The effect of sample temperature on instrumental and sensory properties of mashed potato products

The effect of sample temperature on texture, firmness and the sensory attributes of fresh and frozen/thawed natural and commercial mashed potatoes was studied. Scanning electron microscopy was used to obtain information on the structure of potato cells and how this is affected by processing. Various parameters were measured and were found to increase at 55 °C, these changes could be related to gelatinisation of the starch remaining in the products. In natural mashed potato, texture profile analysis (TPA) and firmness parameters were lower in the processed than in the fresh samples, indicating a weakening of the structure; this was confirmed by photomicrographs. In commercial mashed potato, TPA parameters measured at 55 and 65 °C and firmness parameters measured at 25 °C were higher in the processed samples, indicating enhanced structural strength; this was confirmed by photomicrographs. Firmness per gram of product was the best instrumental parameter for measuring texture in these products. The results of the different analyses indicated that 55 °C was the preferred temperature for consumption of mashed potatoes.