1. Department of Crop Science; School of Agricultural, Earth and Environmental Sciences; University of KwaZulu-Natal; Private Bag X01, Scottsville 3209 Pietermaritzburg South Africa
2. Postharvest Technology Research Laboratory; Department of Horticultural Science; Stellenbosch University; Stellenbosch 7602 South Africa
3. Postharvest Technology Research Laboratory; Department of Food Science; South African Research Chair in Postharvest Technology; Stellenbosch University; Stellenbosch 7602 South Africa
4. Citrus Research International; Department of Horticultural Science; Stellenbosch University; Stellenbosch 7602 South Africa
5. Plant Science Laboratory; Cranfield University; Bedfordshire MK43 0AL UK