Recent Advances in Novel Packaging Technologies for Shelf-Life Extension of Guava Fruits for Retaining Health Benefits for Longer Duration

Comprehensive characterization of biodegradable edible films activated with rose and marigold extracts and application of active edible coatings to extend the postharvest storage life of guava

This study investigated the physical, mechanical, optical, thermal, and biochemical characters of carboxy methyl cellulose (CMC) and gum arabic (GA) based active edible films activated with rose leaf (RL) and marigold petal (MP) extracts, their impact on the shelf life and postharvest quality of guava fruits when stored under cold condition (10 ± 1 °C). Physical, mechanical and optical characteristics were enhanced by the incorporation of plant extracts. Water solubility of films decreased upon addition of plant extracts, with MP extract films showing the lowest solubility. Water vapor transmission rate (WVTR) lowered when plant extracts were added, lowest for RL extract incorporation (50.35, 8.78 g/m2/day) when compared to pure forms (66.58, 15.97 g/m2/day) for CMC and GA, respectively. Thermogravimetric analysis results revealed increased residue content in CMC + MP films and lower residue in CMC + RL films above 300 °C. FTIR analysis demonstrated interactions between CMC hydroxyl groups and plant extract components, with broad OH and CH stretching peaks. When applied to guava fruits, the shelf life was extended up to 18 days for GA + RL, CMC + MP, and CMC + RL coatings. CMC + RL coated fruits retained higher weight retention percentage (91.03 %) and showed lower ethylene production rates along with enhanced biochemical properties. Antioxidant activity (DPPH) was better preserved in coated fruits, with CMC + RL being the most effective. PME and APX enzyme activities were lower in active-coated fruits. CMC + RL coatings outperformed all other coating formulations in maximizing storage life (18 days) and maintaining quality attributes with lowest ripening index (35.93) and total colour difference (82.80).

Advanced application of slightly acidic electrolyzed water for fresh-cut fruits and vegetables preservation

Fresh-cut fruits and vegetables (F&V) play a pivotal role in modern diets due to their convenience and nutritional value. However, their perishable nature renders them susceptible to rapid spoilage, causing quality deterioration, safety risks, and economic losses along the supply chain. Traditional preservation methods, while effective to some extent, often fall short in maintaining the quality and safety of fresh-cut F&V. This comprehensive review examines the utilization of slightly acidic electrolyzed water (SAEW) as a novel preservation technique for fresh-cut F&V. The review encompasses the production mechanisms, sterilization principles, classifications and application of SAEW. It explores the effects of SAEW on microbial inactivation, quality parameters, and metabolic pathways in fresh-cut F&V. Additionally, it assesses the synergistic effects of SAEW when combined with other preservation methods. SAEW demonstrates remarkable potential in extending the shelf life of fresh-cut F&V by effectively inhibiting microbial growth, suppressing browning, preserving chemical content, and influencing various metabolic processes. Moreover, its synergy with different treatments enhances its overall efficacy in maintaining fresh-cut F&V quality. The review highlights the promising role of SAEW as an innovative preservation approach for fresh-cut F&V. However, challenges regarding its widespread implementation and potential limitations require further exploration. Overall, SAEW stands as a significant contender in ensuring the safety and quality of fresh-cut F&V paving the way for future research and application in the food industry.

A novel edible coating based on Albizia [Albizia lebbeck (L.) Benth.] gum delays softening and maintains quality of harvested guava fruits during storage

Guava, a commercially important fruit crop, is being grown in tropical and subtropical regions around the world. Due to the perishable nature of guava fruits, there are great losses during marketing, transport and storage. The application of edible coating is emerging as a low-cost, simple to implement and efficient method for extending the postharvest life of fresh horticultural produces, such as fruits and vegetables. This study aimed to assess the potential of Albizia gum (AZG) to improve storability and maintain the overall fruit quality of stored guava fruits. Freshly harvested guava fruits were coated with 0 % (control), 1.5 %, 3 % or 4.5 % AZG. After coating treatment, the fruits were stored at 20 ± 1 °C and 85-90 % relative humidity for 15 days. The results revealed that 4.5% AZG coating suppressed the weight loss and decay incidence up to 27 % and 36 %, respectively, as compared with control. The fruits coated with 4.5 % AZG had the maximum titratable acidity (0.40 %), ascorbic acid (104.47 mg·100 g-1), total antioxidants (118.84 mmol Trolox·100 g-1), total phenolics (285.57 mg·kg-1) and flavonoids (60.12 g·kg-1) on 15th day of storage. However, the minimum total soluble solids (11.97 %), sugar-acid ratio (29.31), relative ion leakage (68.40 %), malondialdehyde (0.11 nmol·kg-1 FW) and hydrogen peroxide (16.05 μmol·kg-1 FW) were recorded in the fruits of same treatment on 15th day of storage. Furthermore, the activities of antioxidant enzymes "i.e., superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX)" were increased under the influence of AZG coating. Consequently, as compared to uncoated fruits, AZG-coated fruits exhibited reduced activities of fruit softening enzymes "i.e., cellulase, pectin methylesterase (PME), and polygalacturonase (PG)". To sum up, the application of AZG-based edible coating could markedly improve the storage life of guavas and maintain overall fruit quality.

