The review, published in the Journal of Texture Studies, focuses on the interplay between the physical properties of hard solid foods and oral processing, in relation to the perception of texture attributes.
The authors said that in the future existing knowledge about these interactions should be combined better with knowledge on how texture stimuli are evaluated in the oral cavity and processed in the brain to come assessments of texture perception and pleasantness.
“It has become more and more clear that texture perception by consumers of hard solid (brittle) foods is based on the interplay between product structure, fracture behaviour, oral processing and final grading by the brain,” said the researchers, led by Dr. Ton van Vliet, of TI Food and Nutrition and Wageningen University and Research Centre.
“Better understanding of the relations between these aspects is essential for the production of healthy, tasteful food that is liked by consumers,” they added.
Sensing solids
Dr. van Vliet and colleagues said the perception of texture attributes is based on the interplay between important physical, and in certain cases chemical, characteristics of food.
They noted that hard solid foods include a large array of dry products, and ‘wet’ products. Most hard foods have a cellular structure, which the reviewers explained is generally characterized by rigid connected cell walls enclosing a fluid material, which may be liquid-like (like in fruit and vegetables) or a gas (mainly in manufactured foods).
“In general, to understand the perception of texture attributes one should at least have a thorough understanding of the relevant physical properties of the food … (food physics), the way it is processed in the mouth (oral physiology) and how the perceived stimuli are integrated in the brain leading to conscious perception of the sensory attribute (sensory science),” said van Vliet and his co workers.
To advance understanding of texture perception, they said that knowledge from the disciplines of physical chemistry, oral physiology, and sensory science has to be integrated.
Interplay
Some of the most important texture attributes of hard products include: hardness, brittleness, crispness, crunchiness, and toughness. In addition to this juiciness in important ‘wet’ solid foods like fruits and vegetables, whilst drying is important for dry products, and rate of dissolving is key for hard candy foods.
The researchers said that in spite of the obvious differences between the different types of solid foods, all product groups’ rate crispness and hardness as important texture attributes, though they noted that the sensory perception of crispness is far better understood for dry materials than for ‘wet’ materials.
Dr van Vliet and colleagues said that understanding of the relationship between product morphology and fracture behaviour for solid foods has been developed enough to be incorporated “in a profound way in studies on their behaviour during oral manipulation.”
“To our opinion studies of both groups of materials [wet and dry solids] could benefit from studies on the other group of materials regarding basic aspects of their fracture behaviour, oral physiological aspects and brain processing of the texture stimuli registered by the senses,” they said.
“In order to come to a more profound understanding of the texture perception of both dry and wet cellular food products, the interplay between product morphology, fracture behaviour, oral physiology and texture perception needs to be studied more thoroughly than has been done in the past.”
Source: Journal of Texture Studies
Published online ahead of print, doi: 10.1111/j.1745-4603.2010.00273.x
“Interplay between product characteristics, oral physiology and texture perception of cellular brittle foods”
Authors: T. van Vliet, C. Primo-Martin