Investigating The Bioactive Properties of Cheese-Fruit Combinations Following In Vitro Digestion Using an Elderly Model.

Abstract

The prevalence of disease in older adults is increasing, thus there is a need to develop functional foods for this cohort that can promote healthy aging. This study analyzed cheese combined with fruit to identify if certain cheese-fruit combinations improved the bioactive properties of the cheese. Feta, Reduced-Fat Red Cheddar (RFRC), and Goat’s cheese were combined with different fruit (goji berries, red pepper, or blackberries) and digested with a simulated gastrointestinal in vitro digestion model representative of older adults. Antioxidant potential was investigated using DPPH radical scavenging, Ferric reducing antioxidant power (FRAP) and Total phenolic content (TPC) assays. The ability of samples to inhibit digestive enzymes was determined using the α-glucosidase inhibition assay. Antimicrobial activity against Listeria monocytogenes, Group B Streptococcus and Escherichia coli was investigated by the disc diffusion method. Immunomodulatory potential of the digestates was evaluated by their ability to modulate TNF-α levels in stimulated Jurkat T cells. Results demonstrated that combining RFRC with all fruit significantly (p<0.05) increased both the antioxidant and α-glucosidase inhibitory potential of the cheese (≥90.6% DPPH inhibition, ≥980.5 FRAP µmol Fe2+/kg.fw, and ≥58.1% α-glucosidase inhibition). Reducing potential of all cheese significantly (p<0.05) increased when combined with fruit (≥977.0 FRAP µmol Fe2+/kg.fw). Group B Streptococcus was inhibited by cheese-fruit combinations containing feta and goat’s cheese. Combining fruit with feta altered the immunomodulatory potential of the cheese by significantly (p<0.05) decreasing TNF-α secretion by ≥41%, compared to the control. Novel cheese-fruit combinations that promote synergistic bioactive properties could help design functional foods for older adults that promote healthy aging.