Fermentation as a strategy to improve the bioactive and antioxidant properties of walnuts and their derived products
Oxidative stress is a significant factor in the development of many chronic illnesses, and antioxidants play a vital role in mitigating its effects. The walnut (Juglans regia L.) is widely recognized for its diverse range of bioactive compounds, particularly polyphenols, flavonoids, and tocopherols, which exhibit notable antioxidant properties. These beneficial compounds are found in various walnut-based products, including milk, yogurt, cheese substitutes, flowers, protein meals, oils, and extracts from components such as the husk, pellicle, and leaves. Previous studies demonstrated that microbial fermentation using probiotic or non-probiotic starter cultures may significantly enhance the antioxidant capacity of walnut-based products. Outcomes are influenced by factors such as the type of walnut tissue used, the fermentation conditions, the choice of microbial strain, and the extraction method. This review critically summarizes and evaluates current findings on the impact of fermentation on the antioxidant properties of walnuts and walnut-derived products.
https://doi.org/10.1007/s42452-025-08185-6
A Review with Updated Perspectives on Nutritional and Therapeutic Benefits of Apricot and the Industrial Application of Its Underutilized Parts
Fruits maintain the image as the richest sources of vitamins. Focusing on apricots, utilization of apricot species for many applications is possible due to its various benefits. Many research studies demonstrated different perspectives of apricot, especially in medical used as it can act as antioxidant, anti-inflammatory, and antimicrobial agents. Moreover, in the industrial sectors, apricots can be used in the production of biofuels and batteries. All components of the apricot fruit, including seeds and kernels have been found to possess significant interest. This review is to breach the knowledge gap regarding the key nutrients and chemicals of apricot fruit, contributing to its health-promoting properties to emphasize the noble importance of this fruit in the diet and in the management of several diseases. We also cover the application of apricots in the industry that could be developed as a promising and sustainable source.
https://doi.org/10.3390/molecules27155016
Walnut Kernel Oil and Defatted Extracts Enhance Mesenchymal Stem Cell Stemness and Delay Senescence.
Decreased stemness and increased cellular senescence impair the ability of mesenchymal stem cells (MSCs) to renew themselves, change into different cell types, and contribute to regenerative medicine. There is an urgent need to discover new compounds that can boost MSCs' stemness and delay senescence. Therefore, this study aimed to investigate the impact of walnut kernel oil (WKO) and defatted (WKD) extracts on bone marrow (BM)-MSC stemness and senescence. Premature senescence and inflammation were induced in BM-MSCs using H2O2 and LPS, respectively. Phytochemical constituents of WKO and WKD extracts were detected by HPLC. The stemness (proliferation and migration), senescence-related markers (p53, p21, SIRT1, and AMPK), oxidative stress/antioxidant markers, inflammatory cytokines, and cell cycle of BM-MSCs were measured by MTT assay, qPCR, ELISA, and flow cytometry. WKO and WKD extracts improved rat BM-MSC stemness, as evidenced by (1) increased cell viability, (2) decreased apoptosis (low levels of Bax and caspase3 and high levels of Bcl2), (3) upregulated MMP9 and downregulated TIMP1 expression, and (4) cell cycle arrest in the G0/G1 phase and declined cell number in the S and G2/M phases. Additionally, WKO and WKD extracts reduced rat BM-MSC senescence, as indicated by (1) decreased p53 and p21 expression, (2) upregulated expression and levels of SIRT1 and AMPK, (3) reduced levels of ROS and improved antioxidant activity (higher activity of CAT, SOD, and GPx and upregulated expression of NrF2 and HO-1), and (4) declined levels of TNFα, IL1β, and NF-κB. When compared to the WKO extract, the WKD extract had a greater impact on the induction of stemness and reduction of senescence of BM-MSCs due to its stronger antioxidant activity, which could be attributed to its higher levels of flavonoids and phenolic compounds, as detected by HPLC analysis. WKO and WKD extracts enhance rat BM-MSC stemness and protect them from senescence, suggesting their potential use as enhancers to increase MSCs' therapeutic efficacy.
