Date of Award

3-10-2025

Document Type

Doctoral Thesis

Degree Name

Doctor of Philosophy

First Advisor

Dr. Fiona O'Halloran

Second Advisor

Dr. Aoife McCarthy

Abstract

Functional foods for the elderly: comparing the bioactive properties of cheese to identify products that promote healthy ageing.

People are living longer, and a healthy ageing population is a key goal of our National Positive Ageing Strategy. One approach to support this initiative is to promote and develop functional foods that can support healthy ageing by reducing age-related conditions, including cardiovascular disease, diabetes, obesity and cancer. Cheese particularly aged and fermented varieties like cheddar show great potential as a functional food with inherent and established health properties. It naturally contains bioactive peptides, vitamins, minerals, protein and possible cultures that confer health benefits beyond basic nutrition. Furthermore, these health-promoting properties can be enhanced by incorporating ingredients such as fruit, resulting in a healthier cheese product tailored to the needs of a specific target population. This project focused on the potential of cheese as a functional food to promote healthy ageing. Despite the significance of an ageing population there is no universal definition for older adults. Most healthcare, government policies and statistical reports define older adults as those age 65 and over. With age, physiological changes can influence how we digest food and thus, how nutrients and bioactives are released from a food matrix. Studies investigating how the physiological changes associated with ageing affect the release of potential bioactives from cheese are limited. In addition, understanding older adult consumer needs and preferences in terms of taste and texture is important for the success of any functional food in this cohort. Commercial cheese products were selected to represent cheese with different textures and fat content, as it has previously been reported that cheese varying in texture and fat content have different digestibility rates. Products were digested using both adult and elderly simulated gastrointestinal in vitro digestion (SGID) models. Digestates generated with the elderly SGID model had significantly lower (p < 0.05) antioxidant and antidiabetic properties compared to adult cheese digestates. To potentially enhance the bioactivity of cheese for older adults, cheese-fruit combinations were investigated. Cheese and fruit offer complementary flavours, textures and nutritional benefits. Furthermore, cheese and fruit are both accessible, versatile and culturally integrated. The addition of goji berries, red peppers and blackberries influenced bioactivity by significantly improving (p < 0.05) the immunomodulatory, antioxidant, antimicrobial and antidiabetic potential of certain cheese types, particularly reduced fat red cheddar. As part of this project new product development involved manufacturing cheese products that were enhanced with fruit and investigated for their acceptability among older adults as well as their bioactive properties. Overall, no significant difference (p > 0.05) was observed with regards to acceptability of plain cheese and the new fruit-enriched cheese products. The bioactivity of the fruit-fortified cheese was investigated and fortified cheese had significantly greater (p < 0.05) antioxidant and antidiabetic properties compared to plain cheese and these properties were stable during storage. Age-related changes in the GIT can alter the bioactive properties of cheese. However, fruit-fortified cheese products can improve the bioactive potential and health promoting properties of certain cheese types and are accepted by older adult consumers. RFRC is a widely consumed cheese and when fortified with fruit has potential as a functional food for the older population, providing essential nutrients, fibre and a variety of bioactive compounds that can support healthy ageing.

Access Level

info:eu-repo/semantics/openAccess

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