Effect of time and temperature of storage after cooking on the sensory quality of bintje potatoes

Abstract

AbstractSeventeen trained judges used a scoring technique with nine‐point scales to evaluate sensory attributes of cooked potatoes (variety: Bintje) that had been kept hot after cooking for different lengths of time at different temperatures. Maximal storage times before the potatoes were considered unacceptable were determined for each temperature. In addition, comparisons were made with preference data obtained for 55 untrained consumers. For all sensory attributes significant differences in average scores were obtained among samples stored for different periods of time (0, 1, 2, 3 and 4 h) and different temperatures (60, 75 and 90°C), as well as significant interactions between time and temperature. In general the effect of time was largest at the highest temperature. The differences were largest for flavour and smallest for appearance. The maximum times the potatoes could be kept at 60, 75 and 90°C before becoming unacceptable in flavour were 2.9, 2.2 and 1.3 h, respectively. The corresponding values for texture and appearance were higher. Generally potatoes that had been kept hot were described as ‘dark, greyish or brownish, and dry on the surface', and having a 'strong and musty odour; musty, old and bitter flavour, and watery, soggy, and spongy texture ’For 55 untrained consumers, (highly) significant differences were obtained in preference frequencies for appearance, flavour, and texture for pairs of samples stored after cooking at 75°C for different periods of time. The differences were largest for flavour, and smallest for appearance. Generally, the freshly prepared sample was preferred, and the difference in preference increased with increased storage time. The results from the untrained consumers are in close agreement with the results obtained by the trained panel. It was concluded that consumers in general also consider the sensory changes of keeping potatoes hot after cooking as deleterious, and that the unacceptability limits determined by the trained panel were not unreasonably small.