Sensory evaluation of new lines of oca (Oxalis tuberosa) grown in New Zealand

Five new and one local cultivar of oca or New Zealand yam (Oxalis tuberosa) were evaluated by a consumer-type panel for appearance, flesh colour, flav our, texture and overall acceptability of raw, steamed and baked tubers. Th e intensity, 'just right' or liking scores were analysed using the proporti onal odds model. Skin and flesh colour of tubers were also measured objecti vely using a colorimeter. For raw oca, panellists preferred bright red tube rs, but size was also important. Flesh colour, bitterness and mealiness wer e important variables which described the overall acceptability of steamed oca, while only flesh colour and bitterness were important variables for ba ked oca. Cultivars which had flesh colour described as 'bright yellow', fla vour as 'no bitter taste', and a very slightly mealy' texture were more pre ferred. Cultivars with higher yellow/blue (b*) and chroma (c*) values for c ooked tuber skin and flesh colours were more acceptable. (C) 2000 Elsevier Science Ltd. All rights reserved.