Some studies have shown that certain vegetables grown at high northern latitudes with cool summers, long photoperiods and special solar radiation develop different quality than vegetables grown in the south.
However, very little is known about how Brassica vegetables respond to different climatic conditions in a north-south gradient. In a world with a growing population and shortage of arable lands, it is important to utilise also cold regions for horticulture.
This project will investigate the effects of preharvest light and temperature in a northern climate on quality and bioactivity of health promoting substances of Brassica vegetables, primarily for broccoli with kale and wild cabbage as references. The preharvest quality produced in various climates will be monitored in postharvest experiments with light and temperature relevant to the commercial distribution of vegetables. The focus will be effects on health and flavour related constituents, i.e. phenolics, glucosinolates, carotenoids, vitamin C, fatty acids and sugars.
Descriptive sensory analysis by a trained panel will be carried out, and a consumer preference test will be run on the samples with the most divergent sensory attributes. In addition, differences in bioactivity will be exploited using different in vitro antioxidant capacity assays and cell cultures.
To gain knowledge on the molecular mechanisms of quality change, biotechnological methods will be used to pinpoint up- and down regulation of gene expression and enzymes in the product upon selected treatments. The integrated approach, including the whole value chain, support from two main commercial distributors and participation of all the three main Norwegian institutions for research on cultivated plants, is unique. In addition, high-rating research institutes in USA and UK will be involved. The project supports the aims of the research council strategy for the Northern areas (forskning.nord).
Objectives
- The main objective of the project is to create a knowledge base for increased production, value and availability of vegetables with preferred quality in Norway. The project will
- Determine how health related properties of selected Brassica vegetables are influenced by selected
- External factors through the value chain from producer to consumer.
Subgoals
• Evaluate sensory quality and consumer preferences concerning Brassica vegetables grown in Norway
- Determine effects of preharvest factors related to northern climate on bioactivity and sensory quality of Brassica vegetables
- Determine effects of postharvest conditions on bioactivity and sensory quality of Brassica vegetables grown in different ways according to Subgoal 2
- Study the metabolism of health and sensory related components in Brassica vegetables relevant to Subgoal 2-3
- Study bioactivity of Brassica vegetables and selected components thereof relevant to Subgoal 2-3
Research tasks
The project aims to increase the production, value and availability of vegetables with optimal quality in Norway. The most central research tasks in this project is to evaluate the possibilities for growth of selected Brassica vegetables in the northern part of Norway and to investigate how quality characteristics of Brassica vegetables are regulated in response to external factors. The project uses an integrated approach, combining controlled climate conditions, advanced chemical analyses, biomolecular methods and bioactivity experiments. This is a novel approach that, to our knowledge, has not been previously used in similar studies.
Delimitations
The project will be limited to selected cultivars of Brassica oleracea. Broccoli will be the major product of interest, whereas curly kale and wild cabbage will be used as reference and model plants in parts of the project. The project will focus on fresh, whole vegetables, not cut or mixed vegetables. Climate conditions investigated (pre- and postharvest) will be limited to temperature and light exposure. Sensory profiling, consumer preference tests and bioactivity studies will be carried out on samples from the growing conditions giving the largest differences in quality.
Doctoral and postdoctoral fellowships
The project will engage one doctoral fellow that will focus on postharvest factors (positioned at UMB) and two postdoctoral fellows; one that will focus on preharvest factors (positioned at Bioforsk in Tromsø) and one that will focus on metabolomic and bioactivity studies (positioned at Matforsk).
Tasks in Subgoal 1 (Consumer)
Describe sensory profile of the varieties grown at the various locations south and north of Norway in addition to an imported sample.
Perform consumer test revealing preferences for the various samples with and without information about the origin and health values of the samples as well as costs.
Tasks in Subgoal 2 (Preharvest factors)
How does contrasting latitudinal light climates affect the content of health promoting components of selected vegetables?
How does the temperature at contrasting latitudinal sites affect the content of health promoting components of selected vegetables?
How does exposure to freezing temperatures affect the phytochemical content of selected vegetables?
Tasks in Subgoal 3 (Postharvest factors)
Map the variations in temperature and light exposure during postharvest handling in Norway.
Determine the effects of postharvest conditions (light, temperature) on quality characteristics of Brassica vegetables produced at different latitudes.
Tasks in Subgoal 4 (Metabolism)
Increase the knowledge on the regulation of health and sensory related components of Brassica vegetables
Establish whether the biosynthesis and degradation of the investigated components may be co-ordinated
Tasks in Subgoal 5 (Bioactivity)
Investigate the effects of pre- and postharvest factors on the bioactivity of Brassica vegetables
Determine the contribution of the various plant components to the bioactivity of Brassica vegetables
Project organisation and management
The project is based on collaboration between the Norwegian Institute for Agricultural and Environmental Research (Bioforsk), the Norwegian University of Life Sciences (UMB), the Norwegian Food Research Institute (Matforsk), Bama Gruppen AS (Bama), A.L. Gartnerhallen (GH) and COOP. Bioforsk will be responsible for the preharvest experiments, UMB for the postharvest experiments and Matforsk for the consumer, metabolism and bioactivity studies. Bama, GH and COOP will participate in the mapping of postharvest conditions through the value chain. A project steering committee with representatives from the active partners will be responsible for the progress and strategic decisions during the project period.
Importance to Norwegian industry
An elevated production of vegetables with documented health effects will increase the profitability in the whole value chain - from farmers to distributors.
In a world with a growing population and many national recommendations of an increased per capita intake of vegetables, an increased production of high quality vegetables is necessary. Norway is exporting cauliflower and broccoli to southern Europe in the summer when it is too warm to grow this vegetables there. By documenting the effects of climate on vegetables, an increased export may be expected.