Unravelling Post-harvest Ripening Metabolomics of a New White Variety Guava Fruit (Cv Arka Mridula) with Special Emphasis on Phenolics and Corresponding Antioxidants

The phenolic, antioxidant and metabolic profiling of a new white variety guava fruit Arka Mridula (AM) was performed during its storage at the room temperature (28 ± 2 °C). The comparative profiles were generated at three ripening stages (pre-ripe, ripe and over-ripe) of the fruit. Generally, a steady decrease of the phenolic and antioxidant content from the pre-ripe to the ripe stage and a subsequent increase from the ripe to over-ripe stage was observed. Further, a powerful correlation between the phenolic content and antioxidant principles was noted through the principal component analysis. We could identify 53  compounds for the hydro-methanolic fruit extract through LC and GC-MS aided metabolic analysis, and the identified compounds were dominated by phenolics (~ 44%). The statistical analysis revealed that phytochemicals catechin, myricitrin, myricetin, kaempferol glycosides and n-hexadecanoic acid contributed significantly towards the ripening process of AM, during the storage. The present study is expected to provide important insight into the ripening biochemistry of AM. Subsequently, it may help in the future development of metabolically stable guava cultivars with extended post-harvest shelf life.

Improving the Traits of Perilla frutescens (L.) Britt Using Gene Editing Technology

Plant breeding has evolved significantly over time with the development of transformation and genome editing techniques. These new strategies help to improve desirable traits in plants. Perilla is a native oil crop grown in Korea. The leaves contain many secondary metabolites related to whitening, aging, antioxidants, and immunity, including rosmarinic acid, vitamin E, luteolin, anthocyanins, and beta-carotene. They are used as healthy and functional food ingredients. It is an industrially valuable cosmetics crop. In addition, perilla seeds are rich in polyunsaturated fatty acids, such as α-linolenic acid and linoleic acid. They are known to be effective in improving neutral lipids in the blood, improving blood circulation, and preventing dementia and cardiovascular diseases, making them excellent crops whose value can be increased through improved traits. This research will also benefit perilla seeds, which can increase their stock through various methods, such as the increased production of functional substances and improved productivity. Recently, significant attention has been paid to trait improvement research involving gene-editing technology. Among these strategies, CRISPR/Cas9 is highly adaptable, enabling accurate and efficient genome editing, targeted mutagenesis, gene knockouts, and the regulation of gene transcription. CRISPR/Cas9-based genome editing has enormous potential for improving perilla; however, the regulation of genome editing is still at an early stage. Therefore, this review summarizes the enhancement of perilla traits using genome editing technology and outlines future directions.

Xanthan gum-based edible coating effectively preserve postharvest quality of 'Gola' guava fruits by regulating physiological and biochemical processes

BACKGROUND

Guava is a fruit prone to rapid spoilage following harvest, attributed to continuous and swift physicochemical transformations, leading to substantial postharvest losses. This study explored the efficacy of xanthan gum (XG) coatings applied at various concentrations (0.25, 0.5, and 0.75%) on guava fruits (Gola cultivar) over a 15-day storage period.

