Impact of modified atmosphere and humidity packaging on the quality, off-odour development and volatiles of ‘Elsanta’ strawberries

Advances in strawberry postharvest preservation and packaging: A comprehensive review

Strawberries spoil rapidly after harvest due to factors such as the ripening process, weight loss, and, most importantly, microbial contamination. Traditionally, several methods are used to preserve strawberries after harvest and extend their shelf life, including thermal, plasma, radiation, chemical, and biological treatments. Although these methods are effective, they are a concern from the perspective of safety and consumer acceptance of the treated food. To address these issues, more advanced environment-friendly technologies have been developed over the past decades, including modified and controlled atmosphere packaging, active biopolymer-based packaging, or edible coating formulations. This method can not only significantly extend the shelf life of fruit but also solve safety concerns. Some studies have shown that combining two or more of these technologies can significantly extend the shelf life of strawberries, which could significantly contribute to expanding the global supply chain for delicious fruit. Despite the large number of studies underway in this field of research, no systematic review has been published discussing these advances. This review aims to cover important information about postharvest physiology, decay factors, and preservation methods of strawberry fruits. It is a pioneering work that integrates, relates, and discusses all information on the postharvest fate and handling of strawberries in one place. Additionally, commercially used techniques were discussed to provide insight into current developments in strawberry preservation and suggest future research directions in this field of study. This review aims to enrich the knowledge of academic and industrial researchers, scientists, and students on trends and developments in postharvest preservation and packaging of strawberry fruits.

LDPE/M-TiO2 composite films for modified atmosphere packaging to realize comprehensive preservation of strawberry (Fragaria × ananassa Duch.)

BACKGROUND

A shelf-life that is too short is the main problem with strawberries. Nano-TiO₂ can catalyze and oxidize ethylene under ultraviolet (UV) light irradiation to eliminate its ripening effect on fruits and prolong the freshness period.

RESULTS

In this work, nano-TiO₂ modified by methacryloxy propyl trimethoxyl silane (KH570) was blended with low-density polyethylene (LDPE) to prepare modified atmosphere packaging (MAP), and the influence of TiO₂ content on films was analyzed before and after UV treatment. The results show that the modified nano-TiO₂ (M-TiO₂ ) can be uniformly distributed in LDPE, improving its mechanical strength, hydrophobicity, oxygen barrier and UV shielding properties. A modified atmosphere with low ethylene, low O₂ and high CO₂ can be created to inhibit the ripening and spoilage of strawberries. The weight loss rate of fruit can be effectively reduced. The tendency of fruit firmness decline and nutrient loss can be slowed and stabilized, contributing to controllable shelf-life. Excellent freshness preservation function can be realized without special UV treatment.

CONCLUSION

Since UV treatment is rare in actual storage and transportation, LDPE/M-TiO₂ composite film has practical value as MAP for strawberry and similar non-climacteric fruits. © 2022 Society of Chemical Industry.

A Data-Driven Packaging Efficiency Optimization Method for a Low Carbon System in Agri-Products Cold Chain

The of monitoring the Internet of Things (IoT) in the cold chain allows process data, including packaging data, to be more easily accessible. Proper optimization modelling is the core driving force towards the green and low-carbon operation of cold chain logistics, laying the necessary foundation for the development of a data-driven modelling system. Since efficient packaging is necessary for loss control in the cold chain, its final efficiency during circulation is important for realizing continuous loss prevention and efficient supply. Thus, it is urgent to determine how to utilize these continuously acquired data and how to formulate a more accurate packaging efficiency control methodology in the agri-products cold chain. Through continuous monitoring, we examined the feasibility of this topic by focusing on the concept of data-driven evaluation modelling and the dynamic formation mechanism of comprehensive packaging efficiency in cold chain logistics. The packaging efficiency in the table grape cold chain was used as an example to evaluate the comprehensive efficiency evaluation index system and data-driven evaluation framework proposed in this paper. Our results indicate that the established methodology can adapt to the continuity of comprehensive packaging efficiency, also reflecting the comprehensive efficiency evaluation of the packaging for different times and distances. Through the evaluation of our results, the differences and the dynamic processes between different final packaging efficiencies at different moments are effectively displayed. Thus, the continuous improvement of a low-carbon system in cold chain logistics could be realized.

Facile fabrication of multifunctional citrus pectin aerogel fortified with cellulose nanofiber as controlled packaging of edible fungi

Citrus pectin was used as a precursor and cellulose nanofibers as a reinforcing agent, a mixed aerogel with enhanced structural properties was prepared. Pickering emulsion was a template for aerogel formation, embedding thymol. Its potential application in humidity regulating packaging has been investigated. Results showed that emulsion gel containing cellulose nanofibers has slightly larger droplet diameter, better viscoelasticity and emulsification. Composite aerogel has larger pore size and thinner pore wall. Additionally, its tensile and compressive properties have been significantly improved. Moisture absorption was close to 100% of its own weight, thymol was released slowly. Compared with Escherichia coli, aerogel has better resistance to Staphylococcus aureus. When applied on fresh Agaricus bisporus. It was found that relative humidity in package can be stabilized at about 97%. Hardness, color, total phenol content, cell membrane integrity and total antioxidant capacity of Agaricus bisporus were maintained and fresh-keeping period was extended to 5 days.

