Analysis of oligomers to assess exposure to microplastics from foods. A perspective

There is an emerging interest in evaluating the presence of microplastic (MP) and nanoplastic (NP) residues in food. Despite their potential threat to human health, there is still a need for harmonized methods to evaluate and quantify their presence. Incomplete polymerization may occur during the production of plastic. Conversely, oligomers are formed during chemical, mechanical, or enzymatic depolymerization. Oligomers are a few nanometers in size. Recent advances in analytical chemistry have enabled the quantification and identification of these oligomers in various complex biological matrices. Therefore, we propose that the specific nanosized oligomers can be considered markers for the presence of MPs/NPs. This advance may facilitate a broader perspective for the assessment of MPs/NPs exposure, leading to the evaluation of food safety and associated risks to humans

Towards creating sustainable foods from side streams: Heat-induced structure formation in blends of sunflower seed press cakes and cheese whey under moderate shear

Processing of oilseeds generates low value by-products, which still contain valuable components. Sustainable and circular food chains require valorising the entire stream or producing less refined fractions of it. One approach could be blending with other protein-containing side streams to obtain novel, nutritionally valuable and techno-functional food ingredients. In this study, sunflower press cake was co-processed with components from whey, a cheese-making by-product. Blends with constant dry matter and protein content but different press cake to whey protein ratios (0–225 g/kg press cake) were used to investigate the contributions of both side streams to structure formation during heating (80–140 °C) under moderate shear using a Rapid Visco Analyser. The denaturation of whey proteins contributed to an increased viscosity, but the highest viscosities were still achieved at high ratios of press cake, underlining the importance of the fibre fraction for structure formation. Treatments at 120 and 140 °C increased the amount of insoluble material and water holding capacity of the blends, and analyses of the serum phase and curd showed that sunflower and whey proteins formed heat-induced, insoluble aggregates. Confocal laser scanning microscopy confirmed the presence of large protein particles dispersed in the matrix rather than the presence of a continuous network, as was the case for heating without shear. Furthermore, the protein particles were more defined and showed a smoother appearance with increasing press cake concentration. This research provides fundamental insights in the colloidal interactions between biomacromolecule blends during processing (e.g., protein cross-linking, microphase separation), and demonstrates the importance of understanding the critical process parameters (e.g., heat, shear) leading to structure formation, facilitating the successful integration of complex materials such as press cakes and setting the basis for further processing of the blends and their utilisation as ingredients, for instance in functional drinks, snacks, or semi-solid spreads

Applicability of Confocal Raman Microscopy to Observe Microstructural Modifications of Cream Cheeses as Influenced by Freezing

Confocal Raman microscopy is a promising technique to derive information about microstructure, with minimal sample disruption. Raman emission bands are highly specific to molecular structure and with Raman spectroscopy it is thus possible to observe different classes of molecules in situ, in complex food matrices, without employing fluorescent dyes. In this work confocal Raman microscopy was employed to observe microstructural changes occurring after freezing and thawing in high-moisture cheeses, and the observations were compared to those obtained with confocal laser scanning microscopy. Two commercially available cream cheese products were imaged with both microscopy techniques. The lower resolution (1 µm/pixel) of confocal Raman microscopy prevented the observation of particles smaller than 1 µm that may be part of the structure (e.g., sugars). With confocal Raman microscopy it was possible to identify and map the large water domains formed during freezing and thawing in high-moisture cream cheese. The results were supported also by low resolution NMR analysis. NMR and Raman microscopy are complementary techniques that can be employed to distinguish between the two different commercial formulations, and different destabilization levels

Blending side streams. A potential solution to reach a resource efficient, circular, zero-waste food system

Reduction of production losses and increasing resource efficiency is needed to improve sustainability of the food supply chain. One approach to reach more resource-efficient, circular food systems is blending and processing side streams, especially when blending increases their value through compositional, nutritional or functional synergies. In this perspective we present a case study for valorizing sunflower oil press cake and whey. As the need for specialty products grows, small and medium-sized seed oil producers will be challenged with by-products. Similarly, small and geographically scattered dairy companies are faced with inadequate supply chains not allowing handling and downstream processing of whey. By combining two side streams, and applying simple processing steps and novel fermentation approaches, it would be possible not only to improve circularity of the value chain, but also to develop innovative ingredient platforms. A series of solutions appealing to various end users, from beverage producers to bakeries and snack applications, can be developed from fermented side stream blends when specific demands to ensure food safety and appropriate sensory quality are met

Sustainable food packaging: An updated definition following a holistic approach

Food packaging solutions need to be redesigned to be more sustainable, but determining which solution is ‘more optimal’ is a very difficult task when considering the entire food product value chain. Previous papers paved the way toward a sustainable food packaging definition, but it is far from being commonly accepted or well usable in the broad food systems domain, which further results in uninformed choices for sustainable food packaging made by all stakeholders in the value chain: producers, distributors, practitioners and consumers. Therefore, this work aims first at giving a state-of-the-art overview of sustainable food packaging terms (38 similar terms were identified and grouped into four clusters: Sustainable, Circular, Bio and Other sustainable packaging) and definitions using systematic (narrative) review analysis and ‘controlled expert opinion feedback’ methodology. Second, it aims to offer an updated definition for sustainable food packaging, which is also specific to food packaging and be simple, coherent, easily understandable, and communicable to everybody. The applied holistic approach intends to include all aspects of the food-packaging unit, to consider food safety and packaging functionality, while taking into account different disciplines and challenges related to food packaging along the supply chain. Being a balancing act, a sustainable food packaging may not be a perfect solution, but contextual, suboptimal and in need of constant validation.info:eu-repo/semantics/publishedVersio

Sustainable food packaging: An updated definition following a holistic approach

publishedVersio

Inter-laboratory comparability of the in vitro digestibility method based on the static INFOGEST method

Poster presentado en: International Symposium Dietry Protein for Human Health. Utrecht, Paises Bajos. 14-16 septiembre (2023

Standardization of in vitro digestibility and DIAAS method based on the static INFOGEST protocol

Background: The FAO recommends the digestible indispensable amino acid score (DIAAS) as the measure for protein quality, for which the true ileal digestibility needs to be assessed in humans or pigs. However, due to high costs and ethical concerns, the FAO strongly encourages as well the development of validated in vitro methods, which complement the in vivo experiments. Method: Recently, an in vitro workflow, based on the validated static INFOGEST protocol, was developed and compared towards in vivo data. In parallel to the validation with in vivo data, the repeatability and reproducibility of the in vitro protocol were tested in an international ring trial (RT) with the aim to establish an international ISO standard method within the International Dairy Federation (IDF). Five different dairy products (skim milk powder, whole milk powder, whey protein isolate, yoghurt, and cheese) were analyzed in 32 different laboratories from 18 different countries, across 4 continents. Results: in vitro protein digestibilities based on Nitrogen, free R-NH2, and total amino acids as well as DIAAS values were calculated and compared to in vivo data, where available. Conclusion: The in vitro method is suited for quantification of digestibility and will be further implemented to other food matricesinfo:eu-repo/semantics/publishedVersio