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AFM260Br - Detection of the presence of insects or other pests in prepared salad products - FT1552

Metal detectors and X-ray scanners are established technology which can effectively recognise foreign bodies on the basis of electrical properties or density. There are however no effective in-line techniques to detect foreign bodies such as insects, wood and plastics. The dietary imperative to increase fruit and vegetable consumption has put new focus on the consumer acceptability of fresh fruit and vegetable produce, including elimination of insects from fruit and vegetable crops, a task made more important by the concomitant consumer pressure to reduce pesticide use. The most challenging task is perhaps the detection of insect fragments in bagged leaf salads.

A technical solution to this challenging problem is proposed based on an existing, highly successful, method of measuring small quantities of contaminants in the atmosphere. For atmospheric measurements the technique, known as LIDAR (LIght Detection And Ranging), has been used for many years to detect contaminants at parts per million or parts per billion levels. This proposal takes the existing, established method in air and seeks to adapt it for measurement of salad leaves.

By careful selection of measurement protocols it will be possible to design a method to detect the presence of undesirable insect contamination within salad leaves, since the capabilities of the technique will operate in this application to detect a very small contaminant in a large quantity of leafy matter. To prove this theory the characteristics of common insects, salad materials and packaging will be evaluated in order to identify exactly which conditions are required to build a successful instrument. The testing process will be fast, automated, and could be used to check the product after the bag had been filled.

If the approach is successful in this application then there is potential for the same technique to be applied in a variety of other situations where small quantities of contaminants must be detected within other materials.
1) Provide samples of and measure the Raman spectral characteristic of approximately 10 insects and common pests (and casual intruders) of salad crops (Month 1 and 2)
2) Measure the Raman spectral characteristics of the leaves approximately 6 salad crop varieties, including the common baby leaf salad varieties with both red and green hue leaf types and both leafy and more stalky species (Month 2)
3) Measure the Raman spectral characteristics of packaging materials used to package the salad, including printed samples to enable evaluation of both packaging and printing ink as potential interferents (Month 1)
4) Analyse the spectra of the contaminants, salads and packaging to identify a frequency or frequencies at which measurements could be made for contaminant detection, assess the method's ability to identify contaminants and avoid false positives. (Month 2)
5) Agree a plan for designing a prototype instrument (For follow-on project) (Month 3)

Project Documents
• Final Report : No Final Report   (26k)
• Executive Summary : Detection of the Presence of Insects or other Pests in Prepared Salad Products   (31k)
Time-Scale and Cost
From: 2007

To: 2007

Cost: £24,915
Contractor / Funded Organisations
University - East Anglia, Food Processing Faraday Partnership, University - Scottish Agricultural College
Food and Drink              
Food Industry Sustainability Strategy              
Food manufacturing industry              
Food Quality              
Manufacturing Efficiency              
Fields of Study
Resource Efficient and Resilient Food Chain