Europe needs sustainable and profitable value chains for organic fruit and berry products – enter the EcoBerries project.
Growing consumer demand for organic food has contributed to the organic industry becoming one of the most rapidly expanding sectors of the food industry. Since organic production in EU competes with both conventional food and global organic production, it depends heavily on innovations and the use of novel appropriate techniques and research to support scientific evidence of quality and environmental benefits. It is here where the EcoBerries project comes in.
What is the problem?
The number of organic fresh and processed berry and fruit products is still limited, and the industry cannot meet the increasing demand from consumers. Fresh fruits and berries are very perishable, and considerable amounts of fresh produce are wasted in the food chain due to spoilage. Another challenge is that the use of synthetic preservatives and other food additives is not allowed in organic food. Processing is an alternative way to extend shelf life, but processing also influences quality, including nutritional, physical, sensorial and functional properties.
What is needed?
Better packaging solutions are needed to extend the shelf life and minimise waste. Organic technologies for mild pre-treatments and production of dried berries and fruit and their applications in powder form are interesting approaches to minimise the adverse effects of processing and enhance the quality of final products.
Increased knowledge about the potential effects of pre-treatments and processing technologies is also needed. The aim is to identify, develop, and evaluate innovative and sustainable processing and packaging solutions to boost the manufacturing and availability of organic berry and fruit products of high quality and low environmental impact.
What are the major achievements and results?
Several solutions and technologies for extending shelf life and verifying the overall quality of fresh and processed berry and fruit products have been identified and developed during the three years of the EcoBerries project. The major achievements and results are described below.
Identification of packaging conditions and materials
A virtual MAP (modified atmosphere packaging) software (Tailorpack) has been upgraded and used to optimise the design of a MAP system, to identify optimal O2 and CO2 concentrations in headspace and spoilage as a function of time, and to identify the most suitable packaging material for a given application. Protocols for assessment of respiration characteristics of fresh strawberries have been implemented and used for comparison of cultivar respiration characteristics across different European areas.
Organic pre-treatments
Osmotic dehydration (OD) coupled with pulsed electric field (PEF) has been applied to improve functionality of semi-dried products. The application of PEF as a pre-treatment of kiwifruit increased the water mass transfer and reduced the final sugar content, compared with untreated samples. For strawberries, treatment with low PEF voltage resulted in better colour retention, but PEF-OD treated strawberry samples were softer than untreated samples. Comparison with fresh strawberries showed that the treatments did not reduce total content of phenolic compounds or the antioxidative capacity.
The use of edible coatings in improving the shelf life of blueberries was investigated using sodium alginate, pectin, and a combination of sodium alginate and pectin. The tested coatings improved the firmness and colour and reduced the growth kinetics of yeast and mesophilic aerobic bacteria. Storage of coated blueberries during two weeks at 4°C seemed beneficial for the antioxidant capacity/activity and the anthocyanin content.
Microwave-assisted extraction (MAE) was evaluated to improve the recovery of phenolic compounds in berries. Response surface methodology was used to optimise extraction conditions, and microwave power, extraction time, and the ratio of solvent to berry were selected as parameters. The results after optimised MAE showed that 86% of the phenolics of blueberry and 88.7% of phenolics of strawberries could be extracted in a short time.
Added-value products
High-pressure homogenisation (HPH) was applied to organic juices of blueberries and kiwifruit and combined with challenge tests (inoculation with pathogenic/spoilage micro-organisms) to define processing conditions for increased shelf life. For blueberry juice all pathogenic species were inactivated as a result of the combination of HPH and low pH, and a shelf life of two months, at both cold and ambient storage, was obtained. HPH processing of kiwifruit juice resulted in a shelf life of >40 day at cold storage and ten days at ambient temperature.
Extruded snacks based on wholegrain rye flour and with two different levels of dried and milled bilberry flour, obtained from press cake, have been produced and evaluated. Hot air drying resulted in slightly higher scores in the sensory evaluation and microwave-assisted hot air drying gave a little better retention of phenolic compounds in extruded snacks with bilberry flour. The results showed that the use of berry powder in a cereal-based extrusion formulation is a novel way to utilise berry side streams for the production of healthy snacks.
A case study on 3D printing of berry-based confectionaries was carried out through screening of a range of texturising agents commonly used in berry-based foods and with rheological properties that were expected to be suitable for 3D printing. Only non-animal originating additives possible to use in organic products were considered. The texturising agents were added to strawberry purée. Based on the texture and colour of each texture agent-infused strawberry puree, the most promising ones were selected for 3D printing trials, and processing protocols for mixing and temperature control were defined.
Shelf life, environment and consumer studies
A literature study has been made to identify important quality parameters limiting shelf life during storage of berries.
A storage experiment with organically and conventionally grown strawberries highlighted the importance of low temperature storage of berries in closed packages to reduce weight loss and preserve quality. Tailored MAP storage may lead to increased shelf life of the berries but involves a risk of development of off-flavour due to fluctuating temperatures in the value chain.
Consumer behaviour studies have been made to identify factors that influence consumption of mild-processed organic berry products in three different countries. Our studies highlighted a general scepticism towards recent mild-processing technologies (e.g. microwave drying) compared to traditional ones (e.g. air drying), especially among consumers who express a high interest in natural, organic, and healthful properties in food. There is a need to reinforce trust and to communicate about the potential environmental (e.g. energy savings) and health benefits (e.g. higher preservation of nutrients) of mild-processing technologies for organic products in the general population.
The environmental impact of the processing of extruded snacks based on wholegrain rye and bilberry side streams was evaluated. Products containing powders from press cake contributed the least to climate impact – the press cake enters the system with no environmental burden.
Excepted impacts – how will the project benefit society and the environment?
Innovative packaging solutions and processing technologies are crucial to help us prepare for the growing environmental and societal challenges, e.g. by new solutions for the more efficient use of natural resources, to reduce waste, and to provide consumers with healthy foods by preventing the loss of valuable compounds. Berry production is an important agriculture and socio-economic opportunity for many European countries.
Consumer demand for better availability of safe, nutritious, less processed and, at the same time, convenient food is increasing, which also increases the requirements of enhanced shelf life and safety of the products. The use of modified packaging inhibits microbial growth and extends the shelf life of fresh or mildly processed products. This method will provide consumers with safe foods and can reduce food waste. Within the project, innovative berry ingredients and products have been produced, such as functional powders, healthy extruded snacks, and 3D-printed confectionaries. HPH, extrusion (of dried berry powders), and 3D printing are technologies where the whole berry harvest can be used (regardless of visual flaws), and possibly also side streams such as press cake, which can contribute to waste reduction. These technologies are commonly used without any harmful chemicals in the production or cleaning process. HPH is a useful technique for the reduction of preservatives in food products. Moreover, the use of energy and water resources is low, and therefore these technologies can be considered to have less environmental impact than conventional ones. To investigate consumer confidence for the developed solutions and products, consumer perception studies have been performed within the project. The results can be used to understand consumer purchasing decisions and improve communication between consumers, producers and scientists.
The authors acknowledge the financial support for this project provided by transnational funding bodies, being partners of the FP7 ERA-net project, CORE Organic Plus, and with cofunds from the European Commission.
Professor Marie Alminger
Department of Biology and Biological Engineering
Food and Nutrition Science
Chalmers University of Technology
+46 31772 3817
marie.alminger@chalmers.se
www.chalmers.se/en/departments/bio/Pages/default.aspx
http://projects.au.dk/coreorganicplus/research-projects/ecoberries/
