| Summary: | Sustainability and health within food manufacture is high on the agenda of many food companies, without compromising the quality or nutritional value of the products. The use of fruit and vegetables as a source of raw materials to replace in whole or in part some of the current 'white powder' ingredients within food products is one of the ways this can be achieved. The aim of this work was to investigate the relationship between fruit cell wall structure and functionality in frozen food products such as ice cream either as a structuring agent in puree form or as whole fruit pieces. The two stands of this project were investigated by screening populations of tomato; the accepted model for studies on fleshy fruit. These included a set of 76 Solarium pennellii introgression lines, five genetically modified lines with reduced levels of specific cell wall enzymes, and several naturally occurring ripening mutants. An initial high throughput screen was used to elucidate extremes of the populations for structuring (puree) and structural (frozen texture) traits. Selected lines were then used to identify the biochemical and genetic basis for the enhanced frozen properties. Lines with improved ice cream structuring properties were found in both the introgression and ripening mutant sets. The mechanism behind improved structuring was found to be a physical trait linked to the type and size of solids in both parental backgrounds. The ratio of the cell wall enzymes polygalacturonase and pectin methylesterase, directly influenced the frozen and thawed texture of fruit pieces. However, the parental background had a bigger influence upon frozen texture than the effects of the levels of cell wall enzymes on the tissue ultrastructure.
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