The Effects of Genetic Transformation of Tomato with Antisense Phospholipase D cDNA on the Quality Characteristics of Fruits and Their Processed Products

Abstract

The physico-chemical characteristics of tomato juice and sauce, prepared from transgenic tomato fruits (Lycopersicon esculentum Mill, var. Celebrity) transformed with an antisense phospholipase D (PLD) cDNA construct, were evaluated. The antisense transformation resulted in a 30–40% reduction of PLD activity in ripe fruits. The transgenic fruits were firmer, possessed better red color, and flavor. The juice and sauce preparations from transgenic fruits showed improved red color, lycopene content, Brookfield viscosity, and increased levels of major flavor volatiles such as hexenal. The dry matter and ash contents, as well as the precipitate weight ratio (PPT) of the transgenic fruit products were significantly higher when compared to the products from control fruits. The vitamin C content of the transgenic fruits was also higher as compared to the control fruits. The results suggest that a reduction in PLD activity may lead to increased membrane stability and preservation of membrane compartmentalization that can have positive quality impacts in transgenic fruits and their products.

Keywords:

• Lycopersicon esculentum mill
• Lycopene
• Membrane
• Quality attributes
• Sedimentation stability
• Volatiles

Acknowledgments

We are grateful to Ms. Valsala Kallidumbil and Ms. Ramany Paliyath for helping with the maintenance of plants and expert technical assistance. Financial support for this research was provided by the Food System Biotechnology Centre, University of Guelph, the Ontario Ministry of Agriculture and Food, Natural Sciences and Engineering Research Council of Canada, and Foragen Technologies Management Inc. Guelph.