Effect of Different Modified Atmosphere Packaging on the Quality of Mulberry Fruit (Morus alba L. cv Kokuso 21)

The control of temperature and gas composition is essential to maintain the fresh flavor and quality of perishable fruits like mulberry. This study presented a modified atmosphere experiment (MAP) for fresh fruit showing the potential benefits of innovative gas mixing with argon. The effects of MAP were studied on the physicochemical and qualitative attributes of mulberry preserved at 4 ± 1°C and 90 ± 5% R.H. Fresh mulberries were packaged with different gas combinations: MAP1 (4%O₂+6%CO₂+90%N₂), MAP2 (10%O₂+5%CO₂+85%Ar), CTR1 (20.9%O₂+0.04%CO₂), and CTR2 (10%O₂+5%CO₂+85%N₂). Changes in quality parameters were evaluated after 0, 4, 8, and 12 days of storage. Mulberries packaged with MAP had a lower weight loss than CTR samples which lost more than 80% of their initial weight. Furthermore, the results showed that the argon treatment was the best in keeping the fruit juice content, preserving its structure. Despite not showing great differences with MAP1 treatment, Ar allowed to maintain high TSS up to 8 storage days, slowed CO₂ production. The sensory profile of mulberry fruit was not significantly affected by storage in modified atmospheres, and the production of potential unpleasant odors in MAP2 could not be perceived. The results of this study confirm that this innovative approach, using MAP technology, has a potential use in maintaining mulberry fruit quality for a longer time.

Practical long-term storage of strawberries in refrigerated containers at ice temperature

This study investigated the effect of storage temperature in the presence or absence of film packaging on the Benihoppe and Kirapika varieties of Japanese strawberries stored for 28 days at 0°C and 3°C. The study was conducted in a 20-foot reefer container for practicality. Storage at 0°C suppressed decay and reduction in sugars and organic acids more efficiently than that at 3°C. Softening of fruit hardness was also suppressed depending on the variety. The reduction in sugars and organic acids did not affect strawberry palatability. Along with low temperature, long-term storage of strawberries also requires the use of film packaging, which prevents drying. Without film packaging, storage at both 0°C and 3°C decreased fresh weight significantly, resulting in loss of commercial value. In contrast, storage in film packaging decreased weight reduction to <5%, even after 28 days cold storage.

The Postharvest Quality of Fresh Sweet Cherries and Strawberries with an Active Packaging System

This study assessed the effect of the recently-introduced Life⁺ (ILIP, Valsamoggia, Italy) active packaging system on the postharvest quality of sweet cherries and strawberries. This system uses Equilibrium Modified Atmosphere Packaging (EMAP) to achieve specific intra-package conditions with three synergistic elements: an unvented and anti-mist heat sealable container, an active (naturally-antimicrobial) pad, and a heat-sealed, laser micro-perforated film of a specified gas permeability. Post-packaging quality parameters were monitored for 10 (strawberries) and 15 days (cherries): headspace gas concentration, weight loss, titratable acidity, total soluble solids, pH, disease incidence, and sensory quality. Results showed that use of the Life⁺ system delayed postharvest senescence by maintaining fruit color, acidity, and vitamin C content, and decreasing fruit weight loss and decay. The use of EMAP in sweet cherry resulted in enhanced sensory qualities compared to traditional perforated containers. The results suggest that the Life⁺ system leads to better sensory properties and improved shelf-life for strawberries and sweet cherries.

A Holistic Packaging Efficiency Evaluation Method for Loss Prevention in Fresh Vegetable cold chain

With the continuous push for improving packaging efficiency of current packaging practices to prevent losses in a real cold chain, a holistic evaluation method with improved indicators and a conceptual assessment framework to improve packaging efficiency continuously in a fresh vegetable cold chain was proposed. Based on two fresh leafy vegetables with typical packaging practices in a real cold chain in China, the evaluation method was performed and tested from a macro perspective, and then the packaging efficiency constitution with loss prevention perspective was better visualized. The results show that the method can be used for improving the performance of specific packaging efficiency in the fresh vegetable cold chain and improving the suggestions’ sustainability orientation, and systematically summarize their impacts on packaging efficiency; specifically as follows: (1) Since the correlation between the state of fresh vegetables and the environmental stress in the package, the performance of the micro-environment parameters should be given priority for packaging efficiency improvement in loss prevention. (2) Although the use of the packaging materials in current practices was relatively better, it still can improve in food safety and packaging sustainability of the packaging practices through the selection of packaging materials with better sustainability characteristics. (3) Via the visualization of targeted packaging efficiency in cold chain, the fluctuation of loss rates in the cold chain process are well perceived, and there are still room can be performed continuously to realize more efficient packaging for better loss prevention. (4) The method has drawbacks that the optimization of the weights to the given indicators and the indicators based on nutrition and quality of fresh produce was not considered in current research, and it should be strengthened in future research. (5) It is necessary that the perception of differences in targeted packaging efficiency and the consciousness to improve specific packaging efficiency in vegetable cold chain for sustainability.

Are Chinese Residents Willing to Recycle Express Packaging Waste? Evidence from a Bayesian Regularized Neural Network Model

While enriching people’s lives, the rapid development of online shopping has posed a severe challenge to the environment. Questionnaires focusing on the intention to recycle packaging waste are designed. These questionnaires contain first-level variables such as recycling behavior attitude, recycling behavior cognition, situational factors, historical recycling behavior, and recycling behavior intention. With the collected questionnaire data, a regression analysis is first conducted on the selection of variables and the effect of variable prediction. After ensuring the validity of the variables, 15 second-level variables are extracted into eight principal components using principal component analysis. These components serve as input to a Bayesian regularized neural network. Subsequently, a three-layer (8-15-1) neural network model is constructed; the trained neural network model achieves a high degree of fit between the predicted and measured values of the test set, thus further proving the rationality of the selected variables and the neural network model. Finally, this study uses the connection weights matrix of the neural network model and the Garson formula to analyze in depth the specific impact of each second-level variable on the intention to recycle packaging waste. Note that given the particularity of packaging waste recycling behavior, the impact on social norms, recycling behavior knowledge, values, and publicity on behavioral intentions in second-level variables is different from that obtained in similar previous studies.