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Defining quality assurance for sweet onions with rapid Biosensor analysis - HL0164LFV

Aim of Initiative To develop state-of-the-art flavour sensing quality assurance technology; to put the UK onion industry at the forefront in the developing sweet/mild onion market.¨ Scientifically – to develop an understanding of the biochemical nature of sweetness in onions and it’s interaction with agronomy. To develop a hand-held prototype ‘grower friendly’ biosensor using existing knowledge of chemical markers for pungency and new markers for sweetness to be identified in the project.¨ Commercially - Post-link, to produce and sell the device around the world. To reliably expand the UK market for sweet onions.Commercial and Technical BackgroundHortLink 186 “Fundamentals for Mild Onion production” has resulted in the formation of a Sweet Onion Development Group and launch through J.S. and Safeway of the “Supasweet” (Trademark) onion which, was identified during the project. J.S. have also implemented 12 month supply in their taste the difference range. .The flavour protocol demands a pyruvate score <5.0, there is no determination of sweetnessStandardisation of both strength and sweetness is needed. Pyruvate test takes a week @ £20-30 per analysis, added sweetness analysis will complicate what urgently needs to be a rapid packhouse or field based test. Work with biosensors at Cranfield University (from the medical sector), already proven for harvest ripeness in pineapple would revolutionise pyruvate analysis costing much less than a laboratory analysis and to which sweetness could be easily added.The Problem/OpportunityOnions are sold Worldwide in the Mild category as Mild or Mild / Sweet or Sweet. The pyruvate test, as shown by HortLink 186 from correlation with taste panels, can now be an acceptable standard for strength (i.e. Mild vs. Strong).· The problem is that Mild onions can be sweet or very bland. HortLink 186 (unexpectedly) concluded there was no market (in the UK) for a Mild onion per se, demand was either for a Mild Sweet onion to be eaten fresh uncooked or for a stronger “cooking” onion.· The opportunity is to revolutionise the onion market with clearly defined parameters and rapid measurement of both sweetness and strength. There is a major worldwide opportunity for marketing of the system, for pyruvate alone, replacing the current confusion of ad hoc systems with a simpler cheaper standard, and more so if sweetness is added. Scientific BackgroundHortLink 186 – demonstrated that mildness is a prerequisite for sweetness but the biochemical basis of sweetness is not understood. Sweetness is probably relatively complex and due to low levels of sweetness inhibitors, low levels of bitter compounds and possibly more other sweet tasting compounds. Hence there is a need to screen a large number of biomolecules which can be achieved using HPLC-MS and GC-MS. Recent work at Cranfield has used biosensor technology to measure a number of compounds in horticultural produce. In one case pyruvate was an intermediate reaction product hence there is confidence that this technology can be used to measure pyruvate in onions. A successful device for assessing the ripeness of pineapple has been produced, the information from this project can be found in Annex C.Scientific Approach

Project Documents
• Abstract : Defining quality assurance for sweet onions with rapid biosensor analysis   (23k)
Time-Scale and Cost
From: 2003

To: 2006

Cost: £300,799
Contractor / Funded Organisations
Applied Enzyme Technology Ltd, Allium and Brassica Centre Limited, Tesco Stores Plc, Rustler Produce Ltd, F B Parrish & Son, G Marketing, Waitrose Ltd, Gwent Electronic Materials, Moulton Bulb Company Ltd, Sainsbury's Supermarket Ltd, Bedfordshire Growers Ltd, University, Cranfield - Institute of Bioscience and Technology
Crop Improvement              
Sustainable Farming and Food              
Fields of Study