Prolonged food oral processing and slower eating rates are linked to reduced food intake in both younger and older adults(1). Oral processing behaviours are influenced by food texture(2) and in younger adults it has been shown that harder textures are consumed with smaller bites, longer chewing duration and slower eating rates than softer textures(3). Older adults often experience ageing-related changes which affect their eating abilities, and yet the influence of food texture on their oral processing behaviour is under-researched.

This study compared oral processing characteristics, perception of sensory and functional properties, and expected satiation (viewing a 100g portion) in response to different food texture samples across three age groups(4): 18-35 years, (N=19), 70-74 years (N=21) and 75+ years (N=29). Specifically, participants consumed 40 g of a “softer/easier” and a “harder/more challenging” to eat version of two foods: potato and beef. The food samples were mashed potatoes (MP), roast potatoes (RP), minced beef (MB) and roast beef (RB). Consumption was video recorded for behavioural annotation, and analysed for oral processing characteristics (bites, chews, swallows, eating rate, chewing duration). Participants rated each sample for liking, sensory and functional properties and expected satiation. One-way Analysis of Variance was used to compare the three age groups, with post hoc tests identifying group differences.

The results showed that within all age groups, the “softer/easier” foods (MP, MB) required less oral processing than the “harder/more challenging” foods (RP, RB) respectively, and scored lower on sensory attributes, such as dryness and hardness, and higher on the functional attribute of easiness to eat (all p<0.05). When compared to young adults (18-35 years), the 75+ years’ group consumed RB with a slower eating rate [Δ Mean (SD): 5.7 (1.9) g/min, p=0.01), more chews [99 (32), p=0.008) and a longer chewing duration [63.1 (21.8) s, p=0.014). The older adults’ groups (70-74 and 75+ years) consumed RP with more bites and rated expected satiation for RP and MB significantly higher than the young adults (p<0.05). Sensory and liking ratings did not differ across age groups.

These findings demonstrate significant variability in oral processing behaviours across different food textures and age groups. Further research is needed to confirm that these age-related differences in oral processing remain when consuming a meal, and to understand whether these differences influence food intake and satiety. As current research in older adults’ eating abilities and behaviours is limited, these results can provide useful ground for designing appropriate dietary interventions and food products that could improve older adults’ food and nutrient intakes.