The incorporation of probiotic microorganisms into fermented foods has long been recognized as a promising strategy to enhance gut health and overall well-being. Conventional probiotics, mainly from the bacterial genera Lactobacillus, Bifidobacterium, Lacticaseibacillus, Levilactobacillus, Lactiplantibacillus and yeast genus Saccharomyces, contribute to gastrointestinal homeostasis, immune modulation, and metabolic balance. Building on these foundations, recent advances in synthetic biology, systems microbiology, and genetic engineering have enabled the development of smart probiotics: engineered or selectively enhanced strains capable of sensing environmental cues and producing targeted bioactive compounds, such as neurotransmitters and anti-inflammatory peptides. These next-generation microorganisms offer precision functionality in food matrices and hold promise for applications in gastrointestinal health, immune support, and gut–brain axis modulation. However, their deployment also raises critical questions regarding biosafety, regulatory approval, and consumer acceptance. This review provides a comprehensive overview of the mechanisms of action, biotechnological strategies, and health-oriented fermentation applications of smart and functional probiotics, emphasizing their role in the future of personalized and evidence-based functional foods.

The present study investigates the hypothesis that green plantain peel (GPP) could be used as a functional ingredient to enrich fermented milk, thus improving its nutritional profile and bioactive content. The objective of the present study was to develop a fermented milk product with added GPP and to evaluate its physical–chemical, technological, microbiological, and sensory characteristics, as well as the bioaccessibility of bioactive compounds after in vitro digestion (INFOGEST). The methodological strategy involved the formulation of four treatments: one control (Fermented Milk Control, FMC) and three with different concentrations of cooked plantain peel (5%—FM5, 10%—FM10, and 20%—FM20). The results demonstrated that the incorporation of peel had a significant impact on the technological properties, resulting in increased syneresis and color change. In contrast, pH and acidity were more influenced by storage duration. Lactic acid bacteria demonstrated viability at probiotic concentrations (≥10⁶ CFU/mL) for a duration of up to 11 days. The incorporation of GPP resulted in a substantial increase in the phenolic compound content and antioxidant activity of the product, with the FM20 treatment showing the highest antioxidant activity (DPPH: 1555 ± 16 µmol TE/mL, ABTS: 576 ± 29 µmol TE/mL, FRAP: 2427 ± 58 µmol Fe²⁺/mL) compared to FMC. Sensory analysis revealed that texture and color were the most influential attributes, with formulations FM5 and FM10 being the most accepted, as indicated by an acceptability index above 82%. The simulated in vitro digestion led to an increase in the measurable phenolic content and a corresponding enhancement of antioxidant activity. This suggests that the digestive process enhances the release of these compounds from the food matrix, thereby increasing their bioaccessibility.

Plantain (Musa paradisiaca) peel is an agro-industrial waste product with remarkable functional potential, attributed to its composition of bioactive compounds with antioxidant and antimicrobial properties. Given this scenario, this scoping review aimed to map and synthesize the scientific evidence regarding the nutritional composition and potential functionalities of plantain peel. A scoping review approach was used, and data were reported using the PRISMA-ScR checklist. The studies evaluating the use of plantain peel were included without restrictions on language or publication date. The following databases were searched: Embase, MEDLINE (via PubMed), Scopus, and Web of Science. Additional searches were conducted through Google Scholar. The protocol has been registered prospectively on the Open Science Framework. This review’s findings included 53 studies. All of them presented methodological limitations that hindered further analysis and the generation of robust evidence. This analysis detailed the chemical composition of the peel, showing that it varies with ripeness stage and processing and is an excellent source of fiber and minerals. Several technological applications are explored, including the use of peel in the production of functional foods, the development of nanoparticles with antimicrobial activity, and its use as a substrate for the biosynthesis of industrial enzymes and citric acid. This review also addresses the possible health benefits that have already been studied in animal and in vitro models. Plantain peel is a promising agro-industrial by-product with high fiber, starch, and bioactive compound content and functional properties. Despite advances, challenges in sensory acceptance and process standardization limit industrial application. A key research gap remains in the systematic evaluation of antinutrient reduction (e.g., oxalates, phytates) and pesticide residue levels during the processing of plantain peel, a mandatory step before its widespread application in the food industry (e.g., flours and food additives). Further research on optimization and bioactive mechanisms is essential to enable its large-scale use and strengthen its role in the circular bioeconomy and human health.

The incorporation of native Amazonian fruits into dairy products has increased due to their ability to improve technological, sensory, nutritional, and biological properties. Therefore, this study aimed to evaluate the impact of cupuassu (Theobroma grandiflorum) pulp on the chemical, physical, and sensory characteristics of fermented milk, using a central rotational composite design with two factors (sugar and cupuassu pulp). Our results are presented as response surfaces, showing that cupuassu pulp is positively associated with the examined parameters (pH, titratable acidity, total soluble solids, total phenolic compounds, syneresis, and water retention capacity). The analysis suggested a promising formulation containing 27.8% cupuassu pulp and 8.6% sugar. The pulp and this promising formulation were characterized by pH, titratable acidity, total soluble solids, proximate composition, and bioactive compounds (total phenolic compounds (TPC) and antioxidant activity). The physicochemical stability of the beverage was monitored over 28 days. Sensory acceptance and purchase intention for the promising formulation were also evaluated. Cupuassu contributed to an increase in soluble solids, while pH and titratable acidity remained stable during storage. Additionally, cupuassu pulp increased the total phenolic content and enhanced the beverage’s antioxidant activity. Sensory analysis showed that adding cupuassu pulp positively influenced all evaluated attributes (83% acceptance) and was associated with a favorable purchase intention. Incorporating cupuassu pulp into fermented milk proved to be technologically feasible and sensorially acceptable, meeting the demand for innovative dairy beverages with functional and sensory benefits.

Kombucha is a functional beverage produced through the fermentation of Camellia sinensis by a symbiotic culture of bacteria and yeast (SCOBY). Incorporating cashew (Anacardium occidentale L.) and Cajá (Spondias mombin L.) pulps represents a value-addition strategy to mitigate the post-harvest perishability of native Cerrado fruits. This study evaluated physicochemical kinetics, 21-day refrigerated shelf life, consumer acceptance, and biological effects in Caenorhabditis elegans of flavored kombuchas. During a 9-day primary fermentation, the pH decreased to 2.95 while total acidity reached 5.38%. Following flavoring (10% v/v pulp/juice), cashew kombucha exhibited the highest total phenolic content (4.19 mg GAE/mL) and ferric reducing power (FRAP), whereas Cajá kombucha showed superior DPPH scavenging activity (1236 µM TroloxE/mL). Refrigerated storage (4 °C) maintained high counts of viable microorganisms (>10⁵ CFU/mL), though active residual fermentation induced ongoing sugar cleavage and a transient yeast proliferation peak on day 7 (8.15 log CFU/mL in Cajá kombucha). Toxicity assays using C. elegans revealed the initial mortality (31.5–62.5%); however, adjusting the pH to near-neutrality restored high organism viability (<10% mortality), confirming that mortality was acidity-driven. In pH-adjusted media, cashew kombucha promoted a modest extension of nematode lifespan, whereas Cajá kombucha reduced lipid accumulation. Sensory testing revealed moderate consumer acceptance, with cashew kombucha achieving a higher Acceptance Index (72.92%) than Cajá (67.26%). Overall, fruit supplementation enriches the bioactive potential of green tea kombucha, provided that post-fermentation acidity is appropriately managed.