A Study of Force‐compression Conditions Associated With Hardness Evaluation in Several Foods

Abstract

Abstract. The hardness of fourteen foods has been evaluated by panel tests and by compression tests with a table model Instron. Oral evaluation of hardness was correlated with instrumental force ‐% compression data obtained for compressions extending up to 80% and with crosshead speeds up to 20 cm min−1. With soft foods, agreement between panelists' and instrumental data commences at lower % compressions and lower applied forces than with hard foods. As the Instron crosshead speed increases so does the force required to achieve a desired % compression. With very hard foods exhibiting a short relaxation time, e. g. toffee, stress relaxation may influence the registered force. Crosshead speeds exceeding 20 cm min‐1** cannot be utilised in conjunction with the standard Instron recorder because its response time is too long. It should be replaced by a fast response recorder such as a UV recorder. The procedure whereby panelists evaluate hardness during the first downstroke of mastication appears to change from compression to biting as hardness increases. A limited number of tests with Cheddar cheese and table jelly suggest that hardness evaluation by squeezing samples between the thumb and index finger involves lower % compression and lower forces than the oral evaluation of hardness with the same products.

Textural properties of fruit affected by experimental conditions in TPA tests: an RSM approach

“…Qualitatively, this result does not agree with that of . On the other hand, it does agree with those of other researchers (Shama & Sherman, 1973;Boyd & Sherman, 1975;Bourne & Comstock, 1981). Regarding the study of how hardness 1 and hardness 2 are influenced by the degree of deformation within the range 50-90%, Bourne and Comstock proposed a curve that can be broken down into two parts.…”

“…According to some authors, this situation can be explained by a lack of optimisation of this test because test parameters may potentially affect TPA results (Zoon, 1991; Thybo et al , 2000). During the 1970s, crosshead speed had been pointed out as being an important test parameter to be controlled (Shama & Sherman, 1973; Boyd & Sherman, 1975). In addition, in 1981, Bourne and Comstock showed the effect of the degree of deformation on most of the mechanical parameters such as hardness 1, hardness 2, springiness, cohesiveness and gumminess.…”

Bolus Formation and Disintegration during Digestion of Food Carbohydrates

“…Food texture plays a role in the perceived taste of the food (Izutsu and Wani 1985), which could lead to a varying degree of salivary secretion (Mese and Matsuo 2007). The sensory aspect of food texture, as perceived by the individual, has been correlated to laboratory compression measurements in many food products, such as nuts, chocolate, cheese, vegetables (Boyd and Sherman 1975), white pan bread (Gambaro and others 2002), and rye and French bread slices (Brady and Mayer 1985). As the sensory perception of food is important to the food oral processing (Wilkinson and others 2000), food texture is a variable that should be measured when considering the oral digestion of a food.…”

Perception and measurement of food texture: Solid foods

“…Foster et al (2006) also pointed out that the past studies reported contradictory results on the effects of hardness on the mastication frequency which increased or decreased or did not change with increasing hardness, and emphasized the necessity to take into account other mechanical properties. Peyron, Maskawi, Woda, Tanguay, and Lund (1997) pointed out that it is not so simple to find the relationship between the perceived hardness of food although the hardness of food is usually evaluated during the first bite (Boyd & Sherman, 1975;Brandt et al, 1963;Vickers & Christensen, 1980) because the biting can be an isolated voluntary act or the first step of the consecutive masticatory process. Grigoriadis, Johansson, and Trulsson (2014) reported that the number of chewing cycles was larger for hard food (27 6 13.9) than for soft food (21.0 6 9.5) comparing gelatin-based model foods of two different hardnesses.…”