Work packages

The project focuses on the utilisation of berry pomace, a material that, from the viewpoint of fruit processing companies, is currently considered as a by-product which has a very low value. The intention of our consortium is to demonstrate that, following a tailored processing to ensure appropriate shelf life and techno-functional properties, advantage can be taken from the high nutritional value of the processed berry pomace by incorporating it in several types of cereal-based foods. Therefore the project consists of five different work packages (WP).

WP 1 - Review of literature and patents

The aim of workpackage 1 is to bring together different aspects from scientific literature and patent applications, and to define the state-of-the-art concerning aspects of fibre and phytochemicals extraction from berry pomace and their use in cereal-based foods.
The initial project meeting will be used to discuss the strategical approach to the topics that will be part of the literature review:

  1. Technical and technological aspects of pomace processing, and the chemical characterisation of pomace.
  2. Conventional and new methods for polyphenol extraction from berry pomace.
  3. Processes for the extraction and production of fibre fractions from berry pomace.
  4. Current ways to incorporate fibre and polyphenols in soft moisture-rich cereal, and in low-moisture cereal-based products.
  5. Current ways to incorporate fibre and polyphenols in extruded cereal-based products.

WP 2 - Pomace processing and extraction of fibre and phytochemicals

The aim of workpackage 2 is to establish the technical conditions (drying, milling, purification, fractionation) during processing of berry pomace that will result in materials rich in dietary fibre and phytochemicals.
Emphasis will be placed on conditions applied during pomace drying, and during subsequent milling. The conditions during convective drying (e.g., air temperature and velocity) determine the drying rate which, in turn, will affect the mechanical properties of the dried pomace. As convective drying of pressed pomace might result in an extraordinary hard material, microwave assisted vacuum drying with its puffing effects (Boehm et al., 2006, Food Sci. Technol. Int. 12:67) might be a promising alternative. Milling must be carried out in a way that defined particle size distributions are achieved. The fineness of the fibre particles is of special importance in soft bakery products as any sensory grittiness of the crumb that originates from added particles must be avoided. Additionally, particle size and the related specific surface area are relevant for moisture or oil binding capacity.
Another focus of WP 2 will be placed on the application of different methods for the extraction of phenolic compounds, and how the procedures for drying, milling and purification affect the content of polyphenols.

WP 3 - Application of processed berry pomace and fibre in cereal-based foods

The aim of workpackage 3 is to develop ways for a successful incorporation of processed berry pomace with functional properties (rich in polyphenols and/or fibre) for partially replacing wheat flour, sugar or fat in cereal-based foods, to optimise production technology and product quality (sensory, shelf life), and to enhance the nutritional relevance of these foods.
Bulk and macrostructural properties in baked or extruded cereal-based products are, among others, determined by macromolecular interactions of wheat flour components: starch and gluten protein. Irrespective of product type, structural developments in the dough or batter affect baking behaviour and product appearance. When fibre, composed of soluble and insoluble compounds, is integrated in bakery products with the aim to substitute wheat flour or sugar, its higher moisture holding capacity must be considered. An insufficient hydration of wheat macromolecules that compete with fibre for water must be avoided, so that formulations need to be modified by considering the exact properties of the respective fibre.
Therefore, potential interactions between wheat macromolecules and fibre components incorporated in cereal-based products are analysed in WP 3. Food processing is well known as a modulator of polyphenol content and bioactive functionality in fruit products, however little is known about the relationship between polyphenols, protein and starch in terms of specific shear and thermal processing conditions. By modelling these characteristics in processes such as extrusion, we will be able to optimise bioactive recovery and retention of bioavailability whilst still producing consumer acceptable foods. Different fibre products obtained by the methods developed in WP 2 will be used here. All fibre-enriched products will be specifically analysed for characteristics such as texture, colour, dimensions, crumb cell structure and sensory properties, either at the producing institution or at a partner laboratory.

WP 4 - In-depth product characterisation and phytochemical stability

The aim of workpackage 4 is to obtain detailed information on aspects of incorporating processed berry pomace in, and adding purified fibre and polyphenols to cereal-based products. Hence, fibreenriched foods will be produced using the formulations that were established in WP 3.
Apart from properties that are affected by processed berry pomace addition and routinely assessed by the respective partners, each partner performs individual in-depth analyses. This results in e.g. important information on (micro)structural interactions between pomace and other constituents reported in literature (Zahn et al., 2013, LWT - Food Sci. Technol. 50:695). Special competence is also necessary for analysing the impact of baking or extrusion conditions on phytochemical stability, for quantifying polyphenols release from complex food matrices, and for determining the effects of fibre on carbohydrate digestibility. To ensure optimum processability, it is necessary to gather systematic information on how fibre incorporation affects mechanical properties, gas formation and gas holding capacities of the respective batters or doughs. To obtain comprehensive information on properties that can be perceived by the human senses, it is mandatory to perform sensory investigations with both consumer groups and trained sensory analysts using sophisticated and target-group specific methods. The three main topics that are addressed in WP 4 are:

  1. Thermal stability of polyphenols in processed berry pomace.
  2. Microstructural and sensory properties of fibre-enriched products, and processability of batters/doughs.
  3. The influence of processed pomace addition on carbohydrate digestibility and phytochemical bioaccessibility.

WP 5 - Environmental management

To "increase resource efficiency and provide added value in food processing" as requested in the Call for Proposals, workpackage 5 aims at integrating economic and environmental aspects into management decisions, especially an anticipated assessment of resource efficiency for the process design by combining three instruments of environmental management accounting:

  1. Material Flow Cost Accounting
  2. Carbon Footprinting
  3. Life Cycle Cost Analysis

Material Flow Cost Accounting is able to support the redesign of input, waste and side flow strategies by increasing the transparency through visualising material and energy flows with their related costs and internalised environmental impacts. Carbon Footprinting aims at quantifying and communicating emissions data for the whole life cycle of products and coproducts to increase carbon efficiency by customer choices. Finally, Life Cycle Cost Analysis aims at calculating costs over the whole life cycle of a product to optimise the total costs of a product for both producers and customers.
Following these three approaches, the analysis shall be divided into three dedicated parts:

  1. Based on the process model, the material and energy flows and the connected system costs will be displayed from the cradle (i.e., the farm) to the grave (i.e., the disposal). For all steps the connected costs and revenues will be recorded. Based on this information alternatives, process chains will be developed and analysed.
  2. To contribute to a "low-carbon European food and drink sector" as requested in the call, the Carbon Footprint will be calculated over the whole life cycle.
  3. Life Cycle Costs will be recorded for all steps of the production and consumption stages and optimised by adapted production and consumption patterns.