RESULTS

The results indicated that XG coatings, particularly at 0.75%, substantially mitigated moisture loss and decay, presenting an optimal concentration. The coated fruits exhibited a modified total soluble soluble solids, an increased total titratable acidity, and an enhanced sugar-acid ratio, collectively enhancing overall quality. Furthermore, the XG coatings demonstrated the remarkable ability to preserve bioactive compounds, such as total phenolics, flavonoids, and antioxidants, while minimizing the levels of oxidative stress markers, such as electrolyte leakage, malondialdehyde, and H2O2. The coatings also influenced cell wall components, maintaining levels of hemicellulose, cellulose, and protopectin while reducing water-soluble pectin. Quantitative analysis of ROS-scavenging enzymes, including superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase, revealed significant increases in their activities in the XG-coated fruits compared to those in the control fruits. Specifically, on day 15, the 0.75% XG coating demonstrated the highest SOD and CAT activities while minimizing the reduction in APX activity. Moreover, XG coatings mitigated the activities of fruit-softening enzymes, including pectin methylesterase, polygalacturonase, and cellulase.

CONCLUSIONS

This study concludes that XG coatings play a crucial role in preserving postharvest quality of guava fruits by regulating various physiological and biochemical processes. These findings offer valuable insights into the potential application of XG as a natural coating to extend the shelf life and maintain the quality of guava fruits during storage.

An analysis of conventional and modern packaging approaches for cut flowers: a review article

Fresh-cut flowers are considered to be one of the most delicate and challenging commercial crops. It is important to take into consideration how to minimize loss during storage and transportation when preserving cut flowers. Many impinging (bad effect) forces can interact to shorten the flowers' vase life. In the flower industry, effective methods need to be developed to extend freshly cut flowers' life. Fresh-cut flowers' vase life can be shortened by a variety of interlocking causes. The flower industry must develop new techniques to extend the flowers' vase lifespan. This review provides comprehensive, up-to-date information on classical, modified atmosphere packaging (MAP), and controlled atmosphere packaging (CAP) displays. According to this review, a promising packaging technique for fresh flowers can be achieved through smart packaging. A smart package is one that incorporates new technology to increase its functionality. This combines active packaging, nanotechnology, and intelligence. This technology makes it easier to keep an eye on the environmental variables that exist around the packaged flowers to enhance their quality. This article offers a comprehensive overview of creative flower-saving packaging ideas that reduce flower losses and assist growers in handling more effectively their flower inventory. To guarantee the quality of flowers throughout the marketing chain, innovative packaging techniques and advanced packaging technologies should be adopted to understand various package performances. This will provide the consumer with cut flowers of standard quality. Furthermore, sustainable packaging is achieved with circular packaging. We can significantly reduce packaging waste's environmental impact by designing reused or recyclable packaging.

Review of recent advances in post-harvest techniques for tropical cut flowers and future prospects: Heliconia as a case-study

Aesthetic attributes and easy-to-grow nature of tropical cut flowers (TCFs) have contributedto their potential for increased production. The dearth of information regarding agronomic practices and lack of planting materials are the key hindrances against their fast expansion. Unconventional high-temperature storage requirements and the anatomy of the peduncle contribute topoor vase life performance, while troublesome packaging and transport due to unusual size and structureprimarily cause post-harvest quality deterioration. Nonetheless, the exotic floral structuresconsequently increase market demand, particularly in temperate countries. This boosts studies aimed at overcoming post-harvest hindrances. While a few TCFs (Anthurium, Strelitzia, Alpinia, and a few orchids) are under the spotlight, many others remain behind the veil. Heliconia, an emerging specialty TCF (False Bird-of-Paradise, family Heliconiaceae), is one of them. The structural uniquenessand dazzling hues of Heliconia genotypes facilitate shifting its position from the back to the forefrontof the world floriculture trade. The unsatisfactory state-of-the-art of Heliconia research and the absence of any review exclusively on it are the key impetus for structuring this review. In addition to the aforementioned setbacks, impaired water uptake capacity after harvest, high chilling sensitivity, and the proneness of xylem ducts to microbial occlusion may be counted as a few additional factors that hinder its commercialization. This review demonstrates the state-of-the-art of post-harvest research while also conceptualizing the implementation of advanced biotechnological aid to alleviate the challenges, primarily focusing on Heliconia (the model crop here) along with some relevant literature on its other allied members. Standard harvesting indices, grading, and packaging are also part of the entire post-harvest operational chain, but since these phases are barely considered in Heliconia and the majority of tropical ornamentals except a few, a comprehensive account of these aspects has also been given. The hypothesized cues to nip chilling injury, resorting to different bio-chemical treatments, nano-based technology, and advanced packaging techniques, may help overcome preservation difficulties and propel its transition from niche to the commercial flower market. In a nutshell, readers will gain a comprehensive overview of how optimum post-harvest handling practices can rewardingly characterize this unique group of TCFs as the most remunerative component.