Potato Review

44 POTATO REVIEW MARCH/APRIL 2021 STORAGE AND SUSTAINABILITY The ‘live’ debate Science and storage specialists discuss integrated store management, the need to sustain the lifespan of fresh potatoes and advancing defect detection. T HE Natural Resources Institute is on a mission to reduce the amount of fresh produce wasted between eld, supermarket and home, and his sights were rmly set on ‘living’ potatoes at a recent Agri-TechE event. Speaking at the event, which looked at halting disease processes in fresh produce, Debbie Rees, Principal Scientist with NRI, said: “Storage of unprocessed fresh produce is a particular challenge because it is living. If you process vegetables into soup, it is not living, but when we place potato tubers into storage, they are living organisms, responding to the storage environment, even if most people don’t tend to think of them like that.” She said the NRI was interested in anything that allowed its team to monitor and sustain the lifespan of fresh produce without harming it. As we all know, sprouting of potato tubers in storage is a major concern for store managers, particularly now that chlorpropham (CIPC) has been withdrawn and the alternatives currently available are not seen as being so e ective. Sprouting a ects the downstream value of the potato – whether that’s in processing where sprouts need to be removed prior to processing, or the fresh pack sector – because visually they a ect consumer demand. Debbie emphasised that if left untreated, sprout growth will cause water and weight loss as the potato respires and grows, reduction in processing quality and reduction in weight-at-sale by 2-3%, stressing how important it is to keep sprout growth under control during storage. e team at the Natural Resources Institute have been involved in many projects focused on potato sprout control over the past few years. ese have been in collaboration with other potato research groups around the UK, and in particular with Sutton Bridge Crop Storage Research and the James Hutton Institute. Continuous application of ethylene during storage, one available alternative to CIPC, has many limitations, Debbie said. “For example, varietal variability in ethylene sensitivity means that most varieties need to be held at low temperature for e ective sprout control, which impairs processing quality. In addition to this, ethylene can induce increased respiration and sugar accumulation in some varieties, which also leads them to be unacceptable for processors as sugar accumulation causes fried products to become unacceptably dark, and also increases the risk of acrylamide formation.” NRI coordinated a DEFRA funded project “From an integrated store management perspective, more work is needed to help growers integrate that data more seamlessly.” Dr Laura Bouvet, Knowledge and Innovation Facilitator, Agri-TechE (2011 – 2015) which attempted to address some of the issues with ethylene use. e project followed two approaches. e rst was to understand what makes a potato sensitive to the positive e ects of ethylene (control of sprout growth), by comparing ‘responders’ with those that show no response (continue to sprout in its presence), with the aim of identifying the key potato genes involved. e second approach was to develop acceptable storage strategies by combining ethylene treatment with other chemicals. e team at Sutton Bridge Crop Storage Research continued this work after the main project ended. Debbie said: “In our research group we are working on ways to monitor produce in storage, to pick up stress or changes in metabolic status by following the characteristics of respiration. All fresh produce continues to breath in storage. We measure respiration by looking at changes in the concentration of CO 2 and O 2 in a chamber that can be momentarily sealed.” As an example the Natural Resources Institute is currently working with Sutton Bridge Crop Storage Research and Storage Control Systems Ltd on a project with the aim to monitor potato tuber respiratory characteristics within stores as a means of detecting the physiological changes relating to both initiation of sprouting and quality deterioration. e ultimate rationale of the P-Pod technology being developed is to evolve accurate in-store real-time monitoring to allowmore e cient storage protocols, so that existing sprout control methods can be more e ective. Joined-up approach needed Reducing waste in fresh produce needs a joined-up approach, those at the event were told. Agri-TechE is a membership organisation that is bringing together forward- thinking farmers, growers, researchers and