Effect of Cross-Linked Alginate/Oil Nanoemulsion Coating on Cracking and Quality Parameters of Sweet Cherries

Research Progress of Hydrogen Rich Water in Preservation of Postharvest Horticultural Products: A Review

The perishable nature of horticultural products and unfavorable factors during storage lead to postharvest losses and shelf life limitations. As an effective hydrogen (H2) supplier, hydrogen-rich water (HRW) is regarded as a new green postharvest preservation strategy of horticultural products. This review presents a complete overview of the application advance of HRW for the preservation of horticultural products, including the potential production mechanisms of hydrogen in plants, the preparation and application methods of HRW, and potential mechanisms of HRW in improving the quality of postharvest horticultural products. The findings show that HRW can maintain the quality and stress tolerance of horticultural products by regulating metabolic pathways and molecular responses, including oxidative defense, energy homeostasis, respiration, cell-wall intergrity, ethylene biosynthesis, related gene expression and phytohormones signaling crosstalk. The information obtained in this review is expected to provide a scientific basis for the application of HRW for the preservation of postharvest horticultural products.

Nano-edible coatings for quality enhancement and shelf-life extension of fruits and vegetables

In developing countries, significant fruit and vegetable losses stem from inadequate storage and mishandling during harvest. Employing edible coatings on agricultural products offers an alternative method to reduce these losses as it aids in controlling the flow of moisture and gases between the product and its immediate environment. A significant benefit of applying edible films and coatings to agricultural produce is the incorporation of active components to the biopolymer matrix, which can be consumed together with the food, improving its nutritional and sensory appeal as well as its safety. Producing edible coatings at the nanoscale level has become more prevalent since the introduction of nanotechnology. By decreasing the coating particles to a nanometric scale of 1 to 100 nanometers, nanotechnology offers an innovative approach for producing new edible coatings. Such nanomaterials exhibit unique and improved characteristics of slowing ripening and decay of fruit and have additional advantages like affordability, convenience of application, and use of natural ingredients. The primary objective of incorporating edible coatings with nanoparticles is to improve the mechanical and barrier qualities of the biopolymer. Despite the tremendous advancements in nutritional nanotechnology, little is known about the toxicity of nanomaterials and due to their potential for toxicity, nanomaterials require more characterization and strict regulations to be incorporating them along with food. This review provides a comprehensive understanding of nanocoatings, including its synthesis and application for fruits and vegetables quality enhancement and shelf-life extension.

Effect of Balangu seed mucilage/gelatin coating containing dill essential oil and ZnO nanoparticles on sweet cherry quality during cold storage

The current research focused on examining the effect of a coating made from Balangu seed mucilage (TSM-BM) and gelatin (Ge), with varying concentrations of dill essential oil (DEO) (0 %, 1 %, and 2 %) and zinc oxide nanoparticles (ZnO-np) (0 % and 0.5 %), on the quality characteristics of cherries stored at 4 °C over intervals of 0, 4, 7, 11, 18, and 25 days. The study noted that the application of this coating, particularly when combined with DEO and ZnO-np, significantly reduced the rate of changes in several parameters, including weight loss, firmness, titratable acidity, pH, total soluble solids, ascorbic acid, total anthocyanin content, total phenolic content, and antioxidant activity (p˂0.05). During the storage period, the skin color of all treated fruits darkened. Significant reductions were also observed in the values of L∗, Chroma, and hue angle, with the coating slowing these changes (p˂0.05). The BM-Ge coating's gas barrier properties contributed to a lower respiration rate in coated fruits than in uncoated controls, thereby delaying spoilage. The coating effectively prevented moisture loss from the stem and reduced browning over time. The incorporation of DEO into the BM-Ge coating enhanced its moisture barrier capabilities due to DEO's hydrophobic properties. BM-Ge coating containing 2 % DEO and 0.5 % ZnO-np was able to reduce changes of weight loss, firmness, titratable acidity, ascorbic acid, total soluble solids, total anthocyanin content, total phenolic content, and antioxidant activity by 71.23 %, 88.84 %, 60 %, 48.39 %, 30.05 %, 82.65 %, 50.77 %, and 55.46 % respectively. A significant correlation was also observed between the treated fruits' physical, chemical, and visual qualities.

Improvement of antioxidant capacity, aroma quality, and antifungal ability of cherry by phenyllactic acid treatment during low temperature storage

Introduction

Sweet cherries (Prunus avium L.) are highly valued for their taste and nutrients but are prone to decay due to their delicate skin and high respiration rate. Traditional chemical preservatives have drawbacks like residues and resistance, prompting the search for natural alternatives. Phenylactic acid (PLA) has shown promise due to its antibacterial and antioxidant properties, making it a potential natural preservative to extend cherry shelf life.

