerant Bacillus altitudinis SORB11 was evaluated by considering physiochemical nature and structural constituents. The productivity of crude EPS was measured ~ 13.17 g L^-1. The surface topography of the crude EPS showed a porous, webbed structure along with a branched coil-like configuration. The crystalline crude EPS contained a high amount of sulfur. Further, the crude EPS was subjected for purification. The molecular weight of purified EPS was determined ~ 9.8 × 10⁴ Da. The purified EPS was appeared to show glucomannan-like configuration that is composed of → 4)-β-Manp-(1 → and → 4)-β-Glcp-(1 → residues. So, this polysaccharide was comparable to the structure of plant-derived glucomannan. Subsequently, EPS biosynthesis protein clusters like EpsC, EpsD, EpsE, and glycosyltransferase family proteins were predicted from the genome of strain SORB11, which may provide an insight into the production of glucomannan-type of polysaccharide. This low molecular weight linear form of glucomannan-type EPS might be involved to form a network-like unattached aggregation, and helps in cell-to-cell interaction in deep-sea microbial species.

Impact of Bacterial Cellulose Nanocrystals-Gelatin/Cinnamon Essential Oil Emulsion Coatings on the Quality Attributes of ‘Red Delicious’ Apples

This study aimed to assess the effectiveness of bacterial cellulose nanocrystals (BCNCs)-gelatin (GelA)/cinnamon essential oil (CEO) emulsion coatings containing various CEO concentrations (1200, 1800, and 2400 μL/L) in retarding ripening and senescence of ‘Red Delicious’ apples during cold storage (60 days at 4 °C). Coatings decreased the weight loss (WL) (~3.6%), as compared to uncoated fruit (~4.8%). A direct relationship between CEO concentration and respiration rate/ethylene production was also disclosed. Flesh firmness was higher for coated samples, with better results detected especially when the highest amount of CEO was applied (36.48 N for the 2400 μL/L delivered dose vs. 32.60 N for the 1200 μL/L one). These findings were corroborated by additional tests on the surface color, total acidity, soluble solids content, pH, ascorbic acid, and activities of polyphenol oxidase (PPO) and peroxidase (POD). This study demonstrated the capability of BCNCs-GelA/CEO systems to dramatically enhance the storability and quality of apples during refrigerated storage, thus avoiding undesired losses and increasing the economic performance of fresh fruit industries.

ß-Farnesene Exogenous Application as a Novel Damage Induction Model to Fast Explore the Effectiveness of Postharvest Strategies: The Case Study of the ‘Rocha’ Pear DOP

Since the prohibition of diphenylamine, replacement strategies have been needed for long-term disorder prevention, namely superficial scald (SC), in fruit. However, as this disorder only appears after months under cold storage, the assessment of effective strategies to prevent this disorder requires long periods. To tackle this challenge, we report in this paper a rapid and reliable system to induce symptoms, such as SC, based on storage under a β-farnesene-enriched atmosphere. Using this model, SC symptoms in ‘Rocha’ pear were induced after 15 d at 20 °C. As proof of concept, this model system allowed the study of the efficiency of antioxidant natural-based coatings on ‘Rocha’ pear quality maintenance. Pears treated with the coatings were submitted to 4 months of commercial storage under normal atmosphere conditions and the results were compared with those obtained using the induction model system. A PCA of chemical data allowed us to conclude that the model developed simulates the potential of certain strategies to prevent disorders.

Application and toxicity studies of arabinoxylan and β-D-glucan stearic acid ester composite coatings in extending postharvest storage of peach

Peaches are good source of nutrients and known for their taste and aroma. The highly perishable nature of the peaches tends to decay rapidly during transportation and storage is a serious constraint for efficient transportation and storage. Therefore, the effect of arabinoxylan (AX) and β-D-glucan stearic acid ester (SABG) composite coating material was examined for the postharvest storage quality of peach under storage at 22 ± 2 °C with 85% relative humidity (RH). Both, AX-SABG and shellac (1-2%) coatings significantly reduced the change in the quality attributes like weight loss (1.2-1.4 fold), respiration rate (1.1-1.2 fold), ripening index (1.3-1.5 fold) and firmness (1.3-1.5 fold) during 6 days storage as compared to the uncoated peaches. In addition, AX-SABG (1-2%) coating was more effective in retaining aroma volatiles and reducing disease incidence compared to shellac. Further, acute and chronic toxicological studies have shown no tissue related toxicity and mortality in mice. Our results suggest that AX-SABG as an edible coating has the potential to preserve the fruit quality during 6 days storage at 22 ± 2 °C and extend the postharvest shelf life of peach during storage.

Recent advances of cereal β-glucan on immunity with gut microbiota regulation functions and its intelligent gelling application

β-glucan from cereals such as wheat, barley, oats and rye are a water-soluble dietary fiber, which are composed of repeating (1→4)-β-bond β-D-glucopyranosyl units and a single (1→3)-β-D-bond separated unit. β-glucan has a series of physicochemical properties (such as viscosity, gelling properties, solubility, etc.), which can be used as a food gel and fat substitute. Its structure endows the healthy functions, including anti-oxidative stress, lowering blood glucose and serum cholesterol, regulating metabolic syndrome and exerting gut immunity via gut microbiota. Due to their unique structural properties and efficacy, cereal β-glucan are not only applied in food substrates in the food industry, but also in food coatings and packaging. This article reviewed the applications of cereal β-glucan in hydrogels, aerogels, intelligent packaging systems and targeted delivery carriers in recent years. Cereal β-glucan in edible film and gel packaging applications are becoming more diversified and intelligent in recent years. Those advances provide a potential solution based on cereal β-glucan as biodegradable substances for immune regulation delivery system and intelligent gelling material in the biomedicine field.

Hyperspectral Imaging for the Nondestructive Quality Assessment of the Firmness of Nanguo Pears Under Different Freezing/Thawing Conditions

Firmness changes in Nanguo pears under different freezing/thawing conditions have been characterized by hyperspectral imaging (HSI). Four different freezing/thawing conditions (the critical temperatures, numbers of cycles, holding time and cooling rates) were set in this experiment. Four different pretreatment methods were used: multivariate scattering correction (MSC), standard normal variate (SNV), Savitzky-Golay standard normal variate (S-G-SNV) and Savitzky-Golay multiplicative scattering correction (S-G-MSC). Combined with competitive adaptive reweighted sampling (CARS) to identify characteristic wavelengths, firmness prediction models of Nanguo pears under different freezing/thawing conditions were established by partial least squares (PLS) regression. The performance of the firmness model was analyzed quantitatively by the correlation coefficient (R), the root mean square error of calibration (RMSEC), the root mean square error of prediction (RMSEP) and the root mean square error of cross validation (RMSECV). The results showed that the MSC-PLS model has the highest accuracy at different cooling rates and holding times; the correlation coefficients of the calibration set (Rc) were 0.899 and 0.927, respectively, and the correlation coefficients of the validation set (Rp) were 0.911 and 0.948, respectively. The accuracy of the SNV-PLS model was the highest at different numbers of cycles, and the Rc and the Rp were 0.861 and 0.848, respectively. The RMSEC was 65.189, and the RMSEP was 65.404. The accuracy of the S-G-SNV-PLS model was the highest at different critical temperatures, with Rc and Rp values of 0.854 and 0.819, respectively, and RMSEC and RMSEP values of 74.567 and 79.158, respectively.