This month in SCI's journals

From colour changing packaging to industrial air purifiers - a round-up of the latest research from SCI's journals

Could colour-changing films spell the end for best before dates?

Best before dates on food packaging are a helpful guide, but on-package indicator films could offer much more accurate monitoring of food quality in real time. Microbial growth and enzyme activity are the main culprits for food deterioration, and chilled fresh food – especially meat, seafood, and pasteurised products – rapidly lose quality and freshness during packing, distribution and storage.

The food industry has shown increasing interest in intelligent packaging systems for monitoring safety and food quality in recent years. Polysaccharide-based films can be developed into on-package indicator films due to their excellent film-forming properties and biodegradability, and can have colourants added that visibly change depending on pH levels.

In this review, researchers from the Faculty of Agro-Industry at Chiang Mai University, Thailand, compile recent findings regarding the role of natural pigments, the effects of pigments and polysaccharides on indicator films, applications and limitations of on-package indicator films, the physical properties and colour conversion of pigmented indicator films, and development of polysaccharide-based pH-responsive films.

On-package indicator films based on natural pigments and polysaccharides for monitoring food quality: a review doi.org/10.1002/jsfa.12076

The global team of experts modernising agrochemical safety

Agrochemical safety evaluation is anchored in well-established testing and evaluation procedures, but the framework requires modernisation to meet the challenges of rapidly growing populations, food insecurity, and pressures from climate change.

To this end, the Health and Environmental Sciences Institute (HESI) has assembled a technical committee of international experts from regulatory agencies, academia, industry and NGOs to reframe the safety evaluation of crop protection products. Their mission is to establish a framework that supports the development of fit-for-purpose agrochemical safety evaluation that is applicable to changing global, as well as local needs and regulatory decisions, and incorporates relevant evolving science.

In this article, the HESI committee summarises the challenges associated with modernising agrochemical safety evaluation, proposes a potential roadmap, and seeks input and engagement from the broader community to advance this effort.

Transforming the evaluation of agrochemicals doi.org/10.1002/ps.7148

A design-led approach to single-use plastic

Single-use plastic packaging plays a vital role in the food-to-go industry, but the planetary cost of this linear model is clear. A promising alternative is a circular economy, in which there would be multiple closed-loop cycles of plastic reuse before recycling, but there are several barriers to such a transition for the UK’s food-to-go industry.

This perspective article from the Perpetual Plastic for Food to Go (PPFTG) project introduces a design-led approach to polymer research, highlighting three advantages that could help to overcome these barriers: frame creation as a way for synthesising complex issues towards novel research directions; the potential for changing consumer behaviour through scripted material characteristics; and multidisciplinary working to facilitate innovation.

PPFTG is a three-year project funded by the UK’s Industrial Strategy Challenge Fund (ISCF) Smart Sustainable Plastic Packaging Challenge (SSPP), led by Loughborough University in collaboration with industry partners from across the food-to-go supply chain.

Perpetual plastic for food to go: a design-led approach to polymer research doi.org/10.1002/pi.6401

Biofilms – a potential remedy for ocean plastic

Our current knowledge on the interactions of microplastics with various components of ecosystems is limited; however, considering their potential long-term impact, massive research efforts are underway to understand the environmental fate of microplastics and any possible strategies for remediation.

In marine ecosystems, plastic surfaces are mostly colonised by microorganisms that form biofilms. Plastic-biofilm interactions potentially influence the physical and chemical properties of the plastic itself, leading to its degradation. To mitigate the foreseen nuisance of microplastics contamination, researchers are considering biofilms as potential candidates for the remediation of marine environments. The interactions between plastic and microbes are still inadequately understood, and much of the research in the field is focusing on this aspect.

In this review, researchers from the Institute of Biotechnology at Chandigarh University, India, discuss several types and sources of microplastics, along with their trophic transfer and impacts on ecosystems. In their research, the Chandigarh team focused on the current knowledge and gaps in understanding of plastic-microbe interactions in marine environments, highlighting the role of biofilms in the degradation of microplastic debris. The team concludes with proposed research priorities in the field to further elaborate the role of microorganisms in determining the fate of microplastics in aquatic ecosystems.

Role of biofilms in the degradation of microplastics in aquatic environments doi.org/10.1002/jctb.6978

The price of sugar

The National Renewable Energy Laboratory (NREL) published a model in 2017 that enables the minimum selling price of lignocellulosic sugar to be calculated. In this study, researchers at Purdue University, US, use this model to understand the economics of a process configuration that incorporates biomass liquefaction as a preprocessing step in an existing biorefinery setup.

The objective was to understand whether the addition of liquefaction methodology can reduce the cost of lignocellulosic sugars via the bypassing of acid pretreatment and reduction in yield stress of biomass slurry. The costs for liquefaction were calculated by changing feedstocks within an existing facility modelled by NREL.

Effect of biomass liquefaction on glucose and xylose prices predicted by National Renewable Energy Laboratory biochemical sugar model doi.org/10.1002/bbb.2450

Carbon capture and storage – an Indian perspective

Due to its rapidly developing economy, the energy requirement and carbon emissions for India are projected to rise, with a reliance on coal as a principle energy source likely to continue. The use of carbon capture and storage (CCS) in energy supply systems is one method of reducing greenhouse gas emissions.

Researchers from Motilal Nehru National Institute of Technology Alahabad have evaluated three pulverised coal-fired power stations near the Krishna-Godavari basin with and without CCS, using the life cycle assessment and economical approach, and found that up to 89% of power plants' CO₂ emissions can potentially be reduced. The retrofitting of a CO₂ capture unit into a power plant adds the most to emissions and the cost of the CCS system. There is a 66% rise in the electricity cost when CCS is implemented in an existing power station, with a capital cost of about US$3.4billion.

Life cycle assessment of carbon capture and storage in saline aquifers for coal-fired power generation: An Indian scenario doi.org/10.1002/ghg.2198

Air purifiers on an industrial scale

To achieve net zero targets, industries will require a wide portfolio of negative emission technologies (NET). A low-energy and versatile approach that can remove multiple greenhouse gases simultaneously from the air would be a game changer. For this to be feasible, an air processing unit with sufficient airflow, given the extreme dilution of the greenhouse gases, but with low energy demand is required.

In this work, an international team of researchers used experimental measurements and numerical modelling to investigate whether a simplified solar updraft device could generate enough airflow under low solar conditions. Experimental results demonstrated that low-intensity solar radiation, for example, 120 W/m2, is enough to generate considerable updraft. The team developed a fast-analytical mathematical model to effectively and efficiently find design rules for future applications.

A low-energy approach to processing large-scale airflow doi.org/10.1002/ese3.1348