https://doi.org/10.3390/molecules28176281
Antioxidant activity of fresh and dry fruits commonly consumed in India
Epidemiological studies from other parts of the world indicate that increased consumption of fruits and vegetables are associated with lower risk of chronic degenerative diseases. Fruits are an important component of Indian diets. Studies indicate that fruits and vegetables are rich sources of phenolic compounds and antioxidant activity (AOA). Present study was taken up to determine the AOA and phenolic content of fresh and dry fruits commonly consumed in India by two different (radical scavenging) methods and relate it to their total phenolic content (TPC) for the first time. Fourteen commonly consumed fresh fruits and ten dry fruits were studied. AOA and TPC contents of both fresh and dry fruits showed marked variation. Correlation analysis between the TPC and AOA as assessed by the two methods showed that phenolics may contribute maximally to the ABTS (r = 0.84) and to lesser extent to DPPH (r = 0.77) in fresh fruits, where as in dry fruits they correlated well to DPPH activity (r = 0.97) and to a lesser extent to FRAP (r = 0.87). In general, the results indicate that majority of the fresh and dry fruits studied are rich in phenolic antioxidants with potent free radical scavenging activity imply their importance to human health. https://doi.org/10.1016/j.foodres.2009.10.006
Analysis of the Antioxidant Activity, Lipid Profile, and Minerals of the Skin and Seed of Hazelnuts (Corylus avellana L.), Pistachios (Pistacia vera) and Almonds (Prunus dulcis)—A Comparative Analysis
Nuts are dry, single-seeded fruits with a combination of beneficial compounds that aid in disease prevention and treatment. The aims of this research are to evaluate the total antioxidant activity (AI) by ferric reducing antioxidant power (FRAP) assay, fatty acids by acid-catalyzed esterification method, and minerals by inductively coupled plasma optical emission (ICP-OE) spectrometer in hazelnuts, pistachios, and almond seeds and skins. Considering total AI, the results demonstrated that the highest activity was found in hazelnut and pistachio skin. The results considering minerals demonstrated that manganese, zinc, and iron levels are high in almond and hazelnut skins, copper is dominant in pistachio skin and hazelnut seed, and selenium is high in pistachio and almond skins and seed. Finally, the results showed palmitic acid is present in almond skin and pistachio seed, palmitoleic acid is high in almond and pistachio skins, and stearic acid is present in almond and hazelnut skins. Oleic acid was found in hazelnut seeds and their skin, linoleic acid in almond skin and pistachio seeds, and α-linolenic acid in almond and pistachio skins. In conclusion, hazelnut, pistachio, and almond skins are a great source of antioxidants, minerals, and healthy fatty acids, making them useful for nutraceutical development. https://doi.org/10.3390/appliedchem3010008
A review on some properties of almond: ımpact of processing, fatty acids, polyphenols, nutrients, bioactive properties, and health aspects
This review was focused on the proximate compounds, nutritional values, total phenolic, flavonoid, antioxidant activity, fatty acid profile, polyphenols, health aspects and uses of almond kernel and oils. Almond contained about 24–73% crude oil, 50–84% oleic and 6–37% linoleic acids, 77–3908 mg/kg β-stosterol and 5–8 mg/100 g β-tocopherol. Almonds are a good source of mono- and unsaturated fatty acids, phytochemicals, bioactive components, minerals, vitamin E, polyphenols and phytosterols and at the same time almonds have healing effects. Since almond seeds or seed oils have versatile uses, they are consumed on their own or as part of a range of food products. Almonds are considered a healthy snack when consumed due to their potential cardioprotective effects. Since the composition of almonds and its effects on health will be effective both during cultivation and processing, studies should be carried out in a way that preserves the product quality. https://doi.org/10.1007/s13197-022-05398-0
Dietary intake of pistachios or mixed nuts results in higher systemic antioxidant capacity with minimal effects on bone in adolescent male rats.
Nutrition is a key determinant of bone health and attainment of peak bone mass. Excess oxidative stress induces bone loss while increasing antioxidant capacity promotes protective effects on bone. Nuts are rich in antioxidants; therefore, we tested the hypothesis that compared to a control diet high in fat (40 % energy) and cholesterol, diets containing isocaloric amounts of pistachios (8·1 % g/g) or mixed nuts (7·5 % g/g) for 8 weeks would result in greater bone health in male adolescent (3 weeks; a state of continued skeletal growth) Sprague-Dawley rats. We found no difference in bone mechanical properties among groups. Tibial apparent density was ~5 % higher in the pistachio and mixed nuts groups v. control (P < 0·05) with no clear difference detected for the femur. Expressions of genes known to impact bone turnover and serum bone turnover biomarkers were unaffected by either diet relative to control. Serum antioxidant capacity was ~2-fold higher in the pistachio and mixed nuts groups compared with control (P < 0·05) but were similar between groups. Therefore, pistachios and mixed nuts may increase tibial density, in part, due to increasing antioxidant capacity. Longer dietary interventions may be necessary to elicit detectable changes in other bones (e.g. femur) and to detect potential mechanisms for the possible bone protective effects of nuts. https://doi.org/10.1017/jns.2022.121
Antioxidants in Shell and Nut Yield Components after Ca, Mg and K Preharvest Spraying on Hazelnut Plantations in Southern Chile.
