title: Sensory and instrumental texture assessment of roasted pistachio nut/kernel by partial least square (PLS) regression analysis: effect of roasting conditions.
abstract: Roasting is an important step in the processing of pistachio nuts. The effect of hot air roasting temperature (90, 120 and 150 °C), time (20, 35 and 50 min) and air velocity (0.5, 1.5 and 2.5 m/s) on textural and sensory characteristics of pistachio nuts and kernels were investigated. The results showed that increasing the roasting temperature decreased the fracture force (82-25.54 N), instrumental hardness (82.76-37.59 N), apparent modulus of elasticity (47-21.22 N/s), compressive energy (280.73-101.18 N.s) and increased amount of bitterness (1-2.5) and the hardness score (6-8.40) of pistachio kernels. Higher roasting time improved the flavor of samples. The results of the consumer test showed that the roasted pistachio kernels have good acceptability for flavor (score 5.83-8.40), color (score 7.20-8.40) and hardness (score 6-8.40) acceptance. Moreover, Partial Least Square (PLS) analysis of instrumental and sensory data provided important information for the correlation of objective and subjective properties. The univariate analysis showed that over 93.87 % of the variation in sensory hardness and almost 87 % of the variation in sensory acceptability could be explained by instrumental texture properties.
authors.affiliation: Department of Food Science and Technology, Ferdowsi University of Mashhad (FUM), POBox: 91775-1163, Mashhad, Khorasan Razavi Iran.
authors.forename: Toktam
authors.initials: T
authors.lastname: Mohammadi Moghaddam
authors.affiliation: Department of Food Science and Technology, Ferdowsi University of Mashhad (FUM), POBox: 91775-1163, Mashhad, Khorasan Razavi Iran.
authors.forename: Seyed M A
authors.initials: SM
authors.lastname: Razavi
authors.affiliation: Department of Food Science and Technology, Ferdowsi University of Mashhad (FUM), POBox: 91775-1163, Mashhad, Khorasan Razavi Iran.
authors.forename: Masoud
authors.initials: M
authors.lastname: Taghizadeh
authors.affiliation: Department of Medical Physics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Khorasan Razavi Iran.
authors.forename: Ameneh
authors.initials: A
authors.lastname: Sazgarnia
keywords: Hardness; Pistachio; Roasting; Sensory evaluation; Texture