Postharvest Quality of Cherry Tomatoes Coated with Mucilage from Dragon Fruit and Irradiated with UV-C

Chitosan/kaolinite clay biocomposite as a sustainable and environmentally eco-friendly coating material for slow release NPK fertilizers: Effect on soil nutrients and tomato growth

Soil nutrient availability and non-biodegradation of some polymer-based slow-release fertilizers (SRFs) have a direct impact on crop production and soil ecological quality. Proper fertilization practices can lead to obviating adverse effects of over-fertilization on soil nutrients and, consequently, on crop yields. This work aims to assess the effect of a durable liner material based on biodegradable polymers on soil nutrient availability and tomato growth. For this purpose, Chitosan composite (CsGC) was adopted as a durable coating material, including clay as a reinforcing coating material. The influence of chitosan composite coating (CsGC) on the sustained nutrient release of coated NPK fertilizer (NPK/CsGC) was studied. Scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDX) were used to examine the coated NPK granules. Results revealed that the proposed coating film improved the mechanical strength of the NPK fertilizer and enhanced water retention capacity of the soil. The agronomic investigation has also proved their outstanding potential to boost chlorophyll content, biomass, and tomato metabolism. Furthermore, the surface response study confirmed a strong correlation between tomato quality and representative soil nutrients. Therefore, kaolinite clay, as part of the coating system, can be an effective way to improve tomato quality and maintain soil nutrients during tomato ripening.

Response Surface Methodology (RSM) Optimization of the Physicochemical Quality Attributes of Ultraviolet (UV-C)-Treated Barhi Dates

Barhi date fruit is one of the most important fruits that has high consumer preference and market value at the Khalal maturity stage. However, this stage is very short and the fruit is vulnerable to decay and the ripening process under improper handling and storage conditions. Thus, the purpose of this study was to evaluate the feasibility of utilizing ultraviolet (UV-C) as a method to preserve the qualitative features of Barhi dates under various storage circumstances. The core of this study was defining the best conditions for UV-C treatment of Barhi dates, which was accomplished using a response surface methodology (RSM) model with a central composite, rotating four-factors-mixed-levels design (CCRD). The impacts of independent variables [UV-C exposure time (1, 2, 3, 4 min), UV-C dose (1, 3, 5, 7 kJ/m²), storage time (1, 6, 11, 16, 21 days) and storage temperature (1, 5, 15, 25 °C)] on the moisture content (MC), total soluble solids (TSS), total color changes (E), firmness, total phenolic content (TPC), total viable count (TVC), DPPH antiradical activity, fructose and glucose were investigated. The results revealed that the optimum UV-C treatment and storage settings for keeping the quality features of the dates were the UV-C exposure period and dosage of 1 min and 2.07 kJ/m², and the storage time and temperature of 18 days and 12.36 °C, respectively. At the optimum conditions, the values of 59.66% moisture content, 38.24% TSS, 60.24 N firmness value, 48.83 ΔE, 0.07 log CFU/g TVC, 5.29 mg GAE/g TPC, 56.32% DPPH antiradical activity, 6.87 g/100 g fructose and 14.02 g/100 g glucose were comparable predicted values demonstrating the suitability of the used RSM models. Overall, the perfect UV-C treatment and storage circumstances for extending the storability and shelf life and maintaining the quality features of Barhi dates were identified in this study.

Polyvinyl alcohol/xanthan gum composite film with excellent food packaging, storage and biodegradation capability as potential environmentally-friendly alternative to commercial plastic bag

Polyvinyl alcohol (PVA)-xanthan gum (XG) composite films with good degradation properties were prepared by casting method. The effects of XG amount on thickness, moisture content, water solubility, water vapor transmission (WVP), transmittance and mechanical properties of the composite film were investigated. All composite films produced uniform and transparent films and Fourier transform infrared (FT-IR) spectroscopy, as well as X-ray diffraction (XRD) had proven the formation of hydrogen bonds and subsequently compatibility of the two polymers. In general, addition of XG in PVA was able to decrease moisture content, water solubility and WVP more than the pure PVA films, with sample PX30 demonstrated the best performance. This sample also had the best mechanical properties. It also demonstrated food packaging and capability better than that of commercial plastic bag. More importantly, our sample can be fully decomposed in soil and water within 12 h, which was not only significantly shorter than commercial plastic bag, but also other biodegradable materials. Therefore, PVA/XG-based food packaging material has demonstrated huge potential to be commercialized and replaces commercial plastic bag as an alternative packing material which is renewable, sustainable and environmentally friendly.