Methods

'Stella' sweet cherries were treated with varying concentrations of PLA (0, 2, 4, 8, 16 mmol·L-1) and stored at 4°C. Key quality indicators, including firmness, total acidity, total soluble solids, weight loss, decay index, and antioxidant activity, were assessed over time. Additionally, HPLC, GC-MS, GC-IMS, colony counts, in vivo inhibition analyses were conducted to evaluate phenolic content, aroma compounds and antifungal ability.

Results and Discussion

PLA at 8 mmol·L-1 effectively maintained cherry quality by reducing weight loss and decay of cherries, delaying the decline of firmness, while enhancing antioxidant capacity, flavor stability, and antifungal ability. Higher concentrations (16 mmol·L-1) provided stronger antimicrobial effects but caused slight surface wrinkling. Thus, 8 mmol·L-1 was optimal, balancing preservation and appearance, making it a promising natural preservative for extending cherry shelf life.

A computer vision system and machine learning algorithms for prediction of physicochemical changes and classification of coated sweet cherry

The current research utilized visual characteristics obtained from RGB images and qualitative characteristics to investigate changes in surface defects, predict physical and chemical characteristics, and classify sweet cherries during storage. It was achieved with the help of ANN (Artificial Neural Network) and ANFIS (Adaptive Neuro-Fuzzy Inference System) models. The ANN used in this study was a Multilayer Perceptron (MLP) with SigmoidAxon and TanhAxon threshold functions, trained with the Momentum training function. Additionally, ANFIS with a Mamdani system and Triangle, Gauss, and Trapezoidal membership functions, was employed to predict sweet cherries' physical and chemical properties and their quality classification. Both models incorporate four algorithms. Additionally, the algorithms use color statistical features and color texture features combined with physical and chemical properties, including weight loss, firmness, titratable acidity, and total anthocyanin content. The image color and texture characteristics were used by ANN and ANFIS models to predict physical and chemical properties with high accuracy. ANN and ANFIS models accurately estimate sweet cherry quality grades in all four algorithms with over 90 % accuracy. According to the findings, the ANN and ANFIS models have demonstrated satisfactory performance in the qualitative classification and prediction of sweet cherries' physical and chemical properties.

Reducing cherry rain-cracking: Enhanced wetting and barrier properties of chitosan hydrochloride-based coating with dual nanoparticles

The synergistic effects of phosphorylated zein nanoparticles (PZNP) and cellulose nanocrystals (CNC) in enhancing the wetting and barrier properties of chitosan hydrochloride (CHC)-based coating are investigated characterized by Fourier Transform Infrared Spectra (FTIR), X-ray Diffraction (XRD), atomic force microscopy and by investigating the mechanical properties, etc., with the aim of reducing cherry rain cracking. FTIR and XRD showed dual nanoparticles successfully implanted into CHC, CHC-PZNP-CNC combined moderate ductility (elongation at break: 7.8 %), maximum tensile strength (37.5 MPa). The addition of PZNP alone significantly improved wetting performance (Surface Tension, CHC: 55.3 vs. CHC-PZNP: 48.9 mN/m), while the addition of CNC alone led to a notable improvement in the water barrier properties of CHC (water vapor permeability, CHC: 6.75 × 10-10 vs. CHC-CNC: 5.76 × 10-10 gm-1 Pa-1 s-1). The final CHC-PZNP-CNC coating exhibited enhanced wettability (51.2 mN/m) and the strongest water-barrier property (5.32 × 10-10 gm-1 Pa-1 s-1), coupled with heightened surface hydrophobicity (water contact angle: 106.4°). Field testing demonstrated the efficacy of the CHC-PZNP-CNC coating in reducing cherry rain-cracking (Cracking Index, Control, 42.3 % vs. CHC-PZNP-CNC, 19.7 %; Cracking Ratio, Control, 34.6 % vs. CHC-PZNP-CNC, 15.8 %). The CHC-PZNP-CNC coating is a reliable option for preventing rain-induced cherry cracking.

Nanoemulsion based edible coatings for quality retention of fruits and vegetables-decoding the basics and advancements in last decade

Fruits and vegetables (F&V) are highly perishable and have important contributions to nutritional and economic sustainability. Although the developing nations have shown an immense increase in the production of horticultural commodities, the post-harvest losses are significant and have an adverse impact on the resources, economy, and environment as well. Nanoemulsion-based carriers are recognized for their diversity, natural origin, and immense potential to restrict losses while boosting the functional attributes of produce. The recent findings attest to nanoemulsions potential for extending the shelf life, managing quality, and reducing the losses of the perishables for sustainable livelihood of the farmers. However, further studies are required to evaluate the biological fate, safety, or potential toxicity of the nanoemulsion-based edible coatings. This review precisely focuses on various matrices used in the production of nanoemulsions, fabrication methods, characterization techniques, and the use of natural emulsifiers instead of chemicals. The future research focus stresses on developing low-cost fabrication techniques for nanoemulsion, improvement of the transmission properties i. e gas transmission rate (GTR), water vapor transmission rate (WVTR), and enhancing the performance of monolayer, bilayer, and other composite nanoemulsion base films. This beyond reducing the postharvest losses shall also restrict burden of the food waste management and related environmental issues at the same time.