To determine the effects of pre-harvest calcium (Ca), magnesium (Mg) and potassium (K) spraying on the antioxidant activity and capacity of hazelnut (Corylus avellana L.) shells, as an approach to sustain the utilization of the main residue derived from this industry, four commercial hazelnut (Tonda di Giffoni) orchards located in Southern Chile (Cunco, Gorbea, Perquenco and Radal), during the 2018/19 season were sprayed three times with five combinations of Ca (300 and 600 mg L-1), Mg (300 and 600 mg L-1) and K (300 and 600 mg L-1). Yield components were determined in harvested whole nuts, whereas Ca, Mg and K concentrations, as well as total phenolic compounds, free radical scavenging antioxidant activity, and oxygen radical absorbance capacity, were determined in shells. All spray treatments with both Ca, Mg and K combinations showed a significant interaction between locality and treatment (L × T) on increased stabilized nut yield (kg ha-1) in comparison with the control treatments, whereas nut quality was differentially affected by treatment and orchard locality, thus confirming a significant L × T relationship regarding nut length and kernel yield. However, locality showed a major effect on kernels and shells. A significant relationship was determined between locality and the Ca, Mg and K spraying (L × T) concerning antioxidant compounds such as phenolics, whose amounts exceeded those of the control treatments by three times. Antioxidant capacity and activity in shells showed a significant L × T relationship, and nutshells collected from Cunco showed remarkably (3-4 times) higher levels of these factors than the other evaluated localities. Interactions between spray treatment and orchard location were responsible for the different values obtained in the experiments, confirming the influence of the environment on the efficacy of the treatments. Finally, these shells are worth further study as an interesting residue of the hazelnut industry due to their nutritional and antioxidant properties. https://doi.org/10.3390/plants11243536
Modulation of Oxidative Stress and Antioxidant Response by Different Polyphenol Supplements in Five-a-Side Football Players.
Oxidative stress is associated with playing soccer. The objective of the present report was to study the influence of different polyphenolic antioxidant-rich beverages in five-a-side/futsal players. The study was performed with a no supplemented control group (CG) and two supplemented groups with an almond-based beverage (AB) and the same beverage fortified with Lippia citriodora extract (AB + LE). At day 22, participants played a friendly futsal game. Blood extractions were performed at the beginning of intervention (day 1), before and after match (day 22) to determine oxidative stress markers and antioxidant enzyme activities in plasma, neutrophils and peripheral blood mononuclear cells (PBMCs). Malondialdehyde increased significantly in controls after the match in neutrophils, PBMCs and plasma compared to pre-match. Protein carbonyls also increased after the match in plasma in CG. In addition, malondialdehyde levels in neutrophils were significantly lower in the supplemented groups compared to controls. Post-match samples showed significant increases in neutrophil antioxidant activities in CG. Supplemented groups displayed variable results regarding neutrophil antioxidant activities, with superoxide dismutase activity significantly lower than in controls. Finally, post-match myeloperoxidase activity increased significantly in controls compared to pre-match and supplemented groups. In conclusion, polyphenolic antioxidant and anti-inflammatory supplements could be instrumental for optimal recovery after high intensity futsal games. https://doi.org/10.3390/nu15010177
Walnut fruit: Impact of ethylene assisted hulling on in vitro antioxidant activity, polyphenols, PUFAs, amino acids and sensory attributes.
The effects of three different hulling methods wiz natural heaping/traditional (T1), steeping (T2), and spraying (T3), on moisture, colour, fat, free amino acids, fatty acids, antioxidant activities, flavonoids, tannins, total phenolic content, and organoleptic qualities of walnut kernels were examined in this study. The kernels extracted from walnuts subjected to T3 method recorded significantly (p ≤ 0.05) highest DPPH inhibition (68.61 %), ABTS (54.56 %inhibition) and FRAP (0.106 μM trolox/100 g); flavonoids (1993.08 mg QE/100 g), tannin content (0.312 %) and phenols (0.736 mg GAE/g) compared to T1 and T2. Walnut kernels of T3 treatment group were rated better in terms of taste (3.8), odour (3.6) and overall acceptability (3.78) Furthermore, walnut kernels obtained from T3 treatment group exhibited the highest percentage of unsaturated fatty acids (UFAs) and sweet free amino acids. The outcome of the present study offers a fresh viewpoint regarding the hulling processes of green walnuts to meet the quality requirements of walnut kernels. https://doi.org/10.1016/j.foodchem.2022.134763