Açaí, lychee, mamey, passion fruit and jackfruit are some lesser-consumed tropical fruits due to their low commercial production. In 2018, approximately 6.8 million tons of these fruits were harvested, representing about 6.35% of the total world production of tropical fruits. The present work reviews the nutritional content, profile of bioactive compounds, antioxidant and anti-inflammatory capacity of these fruits and their by-products, and their ability to modulate oxidative stress due to the content of phenolic compounds, carotenoids and dietary fiber. Açaí pulp is an excellent source of anthocyanins (587 mg cyanidin-3-glucoside equivalents/100 g dry weight, dw), mamey pulp is rich in carotenoids (36.12 mg β-carotene/100 g fresh weight, fw), passion fruit peel is rich in dietary fiber (61.16 g/100 dw). At the same time, jackfruit contains unique compounds such as moracin C, artocarpesin, norartocarpetin and oxyresveratrol. These molecules play an important role in the regulation of inflammation via activation of mitogen-activated protein kinases (including p38, ERK and JNK) and nuclear factor κB pathways. The properties of the bioactive compounds found in these fruits make them a good source for use as food ingredients for nutritional purposes or alternative therapies. Research is needed to confirm their health benefits that can increase their marketability, which can benefit the primary producers, processing industries (particularly smaller ones) and the final consumer, while an integral use of their by-products will allow their incorporation into the circular bioeconomy.

Hibiscus sabdariffa and Camellia sinensis are traditionally consumed as beverages and are good sources of health-promoting phenolic compounds. The objective of this work was to use response surface methodology to develop an optimized functional beverage with high total phenolic content, antioxidant capacity, and acceptable for potential consumers. Optimum infusion conditions were 4.9 g of hibiscus calyces or C. sinensis leaves/100 ml of water at 26 ℃ for 291 min. These conditions yielded a total phenolic content of 14.80 ± 1.4 and 33.02 ± 0.34 mg gallic acid equivalents/100 ml for hibiscus and green tea, respectively. The optimized beverages were combined in a 7:3 (hibiscus:green tea, v/v) ratio; a consumer preference test showed that this combination had an acceptable taste according to untrained panelists. A chromatographic analysis showed that this formulation contained flavonoids, phenolic acids, and anthocyanins as its main components. Our data suggested that hibiscus and green tea phenolic compounds were efficiently extracted using near-ambient temperature water for prolonged times, contrary to routine methods (high temperature, short time). Our method also preserved antioxidant capacity, possibly by avoiding chemical changes/degradation due to high temperatures. This process can be used to produce organoleptically acceptable functional beverages that deliver a varied phenolic compound profile to the consumer.

The hypoglycemic effect of functional phytochemicals has been evaluated in diabetic rodents but scarcely in its premorbid condition (prediabetes; PD). This study aimed to evaluate a mango (cv. Ataulfo) peel hydroethanolic (20:80) extract (MPE) for in vivo glycemic/lipidemic-normalizing effect and in vitro enzyme inhibitory (α-amylase/α-glucosidase) activity. The polyphenolic MPE (138 mg EAG.g⁻¹, mainly gallic acid and mangiferin) with antioxidant capacity (DPPH• 34 mgTE.g⁻¹) was fed to PD rats (induction: high-fat diet (60% energy) + single dose streptozotocin (35 mg·kg⁻¹), 4 weeks). At the 8th week, fasting glycemia (FG), oral glucose tolerance test, and insulin sensitivity indexes (HOMA-IR, HOMA-β) > blood lipid-normalizing effect were documented as healthy controls > MPE > disease (PD) controls, which was possibly related to the extract’s concentration–response in vitro enzyme inhibitory activity (IC₅₀ ≈ 0.085 mg·mL⁻¹). MPE is a rich source of glucose-lowering phytochemicals for the primary prevention of type 2 diabetes.

Antioxidants, such as phenolic compounds, are essential for mammal physiology. Significant research made on the gut–brain axis has produced volumes of evidence indicating that some plant-derived phenolic compounds can reach brain cells to exert protective effects on them, mainly by maintaining and/or restoring redox homeostasis. Their systemic uptake and transport might be determined by the phenolic’s physicochemical properties, along with complex interactions with protein transporters and carriers, including GLUT, SGLT1, ABC transporters (P-glycoprotein, breast cancer resistance protein), albumin, fibrinogen, organic anion and cation transporters, and MATE1. The present work focuses on the chemical interactions and transport pathways of some phenolic compounds to reach brain cells.

The development of sustainable biopolymer-based active packaging materials is essential to replace single-use petroleum-derived plastics and reduce food deterioration. In this study, chitosan-based films incorporating green-synthesized silver microparticles (Ag microparticles) obtained from pecan nutshell extract rich in phenolic compounds were developed as multifunctional materials with antioxidant and antibacterial properties. Films were prepared by the casting method using chitosan solutions at different concentrations (1.5–2.5% w/v), with Ag microparticles incorporated at 0.25% (w/v). The phenolic profile of the extract (gallic acid, catechin, ferulic acid, and ellagic acid), determined by UPLC-DAD, confirmed its role as a reducing and stabilizing agent during Ag microparticle synthesis. All film-forming solutions exhibited non-Newtonian pseudoplastic behavior, and variations in viscosity and consistency were directly reflected in the mechanical behavior of the films. Strong antioxidant activity, mainly governed by single-electron transfer mechanisms, was observed in ABTS, DPPH, and FRAP assays. The films also showed pronounced antibacterial activity, achieving complete inhibition of Listeria monocytogenes. Finally, it is concluded that film mechanical properties are strongly governed by the rheological behavior of the chitosan-based film-forming solutions. The resulting chitosan-Ag microparticle films combine suitable mechanical behavior with antioxidant activity and antibacterial effects against Listeria monocytogenes, suggesting their potential for future application in active food-packaging systems.