Edible and essential oils nanoparticles in food: a review on the production, characterization, application, stability, and market scenario

The application of oils in the food industry is challenging, owing to their inherent factors such as oxidation. Therefore, new technologies, such as nanoencapsulation, are being developed. Among the nanoencapsulated oils, essential oils (EO) and edible oils stand out for their high consumer demand. This review analyzes the production, characterization, stability, and market scenario of edible and EO nanoparticles applied in foods. Homogenization was found to be the most common technique for producing oil nanoparticles. Different encapsulants were used, and Tween 80 was the main emulsifier. Approximately 80% of the nanoparticles were smaller than 200 nm, and the polydispersibility index and zeta potential values were satisfactory, mainly for nanoparticles containing EO, whereas encapsulation efficiency varied based on the technique and the type of oil used. Oil nanoparticles were mainly applied on meat products. The temperatures and times used in the stability tests of foods containing oil nanoparticles varied depending on the food matrix, especially in microbiological and physicochemical analyses. Only one product with nanoencapsulated oil in its composition was found in the market. Oil nanoparticles have great potential in the development of innovative, economically viable, and sustainable techniques for producing new food products that are high in nutrition value.

Eco-friendly 'ochratoxin A' control in stored licorice roots - quality assurance perspective

According to toxicity data, ochratoxin A (OTA) is the second most important mycotoxin and is produced by Aspergillus and Penicillium. As a natural antifungal agent, clove essential oil (CEO) is a substance generally recognised as safe (GRAS) and shows strong activity against fungal pathogens. Here, we aimed to investigate the control efficacy of CEO in nano-emulsions (CEN) against OTA production in licorice roots and rhizomes during storage. The experiments were performed under simulated conditions of all four seasons (i.e. Spring, Summer, Autumn and Winter). Relative humidity (RH) and temperature were simulated in desiccators along with various salt solutions in incubators. Fresh licorice roots were immersed in CEN at various concentrations (150, 300, 600, 1200 and 2400 µl/l). Before utilising the nano-emulsions, we measured their polydispersity index and mean droplet size by the dynamic light scattering (DLS) technique. Also, the chemical composition of the CEO was determined using GC and GC-MS analyses. Sampling was carried out to monitor OTA once every five days. The samples were dried immediately and analysed by high-performance liquid chromatography (HPLC). Results showed that various concentrations of CEN inhibited the growth of fungi and OTA production. The most effective CEN concentrations were 1200 and 2400 µl/l, which reduced OTA production to 19 and 20 ppb under Winter and Autumn conditions, respectively. These results suggest an effective eco-friendly method for the storage of licorice to reduce postharvest fungal decay.

Introduction to the Special Issue: Advanced Strategies to Preserve Quality and Extend Shelf Life of Foods

We are pleased to present this Special Issue, which includes 13 papers that highlight the most important research activities in the field of food quality assurance and shelf-life extension [...]

Functionality of Films from Nigella sativa Defatted Seed Cake Proteins Plasticized with Grape Juice: Use in Wrapping Sweet Cherries

The main aim of this work is to improve the functionality of Nigella sativa protein concentrate (NSPC) films by using grape juice (GJ). The film’s mechanical, antioxidant, and antimicrobial activities were evaluated. The obtained results showed, for the first time, that GJ at concentrations of 2%–10% (v/v) are able to act as plasticizer for the NSPC films with promising film properties. The results showed that the tensile strength and Young’s modulus of NSPC films were reduced significantly when the GJ increased. However, the NSPC films prepared with 6% GJ observed a higher elongation at break compared with other films. Moreover, the obtained films showed very interesting and promising results for their antioxidant and antimicrobial properties compared with the control films. The sweet cherries wrapped with NSPC film showed that the TSS (Brix) was significantly lower compared to the control, after 10 days of storage. However, the titratable acidity, pH value, and L* of all cherries, either wrapped or not, was not significantly different in all storage times. On the other hand, hue angle was significantly lower after 10 days of storage at −18 °C compared with control films. GJ has a multi-functional effect for protein-based films as plasticizer, antioxidant, and antimicrobial function.