Archive

Research Area: Nutrient and Bioactive Composition

Upcycling commercial nut byproducts for food, nutraceutical, and pharmaceutical applications: A comprehensive review.

Alasalvar, C., G. Huang, B.W. Bolling, P.A. Jantip, R.B. Pegg, X.K. Wong, S.K. Chang, E. Pelvan, A.C. de Camargo, G. Mandalari, A. Hossain, F. Shahidi, 2025. Upcycling commercial nut byproducts for food, nutraceutical, and pharmaceutical applications: A comprehensive review. Food Chem. 467:142222. https://doi.org/10.1016/j.foodchem.2024.142222

This article presents a comprehensive overview of upcycling commercial nut byproducts (such as almond, Brazil nut, cashew, hazelnut, macadamia, peanut (also known as a legume), pecan, pine nut, pistachio, and walnut) for food, nutraceutical, and pharmaceutical applications. Upcycling nut byproducts, namely husk/hull, hard shell, brown skin, defatted flour/meal/cake, pine cone, cashew nut shell liquid, cashew apple, walnut septum, and dreg/okara, has great potential, not only to reduce/minimise waste, but also to fit within the circular economy concept. Each byproduct has its own unique functional properties, which can bring significant value. These byproducts can be used as value-added ingredients to promote better health and well-being, due to their rich sources of diverse bioactive components/phytochemicals, polysaccharides, fibre, lignin, prebiotics, oils, proteins, bioactive peptides, minerals, and vitamins, among other components. This comprehensive review provides a basis for future research and development of product applications for nut byproducts. More studies are needed on novel product development to valorise nut byproducts.

Correlation between intestinal microbiota and urolithin metabolism in a human walnut dietary intervention.

Liu H, Birk JW, Provatas AA, Vaziri H, Fan N, Rosenberg DW, Gharaibeh RZ, Jobin C, 2024. Correlation between intestinal microbiota and urolithin metabolism in a human walnut dietary intervention. BMC Microbiol. 24(1):1–10. https://doi.org/10.1186/s12866-024-03626-5

This study is to investigate the relationship between the intestinal microbiota and urine levels of the ellagic acid derived polyphenols, the urolithins, in a cohort of subjects following a three-week walnut dietary intervention. We longitudinally collected fecal and urine samples from 39 subjects before and after walnut consumption (2 oz per day for 21 days). 16S RNA gene sequencing was performed on fecal DNA to study the association between microbiota composition and the levels of nine urolithin metabolites, which were measured using UHPLC/Q-TOF–MS/MS. Fecal microbial composition was found to be significantly different between pre- and post-walnut intervention (beta diversity, FDR-p = 0.018; alpha diversity, p = 0.018). Roseburia, Rothia, Parasutterella, Lachnospiraceae UCG-004, Butyricicoccus, Bilophila, Eubacterium eligens, Lachnospiraceae UCG-001, Gordonibacter, Paraprevotella, Lachnospira, Ruminococcus torques, and Sutterella were identified as the 13 most significantly enriched genera after daily intake of walnuts. We observed 26 genera that were significantly associated with 7 urolithin metabolites, with 22 genera positively correlating after walnut supplementation (FDR-p ≤ 0.05). PICRUSt analysis showed that several inferred KEGG orthologs were associated with 4 urolithin metabolites after walnut intake. In this study, we found that walnut supplementation altered urolithin metabolites, which associates with specific changes in bacterial taxa and inferred functional contents.

Particle size distribution and predicted lipid bioaccessibility of almonds and the effect of almond processing: a randomised mastication study in healthy adults.

