Making sense of food

Eyes, nose and fingertips are the common means by which consumers assess the quality of food in the shops. For both the consumer and food producer, it is essential that fresh food reaches the selling point at the proper stage of maturity. Clearly, producers cannot control the quality of large quantities of food through sensory evaluation - by looking, smelling and touching the products.

A recently completed European project investigated ways to improve the methods and equipment for measuring and controlling internal and external flaws, odours and tastes of fruit and vegetables. The project lasted three years and brought together 19 research institutes and industrialists from nine different countries.

The methods considered most adapted to this goal were based on vision, imaging and aroma sensing techniques.

The quality of apples was the most intensively studied subject. Picking date and aromatic quality could be evaluated by using instruments called the electronic noses. To predict water losses during storage, the apples' fine wax layer structure was "photographed". The hardness and juiciness of the fruit were determined by ultrasonic measurements.

For pears, a method was developed for detecting internal defects, while for tomatoes, a merchandise recognised as difficult to handle, European scientists set up a method to assess their susceptibility to puncture injury.

The scientists concluded, in a statement released this week, that in the future, the consumer's risk of buying second-class products will diminish thanks to a wide selection of sensing techniques for quality control and safe development of tasty and more nutritious novel foods.

Further information about the above European project can be obtained from the project co-ordinator: Professor Douglas Neil Rutledge, Institut National Agronomique Paris-Grignon, Laboratoire de Chimie Analytique, 16, rue Claude Bernard 75231, Paris, France.