Creedon, A.C., E.S. Hung, E. Dimidi, T. Grassby, S.E. Berry, K. Whelan, 2023. Particle size distribution and predicted lipid bioaccessibility of almonds and the effect of almond processing: a randomised mastication study in healthy adults. Nutrients. 15(3):489. https://doi.org/10.3390/nu15030489

Almonds are rich in unsaturated lipids, which play a role in some of the reported benefits of almond consumption for human health. Almond lipids are poorly bioaccessible due to almonds’ unique physicochemical properties that influence particle size distribution (PSD) following mastication, allowing much intracellular lipid to escape digestion in the upper gastrointestinal tract. To investigate the impact of commercial processing (grinding almonds into flour), on PSD and predicted lipid bioaccessibility following mastication, a randomised cross-over design mastication study was conducted in healthy adults. The PSDs of masticated whole and ground almonds was assessed using two laboratory methods (mechanical sieving and laser diffraction). PSD from mechanical sieving was used to calculate lipid bioaccessibility using a theoretical mathematical model. Thirty-one healthy adults (18-45 years) completed both mastication sessions. Following mastication, ground almonds had a PSD with significantly fewer larger particles and more smaller particles, compared with whole almonds. Predicted lipid bioaccessibility of masticated ground almonds (10.4%, SD 1.8) was marginally but significantly greater than the predicted lipid bioaccessibility of masticated whole almonds (9.3%, SD 2.0; p = 0.017). Commercial grinding of almonds significantly influences the PSD of almonds following mastication, which results in a modest but significant increase in predicted lipid bioaccessibility.

Almond intake alters the acute plasma dihydroxy-octadecenoic acid (DiHOME) response to eccentric exercise. 

Nieman, D.C., A.M. Omar, C.D. Kay, D.M. Kasote, C.A. Sakaguchi, A. Lkhagva, M.M. Weldemariam, Q. Zhang, 2023. Almond intake alters the acute plasma dihydroxy-octadecenoic acid (DiHOME) response to eccentric exercise. Front. Nutr. 9:1042719. https://doi.org/10.3389/fnut.2022.1042719

Introduction: This investigation determined if 4-weeks ingestion of nutrient-dense almonds mitigated post-exercise inflammation and muscle soreness and damage. Methods: An acute 90-min of eccentric exercise (90-EE) was used to induce muscle damage in 64 non-obese adults not engaging in regular resistance training (ages 30-65 years, BMI < 30 kg/m2). Using a parallel group design, participants were randomized to almond (AL) (57 g/d) or cereal bar (CB) (calorie matched) treatment groups for a 4-week period prior to the 90-EE (17 exercises). Blood and 24-h urine samples were collected before and after supplementation, with additional blood samples collected immediately post-90-EE, and then daily during 4 additional days of recovery. Changes in plasma oxylipins, urinary gut-derived phenolics, plasma cytokines, muscle damage biomarkers, mood states, and exercise performance were assessed. Results: The 90-EE protocol induced significant muscle damage, delayed onset of muscle soreness (DOMS), inflammation, reduced strength and power performance, and mood disturbance. Interaction effects (2 group × 7 time points) supported that AL vs. CB was associated with reduced post-exercise fatigue and tension (p = 0.051, 0.033, respectively) and higher levels of leg-back strength (p = 0.029). No group differences were found for post-90-EE increases in DOMS and six cytokines. AL was associated with lower levels of serum creatine kinase immediately- and 1-day post-exercise (p = 0.034 and 0.013, respectively). The 90-EE bout increased plasma levels immediately post-exercise for 13 oxylipins. Interaction effects revealed significantly higher levels for AL vs. CB for 12,13-DiHOME (p < 0.001) and lower levels for 9,10-DiHOME (p < 0.001). Urine levels increased in AL vs. CB for seven gut-derived phenolics including 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone that was inversely related to changes in plasma 9,10-DiHOME (r = -0.029, p = 0.021). Discussion: These data support some positive effects of almond intake in improving mood state, retaining strength, decreasing muscle damage, increasing the generation of gut-derived phenolic metabolites, and altering the plasma oxylipin DiHOME response to unaccustomed eccentric exercise in untrained adults. The elevated post-exercise plasma levels of 12,13-DiHOME with almond intake support positive metabolic outcomes for adults engaging in unaccustomed eccentric exercise bouts.

Keywords: (poly)phenols; almonds; cytokines; exercise; inflammation; metabolites; oxylipins.